WORKFORCE STUDY OF
ENDOCRINOLOGISTS
Final Report
Prepared for:
The Endocrine Society
The American Association of
 Clinical...
WORKFORCE STUDY OF
  ENDOCRINOLOGISTS
               Final Report
                Prepared for:
          The Endocrine So...
Table of Contents



1.       INTRODUCTION AND BACKGROUND ...................................................................
Workforce Study of Endocrinologists



1. INTRODUCTION AND BACKGROUND

   1.1     Purpose
A consortium consisting of The E...
Workforce Study of Endocrinologists


workforce studies is typically the effect of market factors such as managed care and...
Workforce Study of Endocrinologists



2. CURRENT WORKFORCE

    2.1    Defining the Current Workforce
Defining and counti...
Workforce Study of Endocrinologists



                   Table 1. Summary of Selection Criteria by Specialty Group
      ...
Workforce Study of Endocrinologists


                                          Table 2.
                      Major Profe...
Workforce Study of Endocrinologists


The median age of endocrinologists is greater than for physicians as a whole, and fo...
Workforce Study of Endocrinologists



                                                          Figure 2
                ...
Workforce Study of Endocrinologists


   2.3      Geographic Distribution of Endocrinologists
Overall, there are 1.6 endoc...
Workforce Study of Endocrinologists



Tables 7 and 8 present the number of endocrinologists per 100,000 for the 20 MSAs w...
Workforce Study of Endocrinologists


Finally, the following figure summarizes the geographic distribution of endocrinolog...
Workforce Study of Endocrinologists


than perfect for any particular approach. However, it does allow us to pursue a numb...
Workforce Study of Endocrinologists



                                   Table 9
  Methods and Data Sources Used in Analy...
Workforce Study of Endocrinologists


NaSGIM, there were 393 fellows enrolled in endocrinology in 1998-1999, a fill rate o...
Workforce Study of Endocrinologists


In fact, the five-year trend in enrollments is negative for all the major (tradition...
Workforce Study of Endocrinologists


An important “supply” issue is the proportion of IMG fellows who remain in the Unite...
Workforce Study of Endocrinologists



          3.2.2 Retirement Rates
A second factor that affects the supply of endocri...
Workforce Study of Endocrinologists


                                            Figure 8
                        Cumulat...
Workforce Study of Endocrinologists



                                         Table 13
                         Reimburs...
Workforce Study of Endocrinologists


Table 14a provides the same comparison, but is based on claims volume rather than do...
Workforce Study of Endocrinologists


                                           Table 15
                        Endocrin...
Workforce Study of Endocrinologists


suggested about a 25% increase in office visits to endocrinologists between 1995 and...
Workforce Study of Endocrinologists


                                          Figure 10
                Distribution of ...
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Workforce Study of Endocrinologists

  1. 1. WORKFORCE STUDY OF ENDOCRINOLOGISTS Final Report Prepared for: The Endocrine Society The American Association of Clinical Endocrinologists The American Diabetes Association The Association of Program Directors of Endocrinology, Diabetes, and Metabolism American Thyroid Association Lawson Wilkens Pediatric Endocrine Society Prepared by: The Lewin Group Paul F. Hogan Colleen Hirschkorn Jared Hughes Brian Simonson Michael H. Cardwell March 17, 2001
  2. 2. WORKFORCE STUDY OF ENDOCRINOLOGISTS Final Report Prepared for: The Endocrine Society The American Association of Clinical Endocrinologists The American Diabetes Association The Association of Program Directors of Endocrinology, Diabetes, and Metabolism American Thyroid Association Lawson Wilkens Pediatric Endocrine Society Prepared by: The Lewin Group Paul F. Hogan Colleen Hirschkorn Jared Hughes Brian Simonson Michael H. Cardwell March 17, 2001
  3. 3. Table of Contents 1. INTRODUCTION AND BACKGROUND ......................................................................................................1 1.1 PURPOSE ..........................................................................................................................................................1 1.2 WORKFORCE STUDIES ......................................................................................................................................1 1.3 ENDOCRINOLOGISTS AS PHYSICIANS ................................................................................................................2 1.4 MARKET-BASED ANALYSIS AND LIMITATIONS ................................................................................................2 2. CURRENT WORKFORCE..............................................................................................................................3 2.1 DEFINING THE CURRENT WORKFORCE.............................................................................................................3 2.2 DEMOGRAPHIC CHARACTERISTICS OF THE CURRENT WORKFORCE .................................................................5 2.3 GEOGRAPHIC DISTRIBUTION OF ENDOCRINOLOGISTS ......................................................................................8 3. SUPPLY AND DEMAND ISSUES.................................................................................................................10 3.1 METHOD AND DATA.......................................................................................................................................10 3.2 SUPPLY ISSUES ...............................................................................................................................................12 3.2.1 Trends in Residencies and Fellowships ...............................................................................................12 3.2.2 Retirement Rates ..................................................................................................................................16 3.3 DEMAND ISSUES ............................................................................................................................................17 3.3.1 Demand for Services............................................................................................................................17 3.3.2 Population Dynamics...........................................................................................................................24 3.3.3 Managed Care .....................................................................................................................................26 3.3.4 Econometric Estimates of the Effects of Managed Care and Other Factors Affecting Demand .........30 3.3.5 A “Benchmark” Estimate of Current Endocrinologist Clinical Demand ............................................34 3.3.6 Earnings of Endocrinologists ..............................................................................................................36 4. PROJECTIONS OF THE SUPPLY OF AND DEMAND FOR ENDOCRINOLOGISTS .......................39 4.1 BASELINE .......................................................................................................................................................39 4.2 CASE 1: OVERALL ASSESSMENT ....................................................................................................................41 4.3 CASE 2: SENSITIVITY TO ASSUMPTION REGARDING INITIAL EXCESS DEMAND..............................................49 4.4 CASE 3: EFFECT OF INCREASE IN DIABETES ON DEMAND ..............................................................................53 4.5 CASE 4: GROWTH IN FELLOWSHIP POSITIONS ................................................................................................56 4.6 CASE 5: OTHER SUPPLY FACTORS ................................................................................................................59 4.7 CONCLUSION ..................................................................................................................................................63 5. SUMMARY ......................................................................................................................................................64 6. REFERENCES.................................................................................................................................................68 7. APPENDIX A: TECHNICAL ADVISORY PANEL PERSPECTIVES .......................................................1 265991
  4. 4. Workforce Study of Endocrinologists 1. INTRODUCTION AND BACKGROUND 1.1 Purpose A consortium consisting of The Endocrine Society, the American Association of Clinical Endocrinologists and the American Diabetes Association, with participation by The Association of Program Directors of Endocrinology, Diabetes, and Metabolism; the American Thyroid Association; and Lawson Wilkens Pediatric Endocrine Society, has asked The Lewin Group to conduct a workforce study of endocrinologists. The primary purpose of this paper is to present the results of this workforce study. Following this introduction, the report consists of three major sections. In the first, we define and describe the current workforce, its training and certification status, and its demographic characteristics. The second section examines the factors affecting the supply of endocrinologists and the factors affecting the demand for endocrinologists. In the third portion of the paper, we apply the Endocrinologist Workforce Model. Using this model, we examine the endocrinologist workforce over the next 20 years, projecting demand and supply under alternative scenarios regarding the health care market demand for and the supply of the services of endocrinologists. We provide an overall assessment of the workforce over the next 20 years. 1.2 Workforce Studies Interest in physician workforce issues can be traced at least to the late 1960’s. The predominant concern was the adequacy of the physician workforce--ensuring that there were sufficient physicians to meet patient needs. The Graduate Medical Education National Advisory Committee (GMENAC) was founded in 1976 by the U. S. Department of Health Education and Welfare to estimate the need for physicians, by specialty, in the year 1990. The primary concern was to insure that there would be sufficient physicians to meet the need. The Committee systematically began estimating the need for various physician specialties, using estimates based on the judgments of experts--a method that has come to be known as the “GMENAC” method. While the notion of centralized planning of physician supply was implicit in GMENAC, it became somewhat more explicit with the establishment of the Council on Graduate Medical Education (COGME) in 1986. The emphasis shifted from concern regarding too few physicians, in general, to concern that there were too many specialists relative to generalists. Centralized planning of residency positions became explicit in the Clinton Administration’s proposal for health care reform, the Health Security Act, in 1993. The prospect of centralized planning of residency positions placed a premium on determining whether a given physician specialty was a shortage specialty or a surplus specialty. Consequently, it sparked a renewed interest in models of the physician workforce. In a particularly influential and controversial article, Weiner (1994) projected, based on the staffing patterns of staff-model health maintenance organizations (HMOs), that there would be a substantial excess supply of specialists by the year 2000. The challenge of centralized planning for physician supply diminished substantially when Congress failed to pass a major health care reform bill. Today, the focus of physician specialty The Lewin Group, Inc. 1 265991
  5. 5. Workforce Study of Endocrinologists workforce studies is typically the effect of market factors such as managed care and competition from other providers on the demand for the services of the specialty. These issues have become relatively more important than estimates of the more normative or prescriptive concept of need. The goal is a better understanding of the effects of market trends on demand and supply, and how the profession as a whole, as well as individual physicians, can adapt to those trends. 1.3 Endocrinologists as Physicians Endocrinology concerns the study of all factors affecting the secretion and circulation of hormones and their role in health and disease. The primary source of hormones is the endocrine system, which encompasses the major endocrine glands, including the thyroid, pancreas, parathyroid, pineal, adrenal, ovaries, testes and pituitary glands, but other organs also secrete hormones. Endocrinologists include those who are engaged in the research and study of endocrinology, and those who are engaged in the clinical application of that research. This may include physicians, biochemists, physiologists, geneticists, immunologists, pharmacologists, molecular and cellular biologists, and others. Here, our primary focus is endocrinologists who are physicians. Most are engaged in the clinical practice of endocrinology and, perhaps, in the education of physicians in the clinical practice of endocrinology. 1.4 Market-Based Analysis and Limitations Two points should be made at the outset. First, there is no attempt in this study to determine the “right” number of endocrinologists in a normative or needs-based sense. The estimates of demand are based on market conditions which reflect underlying epidemiological conditions or “need”. But, they also embody the market realities that generate effective demand for health care: insurance coverage, the degree of managed care penetration, the distribution of income, and competition from other providers. Hence, no necessary normative significance should be attributed to the demand estimates, nor to associated market “equilibria”.1 Second, we provide predictions of future supply and demand over the next twenty years. While the predictions have the appearance of precision, there are too many variables to achieve such precision, in practice. Events that can not now be anticipated will undoubtedly have a significant and unpredictable influence on the demand for endocrinologists ten or twenty years from now. Thus, our point estimates should be interpreted as representing a broad range, under the assumption that all other factors are constant. Our overall market assessment is based on the systematic analysis of a number of cases or scenarios that our research indicates are likely to affect future demand and supply. Undoubtedly, there will be factors arising that will affect future markets that cannot currently be anticipated. An advantage of a workforce model is that the implications of alternative assumptions or projections regarding the future can be evaluated quickly. 1 The only additional significance of an estimated equilibrium point--a point at which demand is approximately equal to supply--is that the number and incomes of endocrinologists will be stable at that point. If demand exceeds supply, one can anticipate rising incomes and increases in the numbers of endocrinologists, and vice versa if supply were to exceed demand. The Lewin Group, Inc. 2 265991
  6. 6. Workforce Study of Endocrinologists 2. CURRENT WORKFORCE 2.1 Defining the Current Workforce Defining and counting the current workforce may seem like a straightforward task, hardly worth reporting. However, there are a number of alternative criteria for defining the current supply of endocrinologists which lead to different current estimates. The choice is important, because this “baseline” number will permeate all subsequent analyses. The Technical Advisory Panel to our study was instrumental in helping us define the current stock. In defining endocrinologists for the purpose of our workforce study, we consider several issues. • Specialties as self-reported to the AMA • Credentials such as subspecialty board certification from ABIM • Formal professional training in the form of fellowships • Other specialties which, in practice, might substitute for endocrinology in some practice areas but could not be considered endocrinologists, such as OB/GYN, urology, and others. Using the above as general guidelines, we propose to define endocrinologists for the purposes of the workforce study as any MD or DO who meets the following criteria as self-reported to the American Medical Association: 1) Must claim at least one of the following as either a primary or secondary specialty: endocrinology (END), diabetes (DIA), reproductive endocrinology (REN) or pediatric endocrinology (PDE). Physicians who have been trained or certified in an endocrinology subspecialty but do not practice it as a specialty should not be included. 2) Must not claim “Resident” as their current major professional activity. Only physicians who have completed their training and have entered the workforce should be considered. 3) Must not claim obstetrics (OBS or OBG) as either a primary or secondary specialty. Many OB/GYNs claim an endocrinology subspecialty but do not, in fact, practice endocrinology as their primary focus. 4) If REN, must have completed Graduate Medical Training (GMT) in either Pediatrics (PD) or Internal Medicine (IM). 5) Must have completed GMT in one of the four specialties listed above or be board-certified in an endocrinology subspecialty. See Table 1. We separate endocrinologists into three specialty groups: reproductive, pediatric and general/diabetes. The number of DIA specialists is relatively small, and the majority of them also specialize in END. All the DIA specialists included in our population of endocrinologists are board certified in endocrinology. About 63% of them indicate fellowship training in endocrinology, which is only slightly lower than all other endocrinologists. The following is a step-by-step summary, by specialty group, of the implications of our criteria, showing how many physicians are eliminated when a criterion is applied. The Lewin Group, Inc. 3 265991
  7. 7. Workforce Study of Endocrinologists Table 1. Summary of Selection Criteria by Specialty Group Primary Specialty END/DIA REN PDE Total Self-reported endocrinology specialists 4193 1008 884 6085 Residents -7 -2 -85 -94 OBS specialists -53 -573 0 -626 REN, did not complete GMT in PD or IM 0 -394 0 -394 Subtotal 4133 39 799 4971 a) GMT-trained in endocrinology 2547 11 586 3144 b) Board-certified 3611 28 506 4175 c) Board-certified and/or completed GMT 3623 28 719 4506 After eliminating those physicians who did not meet our first four selection criteria, we are left with 4,971. The last three lines on the table above show alternative scenarios for our final selection of physicians. Line (a) shows only those physicians who completed a fellowship in their respective subspecialties. Line (b) shows only those physicians who have been certified by their respective subspecialty boards. Line (c), our preferred definition, shows all physicians who fit the criteria for either (a) or (b): either board-certified or fellowship-trained. The American Board of Internal Medicine reports on its website that 3,987 ABIM certificates have been issued in the US in endocrinology as of January 2000, while our current AMA file shows that 3,824 physicians are board-certified in endocrinology. However, 338 physicians in our file are board-certified in endocrinology but do not claim END or DIA as a specialty. Of those, 238 (73%) claim urology as either a primary or secondary specialty. We exclude them from our analysis.2 Our data also shows that only 2,871 physicians completed a fellowship in endocrinology. If we omit those who did not complete a fellowship, we lose roughly a third of our population in END. Furthermore, it appears that GMT training increases for latter cohorts of physicians. That is, of board-certified endocrinologists who received their MD before 1973, it is reported that only 33% completed a fellowship in endocrinology, while of those who received their MD in 1973 or later, 84% completed a fellowship. For that reason, we recommend including all physicians who are either board-certified or fellowship-trained in an endocrinology specialty or subspecialty. The fact that our estimates of the total number who are board certified are within about 150 of ABIM’s total number of diplomates certified suggests that these are properly certified endocrinologists. 3 The following is a summary of endocrinologists by major professional activity (MPA), using our preferred definition as described above. 2 This decision is based on the advice of the TAP. 3 Some TAP members expressed surprise that there were a significant number of board-certified endocrinologists who did not report formal fellowship training in endocrinology. This information is self-reported by the physicians, and there may be errors. However, we do note that the proportions that report certification but do not report fellowship training in endocrinology were much greater for those who were graduated from medical school prior to 1973. We suspect that the typical path for certification may have changed over time, but the TAP members could not confirm this based on their knowledge and experience. The Lewin Group, Inc. 4 265991
  8. 8. Workforce Study of Endocrinologists Table 2. Major Professional Activities of Endocrinologists Major Professional Activity END/DIA REN PDE Total % of Total Office-Based Practice 2389 21 400 2810 64.30% Research 465 2 102 569 13.02% Full-Time Hospital Staff 355 3 99 457 10.46% Administration 134 1 13 148 3.39% Medical Teaching 130 1 16 147 3.36% Not Classified/Other 150 0 89 239 5.47% Total 3623 28 719 4370 100.0% Table 3 presents the same information separately for adult and pediatric endocrinologists. Table 3 Major Professional Activities Adult and Pediatric Endocrinologists Major Professional Activity Non-PDE % of Total PDE % of Total Office-Based Practice 2410 66.0% 400 55.6% Research 467 12.8% 102 14.2% Full-time Hospital Staff 358 9.8% 99 13.8% Administration 135 3.7% 13 1.8% Medical Teaching 131 3.6% 16 2.2% Not Classified / Other 150 4.1% 89 12.4% Total 3651 719 The primary activity of the majority of both adult and pediatric endocrinologists is office-based clinical practice. Higher proportions of pediatric endocrinologists are full-time hospital staff compared to adult endocrinologists, and only a small portion of each are engaged in teaching. 2.2 Demographic Characteristics of the Current Workforce The median age for all endocrinologists, as we have defined them, is 49, as of 1999. About 71.9% of endocrinologists are male. The median age of male endocrinologists is 51, while the median age of female endocrinologists is 44. Table 4 summarizes the age and sex distribution of endocrinologists, as of 1999. Table 4 Age and Sex Distribution of Endocrinologists Age N % Male % Female <40 638 49.5% 50.5% 40-49 1631 62.9% 37.1% 50-59 1423 82.4% 17.6% 60-69 574 92.5% 7.5% 70 + 104 90.4% 9.6% Total 4370 71.9% 28.1% The Lewin Group, Inc. 5 265991
  9. 9. Workforce Study of Endocrinologists The median age of endocrinologists is greater than for physicians as a whole, and for many specialties. This is probably because the typical path to becoming a fellowship-trained endocrinologist, which would include a residency in internal medicine or pediatrics and a two or three year fellowship program in endocrinology, suggests that there are virtually no endocrinologists under age 30. Most would not become board-certified until they are in their mid-thirties. It is also interesting that, although over 70% of endocrinologists are male, the sex distribution is about even for those under age 40. In 1999, about 46% of endocrinology fellows were female. In adult endocrinology, 44% were female while in pediatric endocrinology about 55% were female.4 The following graph of the age distribution of male, female, and total endocrinologists illustrates the points made in the previous paragraph.5 Figure 1 Age Distribution of Endocrinologists (1999) 250 Total 200 M ale Fem ale Physicians 150 100 50 0 29 33 37 41 45 49 53 57 61 65 69 73 77 Age The next two figures break out the age distribution for adult endocrinologists and pediatric endocrinologists. 4 The National Study of Graduate Medical Education in Internal Medicine (NaSGIM) and the American Board of Pediatrics. 5 We note that there is a “spike” in the age distribution of endocrinologists at about age 56. This would be the cohort that was graduated from medical school in about 1973. The Lewin Group, Inc. 6 265991
  10. 10. Workforce Study of Endocrinologists Figure 2 Age Distribution of Adult Endocrinologists 180 160 Total 140 M ale 120 Female Physicians 100 80 60 40 20 0 31 35 39 43 47 51 55 59 63 67 71 75 80 Age Figure 3 Age Distribution of Pediatric Endocrinologists 45 40 Total 35 M ale 30 Fem ale Physicians 25 20 15 10 5 0 29 33 37 41 45 49 53 57 61 65 69 73 79 Age We note that the age distribution of adult endocrinologists parallels that of the distribution of all endocrinologists. The age distribution of pediatric endocrinologists, on the other hand, suggests that approximately the same number of women and men were becoming pediatric endocrinologists as early as about the 1972 medical school class, while more women than men were becoming pediatric endocrinologists in medical school classes after about 1985. The Lewin Group, Inc. 7 265991
  11. 11. Workforce Study of Endocrinologists 2.3 Geographic Distribution of Endocrinologists Overall, there are 1.6 endocrinologists per 100,000 population (1999). Endocrinologists are more highly concentrated in New England (3.3 per 100,000) and in the Middle Atlantic (2.4 per 100,000) regions of the country, as measured by physicians per 100,000 population. They are least concentrated in the East South Central and Mountain census regions (1.1 per 100,000). Table 5 summarizes this geographic distribution. Table 5 Endocrinologists per 100,000 Population by Census Region Census Division Endocrinologists % of Total Docs/100k Population East North Central 587 13.4% 1.32 East South Central 176 4.0% 1.06 Middle Atlantic 929 21.3% 2.43 Mountain 183 4.2% 1.06 New England 438 10.0% 3.26 Pacific 722 16.5% 1.64 South Atlantic 746 17.1% 1.51 West North Central 247 5.7% 1.32 West South Central 342 7.8% 1.13 Total 4370 1.60 Table 6 presents the number of endocrinologists per 100,000 population for the 20 largest metropolitan statistical areas (MSAs). For information, the HMO penetration rate, the proportion of the population that is enrolled in a health maintenance organization, is displayed. Of the 20 largest metropolitan statistical areas, Boston enjoys the highest concentration of endocrinologists at 5.39 per 100,000, while Riverside-San Bernardino, Ca. has the lowest ratio at 0.89. Boston also enjoys the greatest number of pediatric endocrinologists per 100,000 while Oakland and Phoenix have the lowest ratios for pediatric endocrinologists. Table 6 Endocrinologists per 100,000 Population 20 Largest MSAs Endocrinologists Per 100k Population HMO MSA Population Pediatric Non-Pediatric Total Penetration Los Angeles-Long Beach, CA 9,180,255 0.29 1.81 2.10 56.4% New York City 8,546,786 0.76 2.94 3.70 33.4% Chicago 7,854,558 0.27 1.67 1.94 24.5% Philadelphia 4,916,192 0.41 1.95 2.36 49.0% Detroit 4,770,489 0.19 1.09 1.28 28.5% Washington, DC 4,683,894 0.60 3.27 3.86 35.6% Boston 4,159,286 0.96 4.40 5.39 37.8% Houston 3,973,964 0.23 1.16 1.38 26.7% Atlanta 3,805,402 0.24 1.42 1.66 29.3% Dallas 3,290,011 0.21 1.19 1.40 18.3% Riverside-San Bernadino, CA 3,161,545 0.16 0.73 0.89 53.2% Phoenix-Mesa, AZ 3,034,730 0.13 1.05 1.19 34.1% San Diego 2,862,167 0.24 1.82 2.06 48.2% Minneapolis-St. Paul 2,846,974 0.18 1.62 1.79 37.8% Orange County, CA 2,750,079 0.25 1.53 1.78 45.9% Nassau-Suffolk Counties, NY 2,678,377 1.19 3.14 4.33 38.0% St. Louis 2,599,580 0.27 1.23 1.50 39.5% Baltimore 2,477,762 0.32 1.17 1.49 40.8% Oakland 2,396,765 0.13 1.34 1.46 67.1% Seattle-Bellevue-Everett, WA 2,336,471 0.17 2.23 2.40 19.7% The Lewin Group, Inc. 8 265991
  12. 12. Workforce Study of Endocrinologists Tables 7 and 8 present the number of endocrinologists per 100,000 for the 20 MSAs with the lowest and highest ratios, respectively. The Dallas-Fort Worth and Austin-San Marcos areas of Texas would appear to be areas of opportunity for endocrinologists. Table 7 20 MSAs with the Lowest Concentrations of Endocrinologists Endocrinologists Per 100k Population HMO MSA Population Pediatric Non-Pediatric Total Penetration Fort Worth-Arlington, TX 1,617,803 0.12 0.49 0.62 31.0% Austin-San Marcos, TX 1,132,973 0.09 0.62 0.71 21.6% Norfolk-Virginia Beach-Newport News, VA 1,554,374 0.13 0.58 0.71 29.6% Las Vegas 1,393,611 0.00 0.79 0.79 26.2% Riverside-San Bernadino, CA 3,161,545 0.16 0.73 0.89 53.2% Orlando 1,571,854 0.25 0.64 0.89 37.5% Grand Rapids, MI 1,049,059 0.29 0.67 0.95 31.6% Phoenix-Mesa, AZ 3,034,730 0.13 1.05 1.19 34.1% Salt Lake City-Ogden, UT 1,309,170 0.23 0.99 1.22 33.4% Fort Lauderdale 1,538,042 0.20 1.04 1.24 36.5% Detroit 4,770,489 0.19 1.09 1.28 28.5% Houston 3,973,964 0.23 1.16 1.38 26.7% Milwaukee 1,438,313 0.21 1.18 1.39 41.4% Dallas 3,290,011 0.21 1.19 1.40 18.3% Monmouth-Ocean, NJ 1,100,731 0.36 1.09 1.45 30.8% Oakland 2,396,765 0.13 1.34 1.46 67.1% Charlotte-Gastonia-Rock Hill, NC-SC 1,410,540 0.35 1.13 1.49 21.4% Tampa-St. Petersburg-Clearwater, FL 2,283,594 0.22 1.27 1.49 37.2% West Palm Beach-Boca Raton, FL 1,071,902 0.09 1.40 1.49 36.5% Baltimore 2,477,762 0.32 1.17 1.49 40.8% Table 8 20 MSAs with the Highest Concentration Endocrinologists Per 100k Population HMO MSA Population Pediatric Non-Pediatric Total Penetration Boston 4,159,286 0.96 4.40 5.39 37.8% San Francisco 1,675,185 0.78 3.82 4.60 66.9% Raleigh-Durham-Chapel Hill, NC 1,101,470 1.18 3.18 4.36 24.5% Nassau-Suffolk Counties, NY 2,678,377 1.19 3.14 4.33 38.0% Washington, DC 4,683,894 0.60 3.27 3.86 35.6% New York City 8,546,786 0.76 2.94 3.70 33.4% Hartford 1,250,000 0.32 3.36 3.68 41.5% Indianapolis 1,526,061 0.79 2.49 3.28 22.9% Newark, NJ 1,949,556 0.51 2.56 3.08 25.0% San Antonio 1,554,852 0.13 2.64 2.77 23.8% Nashville 1,170,028 0.34 2.39 2.73 39.8% New Orleans 1,297,554 0.46 2.23 2.70 26.1% Pittsburgh 2,324,660 0.69 1.98 2.67 34.2% Middlesex-Somerset-Hunterdon, NJ 1,134,947 0.18 2.38 2.56 29.5% Portland, OR 1,846,177 0.54 2.00 2.55 49.0% Bergen-Passaic, NJ 1,384,850 0.51 2.02 2.53 24.8% Miami 1,982,883 0.66 1.82 2.47 56.5% Seattle-Bellevue-Everett, WA 2,336,471 0.17 2.23 2.40 19.7% Providence 1,300,000 0.38 2.00 2.38 41.8% Philadelphia 4,916,192 0.41 1.95 2.36 49.0% The Lewin Group, Inc. 9 265991
  13. 13. Workforce Study of Endocrinologists Finally, the following figure summarizes the geographic distribution of endocrinologists across the United States. Areas of highest concentration are in New England, Florida, and along the coast of California. Areas of lowest concentration include the Central and Mountain states. Figure 4 Concentration of Endocrinologists Across the U.S. 0.0 - 0.2 0.2 - 0.4 0.4 - 1.0 1.0 - 3.0 3.0 - 37.5 3. SUPPLY AND DEMAND ISSUES In Section 3.1, we briefly summarize our methods for projecting the supply of and demand for the services of endocrinologists. Next, in Section 3.2, we consider factors affecting supply. In particular, we examine the number and fill rate of fellowship positions, and trends in subspecialization among residents in internal medicine. We also consider trends in retirement and withdrawal from the labor force. In Section 3.3, we consider factors affecting demand. Section 3.3.1 analyzes estimates of the current services for which endocrinologists receive reimbursement, how they have changed over time, and the share of other providers of the services with whom endocrinologists may compete. Section 3.3.2 examines trends in population growth. Section 3.3.3 examines the trends in managed care both across the country and over time. Section 3.3.4 presents econometric (statistical) estimates of factors affecting the demand for the services of endocrinologists, including managed care, household income, and insurance. Section 3.3.5 presents a “benchmark” estimate of the demand for endocrinologists, using a Kaiser Permanente staff model HMO plan as a benchmark. Finally, Section 3.3.6 presents information on the earnings of endocrinologists compared to other physician specialties. 3.1 Method and Data We approach the analysis of supply and demand using a number of different methods and data sources. We do this for two (related) reasons. First, the data for the analysis of supply and, especially, demand for physician specialties, particularly the smaller specialties, is less than abundant. This is unfortunately the case, also, for endocrinology. We attempt to push the available empirical data to the greatest extent possible in our analyses, although the data is less The Lewin Group, Inc. 10 265991
  14. 14. Workforce Study of Endocrinologists than perfect for any particular approach. However, it does allow us to pursue a number of alternative approaches, albeit imperfectly. Second, we believe that the alternative approaches are, in a sense, quite complementary to the overall goals of the analysis. Use of different methods and data sources, none perfect in its own right, provides a test of how robust the estimates are and how sensitive they are to data and method. To the extent that the alternatives tend to converge to similar conclusions, they provide greater confidence in the conclusion. To the extent that they do not, it provides a sense of the degree of uncertainty associated with any single estimate. A major source of information was our Technical Advisory Panel (TAP) chaired by Dr. Helena Rodbard.6 The TAP was a source of institutional and clinical information relevant to the endocrinology physician workforce. Moreover, the TAP’s opinion and judgment of the current state of the health care market for the services of endocrinologists, its future state, and factors affecting it were useful and were integrated with objective sources of data. Appendix A summarizes some of the insights provided by the panel with regard to issues that are a matter of informed judgment. The following table provides a brief overview of the methods and data sources used in the analysis of supply and demand. Table 9 Methods and Data Sources Used in Analysis of Supply and Demand Supply Method Description Data Sources Inventory and Ages existing workforce using mortality and • AMA Masterfile Fellowship Model retirement rates. Adds new entrants as a • ACGME data on residency function of fellowship positions and fill rates. /fellowships positions Models pediatric and adult endocrinologists • Fellowship program director’s separately. survey • ABIM (NaSGIM) and ABP • Roehrig and Janyan (1986) Demand Population ratio Projects demand for physicians as a function of • Area Resource File population. Demand increases with population • AMA masterfile growth, other things being equal, but is adjusted • Census for the effects of managed care growth, insurance coverage, household income and • National Ambulatory Medical other providers. Care Survey 6 The TAP members were Drs. William F. Young, Stephen F. Hodgson, Mark Molitch, Mary Lee Vance, Steven M. Petak, Wayman W. Cheatam, Richard F. Spark, Gerald Bernstein, Francine Kaufman, and Hossein Gharib. They are relieved of any responsibility for how we interpreted and applied their insights. The Lewin Group, Inc. 11 265991
  15. 15. Workforce Study of Endocrinologists Table 9 Methods and Data Sources Used in Analysis of Supply and Demand, continued Demand Econometric Model of Under the hypothesis that endocrinologists will, • AMA masterfile Demand at the margin, migrate toward areas of high • Census demand for their services and away from areas • Interstudy Competitive Edge of low demand, this statistical model relates the geographic distribution of endocrinologists to • Area Resource File factors affecting demand, such as the HMO penetration rate, the proportion of the population insured, and other factors. Epidemiology-Based Office visits and, in some cases, procedures are • HCFA BMAD files Estimates tabulated by disease category. Implied demand • National Ambulatory Care is estimated based on time required to provide Survey the services. Future demand is projected as function of growth/decline in incidence/prevalence and in competing providers. Benchmark estimate Ratio of endocrinologists to covered lives in a • Kaiser Permanente enrollment closed care integrated care delivery system, and provider data such as a staff model HMO, is calculated. After • Census adjusting for differences in the age distribution between closed beneficiary population and the US population, the “benchmark” estimate is project to the US population as a whole. Estimate is interpreted as the demand for Endocrinology services under the same economic conditions and care quality provided in the closed population. The primary demand model is the population ratio model, augmented by estimates of the effect of managed care, income, insurance and other providers derived from the econometric model. The other methods of estimating current and future demand supplement this model. The supply model and the population-driven demand model form a system from which future projections are obtained. Section 4 of this paper will report projections using the supply and demand models. 3.2 Supply Issues 3.2.1 Trends in Residencies and Fellowships The most important factor affecting the supply of endocrinologists is the number completing fellowships in endocrinology each year. To estimate future supply, it is important to determine how many enter the endocrinology workforce from fellowship programs each year. This will depend not only on the positions and fill rates, but also on the lengths of the programs. According to the Accreditation Council for Graduate Medical Education (ACGME), there were 457 adult endocrinology fellowship positions in 132 programs offered in 1999. According to The Lewin Group, Inc. 12 265991
  16. 16. Workforce Study of Endocrinologists NaSGIM, there were 393 fellows enrolled in endocrinology in 1998-1999, a fill rate of about 86%. ACGME also reports that there were 143 positions in pediatric endocrinology in 1999 and, according to the American Board of Pediatrics, there were 115 fellows enrolled in pediatric endocrinology in 1998-1999, for a fill rate of 80%. Using our supply model, we estimate that about 171 fellows in adult endocrinology and about 37 fellows in pediatric endocrinology enter the market each year. An important factor in determining how many enrolled adult endocrinology fellows there will be in the future is the number of third year residents in internal medicine. As Figure 5 indicates, the number of third year IM residents has been growing over time. From about 4,000 in 1976-1977, the number has grown to over 7,000 in 1998-1999. Figure 5 Third Year IM Residents However, the rate and number at which IM residents continue into a subspecialty, such as endocrinology, has been declining. This is indicated in Table 10. Table 10 IM Residents Continuing into Subspecialty Fellowship Programs Year IM Residents First-year IM IM Subspecialization Completing Training Subspecialty Fellows Rate 1978 4547 2965 65.2% 1984 5559 3028 54.5% 1992 5936 3497 58.9% 1995 6306 3107 49.3% 1997 6920 2696 39.0% The Lewin Group, Inc. 13 265991
  17. 17. Workforce Study of Endocrinologists In fact, the five-year trend in enrollments is negative for all the major (traditional) IM subspecialties, except gerontology and nephrology, as shown in Table 11. (Note that these are total enrollments, not simply first year.) Table 11 Trends in Total Fellowship Enrollment for Traditional IM Subspecialties Subspecialty 94/95 95/96 96/97 97/98 98/99 Annual 5-year Change Change Cardiology 2657 2532 2363 2238 2149 -4.2% -19.1% Gastroenterology 1189 1128 1026 901 938 -4.7% -21.1% Pulmonary or CCM 1360 1320 1228 1189 1183 -2.8% -13.0% Nephrology 670 636 634 658 676 0.2% 0.9% Endocrinology 459 435 433 410 393 -3.1% -14.4% Hematology or Oncology 1226 1185 1105 1091 1077 -2.6% -12.2% Infectious Diseases 688 672 612 598 593 -3.0% -13.8% Rheumatology or A&I 330 290 270 261 278 -3.4% -15.8% Geriatrics 185 210 242 278 323 11.1% 74.6% Total 8764 8408 7913 7624 7610 -2.8% -13.2% Over the period, endocrinology has experienced about a 14% decline in total enrollment, or an annual rate of decline of about 3% per year. This is close to the overall average of the subspecialties of about a 13% total decline. Table 12 shows the change in new (first year) enrollments between 1995 and 1997 for the IM subspecialties. They are consistent with the decline in total enrollments, and indicate about a 16% decline in endocrinology, which is consistent with the average 13% decline over all of the major subspecialties. Nephrology experienced the smallest decline over the period. Table 12 Changes in First Tear Subspecialty Enrollments 1995-1997 Subspecialty 1995 1997 % Change Cardiology 764 680 -11.0% Pulmonology/CCM 514 446 -13.2% Hematology/Oncology 450 408 -9.3% Gastroenterology 440 319 -27.5% Nephrology 316 303 -4.1% Infectious Disease 293 264 -9.9% Endocrinology 191 160 -16.2% Rheumatology 139 116 -16.5% Total 3107 2696 -13.2% Hence, though there is an increase in the number of IM residents, there has been a distinct downward trend in the number of IM residents who choose to continue with a subspecialty fellowship program after completing their IM residency. The rate of decline in endocrinology enrollment is slightly above the average rate of decline in enrollments across all major subspecialties. International medical school graduates (IMGs) constituted 57% of fellows in adult endocrinology programs in 1999 and about 50% of fellows in pediatric endocrinology programs. The Lewin Group, Inc. 14 265991
  18. 18. Workforce Study of Endocrinologists An important “supply” issue is the proportion of IMG fellows who remain in the United States after graduation and practice. While we do not have detailed information concerning fellows in endocrinology, per se, about 50% of IMGs are, in fact, United States citizens or have permanent residency status in the United States, across all graduate medical education programs. Only about 30% of IMGs are in the United States with J-1 /J-2 visa status.7 Unless a waiver is granted, those who have J-1/J-2 visas to attend residency or fellowship programs in the United States must leave the U.S. for a period of at least two years upon completion of their training. While there is no data on precisely what proportion of IMGs do, in fact, ultimately practice in the United States, the consensus view of experts is that most ultimately do remain in the United States. Based on our discussions with experts at the Bureau of Health Professions (BHPr) and elsewhere, we estimate that at least 80% of IMGs practice in the United States. Hence, most IMGs contribute to supply in the United States. The proportion of endocrinologists who completed training and leave with job offers in hand has remained constant or increased over the last five years. Most fellows are satisfied with the job options available to them after completing training. In 1999, there were 234 first time board examination takers, 169 in Endocrinology, Diabetes and Metabolism and 65 in Pediatric Endocrinology. The following map illustrates the location and number of advertised job opportunities for endocrinologists, taken from the websites of the Endocrine Society and AACE in July 2000. Figure 6 Advertised Job Opportunities for Endocrinologists July 2000 2 1 1 3 1 4 1 1 4 7 1 2 1 4 8 1 1 2 44 1 3 2 2 1 2 1 1 1 1 1 2 3 1 4 3 in the “Midwest” 7 Journal of the American Medical Association, September 2000, Appendix 6, Table II, p. 1116. The Lewin Group, Inc. 15 265991
  19. 19. Workforce Study of Endocrinologists 3.2.2 Retirement Rates A second factor that affects the supply of endocrinologists is the age and rate at which endocrinologists withdraw from practice. We do not have endocrinologist-specific rates. The following figure presents retirement rate patterns across all physicians, conducted in the late 1980’s.8 Figure 7 Retirement Rate Patterns for Physicians Retirement Rate 0.1000 0.0800 0.0600 0.0400 0.0200 0.0000 30 35 40 45 50 55 60 65 70 75 This pattern of retirement rates suggests that the rate begins to rise when physicians are in their late forties, but begins a more dramatic climb starting at age 59. The rate rises to about eight per cent per year beginning at age 67. At an 8% annual retirement rate, a cohort of practicing physicians is reduced by 50% in about 8 years. In addition, mortality rates begin to become important beyond age 60. Together, retirements and mortality reduce an age cohort of practicing physicians by about 80% through age 75. The combined effect is shown in Figure 8, in the cumulative continuation rate.9 The cumulative rate remains virtually 100% until about age 48, and begins a rapid decline starting at about age 60, reaching 20% at age 75. An important issue is whether events in the healthcare market, coupled with secular trends, have lead to earlier retirements, on average, in recent years. If so, supply would be less than is implied by these rates. 8 Roehrig, CS and Janayan, AM. “Physician Separation Rate Estimation,” unpublished report to the Health Resources and Services Administration, Vector Research, September 4, 1986. 9 Roehrig, CS and Janayan, AM. “Physician Separation Rate Estimation,” unpublished report to the Health Resources and Services Administration, Vector Research, September 4, 1986. The Lewin Group, Inc. 16 265991
  20. 20. Workforce Study of Endocrinologists Figure 8 Cumulative Continuation for Physician Age Cohorts Demand Issues Cumulative Continuation Rate 120% 100% 80% 60% 40% 20% 0% < 30 35 40 45 50 55 60 65 70 75 3.3 Demand Issues 3.3.1 Demand for Services In this section, we examine two sources of information regarding the services performed by endocrinologists. From this data, we will obtain insights regarding reimbursement for those services, how demand has changed over time, and providers who, potentially, compete with endocrinologists in providing those services. Medicare Data Data from the Medicare program is limited in that it applies only to Medicare beneficiaries-- typically those age 65 or over. But, this is an important population and one that is expected to grow from 14.2% of the population in 2000 to 18.6% of the population by 2020. Moreover, it is a group for which detailed and relatively complete claims data is available. The Medicare BMAD Beneficiary file, which includes data regarding reimbursement for physicians office visits, procedures, and other outpatient services, indicates that while total Medicare Part B reimbursements declined by 1.46% across all part B providers between 1995 and 1998, it increased slightly, by 0.4%, for endocrinologists.10 10 Dollar values for both 1995 and 1998 are reported in 1998 dollars. The Lewin Group, Inc. 17 265991
  21. 21. Workforce Study of Endocrinologists Table 13 Reimbursement for Medicare Part B Services 1995-1998 Comparison Medicare Part B Endocrinology As Share of Part B Total Reimbursement Reimbursement 1995 $ 46,355,712,108 $ 148,911,501 0.32% 1998 $ 44,367,066,279 $ 150,711,104 0.34% Change -1.46% $ +0.40% +5.74% In Table 14, we compare the dollar volumes of the top procedures billed by endocrinologists in 1995 and 1998. The “top” procedures or services are defined as those that account for the highest dollar volume of reimbursements to endocrinologists. The dollar volume and the share they represent of total reimbursements of endocrinologists are shown in the table. Office visits are, of course, the most important reimbursement service. Office visits represented about 29.4% of all Part B reimbursements to endocrinologists in 1995 and 32.8% in 1998. Total dollar volume grew by almost 24% and its share grew by about 12% of the period. The service that grew the most over the period was “Dual energy X-ray study”(DEXA study) which grew from $1.1 million to $4.5 million, a growth of over 400% and a growth in its share of 268%.11 This suggests that osteoporosis may be an area of significant growth for endocrinologists as the population ages. There were no procedures or services that suffered a large, absolute dollar decline over the period. “Subsequent hospital care” suffered a decline in its share, bur actually increased in dollar volume. The largest absolute dollar decline was “Assay thyroid stimulating hormone”, “initial hospital care” and “follow-up in-patient consult. Table 14 Top Reimbursement Services and Procedures for Endocrinologists by Dollar Volume 1995 and 1998 Medicare Medicare Reimbursement % of 1995 Reimbursement % of 1998 % Change HCPCS Procedure Code 1995 Total 1998 Total in Share Office/outpatient visit, est $ 39,912,126 29.37% $ 49,446,305 32.81% 11.72% Subsequent hospital care $ 26,853,997 19.76% $ 27,602,371 18.31% -7.31% Office consultation $ 8,157,651 6.00% $ 10,416,608 6.91% 15.15% Initial inpatient consult $ 8,846,257 6.51% $ 10,150,167 6.73% 3.47% Initial hospital care $ 4,905,944 3.61% $ 4,692,793 3.11% -13.74% Dual energy x-ray study $ 1,113,456 0.82% $ 4,551,704 3.02% 268.63% Office/outpatient visit, new $ 2,735,961 2.01% $ 3,009,788 2.00% -0.80% Glycated hemoglobin test $ 2,563,036 1.89% $ 2,917,063 1.94% 2.63% Thyroid panel w/TSH $ 2,622,266 1.93% $ 2,592,287 1.72% -10.85% Assay thyroid stim hormone $ 2,273,161 1.67% $ 1,989,170 1.32% -21.09% Hospital discharge day $ 1,753,476 1.29% $ 1,806,483 1.20% -7.10% Nursing facility care,subseq $ 1,427,019 1.05% $ 1,803,719 1.20% 13.98% Follow-up inpatient consult $ 2,024,267 1.49% $ 1,757,242 1.17% -21.72% Drawing blood for specimen $ 1,660,085 1.22% $ 1,677,514 1.11% -8.88% Lipid panel $ 1,283,228 0.94% $ 1,576,860 1.05% 10.81% 11 In part, this may be due to the Health Care Financing Administration’s recognition of this procedure for billing purposes. The Lewin Group, Inc. 18 265991
  22. 22. Workforce Study of Endocrinologists Table 14a provides the same comparison, but is based on claims volume rather than dollar volume. The charts are generally consistent. Note that the number of glucose blood tests roughly doubled between the two periods, while “reagent strip/blood glucose” procedures declined by 50%, suggesting a substitution in preferred practice and technology. Procedures specifically associated with diseases of the thyroid appear to have dropped between the two periods. Table 14a Top Reimbursement Services and Procedures Endocrinologists by Claims Volume 1995 and 1998 1995 Medicare % of 1995 1998 Medicare % of 1998 % Change HCPCS Procedure Code Claims Total Claims Total in Share Office/outpatient visit, est 1,439,796 24.26% 1,550,927 25.40% 4.69% Subsequent hospital care 819,326 13.80% 731,427 11.98% -13.24% Drawing blood for specimen 582,897 9.82% 593,468 9.72% -1.05% Glycated hemoglobin test 201,456 3.39% 244,663 4.01% 18.03% Assay quantitative, glucose 156,722 2.64% 154,740 2.53% -4.04% Glucose blood test 64,406 1.09% 146,727 2.40% 121.40% Lipid panel 74,545 1.26% 124,119 2.03% 61.81% Automated hemogram 158,035 2.66% 121,090 1.98% -25.54% Office consultation 97,570 1.64% 108,279 1.77% 7.85% Initial inpatient consult 100,366 1.69% 101,213 1.66% -2.00% Assay thyroid stim hormone 104,314 1.76% 101,024 1.65% -5.88% Influenza immunization 84,782 1.43% 85,333 1.40% -2.18% Comprehen metabolic panel -- -- 81,217 1.33% -- Admin influenza virus vac 76,052 1.28% 74,169 1.21% -5.22% Reagent strip/blood glucose 137,478 2.32% 72,960 1.19% -48.42% Finally, Table 15 presents the procedures which, among all procedures performed by endocrinologists, constitute the procedures for which the endocrinologists’ share is the highest. Note that other providers may, in fact, perform a higher share of the total volume for that procedure. However, this will be a procedure for which the endocrinologists share is high, compared to other procedures endocrinologists perform. Note, also, that they are not necessarily those procedures which provide endocrinologists with their largest shares of their total reimbursement. Other providers who perform a large share of the procedures are also shown. The Lewin Group, Inc. 19 265991
  23. 23. Workforce Study of Endocrinologists Table 15 Endocrinologist Services for which Share is High General Family Internal Clinical HCPCS Procedure Code Endocrinology Cardiology Practice Practice Medicine Laboratory Glycated protein 19.14% 4.08% 4.41% 9.71% 31.65% 26.00% Reagent strip/blood glucose 8.89% 1.69% 5.83% 29.77% 37.21% 5.67% Glucose blood test 7.55% 1.83% 8.39% 24.10% 36.24% 13.79% Total assay, TT-3 6.50% 2.81% 1.13% 2.72% 10.19% 71.86% Dual energy x-ray study 6.14% 0.92% 2.13% 6.02% 22.59% 0.04% Assay, free thyroxine 5.50% 2.78% 0.82% 6.17% 19.65% 57.20% Glycated hemoglobin test 5.25% 0.88% 0.79% 7.76% 15.56% 64.90% Thyroid panel w/TSH 3.19% 3.04% 1.33% 5.22% 14.41% 67.89% Assay quantitative, glucose 2.86% 1.75% 3.98% 17.66% 20.08% 47.35% Assay thyroid stim hormone 1.88% 1.33% 0.75% 7.11% 15.88% 66.84% Assay, total thyroxine 1.65% 1.82% 0.75% 4.82% 11.88% 73.98% Hepatic function panel 1.46% 4.15% 1.00% 8.64% 16.95% 56.91% Blood lipoprotein assay 1.44% 5.21% 1.13% 5.80% 15.64% 66.42% Lipid panel 1.37% 4.42% 1.29% 9.72% 20.00% 57.41% Drawing blood for specimen 1.11% 4.41% 2.57% 15.17% 23.63% 35.49% 13-18 blood/urine tests 1.03% 1.89% 1.01% 4.59% 13.23% 64.68% The procedure for which endocrinologists’ share is highest, among all procedures which endocrinologists perform, is a laboratory test for glycated protein. Internal medicine specialists, however, perform the largest share of this procedure. In fact, IM specialists are the largest physician provider of all of the procedures for which endocrinologists’ share is significant. This is true for two reasons. First, almost all endocrinologists are also board certified in internal medicine. Hence, clinical practice areas naturally overlap. Second, there are significantly more IM specialists than endocrinologists, or almost any other specialty. Hence, by sheer numbers, IM specialists will be the dominant specialist in almost any area of clinical practice they conduct. National Ambulatory Medical Care Survey (NAMCS) The NAMCS data is more general than Medicare in that it includes all patients, not just those that are eligible for Medicare. It is a survey that is based on a sample of providers. It captures office visits by provider type and, most importantly, reason for visit. Moreover, it has weights which permit generalization to the U.S. population. A weakness of the data, however, is that there are very few endocrinologists in the survey.12 We analyzed NAMCS data from 1993 through 1998. Data beyond 1998 is not yet available. Because few endocrinologists are captured in the survey each year, our analysis compares two three-year periods: 1993, 1994, and 1995 are compared to 1996, 1997, and 1998. Combining the data into two three-year periods will improve the precision relative to annual comparisons. This data source indicates that office visits to endocrinologists increased substantially between the two periods. There were more than twice as many office visits to endocrinologists in the three-year period 1996-1998 compared to the earlier three-year period, 1993-1995. This is consistent with the direction of change indicated by the more precise Medicare data, which 12 Because it is a random sample, the results for endocrinologists will be “unbiased” in the statistical sense of that term. However, because there are relatively few endocrinologists, the sampling variance may be high and the results imprecise. The Lewin Group, Inc. 20 265991
  24. 24. Workforce Study of Endocrinologists suggested about a 25% increase in office visits to endocrinologists between 1995 and 1998. Hence, both data sources are consistent with a qualitatively similar story that the demand for the services of endocrinologists has increased over the 1990s. We examine, first, the distribution of office visits by reason for visit. In the period 1996-1998, the reason for visit for slightly more than 6% of office visits was “glucose level determination.” Unfortunately, no visits were reported for this reason in the 1993-1995 periods. To make the comparisons more useful, we have combined the reported reasons “glucose level determination” and “diabetes mellitus” into one reason “diabetes mellitus” under the assumption that this distinction in reason for visit was not made in the 1993-1995 period. Figures 9 and 10 show the distribution of visit reasons for the two periods, while Figure 11 shows changes in the distribution between the two periods. Figure 9 Distribution of Office Visits to Endocrinologists by Reason Percentages: 1993-1995 What Endocrinologists Did Most in 1993-1995 General Weakness Injections Cough Back Pain Knee Pain Prenatal Examination General Medical Examinations Tiredness,Exhaustion Weight Gain Diabetes Related Visits Diseases of the Thyroid 0% 2% 4% 6% 8% 10% 12% 14% 16% The Lewin Group, Inc. 21 265991
  25. 25. Workforce Study of Endocrinologists Figure 10 Distribution of Office Visits to Endocrinologists By Reason 1996-1998 What Endocrinologists Did Most in 1996-1998 Medication Progress Visit Cough Other Blood Test Back Pain Diet and Nutritional Counseling Other Test Results General Medical Examinations Tiredness,Exhaustion Diseases of the Thyroid Diabetes Related Visits 0% 5% 10% 15% 20% 25% It is interesting that “diseases of thyroid” was the most frequent reason for visit over the period 1993-1995, but that “diabetes related visits” was the most frequent reason for visit, by a substantial margin, in the 1996-1998 period. Figure 11 shows the percentage point change between the two periods in the distribution proportions (shares) of reasons for visits. Again, we observe that perhaps the most interesting change is the decline in the proportions of visits for disease of the thyroid, and the increase in the proportion of visits for diabetes mellitus.13 Figure 11 Changes in the Distribution of Reasons for Endocrinologist Office Visits 1993-1995 Compared to 1996-1998 1993-1995,1996-1998 Percentage C hange in W hat Endocrinologists D o Most 8% 6% 4% 2% 0% Ti B O D D G O D C P ac re th is ia ie ou ro en th -2% ea be ta dn er gr er k gh er es P se te es nd B al Te ai lo s s s s, M s n N od R V tR of E ed ut el is xh -4% Te th ri t at ic es it au e io al ed s ul t na Th st E ts V io xa lC yr is n oi m it s ou -6% d in ns at el io in ns g -8% -10% 13 Recall, however, that we have combined “glucose level determination” with diabetes as a reason for visit in the latter period. In the 1993-1995 period, “glucose level determination” was not reported as a reason for a visit. The Lewin Group, Inc. 22 265991

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