LQAS: Pitfalls, Controversies, and Addressing Concerns<br />CORE Spring Meeting<br />Jennifer Luna; Todd Nitkin; Bill Yagg...
LQAS is useful<br />However, common mistakes can lead to problems including:<br />Not collecting adequate information<br /...
LQAS session<br />Purpose: Discuss common mistakes and practical ways to avoid them<br />Agenda:<br />Overview of LQAS, re...
LQAS<br />Origin in quality control for industry<br />light bulbs<br />Promoted for use in small population based health s...
Steps<br />Divide project area into supervision areas (SAs) <br />Decide on level below which a supervision area is identi...
Steps<br />Indicators must be dichotomous (yes/no)<br />Was child exclusively breastfed?<br />Not for how many months was ...
Supervision Area (SA)<br />“Lots” that you divide project area into<br />Should have meaning:<br /> i.e. health facility c...
Parallel Sampling<br />Conducting multiple surveys at the same time using the same logistic system<br />Necessary for surv...
LQAS – Coverage estimates<br />Information from supervision areas combined to obtain coverage for entire project area<br /...
LQAS<br />Useful for monitoring of implementation<br />Can be controversial<br />Best not to use for evaluation<br />
Controversy  - Example<br />Concern raised that use of LQAS to identify SAs as having reached the target, might result in ...
American Statistical Association (ASA) Recommendation<br />Report to the American Statistical Association Board of Directo...
ASA recommendation continued<br />If 13 or more of the 19 samples of men in a supervision area (SA) can correctly name the...
Articles <br />Rhoda, Dale A., Soledad A. Fernandez, David J. Fitch, and Stanley Lemeshow (2010), LQAS: User Beware. Inter...
Resources:<br />MCHIP NGO/PVO support website: www.mchipngo.net<br />Rapid Health Surveys Handbook (Public Health Institut...
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LQAS: Pitfalls, Controvery & Addressing Concerns_Luna, Nitkin, Yaggy_5.10.11

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LQAS: Pitfalls, Controvery & Addressing Concerns_Luna, Nitkin, Yaggy_5.10.11

  1. 1. LQAS: Pitfalls, Controversies, and Addressing Concerns<br />CORE Spring Meeting<br />Jennifer Luna; Todd Nitkin; Bill Yaggy<br />May 10, 2011<br />
  2. 2. LQAS is useful<br />However, common mistakes can lead to problems including:<br />Not collecting adequate information<br />Incorrectly interpreting findings<br />Improperly describing actions taken as a result of findings<br />
  3. 3. LQAS session<br />Purpose: Discuss common mistakes and practical ways to avoid them<br />Agenda:<br />Overview of LQAS, resources and discussion of current controversies<br />Experience, advice from AMREF<br />Practical advice from MTI<br />Small group work<br />Brief plenary on results of small group work<br />
  4. 4. LQAS<br />Origin in quality control for industry<br />light bulbs<br />Promoted for use in small population based health surveys<br />Useful for monitoring because it provides information used to identify sub-divisions (supervision areas) of project area that are sub-standard<br />More attention can be given to these areas.<br />Does not provide coverage levels for supervision areas<br />
  5. 5. Steps<br />Divide project area into supervision areas (SAs) <br />Decide on level below which a supervision area is identified as priority for special attention; e.g. <85%<br />Randomly select sample of 19 per SA<br />Use a decision rule table to determine what number of correct responses is the cut-off for identifying SAs that need priority attention <br /><20%, <1 correct response out of 19<br /><50%, <7 correct responses out of 19<br />85%, <14 correct responses out of 19<br />
  6. 6. Steps<br />Indicators must be dichotomous (yes/no)<br />Was child exclusively breastfed?<br />Not for how many months was the child exclusively breastfed? <br />
  7. 7. Supervision Area (SA)<br />“Lots” that you divide project area into<br />Should have meaning:<br /> i.e. health facility catchment areas, sub-districts or other MOH administrative areas<br />A<br />B<br />E<br />D<br />C<br />
  8. 8.
  9. 9. Parallel Sampling<br />Conducting multiple surveys at the same time using the same logistic system<br />Necessary for surveys that collect information on indicators with different age groups as denominators: <br /> i.e. IYCF (denominator children 6-23 months);<br /> use of ORS for diarrhea treatment (denominator children 0-23 months with diarrhea in the last two weeks)<br />Parallel sampling ensures that:<br />Each indicator will have 19 responses/supervision area<br />
  10. 10. LQAS – Coverage estimates<br />Information from supervision areas combined to obtain coverage for entire project area<br />LQAS with information combined from multiple SAs is a form of stratified sampling where supervision areas are strata<br />Requires a weighted average of all supervision areas; confidence intervals<br />Total of 95 responses (5x19 = 95)<br />Remember parallel sampling<br />
  11. 11. LQAS<br />Useful for monitoring of implementation<br />Can be controversial<br />Best not to use for evaluation<br />
  12. 12. Controversy - Example<br />Concern raised that use of LQAS to identify SAs as having reached the target, might result in mistakenly identifying an SA as one in for which resources can be reduced.<br />If this is a mistaken classification, then the population will not receive needed resources<br />
  13. 13. American Statistical Association (ASA) Recommendation<br />Report to the American Statistical Association Board of Directors on Lot Quality Assurance Sampling, August 19, 2010<br />“We believe that LQAS conclusions should be carefully stated to ensure that the user will never mistakenly draw a conclusion about the performance of the SA. We propose the following as a better interpretation of the conclusions that can be drawn from LQAS: <br />Based on considerations related to the power of the test employed, given the sample size used:<br /> <br />
  14. 14. ASA recommendation continued<br />If 13 or more of the 19 samples of men in a supervision area (SA) can correctly name the ways to prevent sexual transmission of HIV, then we classify the SA as not requiring priority intervention at this time or<br />If 12 or fewer of the 19 sampled men in the SA can correctly name the ways to prevent sexual transmission of HIV, then we classify the SA as substandardrequiring immediate intervention.<br />
  15. 15. Articles <br />Rhoda, Dale A., Soledad A. Fernandez, David J. Fitch, and Stanley Lemeshow (2010), LQAS: User Beware. International Journal of Epidemiology, 39:60-68<br />Olives, C., M. Pagano, and J.J. Valadez (2010), Commentary: Understanding practical lot quality assurance sampling. International Journal of Epidemiology, 39: 69-71.<br />
  16. 16. Resources:<br />MCHIP NGO/PVO support website: www.mchipngo.net<br />Rapid Health Surveys Handbook (Public Health Institute)<br />CORE website: (www.coregroup.org)<br />KPC Trainer of Survey Trainers (TOAST)<br />LQAS trainers guides<br />LQAS protocol for parallel sampling<br />LQAS FAQs<br />

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