1. BACK PAIN - CHRONIC
ISSUES
David Borenstein, MD
Clinical Professor of Medicine
Arthritis and Rheumatism Associates
The George Washington University
Medical Center
Washington, DC
2. Chronic Low Back Pain
Issues for Discussion
1. Define the forms of chronic low back pain and
its prevalence (Is it frequent and important
enough to study?)
2. Will patient selection including etiology and
severity influence the performance of drugs in
development? (Is it possible to identify and
separate the individuals with back pain?)
3. Which are the appropriate outcome measures?
(Can improvements in back pain related to
therapy be determined?)
3. Chronic Low Back Pain
Issues for Discussion
4. Will a general indication be useful for different
labeling claims? (somatic v. neuropathic v.
chronic headache)
5. Chronic low back pain - serve as a measure of
efficacy for a general chronic pain indication or
specific indication for chronic low back pain
alone
5. LOW BACK PAIN -
DEFINITION
Pain that occurs in an area with boundaries
between the lowest rib and the crease of the
buttocks
6. Chronic Low Back Pain
• Duration greater than 3 months
• Pain that persists longer than the
expected time period for healing
7. Epidemiology of Low Back Pain
• 20% of the US population develops back
pain yearly
• Back pain -second most common cause of
disability in the US (leading cause among
men) accounting for 16.5% of the total
disabilities in > 18 yo in 1999
• Workers’ compensation 1986-1996 - > 1
year 8.8% of claims - 64.9%-84.7% of
annual costs
___________________________________
CDC. MMWR 2001;50:120-125
Hashemi L et al: J Occup Environ Med 1998;40:1110-1119
8. Natural History of Low Back Pain
443 LBP subjects postal questionnaire 12 months
15 general practices Amsterdam, Netherlands
269 completed survey - less pain answered less often
7 weeks-median time to recover
At 12 weeks-35%, 52 weeks-10% had LBP
75% had 1 or more relapses during study
Pain and disability was less during relapses
Time to relapse-median 7 weeks, duration-median 6
weeks
__________________________________________
van den Hoogen et al: Ann Rheum Dis 1998;57:13-19
9. Low Back Pain - Disorders
Mechanical Referred
Rheumatologic Hematologic
Infectious Neurologic
Neoplastic Psychiatric
Endocrinologic Miscellaneous
(N > 60)
_____________________________________
Borenstein D, Wiesel S, Boden S: Low Back Pain: Medical Diagnosis and
Comprehensive Management. 1995
10. Low Back Pain - Disorders
Mechanical - 85% of all low back pain
• Muscle, ligament, tendon strain
• Discogenic disorders including herniated disc
• Apophyseal joint arthritis
• Spinal stenosis
• Spondylolysis, spondylolisthesis
• Scoliosis
11. Sources of Low Back Pain
• Superficial somatic - skin
• Deep somatic - muscle, joint, tendon, bursa,
fascia
• Radicular - nerve root
• Visceral referred - sympathetic afferents
• Neurogenic - mixed motor sensory nerves
• Psychogenic - cerebral cortex
12. Pain Intensity
• Minimal - mentioned in passing, normal
function
• Mild - component of symptoms, mild
dysfunction
• Moderate - major component of symptoms,
alters function
• Severe - the disease symptom,
incapacitating function
13. Diagnostic Evaluation
Diagnosis of low back pain is unspecified
in 80% of patients
_________________________________________
Dillane JB et al: Acute back syndrome: a study from general practice.
BMJ. 1966;2:82-84
Rowe ML: Low back pain in industry: a position paper. J Occup Med
1969;11:161-169
White AA, Gordon S. Symposium on Idiopathic Low Back Pain.
Mosby Co. 1982
14. LOW BACK PAIN -
DIAGNOSIS
• Specific diagnosis is possible
• Differentiation of muscle, joint, ligamentous
structures
• Mechanical versus systemic disorders is
possible
• Categorize by clinical symptoms
• Subtyping will improve therapy
_____________________________________
Abraham I, Killackey-Jones B: Arch Intern Med 2002;162:1442-1444
15. LOW BACK PAIN -
DIAGNOSIS
• Specific diagnosis is impossible
• Anatomic abnormalities in asymptomatic
individuals
• Overutilization of imaging techniques
• Inconsistency of physical findings
• Non-specific therapy is effective
____________________________________
Deyo RA: Arch Intern Med 162:1444-1446, 2002
16. LOW BACK PAIN -
DIAGNOSIS
• Somatic v. neuropathic v. radicular pains
can be differentiated
• Specific pain generators (individual joint or
muscle) are difficult to identify but
localization is not essential for effective
therapy
17. Chronic Back Pain - Outcome
Measures
• Back specific function
• Pain
• Patient global satisfaction
18. Back Pain - Outcome Measures
Back Specific Function
Roland Morris Disability
Questionnaire
Oswestry Disability Index
19. Back Pain - Outcome Measures
Roland-Morris Disability Questionnaire -
function assessment
• 24 items from the Sickness Impact Profile
• Functions affected by back pain that day
• Scores added ( 0-no disability to 24 -
maximum disability)
• Validated and reproducible instrument
___________________________________
Roland M, Morris R: Spine 1983;8:141-144
20. Back Pain - Outcome Measures
Oswestry Disability Index - pain and function
assessment
• 10 sections on various functions with 6
levels of assessment
• Physical and social functions that day
• Scores added (0-no disability to 100-
maximum disability)
• Validated and reproducible instrument
_____________________________________
Fairbank J, Pynsent P: Spine 2000; 25:2940-2953
21. Back Pain - Outcome Measures
Pain Measurement
SF-36 pain scale
Visual analog scale (VAS)
Brief Pain Inventory (BPI)
Treatment Outcomes in Pain Survey (TOPS)
22. Back Pain - Outcome Measures
Global Satisfaction
Extremely, very, somewhat satisfied
Mixed
Somewhat, very, extremely dissatisfied
23. Back Pain - Outcome Measures
(Optional)
• General health status
– SF-36
• Depression
– Beck Depression scale
24. Back Pain - Outcome Measures
• Instruments exist to measure the effect of
drug interventions on chronic back pain for:
– function
– pain
– global satisfaction
– general health status
29. Chronic Low Back Pain -
Medications - Analgesics
• Nonnarcotic
– Acetaminophen
– Tramadol
• Narcotic
– Short acting
– Long acting
30. Case Study - Chronic Somatic
Pain - Mild To Moderate
• 52 year old person - work-related
myofascial injury
– Treatment regimen
• Change of NSAID - diclofenac 100mg QD
• Maintain methocarbamol 750mg BID
• Diclofenac 50mg prn acute exacerbations
• maintain exercises program
31. Case Study - Chronic Somatic
Pain - Mild to Moderate
• 67 year old person - facet arthritis
– Treatment regimen
• Rofecoxib 25mg QD
• Cyclobenzaprine 10 mg QHS
32. Case Study - Chronic Somatic
Pain - Moderate to Severe
• 72 year old person - s/p laminectomy with
fractured screw
– Treatment regimen
• Celecoxib 200mg BID
• Nortriptyline 50mg QHS
• Fentanyl patch 50 mcg
• Hydrocodone 5 mg prn
33. Case Study - Chronic
Neuropathic Pain - Moderate to
Severe
• 42 year old person - traumatic neuropathy -
sciatic nerve
– Treatment regimen
• Ketoprofen - long acting - 200mg QD
• Gabapentin - 100mg TID
• Oxycodone - long acting - 40mg TID
• Hydrocodone - 7.5mg PRN
34. Chronic Low Back Pain -
Summary
• Model for chronic pain
• Outcome tools are available
• Somatic pain is identifiable
• Degree of pain - effect on study design
– mild to moderate - single drug v. placebo
(active comparator)
– moderate to severe - stable multidrug regimen -
flare with withdrawal
