the public health problem of pain: epidemiology and phenomenology rollin m. gallagher, md, mph...
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The Public Health Problem of Pain: Epidemiology and Phenomenology
Rollin M. Gallagher, MD, MPH
University of Pennsylvania School of Medicine
Philadelphia Veterans Medical Center
Email: [email protected]
“Pain is a more terrible lord of mankind than even death itself.”
Albert S. Schweitzer, 1931
On the Edge of the Primeval Forest.
New York: Macmillan, 1931:652
What is pain?
Most common reasons for under-treated PAIN ???
Attitude: Pain isn’t importantAttitude: Pain isn’t important
Lack of Awareness and Knowledge: Lack of Awareness and Knowledge: 1)1) Pain’s prevalence Pain’s prevalence 2)2) Pain’s impact Pain’s impact
- On people and their familiesOn people and their families- On healthcare costs and on societyOn healthcare costs and on society
3)3) The pathophysiology of the disease of painThe pathophysiology of the disease of pain
Lack of Good TrainingLack of Good Training1)1) The assessment of pain and pain co-morbiditiesThe assessment of pain and pain co-morbidities2)2) The use of evidence-based treatment algorithmsThe use of evidence-based treatment algorithms
Pain’s prevalence and impactPain’s prevalence and impact
- 75 million Americans with chronic or recurring pain75 million Americans with chronic or recurring pain- 40% with moderate to severe impact on their lives40% with moderate to severe impact on their lives- pain levels affect outcome of diseasepain levels affect outcome of disease- National economyNational economy
- $150 billion yearly: medical care, wage replacement, $150 billion yearly: medical care, wage replacement, disability, etcdisability, etc
- Businesses:Businesses:- $61 billion yearly in lost productivity in working adults$61 billion yearly in lost productivity in working adults
Defining Pain
Arthritis
Spinal Stenosis
Failed Back
Neuropathy DM,PHN,HIV,post CVA Cancer
Pain Mechanisms
Acute
Chronic < episodic < persistent
End of life
Pain’s Impact: Issues and challenges Established effects (by research) of chronic pain
Quality of life• Physical functioning• Ability to perform ADLs• Work
Psychological morbidity• Fear, anger, suffering• Sleep disturbances• Loss of self-esteem
Medical morbidity & consequences• Accidents• Medication effects• Immune function• Clinical depression
Pain’s Impact: Issues and challenges Established effects (by research) of chronic pain
Mismanaged chronic pain is often a personal, biopsychosocial catastrophe! ….and is a huge public health problem.
Social consequences• Marital/family relations• Intimacy/sexual activity• Social role and friendships
Societal consequences• Health care costs• Disability• Lost workdays• Business failures• Higher taxes
If chronic pain is a biopsychosocial catastrophe and a huge public cost,
how do you deliver clinical care that is driven by performance based, biopsychosocial outcomes?
You start by understanding: - the causal models of disease- the mechanisms underlying these
models- the biopsychosocial phenomenology of each unique disease population - the biopsychosocial formulation for each individual
You then assess the characteristics of the care delivery system.
Finally, you formulate and implement a goal-oriented management plan.
Back Pain Back Pain
• Low back pain accounts for 75% of all chronic pain conditions (> OA, HA, migraine, FM, cancer pain)
• 50% of working-age report “back pain” symptoms each year
• Most common cause of disability in persons < 45 yo
• At any given time, 1% of US population is chronically disabled because of back problems and another 1% is temporarily disabled
Courtesy of B. Todd Sitzman, MD, MPHCourtesy of B. Todd Sitzman, MD, MPH
Back Pain Back Pain
• Most common reason for office visits to orthopedic surgeons, neurosurgeons, pain medicine physicians
• Estimated total annual societal cost of back pain in the US is greater than $50 billion
• 22% of chronic back pain patients have changed doctors “at least 3 times” in search of pain relief
• The primary reasons why chronic pain patients change physicians is due to their doctor’s:
» Attitude toward pain» Knowledge about pain» Ability to treat pain
Courtesy of B. Todd Sitzman, MD, MPHCourtesy of B. Todd Sitzman, MD, MPH
By Duration:• Acute• Recurrent• Persistent
When does acute pain become chronic? - laboratory changes indicating chronicity changes begin within minutes.- clinically, changes start happening soon after onset, often within 1-2 weeks.
Problems in classifying painBy Intensity
No pain
-Mild
-Moderate
-Severe
-Excruciating
-Unbearable
Is person X’s “10” the same as person Y’s “10” (or person Y’s “8”, “5” , or “3”)?
0
2
4
6
8
10
Problems in classifying pain
By region:
low back pain
By anatomy
- spine
- muscles
- kidneys
Vertebral body
Disk
Facet joint
Nerve Root
OsteoporosisFractureTumorSpondylolisthesisScoliosis
DegeneratedAnnulus tearHerniation with or without fragment
ArthritisInstability
InflammationCompressionAvulsion
BY PATHOLOGY
By Mechanism
- Neuropathic
- Nociceptive
- Myofascial
Problems in classifying pain Sensitization
- peripheral- central
Sympathetically mediatedNerve injury/damage
(surgery, radiation, chemotherapy)NeuromaNeuralgias, NeuropathiesRadiculopathiesDeafferentation / ExcitotoxicityRebound headacheMigraine headache
Tissue injuryAuto-immune disease InflammationInfectionArthritisCancer
RadiculopathyRadiculopathy
• Definition: “Disturbance in the function of one or more
nerve roots”
• Hallmark characteristic:
“Pain in the presence of segmental nerve dysfunction”
• Described as shooting or electric shock-like
• Symptoms result from inflammation or compression of the nerve root
• May include both sensory and motor loss
Radiculopathy - EtiologyRadiculopathy - Etiology
• Mechanical Stimulation:
Common – disc bulge, herniation, fragmentation
– contact with a facet joint osteophyte
– ligamentum flavum thickening
Less Common (serious)– infection, hematoma formation, tumor
Radiculopathy - DiagnosisRadiculopathy - Diagnosis
• 80% of adults over 55 years of age have degenerative disk changes by MRI and are often asymptomatic
Jensen MC et al. Magnetic resonance imaging of the lumbar spine in people without back pain. N Engl J Med 1994, 331:69-73.
Nature or Nurture?
MacGregor et al, Arthritis Rheum 2004• 1064 twins from UK registry• Genetic overlap between:• Conclusions: The following must be
considered in developing a genetic model of LBP:– Psychological variables (e.g.,
depression)– Past pain experience– Patterns of learning– Cultural factors
Course of LBP
Gallagher RM et al Pain 1989, 1995 150 workers disabled by LBP Medical, radiographic, psychological, motivational and functional testing (5 hour battery) Independent predictors of poor return to work at 6 months?
Older Age Less Education Longer time out of work External locus of control
unless received workers compensation benefits!
NOT: physical examination findings
Course of LBP
Hestbaek L et al. Eur Spine J 2003
Review of studies of course of LBP After 12 months, the proportion of patients still
with LBP averaged 62% across studies (range 42-75%) LBP more chronic / recurrent than we thought
Course of LBP
Burton AK et al Man Ther 2004. (UK Study) Predictors of outcome at 4 years:
Depressive symptoms Fear-avoidance
Weiner D et al, Pain Med 2003 Adults > 70 y/o with LBP (Medicare data) Predictors of functional disability
Pain severityDuration of pain
Risk factors for Chronic LBP in VA populations
• Traumatic spine injury, e.g.,– Jumping from moving vehicles– Parachuting– Heavy lifting in hurried conditions
• Repetitive strain:– Industrial level manual labor in high stress
conditions
• Wartime environment leading to denial of injury, redeployment and repetitive injury
• High stress and life disruption leading to psychiatric comorbidities
D
The derivation of a disabled LBP population
D. Pre morbid risk factors:
Scoliosis; Combat exposure;
Prolonged deployment;Airborne troop; Stiff
upper lip;Older; Less education;Psychiatric disorder;Personality Disorder;
Externallocus of control
B. Soldierswith onset of injury causing LBP
A. DISABLED PAIN POPULATION
C. Injured at increased risk for pain disability:
1. Factors increasing risk for disability at injury onset?: TBI; Poor injury mgt; Pain impairments; Anxiety, depression, addiction disorder; Inappropriate back surgery
2. Factors perpetuating pain & disability: Uncontrolled pain;
Stoicism; Redeployment; Psychosocial morbidities; Fear-avoidance; Untreated depression / PTSD / SA; Obesity; Poor coping; No rehab; Inflexible workplace.
TIME
3. Factors reducing risks for chronicity:Competency/ coping skills; Access to pain medicine/rehab; RTW or vocation; Re-entry crisis Rx; Early depression Rx; Occupational mobility; Education level; Social support; Internal locus of controlB
C
(Adapted from Gallagher et al, Geriatrics 1999;
-1 + 6 months0 +1 +2