Pt 1 - Epidemiology

• Low back pain - the scale:

  • A review of population based epidemiology studies of back pain prevalence (Walker 2000) suggests:
  • 12 - 33% point prevalence (in the moment)
  • 19 - 43% in last month
  • 22 - 65% in last year
  • 59 - 84% at some time in lives
• Definition of non-specific low back pain:

  • Pain in the back between the bottom of the rib cage and the buttock creases
  • Unlikely to be because of a serious problem such as cancer, infection, fracture, or as part of more widespread inflammation
  • Other descriptions
  • Non-specific LBP
  • Mechanical LBP
  • Musculoskeletal LBP
  • Simple LBP
• Specific spinal diagnosis:

  • About 10 - 15% of presenting back pain cases, possibly a lot less:
  • fractures
  • Neoplasm (tumour)
  • Structural deformity
  • Scheuerman's disease
  • Spinal infection
  • Spondylolisthesis/Spondylolysis
  • Radiculopathy
• Some Back Pain Definitions:

  • Acute: Recent onset of back pain - had pain for less than 6 weeks
  • Subacute: 6 weeks to 3 months
  • Chronic: pain for more than 3 months duration
  • Recurrent, relapsing: multiple acute episodes
• Non specificity:

  • 85% of cases can not be given a clear structural diagnosis
  • Findings of MRI, X-Ray and CT scan do not closely correlate with incidence, severity or outcome
  • Scientifically the best we can do is label it Non Specific LBP
  • No existing model of classification wins
• The evidence-based natural course - Short Term:

  • Most improve considerably in a months time
  • 30% still have symptoms
  • 20 - 25% still have limitations
• The evidence-based natural course - Long Term:

  • 70 - 80% will report some recurrent symptoms
  • Most will be able to function without significant limitation
  • Around 10% will have chronic disabling ongoing pain
• Risk Factors for acute LBP - often weak predictors:

  • Previous LBP the strongest predictor of future episodes
  • Heavy lifting at work, vibration
  • Lifestyle factors - smoking
  • Obesity
  • Emotional distress/ depressive symptoms
• What (surprisingly?) do not seem to be clear risk factors:

  • Body build, height, length
  • Static work postures and sitting
  • Leisure activities
• Predictors of Chronicity (main predictors):

  • Age (>50-55 yrs)
  • Nerve root pain
  • Pain intensity/ Level of disability
  • Previous LBP
  • Heavy physical work demands
• Predictors of Chronicity (additional predictors):

  • Distress/depression
  • Low self efficacy
  • High disability
  • Illness perceptions
  • Fear Avoidance
  • Catastrophising
  • Low health perception
  • Length of sickness absence
  • Unemployment
  • Compensation
  • Expectations of recovery
  • Smoking
  • Work satisfaction
• What doesn’t seem to predict chronicity?

  • MRI/ X-ray findings
  • Objective examination findings (except neurological)
  • “Diagnosis”
• Biopsychosocial Considerations:

  • LBP related disability has experienced an epidemic in western industrialised societies
  • Modern medicine is failing to manage this explosion
  • An appreciation of the impact of psychosocial factors on the injury/illness experience is vital.
• Psychological Factors - chronic LBP patients have been shown to demonstrate:

  • Somatisation
  • Distress/ depressive signs
  • Low self efficacy/ perceptions of personal control
  • Catastrophising – Be careful with your explanations
  • Fear Avoidance
  • Some of the above indices have been shown to be (a little bit) predictive of prognosis
• The fear avoidance model

  
• Interaction of physical and behavioural factors