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Co-morbidities in Chronic Pain

Recently I have been reviewing the literature in relation to co-morbidities in chronic pain.

The following list is taken from review of Ramond et al (2011), Von Korff et al (2005) and Coronado et al (2011). These are factors potentially related to poor prognosis and/or persistent pain states (I am sure there are more but this is a good starting point).

  1. Psychological Factors
      1. Depression
      2. Anxiety
      3. Somatization
      4. Psychological Distress
  2. Cognitive/Behavioural Factors
      1. Pain control (perception of the patients control over their pain)
      2. Coping Strategies (active versus passive)
      3. Fear Avoidance
      4. Patients expectations (beliefs about getting better/returning to work/sport etc)
  3. Social Factors
      1. Socioeconomic status
      2. Work status
      3. Educational level
      4. Relationship status
      5. Job satisfaction
      6. Compensation issues
      7. Social support
  4. Lifestyle factors
      1. Exercise levels
      2. Hobbies
      3. Smoking
  5. General Health and Co-morbidities

Remembering we can assess for all of the above issues subjectively and/or via the use if questionnaires.

If we look at most of these factors above I think we can conclude that a majority of them will impact centrally (i.e. a top down effect) by causing stress and other mood changes which can impact on areas such as the HPA Axis/Neuromatrix (see the HPA Axis post on how this will impact on the patient).

Other aspects of general health and co-morbidities may contribute to the pain state by way of Dysfunctional Pain or Central Sensitivity Syndromes (see the Subjective Exam – Identifying Pain Types post).

Von Korff (2005) make the following conclusions:

  •  68.6% of all persons with chronic spinal pain have another chronic pain condition.
  • 55.3% have at least one comorbid chronic physical disorder.
  • 35.0% have a comorbid mental disorder
  • 87.1% have at least one of these three forms of comorbidity.
  • This high comorbidity suggests that research and social policies intended to reduce role disability among persons with chronic spinal pain should consider the implications of other comorbid conditions.

Coronado et al (2011) determined that the number and severity of co-morbidities does not differ based on the anatomical region of musculoskeletal pain. They included/assessed general health co-morbidities such as:

  • Angina, anxiety, arthritis, asthma, cancer, chronic obstructive pulmonary disease (COPD), congestive heart failure (CHF), depression, degenerative disc disease (DDD), diabetes mellitus, gastrointestinal disease, headache, hearing impairment, hypertension, incontinence, kidney disease, myocardial infarction (MI), neurological disease, obesity, osteoporosis, peripheral vascular disease (PVD), stroke, and visual impairment.

Beales et al (2012) looked at Low Back Pain and Co-morbidity clusters in adolescents. The co-morbidities included (after a process of exclusion others – see the article for further details) were:

  • Attentional problems, Behavioral problems.
  • Anxiety problems, Back pain.
  • Depression, Neck pain.
  • Migraine or severe headache, Sleep disturbance

Taking into account the co-morbidities above, Beales et al (2012) identified 4 clusters via Latent Class Analysis (LCA):

  • Cluster 1:
    • Healthy individuals: Low probability of being diagnosed with LBP or any other medical condition (79.7% of the subjects).
  • Cluster 2:
    • Spinal pain: High probability of being diagnosed with LBP and neck/shoulder pain, but a low probability of having other diagnosed health conditions (9.6%).
  • Cluster 3:
    • LBP and depression/anxiety disorders: Moderate probability of being diagnosed with LBP, and high probability of having diagnosed with anxiety and depression (6.9%).
  • Cluster 4:
    • LBP and behavioral/attention disorders: Moderate probability of being diagnosed with LBP, and high probability of having a diagnosed behavioral and attention disorders (3.8%).

Obviously cluster 2 was interesting given the low probability of the co-morbidities being present. Beales et al (2012) proposed the following potential mechanisms for each cluster:

  • The identification of clusters 2 to 4 with distinct profiles of co-morbid diagnosed health complaints may represent different underlying biopsychosocial mechanistic processes for LBP in these clusters.
  • Cluster 2:
    • Had a low probability of psychological factors and sleep disturbances. Other factors known to be related to adolescent LBP may underlie the disorder. These factors may be some or all of:
      • physical factors (spinal posture, motor control, obesity, back muscle endurance)
      • lifestyle factors (physical and sedentary activity, school bags, and smoking)
      • neurophysiological factors (altered pain processing and pain thresholds)
      • genetic factors.
  • Clusters 3 and 4:
    • the relationship between pain, psychological factors, and sleep disturbance may be linked to dysregulation of the HPA axis and changes to the neuromatrix. This can influence neurobiology, processing of pain, health behaviors, and health related quality of life.

Ferreira et al (2013)

  • Twin study (becoming popular to investigate risk factors for low back pain (LBP) because they consider the genetic factor and allow for more precise estimates of risks).
  • The genetic component was higher for more chronic and disabling LBP than acute and less disabling LBP
  • Smoking was significantly associated with LBP.
  • Obesity was associated with LBP.
  • No association between alcohol consumption and LBP was identified.
  • Co-morbidities such as asthma, diabetes and osteoarthritis were associated with LBP.
  • The contribution of genetics to LBP appears to be dependent on the severity of the condition.

So….should we screen for co-morbidities and other factors in all patients (peripheral and spinal)?


My conclusion on all of the above is that it is imperative that we assess our patients for potential co-morbidities and other factors. Particularly if they are in a persistent/chronic pain state, or in an acute or sub-acute state and are not getting better (assuming there is no patho-anatomical injury that requires referral!). Some would argue that we should screen every patient for these issues. Logistically this may not be possible for every clinician as it would depend on your available consultation times. My point being that if someone is not responding to treatment as they should, and nothing “structurally” is wrong, we should then at the very least make some additional time to assess these aspects.

What do we do if we think that some of these factors are impacting on a patients recovery?

As far as I can see we have a few options:

    • Ourselves!
      • Education etc regarding the identified factor e.g. passive coping, fear, low exercise levels etc.
      • Treatment to reduce pain levels e.g. exercises, manual therapy etc
    • Referral for medical management to further assess manage the various issues that may be presenting e.g. depression, anxiety, general health issues, poor pain control
    • Clinical psychology referral.
    • This list could go on…….the point being we will often need to involve other disciplines and shouldn’t hesitate too when required.


Beales DJ, Smith AJ, O’Sullivan PB, Straker LM. Low Back Pain and Comorbidity Clusters at 17 Years of Age: A Cross-sectional Examination of Health-Related Quality of Life and Specific Low Back Pain Impacts (2012). Journal of Adolescent Health.

Coronado RA, Alapattu MJ, Hart DL,  George SZ. Total number and severity of comorbidities do not differ based on anatomical region of musculoskeletal pain. Journal of orthopaedic & sports physical therapy (2011) 41;7:477-485.

Ferreira PH, Beckenkamp P, Maher CG, Hopper JL, Ferreira ML. Nature or nurture in low back pain? Results of a systematic review of studies based on twin samples. Eur J Pain. 2013 Jan 20. doi: 10.1002/j.1532-2149.2012.00277.x. [Epub ahead of print]

Ramond A, Bouton C, Richard I, Roquelaure Y, Baufreton C, Legrand E, and Huez J. Psychosocial risk factors for chronic low back pain in primary care—a systematic review. Family Practice (2011); 28:12–21.

Von Korff M, Crane P, Lane M, Miglioretti DL, Simon G, Saunders K, Stang P, Brandenburg N, Kessly R. Chronic spinal pain and physical-mental comorbidity in the United States: results from the national comorbidity survey replication (2005). Pain 113: 331–339.

About the Author:

Mark is a Specialist Musculoskeletal Physiotherapist who consults at both Insight Physiotherapy and Pain Options, in Perth, Western Australia. He specialises in the assessment and management of persistent/chronic musculoskeletal pain. In addition to his clinical role he maintains regular involvement in education of the profession having held a Teaching Fellow position at the University of Western Australia for 10 years and regularly presenting at courses and seminars through the Australian Physiotherapy Association and private education sector. Mark is also a Facilitator for the Australian College of Physiotherapists Specialisation Training Program and a Sessional Academic at Curtin University. The views expressed on this blog are his own.

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