The Prevalence of Chronic Pain in COPD and Its Clinical Implications
Condition: COPD
MeSH terms: Chronic Pain
Study type: Observational

Summary: 
      This study explores the prevalence of chronic pain in individuals with COPD compared to
      healthy controls and examines the clinical implications of pain on symptoms associated with
      COPD, psychological effect and physical activity.
    

Detailed description: 
      Chronic obstructive pulmonary disease (COPD) is a major public health problem with
      considerable direct and indirect healthcare costs. COPD is a disease of the older age-group
      which results in significant disability, high health care costs and is a leading cause of
      morbidity. This rising disease burden is associated with the systemic effects of this
      condition, with the clinical presentation of dyspnoea, reduced exercise capacity, fatigue and
      anxiety all contributing to the reduced health-related quality of life (HRQoL) in people with
      COPD . In addition to these symptoms, the clinical profile may be further complicated by the
      presence of pain. Recent studies have found the prevalence of pain ranging from 37 to 72% in
      COPD, although the duration and frequency of pain experiences across the disease spectrum
      compared to healthy individuals have not been clearly defined. While chronic pain has been
      associated with hyperinflation in patients with asthma, the association between pain and lung
      disease severity, according to spirometry measures and hyperinflation has not been determined
      in COPD.

      According to analysis of body charts, common regions of pain in COPD are the chest, thorax
      and neck, which are largely similar to healthy populations. However, it is not clear whether
      the origin of the pain source is musculoskeletal and/or related to postural changes or is due
      to other sources. Greater exploration of pain within specific spinal regions using well
      validated tools which focus on musculoskeletal pain will provide further insight into
      potential causes.

      Patients with COPD frequently experience co-morbid conditions which include ischaemic heart
      disease, diabetes, cancer and musculoskeletal conditions . Although increased pain intensity
      in COPD appears to be associated with a higher number of co-morbidities, the relationship
      between co-morbidities and locations of pain, duration, frequency in COPD is not clear. Some
      concomitant conditions, such as musculoskeletal disorders may influence the prevalence and
      experience of pain, but this has not been explored in COPD.

      In patients with moderate to severe COPD, increased pain severity has been linked to greater
      interference with activity and a poorer HRQOL. While this provides some insight into the
      clinical impact of pain, it is equally important to identify the link between pain and other
      commonly reported symptoms, including dyspnoea. Both pain and dyspnoea are recognised as
      multidimensional phenomenons, with physiological and psychological consequences and to gain a
      thorough understanding of each, evaluation of the sensory dimensions (intensity, quality,
      time course and location) and affective dimensions (unpleasantness and consequent emotional
      impact) is necessary. Patients with COPD have reported pain with coughing , but the link
      between the extent of breathlessness, including that experienced during activity and the
      experience of pain has not been determined. With the shared characteristics and common neural
      pathways which subserve distress and discomfort in pain and dyspnoea, understanding the
      relationship between these symptoms may provide further insight into the possible sources of
      pain in COPD.

      To achieve a thorough profile of pain, assessment of the psychosocial impact of pain,
      including pain catastrophising is recommended. Pain catastrophising is associated with
      heightened pain experiences, increased levels of disability and depression in non-respiratory
      conditions and in cystic fibrosis. With anxiety and depression frequently reported in COPD,
      these clinical symptoms may interact with pain experiences, but the extent to this is
      unknown.

      International guidelines for managing COPD advocate for the role of pulmonary rehabilitation,
      with compelling evidence of improvement in exercise capacity, reduction in breathlessness and
      improvement in HRQOL, irrespective of disease severity. As part of this, physical activity is
      a critical element to disease management. Recently, pain was associated with reduced level of
      physical activity in those with moderate to severe COPD. However, the relationship between
      pain locations and the influence upon physical activity is unknown.

      Clinical relevance This study aims to impact directly on the important clinical outcomes of
      HRQOL and disease burden in COPD, markers that are strongly associated with hospitalisation
      and health care utilisation. Understanding the extent of this comorbidity of pain, its
      interaction with other symptoms and its broader clinical consequences is the first step in
      identifying whether modifications to the management of COPD, including the development or
      institution of therapeutic approaches to minimize pain are necessary. Understanding the
      psychological consequences of pain in COPD is essential in prioritizing those patients who
      may require further assessment and treatment of pain.
    

Intervention name(s): Prevalence study
Intervention type(s): Other
Intervention description(s): Prevalence study of chronic pain in COPD vs healthy controls
Observational model: Case-Control
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        Diagnosed with COPD according to GOLD criteria and history of smoking > 10 pack years
      
Keywords: Pain