Is health related quality of life related to the pattern of chronic pain?

Background/aims When studying chronic pain in the general population, other factors besides prevalence may be equally important to establish the scope of the problem. Health related quality of life (HRQoL) is an important indicator for how chronic pain influences and interferes with the individual's daily life. The relationships between different characteristics in the nature of pain and HRQoL have been investigated, showing number of pain locations and pain severity to be important. However, little is known about the relationship between pattern of chronic pain (constant/intermittent) and impact on HRQoL. The purpose of this study was to investigate the relationships between the pattern of chronic pain and impact on the individual's HRQoL in a large nationwide population based sample. Methods A postal questionnaire on pain and HRQoL (SF-36), including information letter was sent to a sample of 4500 individuals, aged 20-70 years, randomly drawn from the Icelandic National Registry. Results Of 4500 questionnaires mailed 1586 were returned and completed (35.2%) Majority of respondents were women (56.5%) and the majority were married or cohabitating (73.7%). The total sample mean age was 46.2 years (women 45.3, men 47.3) and respondents were significantly older than non-respondents. The total prevalence of pain ≥3 months was 47.5% with mean duration of 9.3 years (SD = 9.96). One third (31.9%) of participants with pain ≥3 months reported constant pain and 21.4% daily intermittent. The rest reported frequent pain (27.8%) and periodical pain (18.9%). There was a significant relationship between the pattern of pain and both physical and mental components of HRQoL. Participants experiencing constant pain had the lowest scores on both scales. Conclusions The results of this study show that both physical and mental components of HRQoL among individuals experiencing chronic pain are significantly related to the pattern of pain. Constant and daily pain is associated with poorer HRQoL than intermittent or periodical pain.