Psychosocial Factors are Associated with Poor Mental and Physical Health-Related Quality of Life in Subjects with New Onset Chronic Widespread Pain

Purpose: Psychosocial status, a risk marker for the onset of chronic widespread pain (CWP), may be associated with poor physical and psychological health-related quality of life (QOL). Psychological interventions targeted at CWP show improvements in QOL, although not necessarily in levels of pain. This study aimed to identify whether psychosocial factors that may be amenable to intervention predicted poor physical and mental QOL in new onset CWP.

Methods: A total of 2987 subjects aged 25-65 years and who were free of CWP completed the baseline and follow-up phases of a population based survey of pain (participation rate 77.0%). Subjects were recruited from 3 primary care registers in North West England. At baseline psychosocial status was assessed: psychological distress (General Health Questionnaire), somatisation (Illness Behaviour Scale, Somatic Symptom Checklist), sleep (Estimated Sleep Problem Scale), and anxiety and depression (HAD). Subjects were followed-up 15-months later and those with new onset CWP were identified. Physical and mental QOL was determined using the SF-12. The physical (PCS) and mental (MCS) component summary scale scores were categorised into thirds, the lowest third reflecting the worst outcome. Threatening life events were also reported at follow-up. The risk associated with new onset CWP and reporting low PCS and MCS scores was quantified using multinomial regression, adjusted for age, gender and having some pain at baseline. Results are presented as odds ratios (OR) with 95% confidence intervals (95% CI).

Results: Of the 2987 subjects 304 (10.2%: median age 48.2 years; 56.1% female) reported new onset CWP. 248 (81.6%) provided full SF-12 data and were used in this analysis. Baseline somatic symptom (OR = 2.7; 95% CI 1.1-7.0) and illness behaviour (OR 15.9; 4.8-53.1) scores were associated with being in the lowest third of the PCS. In multivariate analysis illness behaviour remained an independent predictor (OR 13.9; 4.1-47.1). High levels of anxiety (OR 7.8; 3.4-17.9), depression (OR 21.7; 8.1-58.0), illness behaviour (OR 8.2; 3.1-22.0), psychological distress (OR 15.7; 6.0-40.9), sleep problems (OR 6.9; 2.7-17.9) and life events (OR 5.8; 2.5-13.3), predicted being in the lowest third of the MCS. In multivariate analysis illness behaviour (OR 3.7; 1.2-11.8), depression (OR 12.2; 3.9-38.6) and life events (OR 3.9; 1.4-10.4) were independent predictors of being in the lowest third of the MCS.

Conclusion: Illness behaviour independently predicts both poor physical and mental QOL associated with new onset CWP. Other markers of psychological state are important determinants of poor mental, but not physical, well-being. These results provide potential targets for improving the physical and mental QOL of subjects with new onset CWP.

 B.I. Nicholl, None; G.J. Macfarlane, None; R. Morriss, None; D. Ray, None; C. Dickens, None; J. McBeth, None.