Pain at multiple body sites and health-related quality of life in older adults: results from the North Staffordshire Osteoarthritis Project

Objectives. Number of pain sites (NPS) is a potentially important marker of health-related quality of life (HRQoL) but remains unexplored in older people. This cross-sectional study investigated whether, in older people including the oldest old, NPS was independently associated with poorer mental and physical HRQoL and if the association was moderated by age. Methods. A postal questionnaire sent to a population sample of adults aged ≥50 years in North Staffordshire, UK, included the 12-item Short Form Health Survey (SF-12) mental component summary (MCS) and physical component summary (PCS), a blank body pain manikin, socio-demographic, health behaviour and morbidity questions. Participants shaded sites of pain lasting ≥1 day in the past 4 weeks on the manikin. OA consultation data were obtained for participants consenting to medical records review. Results. A total of 13 986 individuals (adjusted response 70.6%) completed a questionnaire, of which 12 408 provided complete pain data. The median NPS reported was 4 [interquartile range (IQR) 0–8]. General linear models showed that an increasing NPS was significantly associated with poorer MCS (β = −0.43, 95% CI −0.46, −0.40) and PCS (β = −0.87, 95% CI −0.90, −0.84). Adjustment for covariates attenuated the associations but they remained significant (MCS: β = −0.28, 95% CI −0.31, −0.24; PCS: β = −0.63, 95% CI −0.66, −0.59). The association between NPS and MCS or PCS was moderated by age, but the strongest associations were not in the oldest old. Conclusion. NPS appears to be a potentially modifiable target for improving physical and mental HRQoL in older people. Future analyses should investigate the influence of NPS on HRQoL over time in older people.