Background Osteoarthritis (OA) is the most prevalent rheumatic disease and its impact on patients’ lives is related primarily with pain. In a population setting, it is important to evaluate the factors associated with pain.
Objectives To determine potential factors associated with pain in self-reported OA.
Methods An observational, population-based, cross-sectional study was conducted by Eurotrials Consultants in mainland Portugal, between September and October 2011, by random route. Citizens aged ≥45 years who agreed to participate completed a survey in home interviews including sociodemographics and presence of OA. Prevalent cases were characterized regarding treatment of OA, comorbidities, impact (VAS 0-10, none to higher impact) and pain of OA (VAS 0-10, no pain to worse pain), patient’s perception of importance of OA given by current physician (VAS 0-10, none to higher importance), disability due to OA (VAS 0-10, none to maximum disability) and health status (SF-12 v2.0®; physical and mental health, 0 no health - 100 better health). Spearman correlation coefficient (r) was calculated.
Results A representative sample of 1039 participants completed the screening survey. About 54% were female, mean age of 62 years (range: 45-99), average of 7 school-years, 18% obese (body mass index ≥30+ kg/m2) and 77% retired (0.8% due to OA).
Self-reported OA was present in 9.9% of participants (95% CI, 8.1-11.7%), 92% of those with OA diagnosis confirmed by x-ray (self-reported). In this population, mean level of pain was 4.5 (standard deviation: 3.3). Mental and physical health scores averaged 45.9 and 38.5, respectively. Pain showed to be poorly but significantly associated with height (r=-0.221; p=0.025) and moderately associated with physical health (r=-0.479; p<0.001) and mental health (r=-0.414; p<0.001). Median pain score was higher in participants with neck OA than without (7.9 vs 4.2; p=0.008), hands (5.0 vs 3.1; p=0.029), lumbar spine (7.3 vs 4.1; p=0.020) and shoulders (7.2 vs 4.1; p=0.025). Pain was associated with OA impact (r=0.524; p<0.001), OA severity (r=0.557; p<0.001) and disability due to OA (r=0.587; p<0.001).
Conclusions We found that OA pain is related to factors like severity, mental health and disability due to OA as a contributing factor of clinical impairments. Interestingly, we found that some of the less prevalent locations of osteoarthritis are more related with pain in contrast to knee or hip. Therefore pain reduction should be an important aim in the management of OA because of its close relation to severity, impact and disability.
Disclosure of Interest None Declared