numeric rating scale, anchored with 0 (“no pain”) and 10 (“most severe pain imaginable”). Participants also were asked to mark on a body chart where they felt pain in the week preceding data collection. The number of painful body sites was counted and categorized as: (1) a single pain site, (2) 2 pain sites, (3) 3 or more pain sites but not meeting the criteria for widespread pain, or (4) widespread pain. Widespread pain was defined as pain on the left and right sides of the body, pain above and below the waist, and axial skeletal pain.30 Both the numeric rating scale and the body chart have been shown to be valid and reliable in older people.31-32 Pain frequency during the week before the interview was categorized as: (1) seldom (once a week) or occasionally (2-3 times a week) or (2) often (more than 3 times a week) or always (all days). Pain duration was categorized as: (1) 6 months.
Depressive symptoms were assessed using the short version of the Portuguese translation of the Geriatric Depression Scale (GDS).33 This is a valid and reliable 15-item self-report scale of depression initially developed for adults aged 65 years or older.34 However, Weintraub et al35 showed that its level of sensitivity and specificity for patients aged less than 65 years is comparable to that of patients aged more than 65 years. Participants were asked to respond by answering “yes” or “no” to each of the 15 items: 10 items indicate the presence of depression when answered positively, and 5 items indicate depression when answered negatively. A score of 1 is given when the answer is indicative of depression, and the total score ranges from 0 to 15. For the regression analysis, we dichotomized the results as: (1) no depressive symptoms (5 points).35
Physical activity was assessed using the Portuguese version of the Rapid Assessment of Physical Activity (RAPA) questionnaire.36-37 This questionnaire was specifically designed for use with older people and has 9 items (7 + 2) with response options of “yes” or “no.” The total score of the first 7 items ranges from 1 to 7 points, with the respondent's