Daily Sedentary Behavior Predicts Pain and Affect in Knee Arthritis.

<p><b>BACKGROUND: </b>Sedentary behavior (SB), which has been linked with numerous adverse health outcomes, is prevalent among adults with osteoarthritis (OA). The associations between SB and daily physical and psychological health outcomes for OA patients, however, have received little attention.</p><p><b>PURPOSE: </b>Using accelerometer and self-report data, the current study examined how the amount of time OA patients spent in SB was associated with their pain and affect in daily life, independent of physical activity.</p><p><b>METHODS: </b>Over 22 days, 143 older adults (mean age = 65 years) with knee OA wore an accelerometer to measure SB and physical activity, and also reported their pain and affect three times a day using a handheld computer. Multilevel analyses were conducted to examine the prospective within-person associations between SB and subsequent pain or affect within the same day and across days, independent of physical activity.</p><p><b>RESULTS: </b>The time spent in SB daily predicted less pain but worse affect at the end of that day, above and beyond the effects of physical activity, as well as demographics and individual differences in general health and depression. Moreover, cross-day lagged analyses indicated that time spent in SB on 1 day predicted higher negative affect the next morning. Finally, the average level of SB was also associated with worse average affect at the between-person level.</p><p><b>CONCLUSIONS: </b>SB may be related to less pain in the short term but detract from patients' emotional well-being. Future intervention should aim to reduce daily SB to improve OA patients' emotional well-being.</p>