Background: Pain often accompanies chronic disease in older adults and may exacerbate physical limitations, which the Disablement Model suggests may increase disability and decrease independence. This study tests the hypothesis that chronic pain and change in levels of pain over time have associations with worsening physical performance independent of disease conditions.
Methods: We studied the effects of initial and changing levels of pain on observed physical performance over approximately 22 months in 925 community-dwelling Hispanic and non-Hispanic white participants in the San Luis Valley Health and Aging Study. Logistic regression models controlled for demographic variables, baseline performance, and comorbidities.
Results: We found that chronic pain has an independent association with worsening physical performance, regardless of ethnicity. The intensity of the pain appears to have no independent effect. Although the presence of multiple comorbidities (or vascular disease or diabetes singly) also increases the risk of a worsened physical performance outcome, an independent effect of chronic pain remains after adjusting for these disease conditions. Furthermore, ongoing chronic pain increases the risk of worsening performance; obversely, recovery from chronic pain has a significant and substantial protective effect.
Conclusions: Pain in and of itself appears to increase physical impairment. These results strongly suggest that controlling chronic pain may interrupt the negative disease-impairment-disability trajectory by significantly reducing impaired physical performance, no matter the disease conditions that may underlie the pain.