Abstract
OBJECTIVES: To describe the prevalence and characteristics of flare-ups of chronic nonspecific back pain (CNSBP) among primary care patients, and to examine associations with measures of pain severity and psychosocial factors. METHODS: Six hundred thirty-four participants with nonspecific back pain were interviewed by telephone 2 years after an initial primary care visit for back pain. Participants experiencing flare-ups in the last 6 months reported on frequency, duration, and other characteristics of flare-ups. Using bivariate and multivariate analyses, we compared individuals with and without CNSBP flare-ups with respect to demographic characteristics, measures of pain severity, and psychosocial factors. RESULTS: Approximately 51% of the participants reported flare-ups. Physical activities, including lifting and bending, were the most common perceived triggers of flare-ups. Participants with flare-ups experienced greater levels of pain intensity, disability, opioid medication use, and psychosocial comorbidities. After adjustment for demographic factors, pain intensity, and pain frequency, participants with flare-ups were more disabled than those without [mean (95% confidence interval) disability score 4.2 (3.9-4.4) vs. 3.3 (2.9-3.6); P<0.0001] and demonstrated higher levels of passive coping [mean passive coping score 4.1(3.8-4.3) vs. 3.4 (3.1-3.7); P=0.0008]. DISCUSSION: Flare-ups of CNSBP are common among primary care patients, and are independently associated with higher levels of pain intensity, disability, and passive coping. The presence of flare-ups and the perception of activity as a trigger may predispose patients with flare-ups to experience disability not explained by pain intensity alone. Further longitudinal studies are required to better characterize CNSBP flare-ups and determine their clinical implications.