Course of Back Pain in the Canadian Population: Trajectories, Predictors, and Outcomes.

Abstract

To identify and describe back pain trajectory groups and to compare indicators of health status, medication, and health care use in these groups. A representative sample (n = 12,782) of the Canadian population was followed-up from 1994/1995 to 2010/2011. Participants were interviewed biannually and provided data on sociodemographic (e.g., education) and behavior-related (e.g., physical activity) factors, depression, comorbidities, pain, disability, medication use (e.g., opioids), and health care use (e.g., primary care visits). We used group-based trajectory analysis to categorize participants according to patterns in the course of their back pain during the 16-year follow-up period and compared indicators of pain, disability, medication, and health care use in the trajectory groups. A total of 45.6% of the participants reported back pain at least once during follow-up. Of those, we identified 4 trajectories: persistent (18.0%), developing (28.1%), recovery (20.5%), and occasional (33.4%). The persistent and developing groups were characterized as having pain that prevented activities, disability, depression, and comorbidities. There were significant differences in the patterns of medication and health care use across the groups, with a general trend of most to least health care and medication use in the persistent, developing, recovering, and occasional groups. Those in the recovery group had an increasing trajectory reflecting opioid and antidepressant use. Approximately 1 in 5 people with back pain experience a persistent pain trajectory with an associated increase in pain, disability, and health care use. Further research is needed to determine whether the groups identified represent different diagnoses, which may provide insight into the selection of stratified treatment and aid in designing early prevention and management strategies in the population.