An exploration of the increasing prevalence of chronic pain among Canadian veterans: Life After Service Studies 2016 and 2019

Background: The Life After Service Study (LASS) suggests that the absolute prevalence of chronic pain among Canadian veterans, defined as pain lasting 3 months or longer, increased by 10% from 2016 to 2019. Aims: We explored the association of year of survey administration, sociodemographic characteristics, military service, and health-related factors with the prevalence of chronic pain among Canadian veterans. Methods: We analyzed 2016 and 2019 LASS data and built a multivariable regression model to explore factors associated with chronic pain. Measures of association are reported as adjusted odds ratios (ORs) and absolute risk increases (ARIs). Results: The 2016 LASS (73% response rate; 3002 of 4121) reported a 41.4% prevalence of chronic pain, and the 2019 LASS (72% response rate; 2630 of 3671) reported a 51.5% prevalence of chronic pain among Canadian veterans. Respondents who completed the 2019 LASS were more likely to endorse an anxiety or related disorder, mood disorder, probable posttraumatic stress disorder, and traumatic brain injury. In our adjusted regression model, year of survey administration was not associated with chronic pain (OR = 1.08, P = 0.8); however, we found large associations with obesity class 1 (body mass index [BMI] = 30.0-34.9; OR = 3.66; 95% confidence interval [CI] 1.46-9.17; ARI 27%), obesity class 2 (BMI = 35.0-39.9; OR = 8.10; 95% CI 1.67-39.3; ARI 47%), mood disorder (OR = 3.20; 95% CI 1.49-6.88; ARI 24%), and an anxiety or related disorder (OR = 4.53; 95% CI 1.28-16.0; ARI 33%). Conclusions: The increase in chronic pain among Canadian veterans from 2016 to 2019 appears confounded by increased comorbidities associated with chronic pain among responders in 2019.