Relationship between persistent pain and 5-year mortality: A population-based prospective cohort study

Objectives: To assess the association between self-reported noncancer pain and 5-year mortality. Design: Cohort. Setting: Community-dwelling older adults. Participants: Canadian Study of Health and Aging 1996 wave. Measurements: Registrar of Vital Statistics-established 5-year mortality. Noncancer pain was assessed using the 5-point verbal descriptor scale, dichotomized into no or very mild versus moderate, severe, or very severe pain. Frailty was the accumulation of health deficits. Cognitive status (Modified Mini-Mental State Examination) and depressed mood (five-item mental health screening questionnaire) were also assessed. Multivariable logistic regression and Cox proportional hazards were used to analyze the relationship between pain and 5-year mortality. Results: Of 5,703 participants, 4,694 (82.3%) had complete data for analysis; 1,663 of these (35.4%) reported moderate, severe, or very severe pain, and 1,343 (28.6%) had died at 5-year follow-up. Four hundred ninety-six of those who died (29.8%) reported moderate, severe, or very severe pain and 847 (27.9%) no or very mild pain. Multivariate logistic analysis found that individuals with moderate, severe, or very severe pain had lower odds of 5-year mortality than those with no or very mild pain (odds ratio = 0.78, 95% confidence interval (CI) = 0.66-0.92; P <.001). The risk of death was lower in persons reporting moderate or greater pain than in those with no or very mild pain (HR = 0.85, 95% CI = 0.75-0.96; P =.01). An interaction between pain and sex explained this effect. Men with pain were not significantly more likely than men without pain to die (HR = 1.00, 95% CI = 0.84-1.19; P =.99), whereas women without pain (HR = 0.54, 95% CI = 0.47-0.63; P < 0.01) and women with pain (HR = 0.40; CI = 0.33-0.47; P <.01) had less risk of death than men without and with pain, respectively. Conclusion: Older women with pain were less likely to die within 5 years than older women without pain, men in pain, or men without pain.