Which is More Predictive of Mortality-Pain Severity or Pain Interference? Evidence from 20-Year Longitudinal Data.

Chronic pain is highly prevalent, costly, and has significant impact on individuals' quality of life, yet evidence on its relationship with mortality remains inconsistent. While most prior studies have focused on the presence and severity of pain, relatively little attention has been given to the distinct role of pain interference (i.e., limitations in daily activities due to pain) in predicting mortality risk. Furthermore, potential differences in the pain-mortality relationship across socio-demographic subgroups remain understudied. This study examines whether pain severity or pain interference is more strongly associated with all-cause mortality among U.S. adults aged 51 and older and explores whether these associations vary by race/ethnicity, socioeconomic status (i.e., education, wealth), and sex. Using 20 years of longitudinal data from the Health and Retirement Study (1998-2018, N=19,487), this study fits Cox proportional hazards models to estimate mortality risk and includes multiplicative interaction terms to assess sociodemographic heterogeneity. Findings show that in fully adjusted models, pain severity itself is not significantly associated with increased risk of mortality, but pain interference is (Hazard Ratio: 1.33; 95% Confidence Interval: 1.27-1.39). The associations between pain interference and mortality risk vary only slightly by race/ethnicity, sex, education, and wealth. These results indicate that pain interference may be a strong risk factor for mortality- potentially more so than pain severity. Clinicians should attend more closely to pain interference as a potentially sensitive indicator of mortality risk among middle-aged and older adults. Interventions aimed at reducing the functional impacts of pain may offer meaningful benefits in improving longevity. PERSPECTIVE: Pain interference is a stronger predictor of mortality risk than pain severity in older adults. Clinicians should prioritize assessing and addressing the functional impacts of pain to potentially improve longevity.