The relationship between back pain and mortality in older adults varies with disability and gender: Results from the Cambridge City over-75s Cohort (CC75C) study

BACKGROUND: This study aims to determine whether older adults reporting back pain (BP) are at increased risk of premature mortality, specifically, to examine the association with disabling/non-disabling pain separately. METHODS: Participants aged ≥75 years were recruited to the Cambridge City over-75s Cohort (CC75C) study. Participants answered interviewer-administered questions on BP and were followed up until death. The relationship between BP and mortality was examined using Cox regression, adjusted for potential confounding factors. Separate models were computed for men and women. RESULTS: From 1174 individuals with BP data, the date of death was known for 1158 (99%). A significant association was found between disabling BP and mortality (hazard ratio: 1.4; 95% confidence interval: 1.1-1.8) and this remained, albeit of borderline significance, following adjustment for socio-demographic variables and potential disease markers (1.3; 0.99-1.7). Further, this association was found to vary with sex: women experienced a 40% increase in the risk of mortality associated with disabling BP (1.4; 1.1-1.9), whereas no such increase was observed for men (1.0; 0.5-1.9). Participants with non-disabling BP were not at increased risk of mortality. CONCLUSIONS: This study confirmed previous findings regarding the relationship between pain and excess mortality. Further, we have shown that, among older adults, this association is specific to disabling pain and to women. Clinicians should be aware not only of the short-term implications of disabling BP but also the longer-term effects. Future research should attempt to understand the mechanisms underpinning this relationship to avoid excess mortality and should aim to determine why the relationship differs in men and women.