Pre-existing musculoskeletal pain and its association with mortality in newly diagnosed co-morbid conditions: an electronic health record cohort study.

Objective: Musculoskeletal pain is a common risk factor for co-morbid conditions and might increase the risk of poor outcomes. The objective was to determine whether patients with pre-existing musculoskeletal pain have an increased risk for mortality following a new diagnosis of a co-morbid condition. Methods: Patients aged ≥45 years with a new diagnosis of acute coronary syndrome (ACS), stroke, cancer, dementia or pneumonia recorded in a UK electronic primary care database linked to hospital and mortality records were examined. The association of mortality with musculoskeletal pain (inflammatory conditions, OA and regional pain) was determined. Results: The sample size varied from 128 649 (stroke) to 406 289 (cancer) by cohort, with 22-31% having pre-existing musculoskeletal conditions. In the ACS cohort, there was a higher rate of mortality for all musculoskeletal types. There were also higher unadjusted mortality rates in patients with inflammatory arthritis compared with those without musculoskeletal pain in the stroke, cancer and dementia cohorts and for patients with OA in the stroke and cancer cohorts. After adjustment for the number of prescribed medications and age, the increased risk of mortality remained only for patients with inflammatory arthritis in the ACS cohort (adjusted hazard ratio = 1.07; 95% CI 1.03, 1.10). Conclusion: Older adults with inflammatory arthritis and OA have increased risk of mortality when they develop a new condition, which seems to be related to the prescription of multiple medicines. Pre-existing musculoskeletal pain is an indicator of a complex patient who is at risk of poorer outcomes at the onset of new illnesses.