Hip symptoms are associated with premature mortality: the Johnston County Osteoarthritis Project

Abstract

To investigate the impact of hip osteoarthritis (OA) and/or hip symptoms on excess mortality. We analyzed data from 3,919 individuals in a community-based prospective cohort of African Americans and Caucasians age ≥45 years. Women ≥50 years of age and all men underwent supine anteroposterior pelvic radiography at baseline, with the participant's feet in 15 degrees of internal rotation. Hip radiographic (rOA) was defined as a Kellgren-Lawrence grade of ≥2 in at least one hip. Participants completed questionnaires at baseline to determine presence of hip symptoms and covariate status. Participants with symptomatic hip rOA (SxOA) are a subset of individuals with hip rOA and symptoms in the same hip. Multiple imputation was used to impute missing values of covariates. Mortality was determined through 2015 and follow-up time was calculated from baseline assessment until death or censoring which took place when a participant was lost to follow-up or reached the end of study period. Cox proportional hazards regression was used to estimate hazard ratios (HR) and 95% confidence intervals (CI). We carried out additional analyses stratified by sex, race, age and obesity. Mean follow-up time was 14.2 years during which 1762 deaths occurred. There were 29.9% participants in our population with hip rOA at baseline. Compared to those with neither hip rOA nor hip symptoms, we observed an increased risk of all-cause mortality in participants with hip symptoms alone (HR=1.28, 95% CI=1.13-1.46), but no association for hip rOA either with or without symptoms. In stratified analyses we observed increased associations for hip symptoms alone and hip sxOA in those <65 years (43% and 39% increase, respectively) and in Caucasians (34% and 21% increase, respectively). Individuals who had hip symptoms without hip rOA had an increased risk of mortality. These effects were particularly strong for those who were <65 years of age and Caucasians. Effective interventions to identify those with hip pain in order to lessen it could reduce premature mortality.