Socioeconomic status and its association with the risk of developing hip fractures: A region-wide ecological study

Abstract Purpose To determine the association between socioeconomic deprivation (SES) and hip fracture risk. Methods Retrospective cohort study using a population-based database (primary care records) of over 5 million people. Eligibility: all living subjects registered during the period 2009–2012 and resident in an urban area. Measures: a validated SES composite index (proportion of unemployed, temporary workers, manual workers, low educational attainment and low educational attainment among youngsters) estimated for each area based on census data. Outcome: incident hip fracture rates as coded in medical records using ICD-10 codes. Statistics: zero-inflated Poisson models fitted to study the association between SES quintiles and hip fracture risk, adjusted for age, sex, obesity, smoking and alcohol consumption. Results Compared to the most deprived, wealthy areas had a higher hip fracture incidence (age- and sex-adjusted incidence 38.57 (37.14–40.00) compared to 34.33 (32.90–35.76) per 10,000 person-years). Similarly, most deprived areas had a crude and age- and sex-adjusted lower risk of hip fracture, RR of 0.71 (0.65–0.78) and RR of 0.90 (0.85–0.95), respectively, compared to wealthiest areas. The association was attenuated and no longer significant after adjustment for obesity: RR 0.96 (0.90–1.01). Further adjustment for smoking and high alcohol consumption did not make a difference. Conclusion Wealthiest areas have an almost 30% increased risk of hip fracture compared to the most deprived. Differences in age–sex composition and a higher prevalence of obesity in deprived areas could explain this higher risk.