Risk factors for hip fracture in New Zealand older adults seeking home care services: a national population cross-sectional study

BACKGROUND: Hip fractures are a common injury in older people. Many studies worldwide have identified various risk factors for hip fracture. However, risk factors for hip fracture have not been studied extensively in New Zealand. The interRAI home care assessment consists of 236 health questions and some of these may be related to hip fracture risk. METHODS: The cohort consisted of 45,046 home care clients aged 65 years and older, in New Zealand. Assessments ranged from September 2012 to October 2015. Hip fracture diagnosis was identified by linking ICD (International Classification of Diseases) codes from hospital admissions data (September 2012 to December 2015) to the interRAI home care data. Unadjusted and adjusted competing risk regressions, using the Fine and Gray method were used to identify risk factors for hip fracture. Mortality was the competing event. RESULTS: The cohort consisted of 61% female with a mean age of 82.7 years. A total of 3010 (6.7%) of the cohort sustained a hip fracture after assessment. After adjusting for sociodemographic and potentially confounding variables falls (SHR (Subhazard Ratio) = 1.17, 95% CI (Confidence interval): 1.05–1.31), previous hip fracture (SHR = 4.16, 95% CI: 2.93–5.89), female gender (SHR = 1.38, 95% CI: 1.22–1.55), underweight (SHR = 1.67, 95% CI = 1.39–2.02), tobacco use (SHR = 1.56, 95% CI = 1.25–1.96), Parkinson’s disease (SHR = 1.45, 95% CI: 1.14–1.84), and Wandering (SHR = 1.36, 95% CI: 1.07–1.72) were identified as risk factors for hip fracture. Shortness of breath (SHR = 0.80, 95% CI: 0.71–0.90), was identified as being protective against hip fracture risk. Males and females had different significant risk factors. CONCLUSIONS: Risk factors for hip fracture similar to international work on risk factors for hip fracture, can be identified using the New Zealand version of the interRAI home care assessment. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s12877-019-1107-1) contains supplementary material, which is available to authorized users.