The protective effect of healthy ageing on the risk of fall-related hip fracture injury in older people

Abstract

IntroductionPromoting and maintaining good health in ageing, as well as prevention of fall-related injury are two of the National Priority Areas for health research. These priority areas have been endorsed because of the impact on public health of two concurrent trends - population ageing and the increasing incidence of fall-related injuries. Hip fractures are the most serious fall-related injury because they contribute substantially to increased disability and mortality in older age. The incidence of hip fractures worldwide is increasing with ageing of the population and they present a serious challenge to health care systems in future years.As a response to demographic trends and social forces, Healthy Ageing policies have been advanced to promote quality of life and reduce disability in older age. One of the strategies for promoting healthy ageing is to reduce the incidence of falls and fall-related injuries. Currently, the majority of falls prevention initiatives are based on screening patients at high risk of falling and implementing targeted multi-factorial interventions aimed at both intrinsic and extrinsic proximal risk factors. Opposed to this 'high risk strategy' is the 'mass strategy', which aims to change the distribution of a risk variable in the whole population, thereby producing greater population health gains. However, whole of population approaches to falls injury prevention are rare, due, in part, to lack of evidence of population-wide risk factors which can be addressed by community-based strategies.This thesis was based on the premise that healthy ageing strategies present an opportunity to address fall-related injury prevention using population-based interventions. The purpose of the research was, therefore, to test the hypothesis that healthy ageing factors are protective of fall-related hip fracture injury in older people.AimsThe aims of the study were:1. To define healthy ageing and to document the empirical evidence of determinants that are associated with healthy ageing outcome.2. To demonstrate that healthy ageing determinants are protective of the special case adverse health outcome of fall-related hip fracture injury and to quantify that protection.MethodsA literature review was undertaken of the definition, domains and measurement of healthy ageing, together with a systematic review of the behavioural and psychosocial determinants. This information formed the basis for the questionnaire development in the quantitative study.A primary analytic case control study was conducted with 387 participants, with a case control ratio of 1:2. Incident cases of fall-related hip fracture in community-dwelling people aged 65 and older were recruited from six hospital sites in Brisbane, Australia in 2003-04. Community-based controls, matched by age, sex and postcode were recruited via electoral roll sampling. A questionnaire designed to assess behavioural and psychosocial factors, identified as determinants of healthy ageing, was administered at face-to-face interviews. Data were coded and entered into a computerised database. Conditional logistic regression models, adjusted for health status confounders, examined differences between cases and controls on distribution of healthy ageing factors.ResultsAfter adjustment for health status, behavioural factors which had a significant independent protective effect on the risk of hip fracture included never smoking [AOR: 0.33 (0.12 to 0.88)], moderate alcohol consumption in mid and older age [AOR: 0.49 (0.25 to 0.95)], not losing weight between mid and older age [AOR: 0.36 (0.20 to 0.65)], playing sport in older age [AOR: 0.49 (0.29 to 0.83)], and practising a greater number of preventive medical care [AOR: 0.54 (0.32 to 0.94)] and self-health behaviours [AOR: 0.56 (0.33 to 0.94)].