History and mobility exam index to identify community-dwelling elderly persons at risk of falling.

BACKGROUND

Falls are common in community-dwelling elderly persons and are a frequent source of morbidity. Simple indices to prospectively stratify people into categories at different fall-risk would be useful to health care practitioners. Our goal was to develop a fall-risk index that discriminated between people at high and low risk of falling.

METHODS

We evaluated the risk of falling over a one-year period in 557 elderly persons (mean age 81.6) living in a retirement community. On the baseline interview, we asked subjects if they had fallen in the previous year and evaluated risk factors in six additional conceptual categories. On the follow-up interview one year later, we again asked subjects if they had fallen in the prior year. We evaluated risk factors in the different conceptual categories and used logistic regression to determine the independent predictors of falling over a one-year period. We used these independent predictors to create a fall-risk index. We compared the ability of a prior falls history with other risk factors and with the combination of a falls history and other risk factors to discriminate fallers from nonfallers.

RESULTS

A fall in the previous year (OR = 2.42, 95% CI = 1.49-3.93), a symptom of either balance difficulty or dizziness (OR = 1.83, 95% CI = 1.16-2.89), or an abnormal mobility exam (OR = 2.64, 95% CI = 1.64-4.26) were independent predictors of falling over the subsequent year. These three risk factors together (c statistic =.71) discriminated fallers from nonfallers better than previous history of falls alone (c statistic =.61) or the symptomatic and exam risk factors alone (c statistic =.68). When combined into a risk index, the three independent risk factors stratify people into groups whose risk for falling over the subsequent year ranges from 10% to 51%.

CONCLUSION

A history of falling over the prior year, a risk factor that can be obtained from a clinical history (balance difficulty or dizziness), and a risk factor that can be obtained from a physical exam (mobility difficulty) stratify people into groups at low and high risk of falling over the subsequent year. This risk index may provide a simple method of assessing fall risk in community-dwelling elderly persons. However, it requires validation in other subjects before it can be recommended for widespread use.