The added value of combined functional tests on predicting future falls in Chinese community-dwelling elderly

Abstract

Falls are one of the major causes of mortality and morbidity in older adults, which needs a practical fall risk assessment tool to predict future falls. Recent researches suggested various functional tests produce more power than a single test in many aspects. So we aimed to determine whether combined functional tests could increase predictive ability of future falls, especially recurrent-falls, which may result in stronger adverse impacts. This was a prospective cohort study (N = 875) among residents of Hangu area of Tianjin, China, who were ≥ 60 years old. Falls were ascertained after one year. Meanwhile, sociodemographic information, medical history and physical performance data were also collected. The Timed Up and Go Test (TUGT), walking speed (WS) and grip strength (GS) are more recommended as tests targeting on balance, mobility and muscle strength by many studies. Therefore, we selected these three tests to clarity our hypothesis. The mean age was 67.1 years; 58.6% were women. According to ROC area, the cutoff point of TUGT, GS and WS of falls is 10.31 s, 0.3742 kg/kg and 0.9467 m/s, respectively. Therefore we defined good performance on the tests as “ + ”, and poor performance as “ − ” with the cutoff point. Towards any-falls, combination of “TUGT−, GS−, WS + ” was most correlated with its occurrence, with odds ratio (OR) 2.197, 95% CI: 1.204–4.009. Meanwhile, combined “TUGT−, WS + ” (OR: 2.103, 1.367–3.235) and combined “TUGT−, GS+, WS − ” (OR2.071, 1.124-3.814) were also more related to any-falls than a single test, like TUGT− (OR: 1.676, 1.170–2.401). However, compared with a single test (TUGT−, OR: 2.192, 1.225–3.922), only the combination of “TUGT−, GS−,WS + ” (OR: 2.536, 1.025–6.272) was a more stronger predictor. A simple tool using TUGT, GS and WS has better predictive power on future falls. Based on this result, individuals who show poor ability in TUGT and WS but have good grip strength ought to be more concerned about the high-risk of future falls, especially the likelihood of recurrent-falls.