Screening tools to expedite assessment of frailty in people receiving haemodialysis: a diagnostic accuracy study

Abstract

Background Frailty is associated with multiple adverse outcomes in stage-5 chronic kidney disease (CKD-5) and upwards of one third of people receiving haemodialysis (HD) are frail. While many frailty screening methods are available in both uremic and non-uremic populations, their implementation in clinical settings is often challenged by time and resource constraints. In this study, we explored the diagnostic accuracy of time-efficient screening tools in people receiving HD. Methods A convenience sample of 76 people receiving HD [mean age\u2009=\u200961.1\u2009years (SD\u2009=\u200914), 53.9% male] from three Renal Units were recruited for this cross-sectional study. Frailty was diagnosed by means of the Fried phenotype. Physical performance-based screening tools encompassed handgrip strength, 15-ft gait speed, timed up and go (TUG), and five-repetition sit to stand (STS-5) tests. In addition, participants completed the SF-36 Health Survey, the short-form international physical activity questionnaire and the Tinetti falls efficacy scale (FES) as further frailty-related measures. Outcome measures included the area under the curve (AUC), sensitivity, specificity, positive (PPV) and negative predictive values (NPV). The diagnostic performance of screening tools in assessing fall-risk was also investigated. Results Overall, 36.8% of participants were classified as frail. All the examined instruments could significantly discriminate frailty status in the study population. Gait speed [AUC\u2009=\u20090.89 (95%CI: 0.81–0.98), sensitivity\u2009=\u200975%, specificity\u2009=\u200993%] and TUG [AUC\u2009=\u20090.90 (95%CI: 0.80–0.99), sensitivity\u2009=\u200989%, specificity\u2009=\u200985%] exhibited the highest diagnostic accuracy. There was a significant difference in gait speed AUC (20%, p \u2009=\u20090.013) between participants aged 65\u2009years or older ( n \u2009=\u200936) and those under 65\u2009years of age ( n \u2009=\u200940), with better discriminating performance in the younger sub-group. The Tinetti FES was the only instrument showing good diagnostic accuracy (AUCs≥0.80) for both frailty (sensitivity\u2009=\u200982%, specificity\u2009=\u200979%) and fall-risk (sensitivity\u2009=\u200982%, specificity\u2009=\u200971%) screening. Conclusions This cross-sectional study revealed that time- and cost-efficient walking performance measures can accurately be used for frailty-screening purposes in people receiving HD. While self-selected gait speed had an excellent performance in people under 65\u2009years of age, TUG may be a more suitable screening method for elderly patients (≥65\u2009years). The Tinetti FES may be a clinically useful test when physical testing is not achievable.