Quantitative Sonographic Assessment of Quadriceps Muscle Thickness for Prospective Fall Injury in Patients Undergoing Maintenance Hemodialysis: an Observational Cohort Study

Introduction: Accidental fall risk is high in patients undergoing maintenance hemodialysis. Falls are associated with fatal injury, comorbidities, and mortality. Risk assessment should be conducted as a primary intervention to prevent falls. This study investigated whether quadriceps muscle thickness measured using ultrasonography can prospectively predict fall injury among dialysis patients.Methods: Using an observational cohort study design, 180 ambulatory hemodialysis patients during the period 2015–2016 were recruited in the four dialysis clinics. The sum of the maximum quadriceps muscle thickness on both sides and the average of the maximum thigh circumference and handgrip strength after hemodialysis were calculated. Patients were stratified according to tertiles of quadriceps muscle thickness. Fall injury was surveyed according to the patient’s self-report for the one-year period.Results: Among the 180 hemodialysis patients, 42 (23.3%) had fall injury during the 12-month follow-up period. When the quadriceps muscle thickness levels were stratified into sex-specific tertile, patients in the lowest tertile (men <3.66 cm and women <3.50 cm) were more likely to have higher incidence of fall injury compared with those in the higher two tertiles (0.56 vs. 0.18 and 0.15 fall injuries/person-year). After adjusting for covariates, lower quadriceps muscle thickness was found to be an independent predictor for fall injury (hazard ratio [95% confidence interval], 2.99 [1.46–6.32], P < 0.001). Conversely, no significant differences were found in the thigh circumference and handgrip strength between women with fall injury and those women without fall injury.Conclusions: Quadriceps muscle thickness using ultrasonography can be measured easily at the bedside and is a precise predictor of fall injury in patients undergoing maintenance hemodialysis.