Quadriceps muscle thickness as measured by point-of-care ultrasound is associated with hospital length of stay among hospitalised older patients

Abstract

Background Predicting hospital length of stay (LOS) can potentially improve healthcare resource allocation. Recent studies suggest that point-of-care ultrasound (POCUS), specifically measurements of muscle thickness (MT), may be valuable in assessing patient outcomes, including LOS. This study investigates the hypothesis that quadriceps MT and echo intensity (EI) can predict patient outcomes, particularly LOS. Methods Quadriceps MT and EI were measured using POCUS in patients admitted to a hospital’s acute medical unit. Predictor variables included age, sex, MT, EI and the Charlson Comorbidity Index (CCI). The outcome variable was hospital LOS. Results One hundred twenty participants were included (average age 76 ± 7, with 64 women and 56 men). The mean LOS was 27 ± 31 days, and the mean MT was 20 ± 6 mm. Sex-based differences in MT were statistically significant (P = .032). Patients with prolonged LOS over 30 days had lower MT (mean 17 mm vs. 21 mm, P < .0001). One unit increase in MT was significantly associated with ~1.5 fewer days of hospital LOS, and one CCI score increase was associated with almost three more days of hospital LOS. Having low MT significantly increased the odds of staying in the hospital longer than 30 days by more than three times in all models. Conclusion Muscle thickness is a strong predictor of hospital LOS, highlighting the potential of POCUS for assessing patient outcomes.