Determinants of inpatient rehabilitation length of stay and discharge modality after hip and knee replacement surgery in Switzerland : a retrospective observational study

QUESTIONS UNDER STUDY / PRINCIPLES: The aims of this study were to identify the determinants influencing the inpatient rehabilitation length of stay (LoS) and discharge modality (DisMod) after hip or knee replacement surgery.
METHODS: Data were retrieved for 306 patients (185 females, 121 males) who were admitted to a Swiss orthopaedic rehabilitation facility between 2007 and 2008 after hip or knee replacement surgery. LoS and DisMod were extracted from the medical files along with an additional seven binary and six continuous variables (including scores of timed-get-up-and-go [TUG], walking distance [WDT] and stair climbing tests [FIM_St]). Nonparametric procedures were used to detect differences between the gender groups. For the analysis of the LoS determinants, a linear regression model was used. The nonmotor performance test determinants of DisMod were analysed using a logistic regression model, whereas the motor performance test determinants were examined using binary classification. For both regression models, a backward procedure was used.
RESULTS: Unlike DisMod, LoS calculations were conducted after stratification for gender. The simplified regression models explained 22% (females) and 31% (males) of the LoS variance and 20% (both genders) of the DisMod variance. TUG, WDT and FIM_St were all important predictors for LoS, whereas DisMod could be best predicted by WDT.
CONCLUSIONS: Patients with good motor ability at admission were discharged earlier and more frequently to home. These findings might be of importance for preoperative physiotherapeutic care and might help to improve care planning as well as more accurately predict the access to inpatients beds and the allocation of resources.