Difference between observed and predicted length of stay as an indicator of inpatient care inefficiency

Objectives. To evaluate the performance of the difference between observed and predicted length of stay (OLOS-PLOS) as an inefficiency of care indicat or for inpatients. Setting. The Internal Medicine and the General Surgery departments of Herma nos Ameijeiras Hospital in Havana. Design and study participants. Two sets of clinical histories were needed f or each department: one for deriving the predictive equation and another to validate it. The equation was a linear multiple regression model which inc luded variables recognized as affecting length of stay. The validation grou p of histories was thoroughly examined and separated into two groups: (i) a dequate efficiency or mild problems and (ii) inefficiencies considered to b e moderate or severe. This classification was the gold standard to obtain a receiver operating characteristic (ROC) curve for the indicator. Results. The function explained 41% of the total variation for Internal Med icine and 70% for General Surgery. The indicator's mean difference between the two validation groups of histories was around 10 days for both departme nts. The areas under the ROC curve were 0.80 for Internal Medicine and 0.88 for General Surgery. Sensitivity and specificity > 0.7 for detecting ineff iciencies of care are achieved with a cut off point of 2 days for Internal Medicine and 1 day for General Surgery. Conclusions. The use of predictive equations might be quite useful for dete cting efficiency problems in inpatient health care.