Firm, patient, and process variables associated with length of stay in four diseases.

Factors associated with length of stay in three London teaching hospitals during 1972 and 1975 were examined in patients treated for myocardial infarction, cerebrovascular disease, inguinal hernia without obstruction, and gall stones. Statistical analyses were carried out with multiple regressions on log lengths of stay.Increased length of stay was associated with infection in all four groups and with the seriousness of operative procedures in all but patients with cerebrovascular disease. Although age was a significant variable in patients with hernias and gall stones, it had relatively little practical effect on length of stay. Other significant variables in at least one disease were obesity, number of abnormalities in blood chemistry, administration of parenteral fluids or oxygen, or use of monitoring devices, and whether chest radiography was carried out, blood electrolytes and urea were measured, or anticoagulants were used. Patients with cerebrovascular disease who were not discharged to their own homes stayed on average more than two and a half times longer than other patients.Between a third and a half of the variance was explained by these variables and the variation among firms. The method described is reproducible in other hospital settings, and the study shows that much new information could be available routinely without mounting expensive field trials.