Development of two indices of postoperative morbidity.

Two indices of postoperative morbidity, Nursing Assessment Index and Observed Treatment Index, are described and evaluated in this study of 4,182 consecutive anesthetics. The use of these indices in studies of the quality and effectiveness of surgical and anesthetic care should increase the economy and precision with which the causes of unsatisfactory outcome are identified. Specific illustrations of the relationship of the preanesthetic status of patients to their postoperative morbidity as measured by these indices and mortality rates are given. In addition these two indices of morbidity measured on the seventh postoperative day are shown to be strongly co-related with subsequent in-hospital deaths. Thus, of the 100 patients with a Nursing Assessment Index worse than 3, 19 percent died; only 0.4 percent of the 550 patients who had no morbidity as measured by this index died. Although they ultimately survive, about an equal number of patients become seriously ill as die follow operations.