The postoperative morbidity index: a quantitative weighing of postoperative complications applied to urological procedures

BACKGROUND The reporting of post-operative complications in the urological field is lacking of a uniform quantitative measure to assess severity, which is essential in the analysis of surgical outcomes. The purpose of this study was to evaluate the feasibility of estimating quantitative severity weighing of post-operative complications after common urologic procedures. METHODS Using a large healthcare system's quality database, complications were identified in eleven common urologic procedures (e.g., insertion or replacement of inflatable penile prosthesis, nephroureterectomy, partial nephrectomy, percutaneous nephrostomy tube placement, radical cystectomy, radical prostatectomy, renal/ureteral/bladder extracorporeal shockwave lithotripsy (ESWL), transurethral destruction of bladder lesion, transurethral prostatectomy, transurethral removal of ureteral obstruction, and ureteral catheterization) from January 1, 2011 to December 31, 2011. Complications were classified by the Expanded Accordion Severity Grading System, which was then quantified by validated severity weighting scores. The Postoperative Morbidity Index (PMI) for each procedure was calculated where an index of 0 would indicate no complication in any patient and an index of 1 would indicate that all patients died. RESULTS This study included 654 procedures of which 148 (22%) had one or more complications. As would be expected, a more complex procedure like radical cystectomy possessed a higher PMI (0.267), while a simpler procedure like percutaneous nephrostomy tube placement possessed a lower PMI (0.011). The PMI of the additional nine procedures fell within the range of these PMIs. These PMIs could be used to compare surgeons, hospitals or procedures. CONCLUSIONS Quantitative severity weighing of post-operative complications for urologic procedures is feasible and may provide exceptionally informative data related to outcomes.