Association between in-hospital adverse events and mortality for patients with brain tumors

Abstract

Object: The Agency for Healthcare Research and Quality patient safety indicators (PSIs) and the Centers for Medicare and Medicaid Services hospital-acquired conditions (HACs) are administrative data-based metrics. The use of these outcomes as standard performance measures has been discussed in previous studies. With the objective of determining the applicability of these events as performance metrics among patients undergoing brain tumor surgery, this study had 2 aims: 1) to evaluate the association between PSIs, HACs, and in-hospital mortality rates; and 2) to determine a correlation between hospital volume, PSIs, and HACs.

Methods: Patients with brain tumors treated between 1998 and 2009 were captured in the Nationwide Inpatient Sample database. Hospitals were categorized into groups according to surgical volume. Associations between PSIs, HACs, and in-hospital mortality rates were studied. Factors associated with a PSI, HAC, and mortality were evaluated in a multivariate setting.

Results: A total of 444,751 patients with brain tumors underwent surgery in 1311 hospitals nationwide. Of these, 7.4% of patients experienced a PSI, 0.4% an HAC, and 1.9% died during their hospitalization. The occurrence of a PSI was strongly associated with mortality. Patients were 7.6 times more likely to die (adjusted odds ratio [aOR] 7.6, CI 6.7-8.7) with the occurrence of a PSI in a multivariate analysis. Moderate to strong associations were found between HACs, PSIs, and hospital volume. Patients treated at the highest-volume hospitals compared with the lowest-volume ones had reduced odds of a PSI (aOR 0.9, CI 0.8-1.0) and HAC (aOR 0.5, CI 0.5-0.08).

Conclusions: Patient safety-related adverse events were strongly associated with in-hospital mortality. Moderate to strong correlations were found between PSIs, HACs, and hospital procedural volume. Patients treated at the highest-volume hospitals had consistently lower rates of mortality, PSIs, and HACs compared with those treated at the lowest-volume facilities.

Keywords: AHRQ = Agency for Healthcare Research and Quality; CCI = Charlson Comorbidity Index; CMS = Centers for Medicare and Medicaid Services; DVT = deep venous thrombosis; HAC = hospital-acquired condition; IQR = interquartile range; NIS = Nationwide Inpatient Sample; PE = pulmonary embolism; PSI = patient safety indicator; UCSF-Stanford EPC = University of California at San Francisco-Stanford University Evidence-based Practice Center; UTI = urinary tract infection; V1–V4 = lowest- to highest-volume hospitals; aOR = adjusted odds ratio; hospital procedural volume; hospital-acquired conditions; in-hospital mortality; oncology; patient safety indicators.