To evaluate the utility of using 90-day as an adjunct to 30-day mortality rates after surgical cytoreduction for serous ovarian cancer and to compare them across hospitals of differing case volumes over time.METHODS:
We performed a retrospective cohort study using the National Cancer Database of women undergoing cytoreductive surgery for high-grade serous carcinoma between 2004 and 2012. The primary outcome of the study was mortality rate by hospital volume. The secondary outcome was to evaluate the performance of hospital rankings based on 30- and 90-day mortality rates. Hospitals were categorized by cases per year as low volume (10 or fewer), intermediate (11–20), high (21–30), and ultra-high (31 or more).RESULTS:
A total of 24,827 women from 602 hospitals were included. Overall 30-day mortality was 2.1% (95% CI 1.95–2.3) compared with 90-day mortality of 5.1% (95% CI 4.8–5.4%, P<.001). For each hospital volume category, the 90-day mortality was approximately double that of the 30-day mortality. Substituting 90-day in place of 30-day mortality for hospital ranking, 57 hospitals (9.5%) changed ranks (26 worsened and 31 improved). Based on the logistic regression model (after controlling for age, race–ethnicity, income, Charlson comorbidity index, insurance status, hospital volume, distance from place of residence to the hospital, receipt of neoadjuvant chemotherapy, and year of diagnosis), care at the ultra–high-volume centers was an independent predictor of lower odds of death at 90 days [adjusted odds ratios (OR) 0.60, 95% CI 0.38–0.96, P=.034] but not at 30 days (adjusted OR 0.64, 95% CI 0.35–1.18).CONCLUSION:
Compared with low-volume centers, ultra–high-volume centers are associated with significantly lower 30- and 90-day risk-adjusted mortality. The 90-day mortality rate is double that of the 30-day rate and may be a better metric for assessing the initial quality of care for patients with ovarian cancer.