Impact of facility volume on complications from immunotherapy for renal cell carcinoma.

Abstract

672 Background: Better outcomes have been generally associated with higher volume providers/hospitals. Recent work found an association between higher volume facilities and survival for advanced cancer patients. Volume and treatment complications for medical cancer therapy is unexplored. We studied a retrospective cohort of patients with metastatic renal cell carcinoma receiving immunotherapy at high and low volume hospitals. Methods: We used Premier Healthcare Data, which includes administrative data from all payors at over 700 community and academic hospitals, and captures 20% of all hospital discharges in the US, including infusions performed in hospital clinics. Using ICD9 codes we identified patients with metastatic renal cell carcinoma treated with nivolumab from 2015-17. Clinicodemographic data were obtained for patients and hospitals. The primary exposure was dichotomized hospital treatment volume (top quartile = high volume). Outcomes were immunotherapy-related complications for which the patient re-presented to the Emergency Department or was readmitted, and readmission for other cause. We performed mixed effects logistic regression adjusting for complex survey design to achieve national representation. Results: We included 15,724 weighted hospital encounters (5,835 at low-volume hospitals and 9,889 at high-volume hospitals). Urban, teaching hospitals were more likely to be high volume, but all patient factors were balanced. We observed 1,457 complications at high volume hospitals and 1,734 at low volume hospitals. There were no significant differences by volume of hospital in overall rates of complications (OR 0.92, 95% CI 0.82-1.09) or in rates of individual complications, with the exception of ocular complications (n=11, all low volume hospitals). We observed that high volume hospitals significantly reduced odds for readmission (OR 0.09, 0.03-0.24) unrelated to immunotherapy complications. Conclusions: We found no difference in immunotherapy-related complication rates by facility volume. This is reassuring for community administration of immunotherapy. Further study is needed to elucidate why we saw significantly more therapy-unrelated readmissions at lower volume hospitals.