Comorbidity Level and Risk of 90-day and 18-month Complications Among Patients Undergoing Radical Prostatectomy for Prostate Cancer in the Military Health System

Introduction: Prostate cancer is frequently diagnosed at ages when men may also have comorbidity. Access to care may influence both comorbidity management and cancer treatment and recovery. We examined the association between comorbidity and postoperative outcomes among men with prostate cancer in the universal access Military Health System (MHS). Methods: We identified a cohort of men diagnosed with non-metastatic prostate adenocarcinoma from 2001-2014 who received radical prostatectomy (RP) within 1 year of diagnosis in the MilCanEpi database, which links the Department of War Cancer Registry and MHS Data Repository. We used ICD-9 diagnosis codes to capture 90-day postoperative general and genitourinary (GU) complications and hospital readmissions; and 18-month postoperative GU complications. Poisson regression estimated the adjusted risk ratios (ARRs) and 95% confidence intervals (CIs) for the outcomes associated with comorbidity (0, 1-2, or ≥3) measured using the Elixhauser Index. Results: The study included 5645 men with non-metastatic prostate cancer (mean age 57.9 ± 7.7 years) who received RP; 39.9% of patients had no comorbidity, 43.9% had 1-2 conditions, and 16.2% had ≥3 conditions. Patients with ≥3 comorbidities had statistically significant higher risks of 90-day general (ARR = 1.88, 95% CI = 1.34, 2.64) and GU (ARR = 1.20, 95% CI = 1.06, 1.36) complications and hospital readmission (ARR = 1.59, 95% CI = 1.12, 2.26) relative to men with no comorbidity. At 18-month post-RP, men with 1-2 comorbidities (ARR = 1.19, 95% CI = 1.05, 1.35) and ≥3 comorbidities (ARR = 1.32, 95% CI = 1.13, 1.55) had statistically significant higher risk of measured GU complications relative to men with no comorbidity. Conclusions: In the MHS, higher comorbidity was associated with an increased risk of 30-day and 18-month complications and 90-day readmissions following RP for prostate cancer. This study identifies a need for risk management strategies to reduce complication rates among men with higher comorbidity levels diagnosed with prostate cancer and treated by RP.