Comorbidity-related medical expenditures and health outcomes in cancer patients.

1641 Background: Comorbidities are common among adults with cancer and necessitate effective medical management. However, research is scarce on how cancer affects healthcare utilization and expenditures for comorbid conditions. This study used a U.S. database to compare medical expenditures and health outcomes between adults with comorbidities who have cancer and those without. Methods: This longitudinal analysis utilized the data from the 2008-2014 Medical Expenditure Panel Survey (Household Component). Participants with one or more of 19 chronic health conditions (ICD-9 coded) relevant to primary care were classified based on self-reported cancer history. Outcomes from the second year of each panel (2009-2015) included comorbidity-specific healthcare utilization, medical expenditures, functional status, HRQoL, and health utility. Cost differences conditional on positive expenditures were analyzed using generalized linear models (gamma regression and log-link), while differences in healthcare utilization were examined using negative binomial regression. All models were adjusted for demographic, socioeconomic, and lifestyle covariates. Results: A weighted total of 24,057,137 adults with at least one comorbidity (mean age 58.3±15.8 years; 59% female) were included, of whom 10% (n=2,393,300) reported a history of cancer. Compared with non-cancer patients, cancer patients received more comorbidity-specific home health visits (IRR 2.01, 95% CI 1.13-3.57) but had lower total comorbidity-specific expenditures (OR 0.81, 95% CI 0.71-0.92). Cancer patients also incurred lower comorbidity-specific hospitalization costs and out-of-pocket costs for emergency department (ED) visits (p<0.05). Specifically, they had reduced total expenditures for arthritis (OR 0.60, 95% CI 0.39-0.93) and stomach problems (OR 0.42, 95% CI 0.22-0.81) and reduced out-of-pocket costs for thyroid problems (OR 0.55, 95% CI 0.36-0.86) and osteoporosis (OR 0.41, 95% CI 0.18-0.92). Among multimorbid patients (≥2 conditions; 55.4%), cancer patients incurred lower out-of-pocket costs for ED visits (OR 0.42, 95% CI 0.26-0.68). For health outcomes, cancer patients reported more functional limitations than non-cancer patients in instrumental activities of daily living (10.8% vs 8.5%), role functioning (26.2% vs 20.5%), and cognitive function (13.6% vs 11.2%), all p<0.05. Moreover, multimorbid patients with cancer had lower HRQoL and health utilities (p<0.05). Similar trends were observed for cancer patients with depression, hypertension, chronic lung disease, osteoporosis, and thyroid problems. Conclusions: Cancer patients with comorbidities had greater functional limitations but lower medical expenditures for comorbidity care than non-cancer patients, suggesting inequities in primary care. Healthcare resources should be prioritized for cancer patients with comorbidities and poor functional status.