Effects of marital status and economic resources on survival after cancer: A population-based study.

Abstract

Although married cancer patients have more favorable survival than unmarried patients, reasons underlying this association are not fully understood. The authors evaluated the role of economic resources, including health insurance status and neighborhood socioeconomic status (nSES), in a large California cohort. From the California Cancer Registry, we identified 783,167 cancer patients (386,607 deaths) who were diagnosed during 2000 through 2009 with a first primary, invasive cancer of the 10 most common sites of cancer-related death for each sex and were followed through 2012. Age-stratified and stage-stratified Cox proportional hazard models were used to estimate hazard ratios (HRs) and 95% confidence intervals (95% CIs) for all-cause mortality associated with marital status, adjusted for cancer site, race/ethnicity, and treatment. Compared with married patients, unmarried patients had an elevated risk of mortality that was higher among males (HR, 1.27; 95% CI, 1.26-1.29) than among females (HR, 1.19; 95% CI, 1.18-1.20; Pinteraction < .001). Adjustment for insurance status and nSES reduced the marital status HRs to 1.22 for males and 1.15 for females. There was some evidence of synergistic effects of marital status, insurance, and nSES, with relatively higher risks observed for unmarried status among those who were under-insured and living in high nSES areas compared with those who were under-insured and living in low nSES areas (Pinteraction = 6.8 × 10(-9) among males and 8.2 × 10(-8) among females). The worse survival of unmarried than married cancer patients appears to be minimally explained by differences in economic resources. Cancer 2016;122:1618-25. © 2016 American Cancer Society.