Mental disorders around cancer diagnosis and increased hospital admission rate - a nationwide cohort study of Swedish cancer patients

Background: Whether the emotional distress around cancer diagnosis is associated with the long-term outcomes and care utilization is unknown. We aimed to examine the association of mental disorders around cancer diagnosis with the hospital admission rates of cancer patients thereafter. Methods: We conducted a nationwide cohort study including 218,508 cancer patients diagnosed in Sweden during 2004-2009 and followed them from 90 days after cancer through 2010. We used a clinical diagnosis of stress-related mental disorders from 90 days before to 90 days after cancer diagnosis as the exposure. We studied first all hospital admissions and then separately three common admissions, including external injuries, infections, and cardiovascular diseases. The Cox model was used to estimate hazard ratios (HRs) with 95% confidence intervals (CIs). Results: Four thousand one hundred five patients received a diagnosis of stress-related mental disorders around the cancer diagnosis, and experienced a 35% increased rate of any hospital admission during follow-up (HR: 1. 35, 95% CI: 1.28-1.41) as well as hospital admissions for external injuries (HR: 1.89, 95% CI: 1.67-2.14), infections (HR: 1.28, 95% CI: 1.08-1.52), and cardiovascular diseases (HR: 1.16, 95% CI: 1.03-1.30). Similar association was noted for most common cancer types. Conclusions: These data suggest that cancer patients diagnosed with a stress-related mental disorder immediately before or after cancer diagnosis are subsequently at increased risk of hospital admissions for major comorbidities of cancer.