The impact of preexisting mental health disorders on the diagnosis, treatment, and survival among lung cancer patients in the U.S. military health system

Background: Higher cancer-related mortality has been observed among people with mental health disorders than in the general population. Both delay in diagnosis and inadequate treatment due to health care access have been found to explain the higher mortality. The U.S. Military Health System (MHS), in which all beneficiaries have equal access to health care, provides an ideal system to study this disparity where there are no or minimal barriers to health care access. This study assessed preexisting mental health disorders and stage at diagnosis, receipt of cancer treatment, and overall survival among patients with non-small cell lung cancer (NSCLC) in the U.S. MHS. Methods: The study used data from the linked database from the Department of Defense's Central Cancer Registry and theMHS Data Repository (MDR). The study subjects included 5,054 patients with histologically confirmed primary NSCLC diagnosed between 1998 and 2007. Results: Patients with a preexisting mental disorder did not present with more advanced disease at diagnosis than those without. There were no significant differences in receiving cancer treatments between the two groups. However, patients with a mental health disorder had a higher mortality than those without [adjusted HR, 1.11; 95% confidence interval (CI), 1.03-1.20]. Conclusions: Poor survival in NSCLC in patients with a preexisting mental health disorder is not necessarily associated with delay in diagnosis and/or inadequate cancer treatment. Impact: This study contributes to the current understanding that health care access may not be sufficient to explain the poor survival among patients with NSCLC with preexisting mental health disorders.