Impact of mental illness on outcomes of outpatients with community-acquired pneumonia.

According to the National Alliance on Mental Illness, one in five adults experience a mental health condition yearly. Community-acquired pneumonia (CAP) is often treated with QTc prolonging antibiotics. The primary outcome assessed is if psychiatric diagnosis contributed to treatment failure in CAP. Outpatients with International Statistical Classification of Diseases and Related Health Problems 9 and 10 codes for CAP from January 2008 to January 2018 were analyzed retrospectively by descriptive statistics. Bivariate analysis was used to compare baseline characteristics, treatment regimens, and outcomes between those with a psychiatric diagnosis and those without. A χ-test was used for analysis of categorical variables and either the independent Student's t-test or one-way analysis of variance was used was used for analysis of continuous variables. Criteria were met by 518 patients, of which, 49% had a psychiatric diagnosis. Patients with psychiatric comorbidity were not more likely to experience treatment failure, subsequent admission, or mortality. There was no statistically significant difference between patients with a psychiatric diagnosis and those without in early or late CAP treatment failure (P=0.34 and 0.12), 30-day subsequent admission rates (P=0.41), 30-day mortality (P=0.34), or 90-day mortality (P=0.38). Psychiatric diagnosis increased the likelihood of a concomitant QTc prolonging psychiatric medication (51.78 vs. 3.40% P<0.0001), however, the prescribing rate of a QTc prolonging antibiotic was not statistically significantly different (85.3 vs. 83.4% P=0.54). Outpatients with mental illness can be treated for CAP without fear of increased risk of treatment failure compared with those without such diagnosis. This study emphasizes the necessity to consider the full patient history and diagnosis when treating patients with outpatient infections.