Bidargaddi N, et al. - Researchers used routinely collected hospitalisation records from 37,580 cardiac patients, between 18 and 65 years old, admitted to South Australian hospitals between 2001/02 to 2010/11 financial years with cardiac diagnoses, to investigate how the length of hospital stay and number of hospital admissions in these subjects were influenced by the presence of psychiatric comorbidity. They constructed multi-level models to fulfill this purpose. Possible confounders for these models were, sex, age, indigenous status, country of birth, and rural status. An increase of 12.5% in the length of stay and an increase in the number of stays by 20.0% were reported in association with a mental health diagnosis in cardiac patients. Based on the findings, routinely collected hospitalization records could be useful to demonstrate the impact of psychiatric comorbidity on health service utilization.