Effects of comorbid health conditions on healthcare expenditures among people with severe mental illness

Background and aims: Little is known about the incremental cost burden associated with treating comorbid health conditions among people with severe mental illness (SMI). This study compares the extent to which each individual medical condition increases healthcare expenditures between people with SMI and people without mental illness. Methods: Data were obtained from the 2011 Medical Expenditure Panel Survey (MEPS; N = 17 764). Mental illness and physical health conditions were identified through ICD-9 codes. Guided by the Andersen’s behavioral model of health services utilization, generalized linear models were conducted. Results: Total healthcare expenditures among individuals with SMI were approximately 3.3 times greater than expenditures by individuals without mental illness ($11 399 vs. $3449, respectively). Each additional physical health condition increased the total healthcare expenditure by 17.4% for individuals with SMI compared to the 44.8% increase for individuals without mental illness. Conclusions: The cost effect of having additional health conditions on the total healthcare expenditures among individuals with SMI is smaller than those individuals without mental illness. Whether this is due to limited access to healthcare for the medical problems or better coordination between medical and mental health providers, which reduces duplicated medical procedures or visits, requires future investigation.