About 10 million U.S. adults live with serious mental illness (SMI). 1 Among military veterans, the number of mental health (MH) diagnoses is increasing with the return of troops from deployment in Iraq and Afghanistan. 2-4 This increase has considerable implications for service use at the VA. An estimated 35% of army and marine veterans sought MH services within 1 year of returning from Iraq and Afghanistan. 5 Furthermore, there is an association of MH disorders, physical illnesses, and mortality rates among veterans. 2,6 Rising MH needs will increase the need for services; not unexpectedly, the VA is one of the largest providers of integrated health care in the U.S. 7
Many patients with SMI have additional health issues, secondary to medication adverse effects, medical comorbidities, and other factors. 8-12 Furthermore, their rates of preventable risk factors (eg, smoking, alcohol abuse, and poor exercise and diet 13,14) are higher. Comorbid medical illnesses can sideline the treatment of mental illness and lead to negative health outcomes. 15,16 These medical conditions coupled with SMI may increase overall rates of health care utilization in terms of outpatient visits, procedures, and inpatient hospitalizations. However, the literature on factors associated with health care utilization in veterans with SMI is scant and generally inconclusive.
Findings on utilization of non-MH medical services for veterans with comorbid MH diagnoses are mixed. Operation Enduring Freedom (OEF) and Operation Iraqi Freedom (OIF) veterans with MH diagnoses have been found to use significantly more non-MH medical services than do OEF and OIF veterans without these diagnoses. 17 However, other studies have found that veterans with SMI seem to be less likely to use medical services. 18,19 For example, in a study of the rate of medical visits for veterans with psychiatric diagnoses, veterans with SMI were found to have fewer outpatient medical visits than do other veterans without SMI. 20 Given the high rates of medical comorbidities in veterans with SMI, this finding of reduced rates of medical care is both informative and concerning. However, more information on utilization rates for other types of health care system services is needed.
In addition to MH diagnoses, multiple factors influence the use of health care services. Lower income predicts overall use of mental and medical services for female but not male veterans. 21 A large proportion of VA patients are male, and that disparity may affect female veterans’ perceptions and use of VA health care, underscoring the importance of examining the effects of sex in health care utilization. 22 Unmarried status, unemployment, and combat experience are other factors associated with higher health care utilization. 23,24 Sociodemographic factors, including income and possession of private health insurance, are associated with veterans’ use of VA health care services. 25 It is important to understand the effects of these factors on service utilization by veterans with SMI in order to provide them with optimal, targeted health care.
The authors conducted this study to examine factors affecting MH service utilization and health outcomes in veterans with SMI at the VA Palo Alto Health Care System (VAPAHCS). A retrospective data analysis of medical records was performed. More specifically, this study aimed to identify veteran-specific variables (eg, demographics, psychiatric diagnosis, comorbid medical conditions, combat status) associated with health care utilization and outcomes in veterans with SMI. Dependent variables of interest included service utilization, such as rate and length of inpatient hospitalization and frequency of outpatient encounters. Examining predictors of inpatient medical and psychiatric hospitalization (demographic, clinical, or treatment-related factors) can provide insight into which veterans can benefit from targeted, intensive interventions. A better understanding of the factors affecting comprehensive health care service use for veterans with SMI can clarify targeted interventions and follow-up care for an expanding population.
Study approval was obtained from the institutional review board at Stanford University and the VAPAHCS research and development committee. Medical record data for veterans treated at the VAPAHCS were collected for a 10-year period (fiscal years 2003-2012). The Computerized Patient Record System (CPRS) data were accessed by VA decision support system staff and analyzed with SPSS Version 21.0 (Armonk, NY). Veterans were identified by ICD-9 codes 295.00 through 298.9, as documented in CPRS.
For this study, schizophrenic, psychotic, bipolar, depressive, and mood disorders were classified as SMI. VA clinic codes were used to categorize visits by service: medical (general medical clinic, surgery, pharmacy, laboratory tests), MH (outpatient visits, intakes and assessments), ancillary services (chaplain, social work, administration), residential MH treatment (substance use disorder, domiciliary care), home-based primary care, and