Mental Disorders Among U.S. Military Personnel in the 1990s: Association With High Levels of Health Care Utilization and Early Military Attrition

Abstract

Objective: Epidemiological studies have shown that mental disorders are associ- ated with reduced health-related quality of life, high levels of health care utiliza- tion, and work absenteeism. However, measurement of the burden of mental disorders by using population-based methods in large working populations, such as the U.S. military, has been limited. Method: Analysis of hospitalizati ons among all active-duty military personnel (16.4 million person-years) from 1990 to 1999 and ambulatory visits from 1996 to 1999 was conducted by using the Defense Medical Surveillance System. Rates of hos- pitalization, ambulatory visits, and attri- tion from military service were compared for persons with mental disorder diag- noses and those with diagnoses in 15 other ICD-9 disease categories. Results: Mental disorders was the leading category of discharge diagnoses among men and the second leading category among women; 13% of all hospitalizations and 23% of all inpatient bed days were at- tributed to mental disorders. Six percent of the military population received ambula- tory services for mental disorders annually in 1998 and 1999. Among a 1-year cohort of personnel, 47% of those hospitalized for the first time for a mental disorder left mil- itary service within 6 months. This attrition rate was significantly different from the rate of only 12% after hospitalization for any of the 15 other disease categories (range=11%-18%) (relative risk=4.04, 95% confidence interval=3.91-4.17). The differ- ence remained significant after controlling for effects of age, gender, and duration of service. Conclusions: Mental disorders appear to represent the most important source of medical and occupational morbidity among active-duty U.S. military personnel. These findings provide new population- based evidence that mental disorders are common, disabling, and costly to society.