Excess mortality associated with mental illness and substance use disorders among veteran clinic users with spinal cord injury

Purpose. Among veterans with traumatic spinal cord injury (SCI) or disease aetiologies, examine the association between diagnosed mental illness (MI) and substance use disorders (SUD) on mortality after controlling for demographic and socioeconomic factors, SCI severity, injury duration and chronic physical illnesses. Method. Longitudinal analysis of Veteran Health Administration(VHA) administrative data and Medicare claims for FY 1999-2004 matched with Spinal Cord Dysfunction-Registry (SCD-R) of VHA clinic users (N = 8334) with SCI. SCI was identified through SCD-R; individual MIs (anxiety, bipolar, depressive disorders, psychoses, post-traumatic disorder and schizophrenia) and SUDs (tobacco, alcohol and/or drug) were identified through ICD-9-CM codes. Cox-proportional hazards regressions were used to examine association between MI and SUD and time to death in years. Results. Among veterans with SCI, 17% died by the end of FY 2004. Veterans with psychosis (35%), depression (22%) and alcohol and/or drug use (20%) had significantly higher rates of mortality compared to those without these diagnoses. After adjusting for other independent variables in the study, hazards ratios for psychosis was 1.47 (95%CI - 1.24, 1.75), for alcohol and/or drug use was 1.30 (95% CI = 1.11, 1.53). Conclusions. Some types of MI and SUD were associated with excess mortality among veterans with SCI. Care for MI and SUD needs to be routinely integrated into SCI management. Future research is needed to determine whether depression and SUD treatment provides opportunity to improve survival.