Psychologic Factors and Risk of Mortality After Spinal Cord Injury

Krause JS, Carter R, Zhai Y, Reed K. Psychologic factors and risk of mortality after spinal cord injury. Objective: To identify the association of 2 distinct psychologic constructs, personality and purpose in life (PIL), with risk of early mortality among persons with spinal cord injury (SCI). Design: Prospective cohort study with health data collected in late 1997 and early 1998 and mortality status ascertained in December 2005. Setting: A large rehabilitation hospital in the southeastern United States. Participants: Adults (N=1386) with traumatic SCI, at least 1 year postinjury. Interventions: Not applicable. Main Outcome Measures: We first evaluated the significance of a single psychologic predictor (a total of 6 scales) while controlling for biographic and injury predictors using Cox proportional hazards modeling and subsequently built a comprehensive model based on an optimal group of psychologic variables. Results: There were a total of 224 (16.2%) observed deaths in the full sample. The total number of deaths was reduced to 164 in the final statistical model (of 1128 participants) because of missing data. All 6 psychologic factors were statistically significant in the model that was adjusted for biographic and injury factors, whereas only 3 psychologic factors were retained in the final comprehensive model, including 2 personality scales (Impulsive Sensation Seeking, Neuroticism-Anxiety) and the PIL scale. The final comprehensive model only modestly improved the overall prediction of survival compared with the model with only biographic and injury variables, because the pseudo-R² increased from 0.121 to 0.129, and the concordance increased from 0.730 to 0.747. Conclusions: The results affirm the importance of psychologic factors in relation to survival after SCI.