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.ObjectiveTo 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).DesignProspective cohort study with health data collected in late 1997 and early 1998 and mortality status ascertained in December 2005.SettingA large rehabilitation hospital in the southeastern United States.ParticipantsAdults (N=1386) with traumatic SCI, at least 1 year postinjury.InterventionsNot applicable.Main Outcome MeasuresWe 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.ResultsThere 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.ConclusionsThe results affirm the importance of psychologic factors in relation to survival after SCI.