Minnesota multiphasic personality inventory as related factor for post traumatic stress disorder symptoms according to job stress level in experienced firefighters: 5-year study

Objectives: As first responders to an increasing number of natural and manmade disasters, active-duty firefighters are at increased risk for physical and psychiatric impairment as reflected by high rates of posttraumatic stress disorder (PTSD). Because little is known about related factor with PTSD according to job stress level among firefighters, we assessed utility of the Minnesota Multiphasic Personality Inventory (MMPI) using 5-year medical surveillance. Methods: Data were analyzed from 185 male firefighters without psychiatric disease history and who at assessments in 2006 and 2011 completed all questionnaires on personal behaviors (including exercise, drinking and smoking habits) and job history (including job duration and department). MMPI, Events Scale-Revised-Korean version (IES-R-K) and Korean Occupational Stress Scale-Short Form (KOSS-SF) were used to screen for personality trait, PTSD symptom presence and job stress level, respectively. IES-R-K subgroups were compared using two-sample t- and chi(2) tests, and factors influencing IES-R-K according to KOSS-SF were determined using uni-and multivariate logistic regression. Results: Mean age and job duration were higher in PTSD-positive than negative groups. In multivariate analysis, increased PTSD risk was associated with: job duration (Odds ratio (OR) = 1.064, 95 % CI 1.012-1.118) for firefighters overall; masculinity-femininity (OR = 5.304, 95 % CI 1.191-23.624) and job duration (OR = 1.126, 95 % CI 1.003-1.265) for lower job stress level; and social introversion (OR = 3.727, 95 % CI 1.096-12.673) for higher job stress level. Conclusions: MMPI relates with PTSD according to job stress level among experienced firefighters. Masculinity-femininity and social introversion were the strongest related factor for PTSD symptom development in low and high job stress levels, respectively.