Results
Of the 1,816 DMAT members deployed to the disaster area, 426 agreed to participate in the present study (24% response rate), of whom 424 (65.8% men, 34.2% women; mean age 38.2 (SD = 7.5) years) completed a self-report questionnaire to assess psychological distress. Demographic characteristics are shown in Table 1. Physicians accounted for 24.1% of the sample, nurses 45.8%, and operational coordination staff 30.2%. Most of the women (89%) were nurses, while the occupational distribution was more dispersed for men; 33.7% were physicians, 23.3% were nurses, and 43.0% were operational coordination staff. Among all respondents, 9.2% were concerned over radiation exposure. The prevalence of probable psychological distress as determined by the K6 and CES-D was 4.0% and 21.4%, respectively. Both men and women with such concern showed significantly higher K6, CES-D, PDI, and IES-R scores than in those without concern (Table 2). After controlling for age, occupation, disaster operation experience, duration of time spent watching earthquake news, and past history of psychiatric illness, these associations remained significant in men, but did not remain significant in women for the CES-D and PDI scores. In addition, after excluding those with past history of psychiatric illness, ANOVA results showed no apparent change in the association between concern over radiation and psychological distress in men. In women, however, the association remained significant for the K6 (p = .029) but not for the CES-D, PDI, or IES-R (p = .097, p = .064, p = .064). ANCOVA results for women did not change the association. Moreover, for the ANCOVA, the addition of the two covariates "experience of saving a child during deployment" and "experience of contact with corpses" to the primary analysis of covariance did not change the association in men or women (data not shown).