# Table 1 Sample distribution and probable PTSD-positive rates in 2 groups

Variables Group 1 (N = 17846) Group 2 (N = 7632) Total (N = 25478)
N % N % N % Probable positive rate of PTSD (%)
x1 age
16~ 8025 45.0 3364 44.1 11389 44.7 8.4
35~ 7019 39.3 3046 39.9 10065 39.5 9.2
55~ 2802 15.7 1222 16.0 4024 15.8 11.3
x2 gender
male 8441 47.3 3557 46.6 11998 47.1 8.2
female 9405 52.7 4075 53.4 13480 52.9 10.2
x3 education
high school or higher 1749 9.8 733 9.6 2482 9.7 3.1
elementary school 14360 80.5 6168 80.8 20528 80.6 8.0
illiterate 1737 9.7 731 9.6 2468 9.7 24.9
x4 occupation
nonfarmer 1534 8.6 678 8.9 2212 8.7 6.2
farmer 16312 91.4 6954 91.1 23266 91.3 9.4
x5 type of flood
soaked 9166 51.4 3936 51.6 13102 51.4 2.9
collapsed 6527 36.6 2799 36.7 9326 36.6 12.9
flash flood 2153 12.1 897 11.8 3050 12.0 24.9
x6 severity of flood
mild 7984 44.7 3384 44.3 11368 44.6 1.7
moderate 3965 22.2 1720 22.5 5685 22.3 13.9
severe 5897 33.0 2528 33.1 8425 33.1 16.1
x7.1 were you trapped and waited for rescue during the flood?
no 17364 97.3 7437 97.4 24801 97.3 8.5
yes 482 2.7 195 2.6 677 2.7 32.2
x7.2 were you seriously injured during the flood?
no 17717 99.3 7585 99.4 25302 99.3 9.0
yes 129 0.7 47 0.6 176 0.7 32.4
x7.3 were your relatives or friends seriously injured during the flood?
no 17654 98.9 7547 98.9 25201 98.9 9.0
yes 192 1.1 85 1.1 277 1.1 28.5
x7.4 did you witness others drowning during the flood?
no 17753 99.5 7579 99.3 25332 99.4 9.0
yes 93 0.5 53 0.7 146 0.6 33.6
no 7440 41.7 3169 41.5 10609 41.6 2.7
yes 10406 58.3 4463 58.5 14869 58.4 13.8
x7.6 was your house damaged by the flood?
no 12109 67.9 5243 68.7 17352 68.1 4.4
yes 5737 32.1 2389 31.3 8126 31.9 19.3
x8.1 would you consider yourself tensed or highly strung-up?
no 15078 84.5 6406 83.9 21484 84.3 7.5
yes 2768 15.5 1226 16.1 3994 15.7 18.1
x8.2 do you often feel life is very boring?
no 15766 88.3 6707 87.9 22473 88.2 7.6
yes 2080 11.7 925 12.1 3005 11.8 20.7
x8.3 do you often feel lonely?
no 16217 90.9 6901 90.4 23118 90.7 7.8
yes 1629 9.1 731 9.6 2360 9.3 22.6
x8.4 are you easily hurt when people find faults with you or your work?
No 15081 84.5 6428 84.2 21509 84.4 7.2
Yes 2765 15.5 1204 15.8 3969 15.6 19.8
y PTSD
No 16209 90.8 6933 90.8 23142 90.8
Yes 1637 9.2 699 9.2 2336 9.2
1. Note: Chi-square tests of all variables showed no significant differences between the two groups (P > 0.05).