Table 1 Demographic characteristics of native Dutch respondents and non-respondents at the three waves of the longitudinal study*
From: Selective attrition and bias in a longitudinal health survey among survivors of a disaster
| Â | Respondents at Wave 1 only (N = 128) | Respondents at Waves 1 & 2 (N = 198) | Respondents at Waves 1 & 3 (N = 94) | Respondents at Waves 1, 2, 3 (N = 663) | p value |
|---|---|---|---|---|---|
| Â | % (95% CI) | % (95% CI) | % (95% CI) | % (95% CI) | Â |
Male | 59.8 (51.2–68.3) | 49.0 (42.0–56.0) | 48.9 (38.7–59.0) | 42.8 (39.0–46.6) | 0.004 |
Age | Â | Â | Â | Â | Â |
   18 – 24 | 16.4 (9.9–22.8) | 9.6 (5.5–13.7) | 19.2 (11.1–27.2) | 10.4 (8.1–12.7) | 0.004 |
   25 – 44 | 43.0 (34.3–51.6) | 43.9 (37.0–50.8) | 53.2 (43.0–63.3) | 43.9 (40.1–47.7) |  |
   45 – 64 | 26.6 (18.9–34.3) | 30.3 (23.9–36.7) | 22.3 (13.8–30.7) | 35.0 (31.4–38.6) |  |
   65+ | 14.1 (8.0–20.1) | 16.2 (11.1–21.3) | 5.3 (0.7–9.8) | 10.7 (8.4–13.1) |  |
Age, Mean | 42.0 (39.4–44.9) | 45.1 (42.7–47.4) | 37.3 (34.4–40.2) | 43.5 (42.4–44.7) | 0.0005 |
Education | Â | Â | Â | Â | Â |
   Primary school | 14.9 (8.7–21.1) | 14.5 (9.6–19.4) | 8.0 (2.4–13.5) | 10.4 (8.1–12.7) | 0.4 |
   Junior high | 37.2 (28.7–45.6) | 32.3 (25.8–38.8) | 8.0 (2.4–13.5) | 10.4 (8.1–12.7) |  |
   Senior high/professional | 34.7 (26.4–43.0) | 33.9 (27.3–40.5) | 30.7 (21.3–40.0) | 33.7 (30.1–37.3) |  |
   High professional/university | 13.2 (7.3–19.1) | 19.4 (13.9–24.9) | 25.0 (16.1–33.8) | 21.6 (18.5–24.7) |  |
Paid job | 62.0 (53.5–70.4) | 57.4 (50.5–64.3) | 75.3 (66.5–84.0) | 64.0 (60.4–67.7) | 0.03 |
Single | 24.4 (16.9–31.8) | 26.5 (20.4–32.6) | 20.0 (11.8–28.1) | 17.8 (14.9–20.7) | 0.04 |