Participants’ demographic characteristics
| Demographic characteristics | First survey N=85 n (%) | Second survey N=66 n (%) | Third survey N=56 n (%) |
| Response rate (%) | 85 | 77.6 | 84.8 |
| Age (year) | |||
| 20–29 | 4 (4.7) | 3 (4.6) | 2 (3.6) |
| 30–39 | 30 (35.3) | 22 (33.3) | 14 (25.0) |
| 40–49 | 28 (32.9) | 21 (31.8) | 16 (28.6) |
| 50–59 | 12 (14.1) | 11 (16.7) | 10 (17.9) |
| 60–69 | 5 (5.9) | 4 (6.1) | 6 (10.7)* |
| 70–79 | 6 (7.1) | 5 (7.6) | 8 (14.3) |
| Gender | |||
| Male | 47 (55.3) | 36 (54.5) | 29 (51.8) |
| Female | 37 (43.5) | 29 (43.9) | 27 (48.2) |
| Prefer not to answer | 1 (1.2) | 1 (1.5) | 0 |
| Others | 0 | 0 | 0 |
| Education | |||
| High school | 7 (8.2) | 5 (7.6) | 4 (7.1) |
| College | 11 (12.9) | 10 (15.2) | 11 (19.6) |
| University | 46 (54.1) | 38 (57.6) | 31 (55.4) |
| Masters | 16 (18.8) | 11 (16.7) | 7 (12.5) |
| Doctorate | 5 (5.9) | 2 (3) | 3 (5.4) |
| Occupation | |||
| Doctor | 43 (50.6) | 33 (50) | 28 (50) |
| Nurse | 8 (9.4) | 7 (10.6) | 4 (7.1) |
| Public health nurse | 4 (4.7) | 3 (4.5) | 3 (5.4) |
| Local government staff | 2 (2.4) | 1 (1.5) | 2 (3.6) |
| Others (rural residents, academic faculty, etc) | 21 (24.7) | 16 (24.2) | 11 (19.6) |
| Not employed | 7 (8.2) | 6 (9.1) | 8 (14.3) |
*Although the participants who did not join the second survey were not invited to the third survey, in some categories (eg, 60–69 years old), the number of participants in the third survey was higher than that in the second survey. This might be explained by the wrong input of the participants or participant ageing between surveys.