Number of participants approached and not approached in each study year; number of non-respondents and respondents of those approached each study year; number of respondents with missing data and number in analyses of OECD score
| Year | Total | Not approached1-150 (% death) | Approached1-151 | Non-respondents | Respondents | Missing data (%) | Number in analyses1-152 |
| 1991 | 1784 | — | 1784 | — | 1784 | 141 (7.9) | 1643 |
| 1992 | 1784 | 86 (19) | 1698 | 189 | 1509 | 134 (8.9) | 1375 |
| 1993 | 1784 | 165 (29) | 1619 | 227 | 1392 | 103 (7.4) | 1289 |
| 1994 | 1784 | 233 (32) | 1551 | 206 | 1345 | 100 (7.4) | 1245 |
| 1995 | 1784 | 292 (34) | 1492 | 247 | 1245 | 82 (6.6) | 1163 |
| 1997 | 1784 | 356 (44) | 1428 | 161 | 1267 | 97 (7.7) | 1170 |
↵1-150 Initial participants could not be approached again to participate for any of the following reasons: (1) mortality; (2) explicit refusal to further participate in the study; (3) emigration; (4) loss to follow up.
↵1-151 Number approached = total number minus number not approached.
↵1-152 Number in analyses = number of respondents minus number with missing data.