Table 1.
Baseline socioeconomic characteristics of the study population
| Directly mailed group (N=3,265) |
Opt-in group (N=3,264) |
Control group (N=3,262) |
|
|---|---|---|---|
|
| |||
| n (%) | n (%) | n (%) | |
| Civil status | |||
| Married/cohabiting | 2,256 (69.1) | 2,255 (69.1) | 2,281 (69.9) |
| Living alone | 974 (29.8) | 969 (29.7) | 955 (29.3) |
| Ethnicity | |||
| Danish | 2,703 (82.8) | 2,684 (82.2) | 2,656 (81.4) |
| Western immigrants | 210 (6.4) | 231 (7.1) | 241 (7.4) |
| Non-Western immigrants | 316 (9.7) | 308 (9.4) | 338 (10.4) |
| Occupation | |||
| Self-employed/chief | 151 (4.6) | 155 (4.8) | 152 (4.7) |
| executive | |||
| Employed | 2,100 (64.3) | 2,088 (63.9) | 2,071 (63.5) |
| Social welfare recipienta | 452 (13.8) | 429 (13.1) | 491 (15.1) |
| Retiredb | 302 (9.3) | 317 (9.7) | 292 (8.9) |
| Other | 232 (7.1) | 242 (7.4) | 232 (7.1) |
| Education (years)c | |||
| ≤10 | 561 (17.2) | 577 (17.7) | 588 (18.0) |
| 11–15 | 2,105 (64.5) | 2,058 (63.1) | 2,055 (63.0) |
| >15 | 301 (9.2) | 307 (9.4) | 295 (9.0) |
| Incomed | |||
| Low | 1,033 (31.6) | 1,005 (30.8) | 1,023 (31.4) |
| Middle | 1,024 (31.4) | 1,002 (30.7) | 1,040 (31.8) |
| High | 1,012 (31.0) | 1,041 (31.9) | 996 (30.5) |
| Residence area | |||
| Urban | 787 (24.1) | 845 (25.9) | 840 (25.8) |
| Mixed rural/urban | 1,059 (32.4) | 1,036 (31.7) | 1,023 (31.4) |
| Rural | 1,384 (42.4) | 1,343 (41.2) | 1,373 (42.1) |
Notes: Number and proportion vary because of missing data. No statistically significant differences in the distribution of the socioeconomic characteristics were found between the groups (chi-square test >0.05).
a
Including social security, unemployment benefit, and sick leave.
b
Including disability pension and state pension.
c
Highest obtained educational level.
d
OECD-adjusted disposable household income: see Methods section.
Abbreviation: OECD, Organization for Economic Co-operation and Development.