Table 2.
Comparison of the effect of the invitation strategies according to different socioeconomic status
| Directly mailed group participants
|
Opt-in group participants
|
Control group participants
|
Direct mailed group vs control group
|
Opt-in group vs control group
|
Direct mailed group vs opt in group
|
|||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| N | n (%) | N | n (%) | N | n (%) | PD1 (%) (95% CI) | RR1 (95% CI) | PD2 (%) (95% CI) | RR2 (95% CI) | PD3 (%) (95% CI) | RR3 (95% CI) | |
| Civil status | ||||||||||||
| Married/cohabiting | 2,256 | 930 (41.2) | 2,255 | 770 (34.1) | 2,281 | 632 (27.7) | 13.5 (10.8–16.3) | 1.49 (1.37–1.62) | 6.4 (3.8–9.1) | 1.23 (1.13–1.35) | 7.1 (4.3–9.9) | 1.21 (1.12–1.30) |
| Living alone | 974 | 300 (30.8) | 969 | 233 (24.0) | 955 | 187 (19.6) | 11.2 (7.4–15.1) | 1.57 (1.34–1.84) | 4.5 (0.8–8.1) | 1.22 (1.04–1.45) | 6.8 (2.8–10.7) | 1.28 (1.11–1.48) |
| Pinteraction1=0.34 | Pinteraction1=0.54 | Pinteraction2=0.39 | Pinteraction2=0.97 | Pinteraction3=0.89 | Pinteraction3=0.48 | |||||||
| Ethnicity | ||||||||||||
| Danish | 2,703 | 1,055 (39.0) | 2,684 | 899 (33.5) | 2,656 | 715 (26.9) | 12.1 (9.6–14.6) | 1.45 (1.34–1.57) | 6.6 (4.1–9.0) | 1.24 (1.15–1.35) | 5.5 (2.9–8.1) | 1.17 (1.09–1.25) |
| Western immigrants | 210 | 72 (34.3) | 231 | 37 (16.0) | 241 | 39 (16.2) | 18.1 (10.2–26.0) | 2.12 (1.50–2.99) | –0.2 (–6.8–6.5) | 0.99 (0.66–1.49) | 18.1 (10.2–26.2) | 2.14 (1.51–3.04) |
| Non-Western immigrants | 316 | 103 (32.6) | 308 | 67 (21.8) | 338 | 65 (19.2) | 13.4 (6.7–20.0) | 1.69 (1.29–2.22) | 2.5 (–3.7–8.8) | 1.13 (0.83–1.53) | 10.8 (3.9–17.8) | 1.50 (1.15–1.95) |
| Pinteraction1=0.36 | Pinteraction1=0.08 | Pinteraction2=0.11 | Pinteraction2=0.49 | Pinteraction3=0.01 | Pinteraction3<0.01 | |||||||
| Occupation | ||||||||||||
| Self-employed/chief executive | 151 | 55 (36.4) | 155 | 50 (32.3) | 152 | 40 (26.3) | 10.1 (–0.3–20.5) | 1.38 (0.99–1.94) | 5.9 (–4.2–16.1) | 1.23 (0.86–1.74) | 4.2 (–6.5–14.8) | 1.13 (0.83–1.54) |
| Employed | 2,100 | 884 (42.1) | 2,088 | 731 (35.0) | 2,071 | 610 (29.5) | 12.6 (9.8–15.5) | 1.43 (1.31–1.55) | 5.6 (2.7–8.4) | 1.19 (1.09–1.30) | 7.1 (4.1–10.0) | 1.20 (1.11–1.30) |
| Social welfare recipientsa | 452 | 146 (32.3) | 429 | 107 (24.9) | 491 | 84 (17.1) | 15.2 (9.7–20.6) | 1.89 (1.49–2.39) | 7.8 (2.6–13.1) | 1.46 (1.13–1.88) | 7.4 (1.4–13.3) | 1.30 (1.05–1.60) |
| Retiredb | 302 | 81 (26.8) | 317 | 69 (21.8) | 292 | 52 (17.8) | 9.0 (2.4–15.7) | 1.51 (1.11–2.05) | 4.0 (–2.4–10.2) | 1.22 (0.88–1.69) | 5.1 (–1.7–11.8) | 1.23 (0.93–1.63) |
| Other | 232 | 66 (28.4) | 242 | 47 (19.4) | 232 | 33 (14.2) | 14.2 (6.9–21.6) | 2.00 (1.37–2.91) | 5.2 (–1.5–11.9) | 1.37 (0.91–2.05) | 9.0 (13.8–16.7) | 1.46 (1.06–2.03) |
| Pinteraction1=0.66 | Pinteraction1=0.12 | Pinteraction2=0.91 | Pinteraction2=0.64 | Pinteraction3=0.92 | Pinteraction3=0.76 | |||||||
| Educationc (years) | ||||||||||||
| ≤10 | 561 | 147 (26.2) | 577 | 126 (21.8) | 588 | 107 (18.2) | 8.0 (3.2–12.8) | 1.44 (1.15–1.80) | 3.6 (–0.9–8.2) | 1.20 (0.95–1.51) | 4.4 (–0.6–9.3) | 1.20 (0.97–1.48) |
| 11–15 | 2,105 | 856 (40.7) | 2,058 | 705 (34.3) | 2,055 | 554 (27.0) | 13.7 (10.8–16.5) | 1.51 (1.38–1.65) | 7.3 (4.5–10.1) | 1.27 (1.16–1.39) | 6.4 (3.5–9.3) | 1.18 (1.09–1.28) |
| >15 | 301 | 144 (47.8) | 307 | 127 (41.4) | 295 | 105 (35.6) | 12.2 (4.4–20.1) | 1.34 (1.11–1.63) | 5.8 (–1.9–13.5) | 1.16 (0.95–1.42) | 6.4 (–1.4–14.4) | 1.16 (0.97–1.38) |
| Pinteraction1=0.13 | Pinteraction1=0.55 | Pinteraction2=0.40 | Pinteraction2=0.70 | Pinteraction3=0.77 | Pinteraction3=0.96 | |||||||
| Incomed | ||||||||||||
| Low | 1,033 | 324 (31.4) | 1,005 | 248 (24.7) | 1,023 | 199 (19.5) | 11.9 (8.2–15.6) | 1.61 (1.38–1.88) | 5.2 (1.6–8.8) | 1.27 (1.08–1.50) | 6.7 (2.8–10.6) | 1.27 (1.10–1.46) |
| Middle | 1,024 | 414 (40.4) | 1,002 | 333 (33.2) | 1,040 | 278 (26.7) | 13.7 (9.7–17.7) | 1.51 (1.33–1.71) | 6.5 (2.5–10.5) | 1.24 (1.09–1.42) | 7.2 (3.0–11.4) | 1.22 (1.08–1.36) |
| High | 1,012 | 442 (43.7) | 1,041 | 386 (37.1) | 996 | 313 (31.4) | 12.3 (8.0–16.5) | 1.39 (1.24–1.56) | 5.7 (1.5–9.7) | 1.18 (1.05–1.33) | 6.6 (2.4–10.8) | 1.18 (1.06–1.31) |
| Pinteraction1=0.80 | Pinteraction1=0.29 | Pinteraction2=0.89 | Pinteraction2=0.75 | Pinteraction3=0.97 | Pinteraction3=0.70 | |||||||
| Residence area | ||||||||||||
| Urban | 787 | 321 (40.8) | 845 | 272 (32.2) | 840 | 232 (27.6) | 13.2 (8.6–17.7) | 1.48 (1.29–1.70) | 4.6 (0.2–8.9) | 1.17 (1.01–1.35) | 8.6 (3.9–13.3) | 1.27 (1.11–1.44) |
| Mixed rural/urban | 1,059 | 407 (38.4) | 1,036 | 333 (32.1) | 1,023 | 258 (25.2) | 13.2 (9.3–17.2) | 1.52 (1.34–1.74) | 6.9 (3.0–10.8) | 1.27 (1.11–1.46) | 6.3 (2.2–10.4) | 1.20 (1.06–1.34) |
| Rural | 1,384 | 502 (36.3) | 1,343 | 398 (29.6) | 1,373 | 329 (23.9) | 12.3 (8.9–15.7) | 1.51 (1.35–1.70) | 5.7 (2.3–9.0) | 1.24 (1.09–1.40) | 6.6 (3.1–10.2) | 1.22 (1.10–1.36) |
| Pinteraction1=0.93 | Pinteraction1=0.94 | Pinteraction2=0.73 | Pinteraction2=0.68 | Pinteraction3=0.73 | Pinteraction3=0.81 | |||||||
Notes: N, number of randomized women; n, total number of participants having a self-sample or cervical cytology within 180 days after their second reminder; %, total participation rate, row percentages; PD1, participation difference in the total participation in the directly mailed group compared with the total participation in the control group; RR1, total participation in the directly mailed group compared to the total participation in the control group; Pinteraction1, Wald’s test for interaction: shows if the effect of the directly mailed strategy is modified by socioeconomic status; PD2, participation difference in the total participation in the opt-in group compared with the total participation in the control group; RR2, total participation in the opt-in group compared to the total participation in the control group; Pinteraction2, Wald’s test for interaction: shows if the effect of the opt-in strategy is modified by socioeconomic status; PD3, participation difference in the total participation in the directly mailed group compared with the opt-in group; RR3, total participation in the directly mailed group compared to the total participation in the opt-in group; Pinteraction3, Wald’s test for interaction: shows if the effect of the directly mailed strategy is modified by socioeconomic status.
Including social security, unemployment benefit, and sick leave.
Including disability pension and state pension.
Highest obtained educational level.
OECD-adjusted disposable household income: see Methods section.
Abbreviation: OECD, Organization for Economic Co-operation and Development.