Table 2.
Multinomial regression showing the risk of delayed and one-time attendance according to exposure variables, reported in relative risk ratios (RRR) with 95% confidence intervals (CI)
| Delayed attendees | One-time attendees | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| n (%) | RRR crude (95%CI) | RRR semi adjusted (95%CI) | RRR fully adjusted (95%CI) | P-value | n (%) | RRR crude (95%CI) | RRR semi adjusted (95%CI) | RRR fully adjusted (95%CI) | P-value | |
| Sex | ||||||||||
| Male | 40,610 (55.4) | 0.93 (0.91;0.94) | 0.92 (0.90;0.94) | 0.94 (0.92;0.96) | 0.0000 | 13,357 (56.6) | 0.97 (0.94;1.00) | 0.97 (0.94;1.00) | 1.04 (1.01;1.08) | 0.0083 |
| Female | 32,632 (44.6) | Ref | Ref | Ref | 10,236 (43.4) | Ref | Ref | Ref | ||
| Age, Years | ||||||||||
| 18–39 | 5823 (8.0) | Ref | Ref | Ref | 1538 (6.5) | Ref | Ref | Ref | ||
| 40–59 | 21,027 (28.7) | 0.69 (0.66;0.72) | 0.69 (0.66;0.72) | 0.79 (0.75;0.83) | 0.0000 | 7145 (30.3) | 0.89 (0.83;0.94) | 0.89 (0.83;0.94) | 0.70 (0.65;0.75) | < 0.001 |
| 60–79 | 40,223 (54.9) | 0.63 (0.61;0.66) | 0.64 (0.61;0.66) | 0.76 (0.72;0.81) | 0.0000 | 11,865 (50.3) | 0.71 (0.67;0.75) | 0.71 (0.67;0.75) | 0.53 (0.49;0.58) | < 0.001 |
| 80+ | 6169 (8.4) | 0.62 (0.59;0.65) | 0.62 (0.59;0.65) | 0.78 (0.73;0.84) | 0.0000 | 3045 (12.9) | 1.16 (1.08;1.24) | 1.16 (1.08;1.24) | 0.83 (0.75;0.92) | < 0.001 |
| Marital Status | ||||||||||
| Never married | 11,050 (15.1) | Ref | Ref | Ref | 3819 (16.2) | Ref | Ref | Ref | ||
| Married | 42,718 (58.3) | 0.97 (0.95;1.00) | 1.08 (1.05;1.11) | 1.19 (1.15;1.23) | 0.0000 | 12,213 (51.8) | 0.80 (0.77;0.84) | 0.82 (0.78;0.85) | 0.85 (0.81;0.89) | < 0.001 |
| Widowed or divorced | 19,474 (26.6) | 0.97 (0.94;1.00) | 1.11 (1.07;1.15) | 1.14 (1.10;1.18) | 0.0000 | 7561 (32.0) | 1.08 (1.04;1.13) | 1.12 (1.06;1.17) | 1.09 (1.03;1.15) | 0.0014 |
| Diabetes type, N (%) | ||||||||||
| Type 1 diabetes | 8375 (11.4) | Ref | Ref | Ref | 1132 (4.8) | Ref | Ref | Ref | ||
| Type 2 diabetes | 48,791 (66.6) | 0.51 (0.49;0.53) | 0.53 (0.51;0.55) | 0.67 (0.64;0.70) | 0.0000 | 18,661 (79.1) | 1.44 (1.35;1.54) | 1.55 (1.44;1.66) | 1.47 (1.36;1.59) | < 0.001 |
| Unknown | 16,076 (21.9) | 0.91 (0.87;0.94) | 0.94 (0.91;0.98) | 0.99 (0.95;1.04) | 0.7542 | 3800 (16.1) | 1.59 (1.48;1.70) | 1.69 (1.57;1.82) | 1.53 (1.41;1.66) | < 0.001 |
| DR level (ICDR), N (%)A | ||||||||||
| No DR | 55,464 (75.7) | Ref | Ref | Ref | 20,662 (87.6) | Ref | Ref | Ref | ||
| Mild NPDR | 10,157 (13.9) | 1.94 (1.88;2.00) | 1.92 (1.86;1.98) | 1.68 (1.63;1.74) | 0.0000 | 1798 (7.6) | 0.92 (0.88;0.97) | 0.92 (0.87;0.97) | 0.95 (0.90;1.01) | 0.0959 |
| Moderate NPDR | 3583 (4.9) | 2.57 (2.43;2.70) | 2.54 (2.41;2.68) | 2.27 (2.14;2.40) | 0.0000 | 563 (2.4) | 1.08 (0.99;1.19) | 1.08 (0.99;1.19) | 1.18 (1.06;1.30) | 0.0017 |
| Severe NPDR | 687 (0.9) | 3.62 (3.17;4.13) | 3.51 (3.07;4.00) | 3.14 (2.72;3.62) | 0.0000 | 139 (0.6) | 1.96 (1.61;2.40) | 1.96 (1.61;2.39) | 2.07 (1.67;2.57) | < 0.001 |
| PDR | 3007 (4.1) | 3.00 (2.82;3.18) | 2.96 (2.79;3.14) | 2.44 (2.29;2.61) | 0.0000 | 431 (1.8) | 1.15 (1.04;1.28) | 1.15 (1.04;1.28) | 1.26 (1.13;1.42) | < 0.001 |
| Charlson comorbidity index score, N (%)B | ||||||||||
| Low | 51,920 (70.9) | Ref | Ref | Ref | 16,903 (71.6) | Ref | Ref | Ref | ||
| Moderate low | 11,798 (16.1) | 1.40 (1.36;1.44) | 1.41 (1.37;1.45) | 1.08 (1.04;1.11) | 0.0000 | 2946 (12.5) | 1.07 (1.03;1.12) | 1.07 (1.03;1.12) | 1.04 (0.99;1.09) | 0.1280 |
| Moderate high | 6137 (8.4) | 0.92 (0.89;0.95) | 0.96 (0.93;1.00) | 0.87 (0.84;0.90) | 0.0000 | 2332 (9.9) | 1.07 (1.02;1.13) | 1.08 (1.03;1.14) | 1.07 (1.02;1.13) | 0.0068 |
| High | 3387 (4.6) | 0.85 (0.82;0.89) | 0.91 (0.87;0.95) | 0.74 (0.71;0.78) | 0.0000 | 1412 (6.0) | 1.09 (1.03;1.16) | 1.10 (1.04;1.17) | 1.09 (1.02;1.16) | 0.0090 |
| Screening facility, N (%) | ||||||||||
| Practicing Ophthalmologist | 53,241 (72.7) | Ref | Ref | Ref | 18,967 (80.4) | Ref | Ref | Ref | ||
| Hospital | 20,001 (27.3) | 1.68 (1.64;1.72) | 1.65 (1.61;1.69) | 1.07 (1.04;1.10) | 0.0000 | 4626 (19.6) | 1.09 (1.05;1.13) | 1.09 (1.05;1.14) | 0.92 (0.88;0.96) | < 0.001 |
| Region of screening, N (%) | ||||||||||
| Capital region of Denmark | 20,908 (28.6) | 1.33 (1.29;1.37) | 1.31 (1.28;1.35) | 1.30 (1.26;1.34) | 0.0000 | 8032 (34.0) | 1.30 (1.25;1.36) | 1.30 (1.25;1.36) | 1.31 (1.26;1.37) | < 0.001 |
| Region Zealand | 11,332 (15.5) | Ref | Ref | Ref | 4436 (18.8) | Ref | Ref | Ref | ||
| Central Denmark region | 12,733 (17.4) | 0.80 (0.78;0.83) | 0.79 (0.77;0.82) | 0.77 (0.74;0.79) | 0.0000 | 4185 (17.7) | 0.67 (0.64;0.70) | 0.67 (0.64;0.70) | 0.68 (0.65;0.72) | < 0.001 |
| North Denmark region | 9761 (13.3) | 1.52 (1.46;1.57) | 1.52 (1.46;1.57) | 1.52 (1.46;1.58) | 0.0000 | 2542 (10.8) | 1.01 (0.96;1.07) | 1.01 (0.96;1.07) | 1.01 (0.96;1.08) | 0.6338 |
| Region of Southern Denmark | 18,488 (25.2) | 0.87 (0.85;0.90) | 0.87 (0.85;0.90) | 0.84 (0.81;0.87) | 0.0000 | 4397 (18.6) | 0.53 (0.51;0.56) | 0.53 (0.51;0.56) | 0.51 (0.49;0.54) | < 0.001 |
| socioeconomic status | ||||||||||
| income (Household net worth), N (%) | ||||||||||
| Low | 19,704 (26.9) | 1.20 (1.17;1.23) | 1.19 (1.16;1.22) | 1.19 (1.16;1.23) | 0.0000 | 6838 (29.0) | 1.30 (1.25;1.35) | 1.30 (1.25;1.35) | 1.18 (1.13;1.24) | < 0.001 |
| Moderate low | 18,140 (24.8) | Ref | Ref | Ref | 5787 (24.6) | Ref | Ref | Ref | ||
| Moderate high | 17,640 (24.1) | 0.92 (0.90;0.95) | 0.93 (0.90;0.95) | 0.91 (0.89;0.94) | 0.0000 | 5456 (23.2) | 0.89 (0.86;0.93) | 0.89 (0.86;0.93) | 0.92 (0.88;0.96) | < 0.001 |
| High | 17,711 (24.2) | 0.87 (0.85;0.90) | 0.88 (0.86;0.90) | 0.84 (0.82;0.87) | 0.0000 | 5458 (23.2) | 0.84 (0.81;0.88) | 0.84 (0.81;0.88) | 0.85 (0.81;0.89) | < 0.001 |
| Education, N (%) | ||||||||||
| Lower secondary | 27,676 (39.1) | 0.98 (0.96;1.01) | 1.01 (0.98;1.04) | 0.97 (0.94;1.00) | 0.0254 | 9500 (42.2) | 1.18 (1.13;1.23) | 1.19 (1.14;1.24) | 1.11 (1.06;1.16) | < 0.001 |
| Upper secondary | 29,880 (42.2) | 0.94 (0.92;0.97) | 0.95 (0.93;0.98) | 0.94 (0.91;0.96) | 0.0000 | 9230 (41.0) | 1.01 (0.97;1.06) | 1.02 (0.97;1.06) | 0.97 (0.93;1.02) | 0.2127 |
| Post-secondary | 13,232 (18.7) | Ref | Ref | Ref | 3787 (16.8) | Ref | Ref | Ref | ||
| OCCUPATION, N (%) | ||||||||||
| Employed or employer | 21,332 (29.1) | 0.91 (0.85;0.96) | 1.10 (1.03;1.17) | 1.22 (1.14;1.31) | 0.0000 | 6185 (26.2) | 0.78 (0.72;0.86) | 0.76 (0.69;0.83) | 0.93 (0.84;1.03) | 0.1658 |
| Student or other | 1953 (2.7) | Ref | Ref | Ref | 655 (2.8) | Ref | Ref | Ref | ||
| Early retirement | 10,526 (14.4) | 0.95 (0.89;1.02) | 1.10 (1.03;1.19) | 1.23 (1.14;1.33) | 0.0000 | 3270 (13.9) | 1.18 (1.07;1.31) | 1.16 (1.04;1.28) | 0.85 (0.76;0.95) | 0.0043 |
| Retirement | 34,882 (47.6) | 0.95 (0.89;1.01) | 1.20 (1.12;1.28) | 1.33 (1.23;1.44) | 0.0000 | 11,590 (49.1) | 0.88 (0.80;0.97) | 0.84 (0.76;0.93) | 0.87 (0.78;0.98) | 0.0209 |
| Unemployed | 4549 (6.2) | 0.84 (0.79;0.89) | 1.30 (1.21;1.40) | 1.08 (0.99;1.16) | 0.0680 | 1892 (8.0) | 0.83 (0.76;0.91) | 0.77 (0.69;0.85) | 1.03 (0.92;1.16) | 0.5775 |
| Ethnic background, N (%) | ||||||||||
| Danish heritage | 65,072 (88.9) | Ref | Ref | Ref | 20,167 (85.5) | Ref | Ref | Ref | ||
| Other heritage | 8160 (11.1) | 1.13 (1.10;1.17) | 1.08 (1.05;1.12) | 0.98 (0.94;1.01) | 0.2181 | 3415 (14.5) | 1.53 (1.47;1.59) | 1.53 (1.47;1.60) | 1.20 (1.14;1.26) | < 0.001 |
Data are given as numbers (n, (%)) and relative risk ratios (95% CI). Reference group is patients with timely attendance. AClassification of DR given by the International Clinical Diabetic Retinopathy Severity Scale [30], BExcluding diabetes. Semi adjusted model adjusted for sex and age. Fully adjusted model adjusted for all statistically significant variables in Table 1