Table 1 Characteristics of the study cohort
Variable | Study cohort (n = 77,210) | First level (n = 26,520) | Second level (n = 38,010) | Third level (n = 12,680) | p-value |
|---|---|---|---|---|---|
Age, years | 67.4 ± 12.2 | 65.3 ± 13.0 | 68.1 ± 12.0 | 69.5 ± 10.5 | < 0.0001 |
Age group, categorical |  |  |  |  | < 0.0001 |
  < 60 | 20,020 (25.9) | 8840 (33.3) | 8940 (23.5) | 2240 (17.7) |  |
 60–75 | 32,780 (42.5) | 10,400 (39.2) | 16,410 (43.2) | 5970 (47.1) |  |
  ≥ 75 | 24,410 (31.6) | 7280 (27.5) | 12,660 (33.3) | 4470 (35.2) |  |
Sex |  |  |  |  | < 0.0001 |
 Male | 48,570 (62.9) | 15,480 (58.4) | 24,490 (64.4) | 8600 (67.8) |  |
 Female | 28,640 (37.1) | 11,040 (41.6) | 13,520 (35.6) | 4080 (32.2) |  |
Number of injections, times | 12.0 ± 2.9 | 8.7 ± 3.4 | 12.3 ± 1.7 | 18.1 ± 4.2 | < 0.0001 |
Number of injections, categorical | |||||
 First level (< 10) | 26,520 (34.4) | 26,520 | 0 | 0 |  |
 Second level (10–15) | 38,010 (49.2) | 0 | 38,010 | 0 |  |
 Third level (≥15) | 12,680 (16.4) | 0 | 0 | 12,680 |  |
Diabetes |  |  |  |  | < 0.0001 |
 Yes | 27,490 (35.6) | 10,770 (40.6) | 12,510 (32.9) | 4210 (33.2) |  |
 No | 49,720 (64.4) | 15,750 (59.4) | 25,500 (67.1) | 8470 (66.8) |  |
Hypertension |  |  |  |  | < 0.0001 |
 Yes | 49,900 (64.6) | 16,940 (63.9) | 24,420 (64.2) | 8540 (67.3) |  |
 No | 27,310 (35.4) | 9580 (36.1) | 13,590 (35.8) | 4140 (32.7) |  |
Hyperlipidemia |  |  |  |  | < 0.0001 |
 Yes | 34,200 (44.3) | 11,760 (44.3) | 16,480 (43.4) | 5960 (47.0) |  |
 No | 43,010 (55.7) | 14,760 (55.7) | 21,530 (56.6) | 6729 (53.0) |  |
Ischemic heart disease |  |  |  |  | < 0.0001 |
 Yes | 22,990 (29.8) | 7630 (28.8) | 11,350 (29.9) | 4010 (31.6) |  |
 No | 54,220 (70.2) | 18,890 (71.2) | 26,660 (70.1) | 8670 (68.4) |  |
Glaucoma |  |  |  |  | < 0.0001 |
 Yes | 12,730 (16.5) | 4570 (17.2) | 5890 (15.5) | 2270 (17.9) |  |
 No | 64,480 (83.5) | 21,950 (82.8) | 32,120 (84.5) | 10,410 (82.1) |  |
Follow-up period, years | 3.50 ±1.86 | 3.51 ±1.87 | 3.49 ±1.86 | 3.53 ±1.84 | 0.09 |
Incident ION | 180 (0.23) | 40 (0.15) | 100 (0.26) | 40 (0.32) | < 0.01 |