Crude and adjusted ORs for PCR obtained from the logistic regression model, 2008–2013 (n=150 213)
| Risk factor | Control group (n=145 559) | PCR group (n=4654) | Simple logistic regression | Multiple logistic regression† (n=118 534) | ||||
|---|---|---|---|---|---|---|---|---|
| n (%) | n (%) | Crude OR (95% CI) | X2-stat (df)‡ | p Value‡ | Adj. OR (95% CI) | X2-stat (df)‡ | p Value‡ | |
| Age at surgery, years | 15.65 (3) | 0.001 | 14.97 (3) | 0.002 | ||||
| 50–59 | 28 590 (19.6) | 833 (17.9) | 1.00 – | 1.00 – | ||||
| 60–69 | 57 181 (39.3) | 1794 (38.5) | 1.08 (0.99 to 1.17) | 3.03 (1)§ | 0.082§ | 1.07 (0.97 to 1.17) | 1.82 (1)§ | 0.177§ |
| 70–79 | 50 077 (34.4) | 1679 (36.1) | 1.15 (1.06 to 1.25) | 10.65 (1)§ | 0.001§ | 1.17 (1.06 to 1.29) | 10.57 (1)§ | 0.001§ |
| ≥80 | 9711 (6.7) | 348 (7.5) | 1.23 (1.08 to 1.40) | 10.17 (1)§ | 0.001§ | 1.23 (1.06 to 1.42) | 7.86 (1)§ | 0.005§ |
| Gender | ||||||||
| Male | 68 111 (46.8) | 2294 (49.3) | 1.11 (1.04 to 1.17) | 11.40 (1) | 0.001 | 1.11 (1.04 to 1.18) | 9.67 (1) | 0.002 |
| Female | 77 423 (53.2) | 2358 (50.7) | 1.00 – | 1.00 – | ||||
| Ethnicity | 3.77 (3) | 0.287 | ||||||
| Malay | 61 184 (42.0) | 2020 (43.4) | 1.09 (1.00 to 1.20) | 3.62 (1)§ | 0.057§ | |||
| Chinese | 49 173 (33.8) | 1585 (34.1) | 1.07 (0.97 to 1.17) | 1.82 (1)§ | 0.177§ | |||
| Indian | 20 234 (13.9) | 611 (13.1) | 1.00 – | |||||
| Others | 9521 (6.5) | 302 (6.5) | 1.05 (0.91 to 1.21) | 0.47 (1)§ | 0.491§ | |||
| Ocular comorbidity | ||||||||
| Pterygium involving cornea | 2042 (1.4) | 83 (1.8) | 1.28 (1.02 to 1.59) | 4.35 (1) | 0.037 | |||
| No | 143 351 (98.5) | 4564 (98.1) | 1.00 – | |||||
| Pseudoexfoliation | 1515 (1.0) | 69 (1.5) | 1.43 (1.12 to 1.83) | 7.54 (1) | 0.006 | 1.36 (1.02 to 1.82) | 4.08 (1) | 0.043 |
| No | 143 878 (98.8) | 4578 (98.4) | 1.00 – | 1.00 – | ||||
| Corneal opacity | 1251 (0.9) | 46 (1.0) | 1.15 (0.86 to 1.55) | 0.84 (1) | 0.359 | |||
| No | 144 142 (99.0) | 4601 (98.9) | 1.00 – | |||||
| Chronic uveitis | 268 (0.2) | 7 (0.2) | 0.82 (0.39 to 1.73) | 0.30 (1) | 0.586 | |||
| No | 145 125 (99.7) | 4640 (99.7) | 1.00 – | |||||
| Phacomorphic | 442 (0.3) | 27 (0.6) | 1.92 (1.30 to 2.83) | 8.91 (1) | 0.003 | 1.96 (1.25 to 3.06) | 7.26 (1) | 0.007 |
| No | 144 951 (99.6) | 4620 (99.3) | 1.00 – | 1.00 – | ||||
| Diabetic retinopathy (any form) | 13 947 (9.6) | 511 (11.0) | 1.16 (1.06 to 1.28) | 9.80 (1) | 0.002 | |||
| No | 131 446 (90.3) | 4136 (88.9) | 1.00 – | |||||
| Surgeon status | 344.11 (2) | <0.001 | 221.58 (2) | <0.001 | ||||
| Specialist | 122 198 (84.0) | 3401 (73.1) | 1.00 – | 1.00 – | ||||
| Gazetting specialist | 9895 (6.8) | 518 (11.1) | 1.88 (1.71 to 2.07) | 171.02 (1)§ | <0.001§ | 1.84 (1.66 to 2.05) | 130.41 (1)§ | <0.001§ |
| Medical officer | 12 801 (8.8) | 710 (15.3) | 1.99 (1.83 to 2.17) | 265.82 (1)§ | <0.001§ | 1.88 (1.70 to 2.08) | 147.84 (1)§ | <0.001§ |
| Systemic comorbidity | ||||||||
| Diabetes mellitus | 61 008 (41.9) | 2153 (46.3) | 1.19 (1.12 to 1.26) | 33.64 (1) | <0.001 | 1.20 (1.13 to 1.29) | 29.05 (1) | <0.001 |
| No | 83 375 (57.3) | 2472 (53.1) | 1.00 – | 1.00 – | ||||
| Hypertension | 85 297 (58.6) | 2797 (60.1) | 1.06 (1.00 to 1.13) | 3.64 (1) | 0.056 | |||
| No | 59 086 (40.6) | 1828 (39.3) | 1.00 – | |||||
| Ischaemic heart disease | 13 179 (9.1) | 450 (9.7) | 1.07 (0.97 to 1.18) | 1.92 (1) | 0.166 | |||
| No | 131 204 (90.1) | 4175 (89.7) | 1.00 – | |||||
| Renal failure | 3731 (2.6) | 170 (3.7) | 1.44 (1.23 to 1.68) | 18.72 (1) | <0.001 | 1.30 (1.09 to 1.55) | 7.66 (1) | 0.006 |
| No | 140 652 (96.6) | 4455 (95.7) | 1.00 – | 1.00 – | ||||
| Cerebrovascular accident | 1587 (1.1) | 61 (1.3) | 1.20 (0.93 to 1.56) | 1.87 (1) | 0.172 | |||
| No | 142 796 (98.1) | 4564 (98.1) | 1.00 – | |||||
| COAD/asthma | 5556 (3.8) | 206 (4.4) | 1.16 (1.01 to 1.34) | 4.23 (1) | 0.040 | |||
| No | 138 827 (95.4) | 4419 (95.0) | 1.00 – | |||||
| Type of admission | ||||||||
| Not day care | 64 777 (44.5) | 2028 (43.6) | 1.00 – | 2.91 (1) | 0.088 | 1.00 – | 45.26 (1) | <0.001 |
| Day care | 74 999 (51.5) | 2473 (53.1) | 1.05 (0.99 to 1.12) | 1.28 (1.19 to 1.37) | ||||
| Type of surgery | ||||||||
| Phaco | 120 014 (82.5) | 3642 (78.3) | 1.00 – | 51.70 (1) | <0.001 | 1.00 – | 15.76 (1) | <0.001 |
| ECCE | 25 545 (17.5) | 1012 (21.7) | 1.31 (1.22 to 1.40) | 0.83 (0.76 to 0.91) | ||||
| Local anaesthesia | ||||||||
| Retrobulbar | 3718 (2.6) | 114 (2.4) | 0.96 (0.79 to 1.16) | 0.20 (1) | 0.653 | |||
| No | 141 304 (97.1) | 4523 (97.2) | 1.00 – | |||||
| Peribulbar | 3604 (2.5) | 141 (3.0) | 1.23 (1.04 to 1.46) | 5.34 (1) | 0.021 | 1.78 (1.42 to 2.23) | 22.36 (1) | <0.001 |
| No | 141 419 (97.2) | 4496 (96.6) | 1.00 – | 1.00 – | ||||
| Subtenon | 53 323 (36.6) | 2321 (49.9) | 1.72 (1.63 to 1.83) | 328.49 (1) | <0.001 | 2.18 (1.97 to 2.41) | 220.19 (1) | <0.001 |
| No | 91 701 (63.0) | 2316 (49.8) | 1.00 – | 1.00 – | ||||
| Conjunctival | 4282 (2.9) | 149 (3.2) | 1.09 (0.92 to 1.29) | 1.03 (1) | 0.310 | 1.52 (1.24 to 1.86) | 14.82 (1) | <0.001 |
| No | 140 740 (96.7) | 4489 (96.5) | 1.00 – | 1.00 – | ||||
| Facial block | 253 (0.2) | 11 (0.2) | 1.36 (0.74 to 2.49) | 0.91 (1) | 0.340 | 2.65 (1.42 to 4.94) | 7.30 (1) | 0.007 |
| No | 144 769 (99.5) | 4626 (99.4) | 1.00 – | 1.00 – | ||||
| Topical | 74 598 (51.2) | 2013 (43.3) | 0.72 (0.68 to 0.77) | 116.29 (1) | <0.001 | 1.14 (1.03 to 1.25) | 6.97 (1) | 0.008 |
| No | 70 431 (48.4) | 2625 (56.4) | 1.00 – | 1.00 – | ||||
| Intracameral | 13 857 (9.5) | 386 (8.3) | 0.86 (0.77 to 0.96) | 8.21 (1) | 0.004 | 1.29 (1.13 to 1.46) | 14.30 (1) | <0.001 |
| No | 131 165 (90.1) | 4251 (91.3) | 1.00 – | 1.00 – | ||||
| Combined surgery | ||||||||
| Filtering surgery | 518 (0.4) | 16 (0.3) | 0.97 (0.59 to 1.59) | 0.02 (1) | 0.892 | |||
| No | 122 888 (84.4) | 3929 (84.4) | 1.00 – | |||||
| Vitreoretinal | 1661 (1.1) | 91 (2.0) | 1.73 (1.40 to 2.14) | 21.77 (1) | <0.001 | 2.88 (2.29 to 3.63) | 63.18 (1) | <0.001 |
| No | 121 745 (83.6) | 3854 (82.8) | 1.00 – | 1.00 – | ||||
| Pterygium excision | 545 (0.4) | 19 (0.4) | 1.09 (0.69 to 1.73) | 0.14 (1) | 0.713 | |||
| No | 122 861 (84.4) | 3926 (84.4) | 1.00 – | |||||
Number and percentage (%) by column, the remaining unreported % is the missing value.
†Backward LR was applied (all variables were included in the multiple logistic regression). Multicollinearity was checked and not found. Classification table (overall correctly classified percentage=96.9%) and area under the receiver operating characteristic curve (62.1%) were applied to check the model fitness.
‡LR test.
§Wald test.
Adj. OR, adjusted OR; COAD, chronic obstructive airways disease; df, degree of freedom; ECCE, extracapsular cataract extraction; LR, likelihood ratio; PCR, posterior capsular rupture.