Table 1. Sociodemographic and Clinical Characteristics by Ethnicity.
| Characteristic | All (N = 9962) |
Chinese (n = 3338) |
Malay (n = 3253) |
Indian (n = 3371) |
P Value |
|---|---|---|---|---|---|
| Categorical Variables, No. (%) | |||||
| Males | 4909 (49.3) | 1657 (49.6) | 1564 (48.1) | 1688 (50.1) | .23 |
| Age, y | |||||
| 40-49 | 2464 (24.7) | 705 (21.1) | 811 (24.9) | 948 (28.1) | <.001a |
| 50-59 | 3133 (31.4) | 1111 (33.3) | 951 (29.2) | 1071 (31.8) | |
| 60-69 | 2543 (25.5) | 891 (26.7) | 775 (23.8) | 877 (26.0) | |
| 70-80 | 1822 (18.3) | 631 (18.9) | 716 (22.0) | 475 (14.1) | |
| AMD severityb | |||||
| No AMD | 9312 (93.5) | 3072 (92.0) | 3071 (94.4) | 3169 (94.0) | <.001a |
| Early AMD | 590 (5.92) | 241 (7.22) | 161 (4.95) | 188 (5.58) | |
| Late AMD | 60 (0.60) | 25 (0.75) | 21 (0.65) | 14 (0.42) | |
| AMD laterality | |||||
| Unilateral | 473 (72.8) | 203 (76.3) | 131 (72.0) | 139 (68.8) | .19 |
| Bilateralc | 177 (27.2) | 63 (23.7) | 51 (28.0) | 63 (31.2) | |
| Educational level | |||||
| Primary or lower | 6017 (60.5) | 1780 (53.3) | 2365 (72.8) | 1872 (55.7) | <.001a |
| Secondary | 2333 (23.5) | 845 (25.3) | 673 (20.7) | 815 (24.2) | |
| Postsecondary | 1595 (16.0) | 712 (21.3) | 209 (6.44) | 674 (20.1) | |
| Income, SGD/mo (US $/mo) | |||||
| <1000 (US $710) | 5383 (55.2) | 1536 (47.4) | 2230 (69.0) | 1617 (49.2) | <.001a |
| 1000 to <2000 (US $710 to <US $1420) | 2197 (22.5) | 735 (22.7) | 654 (20.2) | 808 (24.6) | |
| ≥2000 (US $1420) | 2180 (22.3) | 969 (29.9) | 347 (10.7) | 864 (26.3) | |
| Smoking status | |||||
| Never | 6923 (69.6) | 2454 (73.5) | 1996 (61.5) | 2473 (73.4) | <.001a |
| Current | 1593 (16.0) | 440 (13.2) | 658 (20.3) | 495 (14.7) | |
| Past | 1437 (14.4) | 444 (13.3) | 593 (18.3) | 400 (11.9) | |
| Cardiovascular diseased | 1074 (10.8) | 233 (6.98) | 361 (11.1) | 480 (14.3) | <.001a |
| Hypertension | 6119 (61.6) | 1972 (59.1) | 2237 (69.1) | 1910 (56.8) | <.001a |
| Diabetes | |||||
| Yes | 2364 (24.7) | 483 (15.1) | 762 (24.4) | 1119 (34.6) | <.001a |
| No | 7191 (75.2) | 2709 (84.9) | 2363 (75.5) | 2119 (65.4) | <.001a |
| Diabetes without retinopathy | 1550 (16.2) | 339 (10.6) | 495 (15.8) | 716 (22.1) | <.001a |
| Diabetes with retinopathy | 818 (8.56) | 144 (4.51) | 271 (8.66) | 403 (12.5) | |
| Cataract | 4229 (44.0) | 1379 (42.1) | 1519 (48.9) | 1331 (41.2) | <.001a |
| Glaucoma | 359 (3.60) | 133 (3.98) | 149 (4.58) | 77 (2.28) | <.001a |
| Continuous Variables, Mean (SD) | |||||
| PVA—better eye, logMAR | 0.20 (0.23) | 0.20 (0.20) | 0.22 (0.27) | 0.19 (0.22) | <.001a |
| PVA—worse eye, logMAR | 0.39 (0.46) | 0.38 (0.42) | 0.42 (0.51) | 0.37 (0.46) | <.001a |
| Blood pressure, mean (SD) | |||||
| Systolic, mm Hg | 139.9 (21.9) | 136.6 (19.5) | 147.5 (24.0) | 135.9 (20.1) | <.001a |
| Diastolic, mm Hg | 78.3 (10.6) | 77.6 (9.90) | 79.8 (11.3) | 77.6 (10.3) | <.001a |
| BMI | 25.4 (4.71) | 23.7 (3.65) | 26.4 (5.12) | 26.2 (4.75) | <.001a |
| Hemoglobin A1c, % | 6.32 (1.32) | 6.06 (0.91) | 6.45 (1.55) | 6.43 (1.39) | <.001a |
| Total cholesterol level, mg/dL | 97.66 (20.36) | 98.20 (19.28) | 101.44 (21.08) | 23.51 (20.00) | <.001 |
| VSF score, mean (SD) [range] | 3.78 (1.18) [−4.97 to 4.70] |
4.05 (0.91) [−1.68 to 4.70] |
3.63 (1.30) [−3.70 to 4.70] |
3.67 (1.25) [−4.97 to 4.70] |
<.001a |
Abbreviations: AMD, age-related macular degeneration; BMI, body mass index (calculated as weight in kilograms divided by height in meters squared); PVA, presenting visual acuity; SGD, Singapore dollars; VSF, vision-specific functioning.
SI conversion factors: To convert total cholesterol to millimoles per liter, multiply by 0.0259; hemoglobin A1c to a proportion of total hemoglobin, multiply by 0.01.
a
Indicates statistical significance.
b
For definitions of early and late AMD used in this study, see the Assessment and Definitions of AMD subsection in the Methods section.
c
Both eyes have at least early AMD.
d
Includes myocardial infarction, angina, or stroke.