Demographic details of participating parents/guardians and willingness to pay for custom-made spectacles
| Demographic | N (%) | Estimated mean WTP* (Log transformed) | WTP to pay ≥70 000 KHR (US$17.5)† | |||
| Mean WTP (KHR) | P value | No N (%) | Yes N (%) | P value | ||
| Province | ||||||
| Phnom Penh | 364 (74.1) | 74 595 (US$18.6) | 0.008 | 147 (40.4) | 217 (59.6) | 0.008 |
| Kandal province | 127 (25.9) | 55 651 (US$13.9) | 83 (65.4) | 44 (34.6) | ||
| Sex of parent/guardian | ||||||
| Male | 194 (39.5) | 78 694 (US$19.7) | 0.002 | 68 (35.1) | 126 (64.9) | 0.002 |
| Female | 297 (60.5) | 63 552 (US$15.9) | 162 (54.5) | 135 (45.5) | ||
| Age | ||||||
| ≤40 years | 164 (33.4%) | 73 584 (US$18.4) | 0.005 | 71 (43.3) | 93 (56.7) | 0.37 |
| 41–50 years | 208 (42.4%) | 69 811 (US$17.5) | 99 (47.6) | 109 (52.4) | ||
| ≥51 years | 119 (24.2%) | 62 432 (US$15.6) | 60 (50.4) | 59 (49.6) | ||
| Family role | ||||||
| Head of the household | 419 (85.3) | 68 793 (US$17.2) | 0.001 | 193 (46.1) | 226 (53.9) | 0.40 |
| Second financial decision-maker | 29 (5.9) | 95 033 (US$23.8) | 13 (44.8) | 16 (55.2) | ||
| Guardian | 43 (8.8) | 58 705 (US$14.7) | 24 (55.8) | 19 (44.2) | ||
| Education | ||||||
| Never been to school/primary school | 129 (26.3) | 50 744 (US$12.7) | <0.001 | 92 (71.3) | 37 (28.7) | <0.001 |
| Secondary school | 175 (35.6) | 63 691 (US$15.9) | 90 (51.4) | 85 (48.6) | ||
| High school | 125 (25.5) | 83 695 (US$20.9) | 39 (31.2) | 86 (68.8) | ||
| College/university/vocational/other | 62 (12.6) | 113 020 (US$28.3) | 9 (14.5) | 53 (85.5) | ||
| Occupation (principal income earner) | ||||||
| Employee of a private company | 52 (10.6) | 69 834 (US$17.5) | <0.001 | 24 (46.2) | 28 (53.8) | 0.001 |
| Employee of government | 53 (10.8) | 108 371 (US$27.1) | 8 (15.1) | 45 (84.9) | ||
| Farm/agriculture/garment factory/labour | 66 (13.4) | 47 436 (US$11.9) | 51 (77.3) | 15 (22.7) | ||
| Self-employed/other | 277 (56.4) | 73 644 (US$18.4) | 114 (41.2) | 163 (58.5) | ||
| Retired/housewife/househusband/unemployed | 43 (8.8) | 46 698 (US$11.7) | 33 (76.7) | 10 (23.3) | ||
| Monthly household income (KHR) | ||||||
| ≤8 04 000 (US$201) | 88 (17.9) | 47 714 (US$11.9) | <0.001 | 64 (72.7) | 24 (27.3) | <0.001 |
| 804 000–1 200 000 (US$201–US$300) | 181 (36.9) | 56 459 (US$14.1) | 120 (66.3) | 61 (33.7) | ||
| >1 200 000 (US$300) | 222 (45.2) | 94 511 (US$23.6) | 46 (20.7) | 176 (79.3) | ||
| Ever had eye examination | ||||||
| No | 424 (86.4) | 67 195 (US$16.8) | 0.09 | 207 (48.9) | 216 (51.1) | 0.06 |
| Yes | 67 (13.6) | 81 309 (US$20.3) | 23 (34.3) | 44 (65.7) | ||
| Currently wear spectacles | ||||||
| No | 433 (88.2) | 68 257 (US$17.1) | 0.13 | 209 (48.3) | 224 (51.7) | 0.02 |
| Yes | 58 (11.8) | 76 207 (US$19.1) | 21 (36.2) | 37 (63.8) | ||
| Ever noticed child has vision problems | ||||||
| No | 259 (52.7) | 62 233 (US$15.6) | <0.001 | 137 (52.9) | 122 (47.1) | 0.03 |
| Yes | 228 (46.4) | 77 064 (US$19.3) | 93 (40.8) | 135 (59.2) | ||
| Your child ever had eye examination | ||||||
| No | 275 (56.0) | 62 839 (US$15.7) | 0.002 | 142 (51.6) | 133 (48.4) | 0.07 |
| Yes | 216 (44.0) | 78 113 (US$19.5) | 88 (40.7) | 128 (59.3) | ||
US$1 = KHR4000.
*Univariate analysis—general linear model.
†Univariate analysis—χ2.
KHR, Cambodian (Khmer) Riel; US$, United States Dollar; WTP, willingness to pay.