Table 4. Multiple linear regression on the associated factors related to the willingness-to-pay values of screening for diabetic retinopathy among type 2 diabetics in Kinmen.
| Variables | β | SE | 95% CI | p-value |
| Intercept | 586.49 | 117.92 | 354.18; 818.79 | <0.0001 |
| Sex (female vs male) | 10.61 | 47.10 | -82.18; 103.40 | 0.82 |
| Age (60+ vs -59 yearrs) | 41.00 | 22.87 | -86.05; 74.06 | 0.07 |
| Diabetic retinopathy | ||||
| Non-proliferative diabetic retinopathy vs no diabetic retinopathy | 34.52 | 51.14 | -66.24; 135.29 | 0.50 |
| Proliferative diabetic retinopathy vs no diabetic retinopathy | 243.99 | 100.22 | 46.55; 441.44 | 0.02 |
| Legal blindness vs no diabetic retinopathy | 420.06 | 112.78 | 197.88; 642.24 | 0.0002 |
| Duration of type 2 diabetes (15; vs -14 years) | -34.13 | 81.99 | -195.66; 127.40 | 0.68 |
| Education | ||||
| Junior high school or lower vs illiteracy | 81.70 | 46.62 | -9.68; 173.08 | 0.14 |
| Senior high school or higher vs illiteracy | 113.89 | 53.66 | 8.72; 219.06 | 0.04 |
| Income level (20,000+ vs -19,999 new Taiwan dollars/month) | 53.77 | 60.73 | -65.27; 172.80 | 0.09 |
| Marriage (yes vs no+widow) | -54.05 | 65.55 | -183.19; 75.09 | 0.41 |
| Body mass index (25+ vs -24 Kg/m2) | 14.50 | 45.15 | -74.45; 103.46 | 0.75 |
| Total cholesterol (200+ vs -199 mg/dL) | -111.24 | 55.67 | -220.91; 15.74 | 0.18 |
| Triglyceride (200+ vs -199 mg/dL) | 80.23 | 54.76 | -27.66; 188.12 | 0.14 |
| Hemoglobin A1c (7+ vs -6.9 %) | -73.40 | 46.41 | -164.83; 18.03 | 0.12 |
| Urine protein/Urine creatinine (0.2+ vs -0.19) | 3.30 | 51.19 | -100.55; 101.15 | 0.99 |
| Medication (insulin injection vs oral hypoglycemic agents) | 22.05 | 163.55 | -300.15; 344.25 | 0.89 |
| Other chronic diseases (2+ vs 0 or 1) | 34.28 | 32.14 | -97.60; 69.05 | 0.29 |
P-value of Komogorov-Smirnov test of normal distribution for WTP value =0.056
SE: standard error, CI: confidence interval