Table 3. Parametric model for Clayton copula with Weibull margin for glaucoma patients’ data set .
| Variables | Estimate | P value |
| Lambda | 0.28 | 0.002 |
| K | 1.65 | 0.002 |
| Age (y) | 0.01 | 0.002 |
| Place of residence | ||
| Rural | Ref. | |
| Urban | -0.23 | 0.002 |
| Gender | ||
| Female | Ref. | |
| Male | 0.02 | 0.002 |
| Type of medication | ||
| Diamox | Ref. | |
| Timoglue | -0.06 | 0.002 |
| Timolol | -0.04 | 0.002 |
| Diabetic disease | ||
| No | Ref. | |
| Yes | 0.04 | 0.002 |
| Stage of glaucoma | ||
| Absolute | Ref. | |
| Early | -0.33 | 0.002 |
| Moderate | -0.51 | 0.002 |
| Advanced | -0.04 | 0.002 |
| Intraocular Pressure | ||
| Normal | Ref. | |
| Not normal | 0.03 | 0.002 |
| Duration of treatment | ||
| Short | -2.48 | 0.002 |
| Medium | -1.26 | 0.002 |
| Long | Ref. | |
| Cup-disk ratio | ||
| > 0.7 | Ref. | |
| ≤ 07 | -0.02 | 0.002 |
| Eta | 9.57 | 1.000 |
K: The scale parameters of the baseline Weibull distribution
Source: Jimma University Medical Center, Ethiopia; from January 1, 2016, to August 30, 2020.