TABLE 3.
Statistical Models for Medication Adherence and Discontinuation of First-Line Therapy
| Medication Adherence (MPR)a | Discontinuation of First-Line Therapyb | |||||
|---|---|---|---|---|---|---|
| Coefficient (95% CI) | Wald X2 | P Valuec | Hazard Ratio (95% CI) | Estimate | P Valuec | |
| PGA type | ||||||
| Latanoprost (ref.) | – | – | – | – | – | – |
| Travoprost | -1.32 (-3.36, 0.71) | 1.63 | 0.202 | 1.41 (1.22, 1.63) | 20.95 | < 0.0001 |
| Bimatoprost | -7.21 (-9.24, -5.18) | 48.31 | < 0.0001 | 1.48 (1.28, 1.71) | 28.20 | < 0.0001 |
| Age (continuous) | 0.15 (0.04, 0.26) | 7.60 | 0.006 | 0.99 (0.99, 1.00) | 2.65 | 0.104 |
| Gender | ||||||
| Male (ref.) | – | – | – | – | – | – |
| Female | 1.75 (0.07, 3.43) | 4.16 | 0.041 | 0.89 (0.80, 1.00) | 3.96 | 0.047 |
| Race/ethnicity | ||||||
| White (ref.) | – | – | – | – | – | – |
| Nonwhite | -2.25 (-4.17, -0.34) | 5.31 | 0.021 | 1.17 (1.03, 1.33) | 5.81 | 0.016 |
| Geographic region | ||||||
| Non-South (ref.) | – | – | – | – | – | – |
| South | 3.25 (1.41, 5.10) | 11.91 | 0.001 | 0.92 (0.81, 1.04) | 1.93 | 0.165 |
| CCI score (continuous) | 0.28 (-0.38, 0.94) | 0.68 | 0.408 | 0.95 (0.91, 1.00) | 4.51 | 0.034 |
| Type of glaucoma | ||||||
| Non-OAG (ref.) | – | – | – | – | – | – |
| OAG | 2.20 (0.32, 4.08) | 5.28 | 0.022 | 1.02 (0.90, 1.16) | 0.11 | 0.740 |
| Ocular disorder | ||||||
| No (ref.) | – | – | – | – | – | – |
| Yes | -1.24 (-3.23, 0.75) | 1.49 | 0.222 | 0.88 (0.77, 1.00) | 3.60 | 0.058 |
| Hypertension | ||||||
| No (ref.) | – | – | – | – | – | – |
| Yes | -1.01 (-3.10, 1.07) | 0.91 | 0.340 | 1.17 (1.02, 1.35) | 4.66 | 0.031 |
| Diabetes | ||||||
| No (ref.) | – | – | – | – | – | – |
| Yes | -2.79 (-5.01, -0.57) | 6.06 | 0.014 | 1.19 (1.03, 1.39) | 5.24 | 0.022 |
| Pre-index number of outpatient visits (continuous) | -0.01 (-0.08, 0.06) | 0.10 | 0.754 | 1.00 (1.00, 1.01) | 0.98 | 0.323 |
| Pre-index inpatient visits | ||||||
| No (ref.) | – | – | – | – | – | – |
| Yes | -1.93 (-4.49, 0.63) | 2.19 | 0.139 | 1.23 (1.04, 1.45) | 5.81 | 0.016 |
aGeneralized linear model with normal distribution with the identity link function was used for medication adherence.
bCox proportional hazard model was used for the time to discontinuation of first-line therapy.
cSignificant at P < 0.05 (in bold).
CCI = Charlson Comorbidity Index; CI = confidence interval; MPR = medication possession ratio; OAG = open-angle glaucoma; PGA = prostaglandin analog; ref = reference; X2 = chi-square.