Table 3.
Association of non-adherence to endocrine therapy with copayment amount.
| Univariable Analysis |
Multivariable Analysis |
|||||
|---|---|---|---|---|---|---|
| Variable | RR | (95% CI) | P | aRR | (95% CI) | P |
| Median monthly copaymenta, $ | 1.004 | (1.002, 1.006) | 0.001 | 1.006 | (1.003, 1.008) | <0.001 |
| Age, years | ||||||
| 18–44 | 1.625 | (1.243, 2.125) | <0.001 | 1.561 | (1.187, 2.053) | 0.002 |
| 45–54 | 1.508 | (1.211, 1.879) | <0.001 | 1.504 | (1.208, 1.873) | <0.001 |
| 55–59 | 1.297 | (1.013, 1.661) | 0.039 | 1.279 | (1.002, 1.633) | 0.048 |
| 60–64 | Reference | -- | -- | Reference | -- | -- |
| Charlson-Deyo comorbidity score | ||||||
| 0 | Reference | -- | -- | Reference | -- | -- |
| 1 | 1.350 | (1.053, 1.731) | 0.018 | 1.427 | (1.115, 1.825) | 0.005 |
| 2 or higher | 0.901 | (0.457, 1.777) | 0.764 | 1.002 | (0.524, 1.915) | 0.995 |
| Year of index claim | ||||||
| 2007–2008 | 0.962 | (0.816, 1.133) | 0.640 | 0.869 | (0.735, 1.028) | 0.102 |
| 2009–2010 | 0.212 | (0.160, 0.282) | <0.001 | 0.195 | (0.146, 0.259) | <0.001 |
| 2011–2012 | 0.279 | (0.221, 0.351) | <0.001 | 0.274 | (0.218, 0.346) | <0.001 |
| 2013–2015 | Reference | -- | -- | Reference | -- | -- |
| Oral endocrine therapy | ||||||
| Anastrozole | 0.806 | (0.673, 0.964) | 0.019 | 0.865 | (0.722, 1.037) | 0.116 |
| Exemestane | 0.875 | (0.676, 1.134) | 0.314 | 0.793 | (0.601, 1.048) | 0.103 |
| Letrozole | 0.954 | (0.781, 1.165) | 0.645 | 0.999 | (0.814, 1.226) | 0.992 |
| Tamoxifen | Reference | -- | -- | Reference | -- | -- |
a
Calculated on a per patient, per drug level and normalized to a 30-day prescription.
Abbreviations: RR (risk ratio of non-adherence); aRR (adjusted risk ratio of non-adherence)