Table 2. Validated Definitions for Adherence and Persistence to Anti–Vascular Endothelial Growth Factor Therapy in Neovascular Age-Related Macular Degeneration.
| Definition | Mean (SD) Delphi score | |
|---|---|---|
| Stage 1 | Stage 2 | |
| Adherence | ||
| Full adherence | ||
| Attendance at every scheduled clinic visit (treatment or monitoring) and undergoing every treatment or monitoring procedure advised by the treating physician over 12 mo | 9.69 (0.61) | 9.91 (0.31) |
| Adherence | ||
| Missing ≤1 treatment or monitoring visit scheduled as advised by the treating physician over 12 moa,b | 8.75 (2.20) | 9.82 (0.40) |
| Nonadherence | ||
| Missing ≥2 treatment or monitoring visits scheduled as advised by the treating physician over 12 mob | 8.33 (2.17) | 9.67 (0.67) |
| Persistence | ||
| Persistence | ||
| Maintaining treatment or monitoring as advised by the treating physician and attending the most recent appointment within the last 6 moc | 9.31 (0.82) | 9.82 (0.40) |
| Nonpersistence | ||
| Not attending any treatment or monitoring visit for any reason within the last 6 mo or not scheduling follow-up appointments for any reason for 6 mod | 9.50 (0.67) | 9.27 (1.27) |
| Planned discontinuation and transfer of care | ||
| Planned discontinuation | NA | 9.27 (1.27) |
| Lack of treatment response (treatment futility) or no disease activity requiring ongoing treatment, as judged by the treating physician | ||
| Transfer of care | ||
| The ongoing management of the patient’s neovascular age-related macular degeneration, transferred to another physician | ||
Abbreviation: NA, not applicable.
a
A visit is considered missed if the recommended appointment date is exceeded by more than 2 weeks for any reason. The number of missed visits is determined based on the total potential visits missed during the nonadherent period, using the last recommended visit interval.
b
The period of 12 months begins from the time of the first injection. For subsequent years of treatment, adherence is calculated every 12 months.
c
A patient is not required to be adherent to be persistent.
d
The first day of the 6-month period after the most recent appointment attended should serve as the date of onset of nonpersistence. A minimum of 6 months since the first injection is required to assess persistence.