Table 1.
Studies reporting data on adherence, persistence or compliance in patients taking branded or generic atorvastatin
| First author of study (year) [refererence], study type | Sample size, N | Treatment regimen (generic or brand), n | Dose (mg)/prevention type | Measure of adherence/ persistence/compliance | Adherent/persistent/compliant | p value | Follow-up period |
|---|---|---|---|---|---|---|---|
| Adherence | |||||||
| Tsioufis (2017) [58], observational | 190 | ATO (continued brand), 95 | NA | Adherence: PDC (%) | 79.1 | < 0.001 | 18 months |
| ATO (switched to generic), 95 | 73.0 | ||||||
| ATO (continued brand), 95 | Compliance: high adherence (%; rate, MMAS-4) | 73.7 | < 0.001 | ||||
| ATO (switched to generic), 95 | 26.3 | ||||||
| Mano (2015) [59], observational | 282 | ATO (continued brand), 147 | 5–30 | Adherence: median % PDC (% change pre- to post-index) |
89.4 (− 10.3) 92.2 (− 8.6) |
0.058 (0.443d) | 180 days |
| ATO (switched to generic), 135 | 2.5–10 | ||||||
| ATO (continued brand), 147 | Patients achieving ‘adherence’: PDC ≥ 80%), n (%) | 93 (63.3) | 0.162 | ||||
| ATO (switched to generic), 135 | 96 (71.1) | ||||||
| Jackevicius (2016) [60]a, observational | 15,726 | ATO (prescribed brand), 7863 | Mean dose: 47.7/secondary | Adherence: MPR (%) | 88.4 | 1 year | |
| ATO (prescribed generic), 7863 | Mean dose: 47.2/secondary | 88.4 | |||||
| Romanelli (2014) [57]b, observational | 3417 |
ATO (switched to generic): 1786 Other statins (switched to generic): 1631 |
‘Adherent’ patients: MPR ≥ 80%, n (%) | 2575 (75.4) | 6 months | ||
| Kwon (2016) [61], observational | 747 | ATO (prescribed brand), NA | NA | Coverage ratio (< 1 indicates missed ≥ 1 dose) | 0.9 ± 2.1 | < 0.0001 | 24 months |
| ATO (prescribed generic), NA | 0.6 ± 0.9 | ||||||
| Persistence | |||||||
| Tsioufis (2017) [58], observational | 190 | ATO (continued brand), 95 | NA | Persistence rate (%) | 90.1 | 0.1627 | 18 months |
| ATO (switched to generic), 95 | 76.4 | ||||||
| Mano (2015) [59], observational | 282 | ATO (continued brand), 147 | 5–30 | Persistence rate (%) | 67.3 | 0.097 | 180 days |
| ATO (switched to generic), 135 | 2.5–10 | 75.6c | |||||
ATO Atorvastatin, MMAS-4 4-Item Morisky Medication Adherence Scale, MPR medication possession ratio, NA not available, PDC proportion of days covered
aPatients who switched from branded to generic formulations, or vice versa, were censored
bIncludes other statins in addition to atorvastatin. Of those receiving branded atorvastatin, 57% were switched to generic atorvastatin
cNo significant difference after Cox proportional-hazards regression model analysis (adjusted hazard ratio 0.97; 95% confidence interval 0.61–1.55)
dParentheses indicate comparison of % change pre- to post-index