Persistence with Cholinesterase Inhibitor Therapy for Dementia An Observational Administrative Health Database Study

Objective: To determine if choice of drug and ease of administration affect persistence of therapy with cholinesterase inhibitors (ChEIs) for treatment of dementia. Methods: An observational administrative health database study was conducted in 5622 patients aged >= 65 years who received a new prescription for donepezil (DON), rivastigmine (RIV) or galantamine (GAL) from February to May 2006. Patients were followed for I year from initiation of therapy to determine percentage persistence and days of therapy. Once-daily galantamine extended release (GAL-ER) was compared with twice-daily galantamine immediate release (GAL-IR) to determine if ease of administration affected persistence. Previous treatment with ChEIs was also documented. Results: One-year persistence rates were significantly different among the ChEIs: GAL-ER 54% (95% CI 51, 57), DON 46% (95% CI 43, 49) and RIV 40% (95% Cl 37, 43). Average days of therapy were greater for GAL-ER (293) than for RIV (272), but there were no differences between DON (287) and GAL-ER or DON and RIV. One-year persistence was significantly greater for GAL-ER 54% (95% CI 48, 59) than for GAL-IR 44% (95% Cl 39, 50), although there was no significant difference in days of therapy (293 vs 286, respectively). More patients currently treated with RIV (40.5%) or GAL-ER (32.3%) had received previous treatment with a different ChEI than with DON (21.9%). Conclusion: Among possible factors affecting persistence of ChEI therapy for dementia, choice of drug, ease of administration and previous treatment appear to be important.