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 1 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% CI 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% CI 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.