included. The distribution of enrolees covered by prescription insurance during the entire study period
different types of health plan in 2001 was as follows: (i.e. patients who did not have a break in their health
(i) comprehensive (where coverage is handled by insurance coverage for >45 days).
only one policy, with a deductible and coinsurance, Patients were excluded from the study if they: (i)
and the patient has no incentive to use a particular filled a prescription for any cholinesterase inhibitor
list of providers [28%]); (ii) health maintenance during the 18 months prior to the IPD (to select only
organisation (12%); (iii) noncapitated point-of-ser- newly treated patients); (ii) were diagnosed with AD
vice (11%); (iv) preferred provider organisation from 3 months up to 18 months prior to the IPD (to
(31%); and (v) capitated or partially capitated point- allow a gap between the first diagnosis and the first
of-service (17%).