Approximately half of the patients treated with oral cholinesterase inhibitors are compliant during the first year. Patients who are compliant and persistent have lower total health care costs.
BALTIMORE—Real-world data from a large cohort of patients with Alzheimer’s disease indicate that half of patients who are initiated on oral cholinesterase inhibitors (eg, rivastigmine, donepezil, galantamine) are compliant during the first year of therapy. Further, those who are compliant have lower health care costs than those who are noncompliant, according to data presented at the 134th Annual Meeting of the American Neurological Association.
Francis Vekeman, MA, BSc, Senior Economist at Analysis Group in Montreal, and colleagues, conducted a retrospective claims analysis. Their study included 17,717 patients (mean age, 81.0; 59.3% female) with Alzheimer’s disease who were newly initiated on an oral cholinesterase inhibitor.
On average, participants were observed for approximately 546 days. Inclusion criteria were nine or more months of continuous insurance eligibility, three or more months of follow-up, and one or more Alzheimer’s disease diagnosis between January of 2004 and June of 2008.
Compliance was defined as medication possession ratio (MPR): the sum of days supply or medication divided by the observation period. Persistence was defined as continuous drug use without having a gap of 30 days or more between refills. Health care costs associated with compliance and persistence were also observed.
Health Care Costs and Compliance Associated With Cholinesterase Inhibitors
“During the first year, the mean MPR was 0.67, and 49.9% were compliant,” Mr. Vekeman and his coauthors reported. “Kaplan-Meier persistence rates after six, 12, and 24 months were 52.6%, 36.1%, and 19.7%, respectively.”
In the first year of observation, a 15% lower health care cost was associated with compliance versus noncompliance ($15,470 versus $13,218). Yearly health care costs for outpatient services in the persistent group were $4,342, compared with $6,344 for the nonpersistent group.
For inpatient services, the costs for the persistent group totaled $2,372, compared with a total of $5,024 for the nonpersistent group. Total costs for the persistent and nonpersistent groups, including pharmacy claims, were $12,592 and $15,421, respectively.
Mr. Vekeman and colleagues noted some limitations regarding the study, including the fact that pharmacy-dispensing claims may not reflect patients’ actual compliance to the medications. There are also inherent limitations within claims data, such as inaccuracy in billing diagnoses and pharmacy dispensing information. “Due to the lack of clinical information in claims data, Alzheimer’s disease and comorbidites were identified based solely on ICD-9 codes,” Mr. Vekeman and coauthors noted. “For the same reason, it was not possible to determine the degree of Alzheimer’s disease severity of patients.”
“Based on real-world data from a large cohort of Alzheimer’s disease patients initiated on cholinesterase inhibitors, 50% were compliant during the first year following treatment initiation,” Mr. Vekeman’s group concluded. “Approximately 36% were persistent on therapy during the same period,” the researchers added, “and only 20% of the patients were persistent with their oral cholinesterase inhibitors two years after initiating therapy.”
—Laura Sassano