Medication adherence and health care costs with the introduction of latanoprost therapy for glaucoma in a Medicare managed care population.
BACKGROUND
Latanoprost, a prostaglandin inhibitor, is increasingly being used in the therapeutic management of glaucoma. However, there is scant literature examining the cost and outcome ramifications of latanoprost.


OBJECTIVE
This study examined the medication use behavior (medication-related persistence and adherence rates) and costs associated with the introduction of latanoprost therapy in a treatment-naive older population (aged >or=65 years) enrolled in Medicare.


METHODS
The study employed a retrospective observational cohort design and used administrative claims data from a Medicare health maintenance organization (HMO), which offered complete coverage to enrollees, including prescription benefits. The case group consisted of patients with glaucoma who began latanoprost therapy. The control group consisted of enrollees with glaucoma who started any therapy other than latanoprost. Both groups were followed up for 1 year before and after initiation of therapy. Bivariate and multivariate techniques incorporating health care utilization in the year before the start of new therapy were used to determine the study outcomes.


RESULTS
The case group comprised 101 patients (mean age, 77.60 years), while the control group included 168 patients (mean age, 77.59 years). There were no significant differences across the 2 groups with respect to age, sex, general health scores on the 12 item Short-Form Health Survey, severity of comorbidity, or the proportion of respondents with perception of worsened health. Introduction of latanoprost therapy was associated with higher medication persistence (hazard ratio, 0.90; 95% CI, 0.68-0.98) and adherence rates (mean [SD], 0.51 [0.26] vs 0.40 [0.25]; P < 0.001) compared with patients starting other glaucoma medication. Furthermore, there were no additional increases in total health care costs in the entire population associated with the introduction of latanoprost therapy, after adjusting for group and time effects, as well as other confounders (mean [SD], $4718.24 [$8982.92] vs $4046.55 [$6505.39]).


CONCLUSIONS
Latanoprost therapy offered improved medication use behavior in these older adults enrolled in a Medicare HMO. There were no significant additional increases in overall health care costs as a result of introduction of latanoprost therapy, after adjusting for group and time effects, as well as other baseline confounders in this study cohort.
Bhosle
Monali J
MJ
Department of Pharmacy Practice and Administration, The Ohio State University, Columbus, Ohio 43210, USA.
Reardon
Gregory
G
Camacho
Fabian T
FT
Anderson
Roger T
RT
Balkrishnan
Rajesh
R
D000368:Aged; D015331:Cohort Studies; D003365:Costs and Cost Analysis; D004359:Drug Therapy, Combination; D005260:Female; D005901:Glaucoma / Q000188:drug therapy*; D017048:Health Care Costs; D006801:Humans; D007429:Intraocular Pressure / Q000187:drug effects; D000077338:Latanoprost; D008297:Male; D008329:Managed Care Programs / Q000191:economics*; D006278:Medicare / Q000191:economics*; D009798:Ocular Hypertension / Q000188:drug therapy; D010349:Patient Compliance; D016016:Proportional Hazards Models; D011461:Prostaglandins F, Synthetic / Q000627:therapeutic use*; D012189:Retrospective Studies; D016019:Survival Analysis; D009626:Terminology as Topic; D016896:Treatment Outcome
D011461:Prostaglandins F, Synthetic; D000077338:Latanoprost