Evaluation of Practice Patterns for the Care of Open-angle Glaucoma Compared with Claims Data: The Glaucoma Adherence and Persistency Study
Received 20 December 2006; received in revised form 10 March 2007; accepted 12 March 2007. published online 18 June 2007.
Objective
To perform a chart review to measure the validity of large claims databases in estimating patient cooperation with eyedrop therapy and to assess physician adherence with guidelines for a preferred practice pattern (PPP) using a new metric.
Design
Claims database analysis, chart review, and telephone survey.
Participants
From 10 260 persons who were recently prescribed a prostaglandin eyedrop for open-angle glaucoma (OAG), a sample of 300 charts (3650 visits) was selected for detailed abstraction.
Methods
Database review of pharmacy refill, diagnostic testing, and visit information, with chart review of a sample of patients from the database and interviews with an overlapping sample of patients and physicians.
Main Outcome Measures
The individual patient medication possession ratio (MPR), an index estimating the proportion of time that patients have prescribed drug available for use, frequency of examination findings present in charts, and associations between MPR and physician adherence to a PPP.
Results
Chart data confirm that the claims database accurately identified the specific glaucoma eyedrop prescribed, but often identified long-term OAG patients as being new to treatment. Physicians frequently used billing codes for OAG in patients with normal visual field tests. Physicians varied dramatically in their adherence to the PPP, performing intraocular pressure measurements, disc evaluations and imaging, and visual field tests on 90% of OAG patients, but carrying out gonioscopy, central corneal thickness measurement, and setting of target intraocular pressure (IOP) on half of patients.
Conclusions
Large claims databases permit conclusions regarding patient cooperation with glaucoma eyedrop therapy, but they should be used cautiously in imputing severity of disease and prior treatment history. Physician adherence to practice guidelines varied substantially; thus, scoring systems for physician behavior have promise in measuring outcome improvements related to better care.
Available online: June 18, 2007.
1Glaucoma Service and Dana Center for Preventive Ophthalmology, Wilmer Ophthalmological Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland.
2Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland.
3Albert Einstein College of Medicine, Bronx, New York.
Correspondence to Harry A. Quigley, MD, Wilmer 122, Johns Hopkins Hospital, 600 North Wolfe Street, Baltimore, MD 21287.
Manuscript no. 2006-1469.
Supported in part by Pfizer, Inc., New York, New York.
⁎ Drs Quigley, Friedman, and Hahn are paid consultants to PACE, Inc., on behalf of Pfizer.
ABSTRACT