title: Patients with newly diagnosed carcinoma of the breast: validation of a claim-based identification algorithm.
abstract: The objectives of this study were to validate a claims-based algorithm for identification of patients with newly diagnosed carcinoma of the breast and to optimize the algorithm. Claims data from all females aged 21 years or older who enrolled in a large California health maintenance organization during the study period from October 1, 1994 through March 31, 1996 were analyzed. Medical records of the patients identified through the claims-based algorithm were reviewed to determine whether the patients were correctly identified. The initial algorithm had a positive predictive value of 84% which was similar to the previous study. The percentages of correct identification significantly increased with the patient's age at diagnosis. Other patient demographic characteristics and facility characteristics were not related to the accuracy of the identification. Using a classification tree procedure and additional information from the false-positive cases, the initial algorithm was modified for improvement. The best-modified algorithm had a positive predictive value of 92% while only 0.5% (4/837) of the true-positive cases were excluded. The results once again demonstrated that patients with newly diagnosed carcinomas of the breast can be identified using claims data. These databases provide an efficient and effective tool for performing health services studies on large patient populations.
authors.affiliation: Quality Initiatives Division, Foundation Health Systems, Woodland Hills, California 91367, USA.
authors.forename: K M
authors.initials: KM
authors.lastname: Leung
authors.forename: A G
authors.initials: AG
authors.lastname: Hasan
authors.forename: K S
authors.initials: KS
authors.lastname: Rees
authors.forename: R G
authors.initials: RG
authors.lastname: Parker
authors.forename: A P
authors.initials: AP
authors.lastname: Legorreta
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000465:Algorithms; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000628:therapy; D002140:California; D003663:Decision Trees; D003953:Diagnosis-Related Groups / Q000145:classification; D005260:Female; D006279:Health Maintenance Organizations; D006296:Health Services / Q000706:statistics & numerical data; D006302:Health Services Research / Q000379:methods; D006801:Humans; D007344:Insurance Claim Reporting / Q000706:statistics & numerical data; D008875:Middle Aged; D011237:Predictive Value of Tests; D015203:Reproducibility of Results