The data originated from a peer-reviewed case–control study of patients 55 years of age and older with new-onset AMD of any subtype between January 2008 and December 2017 in the Merative MarketScan Commercial and Medicare Databases (Merative, Ann Arbor, MI, USA).
31 These annual databases represent the health services of approximately 19 million to 57 million employees, dependents, and retirees in the United States with primary or Medicare coverage through privately insured fee-for-service, point-of-service, or capitated health plans. Each case was matched to a control by year, age, U.S. Census Bureau region, hypertension, anemia, and Charlson Comorbidity Index group (0, 1, 2, ≥3). The sample included 312,404 cases and 312,376 controls, and it achieved statistical balance.
23 Complete methodological information, including inclusion criteria and diagnostic and procedural coding, is available in the Methods and Supplemental Online Content of our previous study.
23 The subset of cases with dry AMD were identified by
International Classification of Diseases (ICD), Ninth Revision (ICD-9), code 362.51 and ICD, Tenth Revision (ICD-10), code H35.31. Patients who were diagnosed with wet AMD prior to or on the date of the dry AMD diagnosis were excluded. Therefore, cases had no previous diagnoses of AMD of any subtype before their dry AMD diagnosis, which included any new diagnosis of early-, intermediate-, advanced-, or unspecified-stage dry AMD. Not until 2017 (the final year in this study) were ICD-10 codes expanded to allow us to distinguish among these stages (e.g., H35.31xx).
32 This sample included 194,135 cases and 193,990 matched controls.