Background: In pharmaco-epidemiological studies using the claims databases, frailty would be an important confounder among the elderly, as frailty is a clinical state that cannot be captured or measured directly from the claims databases. At present, researchers have developed various algorithms using diagnostic codes in the claims databases to measure frailty. Due to the discrepant definitions of frailty, the measurement methods are different, and its generalizability needs to be addressed.
Objectives: To summarizes the latest advances in frailty measurement in claims databases and evaluate the claims-based frailty index (CFI) generalizability.
Methods: We used the following academic search engines (“google scholar”, “Base”, “Core” and “PubMed”) to search claims-based frailty index related articles. Included the articles with “frailty” in the title field and used the claims databases as the data sources. Articles were classified into 4 categories, “Development and validation”, “Applications”, “Review” and “Comparison”. The initial search was supplemented by an additional article from the references of the included articles. The CFI used in the “Applications” was further grouped to 3 approaches as “clinical knowledge-driven selection”, “data-driven selection without a reference standard” and “data-driven selection with a reference standard”.
Results: We included 12 articles in” Development and validation”, 40 articles in “Applications”, 13 articles in “Review” and 5 articles in “Comparison”. Eight of the 12 articles in “Development and validation” used Medicare to developed CFI, another 2 articles using Taiwan’s National Health Insurance Database, and 2 articles using England Inpatient claims database and Registry of senior Australia, respectively. Fifteen of 40 articles in “Applications” used CFI developed by “clinical knowledge-driven selection”, 14 articles by “data-driven selection with a reference standard” and 11 by “data-driven selection without a reference standard”.
Conclusions: Different approaches to develop frailty measurement in claims databases have their own strengths and limitations. The development of CFI depends on the integrity of the claims databases, therefore different claims databases should develop their own CFI.
