A: An article by DesRoches et al (2015) compared the National Provider and Plan Enumeration System (NPPES), the American Medical Association Masterfile, and the SK&A physician file to evaluate data accuracy. The authors performed this analysis in the context of using the selected datasets for sampling frameworks and counting physicians in a given area. The authors found that while none of the files were perfect, the NPPES contained broader coverage and NPPES and SK&A data had reasonably accurate and current address information. The AMA Masterfile had lower rates of correct address information.
State licensure data are another matter. Some state medical boards require only basic information, including a mailing address for licensing correspondence. Some states collect more robust data through licensure, including multiple practice addresses, and demographic, education, and practice characteristics. Some states conduct regular surveys. States may or may not systematically verify the licensure or survey data.
Different data sources have different limitations. Before using any dataset as a sampling frame or for research, it is essential to understand the data’s purpose and how they are collected, verified, and updated.