Validity of using an electronic medical record for assessing quality of care in an outpatient setting

We sought to evaluate the validity of retrieving data from a commercial, outpatient electronic medical record (EMR) to assess the management of pharyngitis. For children ages 3-18 years, we electronically identified clinical encounters with diagnoses of pharyngitis using 3 different strategies (an EMR-based strategy, an administrative data-based strategy, and a reference strategy which used medical record review). By each strategy, we calculated the proportion of episodes of pharyngitis during 1 year for which management of pharyngitis adhered to published guidelines. Among 479 total episodes of pharyngitis, 434 (91%) were from the EMR-based strategy and 281 (59%) from the administrative data-based strategy. Review of the records (the reference strategy) found that 391 of 479 (82%) were confirmed episodes of pharyngitis. Complete evaluations to validate strategies for extracting data from electronic databases are necessary before assuming that measures of quality of care will be the same regardless of the source of data.