Countrywide computer alerts to community physicians improve potassium testing in patients receiving diuretics

More than 20% of approximately 35,000 patients filling a diuretic prescription had no potassium blood test recorded within the previous year. A laboratory reporting system used throughout Israel by Maccabi Healthcare Services physicians was modified to provide physician alerts regarding potassium testing. The physicians were experienced users of a computerized medical record (CMR) that provided online laboratory test results. A nightly batch file checked pharmacy diuretic purchases against the patient's potassium blood test status. On-screen computer-generated reminders were sent to physicians of patients lacking a recent potassium test. Reminders to clinicians increased potassium testing by 9.8% (p < 0.001). Physician age and gender played a small part in predicting compliance to the alert, but specialty and practice size did not. The time delay between the date a reminder was sent and the potassium test date decreased steadily during the intervention. The success of this reminder system encourages expansion to include more drug-laboratory interactions. Furthermore, direct alerts to patients at multiple organization/patient contact points are planned.