We tested whether off-line data analysis, instead of event monitoring, was a viable method for initiating a clinical quality alert. A cohort of patients eligible for an alert was identified by off-line data analysis and a flag was set in their ambulatory Electronic Medical Records. One hundred clinicians were randomly assigned either to a control group or to a group that received the alert when viewing the electronic medical record of eligible patients. Primarily due to actions of their clinicians, 315 of the 580 patients (54.3%) seen by alerted clinicians were no longer eligible for the alert at the end of the one month study, compared to 128 of the 496 patients (25.8%) seen by control clinicians (p<.001). When not alerted, Allied Health clinicians were less likely than physicians to prescribe aspirin, but they responded similarly to the alert. There were no differences in response by specialty or gender of the clinician. Off-line data analysis proved to be an effective method of initiating a clinical alert.