Range of possible relationships between the patient visit, the letter due date, and the first reminder.

<p>Recheck patients should get a letter every year (or 2 years for internal medicine). If a recheck patient had a visit during the trial, they were eligible for a reminder if the letter was due before the visit (sometimes, long before the start of the trial) or up to 1 week after the visit. Reminders were sent for appointments that had already occurred and appointments scheduled for the coming week, meaning that reminders were sent no more than 2 weeks before the letter was due. New patients should get a letter within 8 weeks of their visit. Patients were considered eligible for a reminder if they did not yet have a letter at 6 weeks after their visit, meaning that the first reminder for a patient was issued 6 to 10 weeks (an average of 8 weeks) after the visit.</p

CONSORT diagram.

<p>All 7690 patients visiting the internal medicine or geriatrics outpatient clinic were included. Doctors allocated to the intervention group received reminders for patients who were due for a letter during the trial.</p

Forest plot of effect of intervention on each matched pair of clinicians, with correction for the (non-significant) differences in baseline performance (the percentage of patients with letters sent within 90 days of the visit) at the time of randomization.

<p>For each pair of doctors, we show the number of letters sent before 90 days/ the total number of letters which were due during the trial, and the resulting percentage of letters sent on time. The log odds ratio and confidence intervals are shown graphically (black bars = actual performance, grey diamonds = predicted performance according to the meta-analytic model), and numerically (in the right column).</p