Influence of an e-mail with a drug information attachment on sales of prescribed drugs: a randomized controlled study.

Background: To provide doctors with producer-independent information to facilitate choice of treatment is an important task. The objective of the present study was to evaluate if an e-mail with a drug information attachment has effects on sales of prescribed drugs and if the design of the attachment is of importance.

Methods: The Swedish pharmaceutical benefit board found rizatriptan (Maxalt) 10 mg to be the most cost-effective triptan. All 119 heads of primary care units in western Sweden were randomized to receive information concerning this conclusion via (i) e-mail with attachment I, (ii) e-mail with attachment II or (iii) no information (control). Attachment I was a short one (heading plus three lines text), whereas attachment II was a long one (heading plus one page text and one page with tables). The change in percentage rizatriptan of total triptans sold before and after the intervention (May - July 2004 and May - July 2005, respectively) was compared between the groups.

Results: Totally 48,229 (2004) and 50,674 (2005) defined daily doses of triptans were prescribed and sold during May - July in primary care units in the western part of Sweden. The absolute change in percentage rizatriptan was greater in the intervention groups compared with the control group 2 (25th - 75th percentile: -3 - 7) vs 0 (-7 - 5), P = 0.031). The absolute change in percentage rizatriptan did not differ between the two attachment groups (P = 0.93).

Conclusion: An e-mail with a drug information attachment may influence sales of prescribed drugs. No difference between different designs of the attachment could be detected.