Printed educational messages fail to increase use of thiazides as first-line medication for hypertension in primary care: a cluster randomized controlled trial [ISRCTN72772651]

Table 1 Study design and number of practice groups/number of physicians

	Randomized		Included in the analysis
	Randomized		(started at least one patient with uncomplicated hypertension on medication during the follow-up year)
Intervention	Number of practice groups	Number of physicians	Number of practice groups	Number of physicians
1. informed only (no PEM)	1057	1330	947	1166
2. informed plus insert	1058	1265	926	1093
3. informed plus outsert
a. Atheoretical outsert	529	644	475	565
b. TPB-based outsert	529	652	476	585
4. informed plus insert and outsert
a. Atheoretical outsert	529	648	461	550
b. TPB-based outsert	529	640	449	545
Total	4231	5179	3734	4504

Physician practices were randomly assigned to one of four intervention groups. The two intervention groups selected to receive an outsert were further randomly divided into two sub-groups, one of which received the outsert developed by the OPEM team (atheoretical outsert), the other receiving the TPB-based outsert. Interventions were included in the July 2005 edition of informed
PEM printed educational message, TPB theory of planned behaviour

ISSN: 1748-5908