Condition category
Nutritional, Metabolic, Endocrine
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting
Publication status

Plain English Summary

Not provided at time of registration

Trial website

Contact information



Primary contact

Dr Merrick Flynn Zwarenstein


Contact details

Institute for Clinical Evaluative Sciences
2075 Bayview Ave
M4N 3M5
+1 (0)416 480 4055 ext. 7439

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

Printed Educational Materials (PEMs) and their impact on physician decision making towards more evidence based choices: a single centre randomised tria



Study hypothesis

Printed Educational Materials (PEMs) will change physician decision making towards more evidence based choices.

Study Objective:
To measure the impact of PEMs on physician behaviour.

This description covers three replicates, independantly randomised. Each of the three sequential studies, aimed to asses the effects of printed educational materials on practice change by physicians. Each of the three replicates was aimed at a different condition and group of patients, and used different messages, but the same message formats.

These three seperate trials, essentially identical in design, tested the impact of printed educational messages aimed at:
1. Increasing coverage of retinal screening among all adult patients with diabetes
2. Intensification of cardiovascular treatment for patients over 65 years of age, with diabetes, and
3. At encouraging physicians to choose thiazides for initiation of hypertension therapy in their patients over 65 years, with newly diagnosed uncomplicated hypertension.

Ethics approval

Research Ethics Board of Sunnybrook & Women's College Health Science Centre, Toronto, Ontario (Canada), 29/04/2004, ref: #135-2004

Study design

Single-centre randomised cluster and factorial trial

Primary study design


Secondary study design

Cluster randomised trial

Trial setting

GP practices

Trial type


Patient information sheet

Not available in web format, please use contact details to request a participant information sheet


Diabetes, hypertension


Posted printed educational materials (PEM) as follows:
Intervention arm 1 will receive 'informed' with an attached short outsert
Intervention arm 2 will receive 'informed' with an attached short outsert and longer insert
Intervention arm 3 will receive 'informed' with an attached long insert
Control arm will receive 'informed' only with no attachments

Intervention type



Not Applicable

Drug names

Primary outcome measure

Three trials:
1. Proportion of new hypertensives on diuretics
2. Proportion of diabetics who receive retinal screening
3. Proportion of diabetics who receive lipid lowering and antihypertensive medication and an ACE inhibitor

All measured from routinely collected health insurance and administrative information: OHRI, ODB, CIHI

Secondary outcome measures

No secondary outcome measures

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

5547 actively practicing family (FP) and general practitioners (GP) in Ontario (~25 years and above, either sex) that have more than 100 patients over 65 years of age in fee for service practice with greater $50,000 billings to OHIP in 2003, randomised each time for three mail-outs of PEMs - the Printed Educational Materials

Participant type


Age group




Target number of participants


Participant exclusion criteria

Physicians who have elected not to receive 'informed', a newsletter on evidence based practice out of the Institute for Clinical Evaluative Sciences (ICES)

Recruitment start date


Recruitment end date



Countries of recruitment


Trial participating centre

Institute for Clinical Evaluative Sciences
Toronto, Ontario
M4N 3M5

Sponsor information


Institute for Clinical Evaluative Sciences - Toronto (Canada)

Sponsor details

Room G1 06
2075 Bayview Avenue
M4N 3M5

Sponsor type

Research organisation



Funder type

Research organisation

Funder name

Canadian Institutes of Health Research (CIHR) (Canada), ref: MCT-67916

Alternative name(s)

Instituts de Recherche en Santé du Canada, CIHR, IRSC

Funding Body Type

government organisation

Funding Body Subtype

National government



Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Basic results (scientific)

Publication list

2007 protocol in:
2007 process evaluation protocol in:
2007 sub-trial protocol in:
2014 diabetic retinopathy results in:
2014 diabetic retinopathy results in:
2016 hypertension results in:
2016 hypertension results in:

Publication citations

  1. Protocol

    Zwarenstein M, Hux JE, Kelsall D, Paterson M, Grimshaw J, Davis D, Laupacis A, Evans M, Austin PC, Slaughter PM, Shiller SK, Croxford R, Tu K, The Ontario printed educational message (OPEM) trial to narrow the evidence-practice gap with respect to prescribing practices of general and family physicians: a cluster randomized controlled trial, targeting the care of individuals with diabetes and hypertension in Ontario, Canada., Implement Sci, 2007, 2, 37, doi: 10.1186/1748-5908-2-37.

  2. Protocol

    Grimshaw JM, Zwarenstein M, Tetroe JM, Godin G, Graham ID, Lemyre L, Eccles MP, Johnston M, Francis JJ, Hux J, O'Rourke K, Légaré F, Presseau J, Looking inside the black box: a theory-based process evaluation alongside a randomised controlled trial of printed educational materials (the Ontario printed educational message, OPEM) to improve referral and prescribing practices in primary care in Ontario, Canada., Implement Sci, 2007, 2, 38, doi: 10.1186/1748-5908-2-38.

  3. Protocol

    Francis JJ, Grimshaw JM, Zwarenstein M, Eccles MP, Shiller S, Godin G, Johnston M, O'Rourke K, Presseau J, Tetroe J, Testing a TheoRY-inspired MEssage ('TRY-ME'): a sub-trial within the Ontario Printed Educational Message (OPEM) trial., Implement Sci, 2007, 2, 39, doi: 10.1186/1748-5908-2-39.

  4. Results

    Zwarenstein M, Shiller SK, Croxford R, Grimshaw JM, Kelsall D, Paterson JM, Laupacis A, Austin PC, Tu K, Yun L, Hux JE, Printed educational messages aimed at family practitioners fail to increase retinal screening among their patients with diabetes: a pragmatic cluster randomized controlled trial [ISRCTN72772651]., Implement Sci, 2014, 9, 1, 87, doi: 10.1186/1748-5908-9-87.

  5. Results

    Grimshaw JM, Presseau J, Tetroe J, Eccles MP, Francis JJ, Godin G, Graham ID, Hux JE, Johnston M, Légaré F, Lemyre L, Robinson N, Zwarenstein M, Looking inside the black box: results of a theory-based process evaluation exploring the results of a randomized controlled trial of printed educational messages to increase primary care physicians' diabetic retinopathy referrals [Trial registration number ISRCTN72772651]., Implement Sci, 2014, 9, 86, doi: 10.1186/1748-5908-9-86.

Additional files

Editorial Notes

19/09/2016: Publication reference added. 14/09/2016: Publication reference added.