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]

Implementation Science

Merrick Zwarenstein⁷  Nicole Robinson^1,10  Louise Lemyre¹  France Légaré⁴  Marie Johnston⁵  Janet E Hux³  Ian D Graham⁶  Gaston Godin⁸  Jill J Francis²  Martin P Eccles⁹  Jacqueline Tetroe^1,12  Justin Presseau⁹  Jeremy M Grimshaw^1,11 

[1] School of Psychology, 120 University, Social Sciences Building, Ottawa, Ontario K1N 6N5, Canada;School of Health Sciences, City University London, Northampton Square, London EC1V 0HB, UK;Canadian Diabetes Association, 522 University Ave, Toronto, ON M5G 2A2, Canada;Department of Family Medicine and Emergency Medicine, Université Laval, Québec City, Québec G1K 7P4, Canada;Institute of Applied Health Sciences, College of Life Sciences and Medicine, 2nd floor, Health Sciences Building, Foresterhill, Aberdeen AB25 2ZD, UK;School of Nursing, Faculty of Health Sciences, University of Ottawa, 451 Smyth Rd, Ottawa, Ontario K1H 8 M5, Canada;Institute for Clinical Evaluative Sciences, University of Toronto, 2075 Bayview Avenue, Toronto, Ontario M4N 3M5, Canada;Faculty of Nursing, Laval University, Pavillon Ferdinand-Vandry, 1050 Avenue de la Medicine, Room 1445, Quebec City, Quebec G1V 0A6, Canada;Institute of Health and Society, Newcastle University, Baddiley-Clark Building, Richardson Road, Newcastle Upon Tyne NE2 4AX, England;Ottawa Hospital Research Institute, The Ottawa Hospital - General Campus, 501 Smyth Road, Box 711, Ottawa, Ontario K1H 8 L6, Canada;Department of Medicine, University of Ottawa, 451 Smyth Rd, Ottawa, Ontario K1H 8 M5, Canada;Canadian Institutes of Health Research, 160 Elgin St, Ottawa, Ontario K1A 0 W9, Canada

关键词: Behavior change;    Healthcare professional behavior;    Printed educational material;    Theory of planned behavior;    Process evaluation;   

Others  :  1146864
DOI  :  10.1186/1748-5908-9-86

 received in 2013-09-14, accepted in 2014-04-21,  发布年份 2014

【 摘 要 】

Background

Theory-based process evaluations conducted alongside randomized controlled trials provide the opportunity to investigate hypothesized mechanisms of action of interventions, helping to build a cumulative knowledge base and to inform the interpretation of individual trial outcomes. Our objective was to identify the underlying causal mechanisms in a cluster randomized trial of the effectiveness of printed educational materials (PEMs) to increase referral for diabetic retinopathy screening. We hypothesized that the PEMs would increase physicians’ intention to refer patients for retinal screening by strengthening their attitude and subjective norm, but not their perceived behavioral control.

Methods

Design: A theory based process evaluation alongside the Ontario Printed Educational Material (OPEM) cluster randomized trial. Postal surveys based on the Theory of Planned Behavior were sent to a random sample of trial participants two months before and six months after they received the intervention. Setting: Family physicians in Ontario, Canada. Participants: 1,512 family physicians (252 per intervention group) from the OPEM trial were invited to participate, and 31.3% (473/1512) responded at time one and time two. The final sample comprised 437 family physicians fully completing questionnaires at both time points. Main outcome measures: Primary: behavioral intention related to referring patient for retinopathy screening; secondary: attitude, subjective norm, perceived behavioral control.

Results

At baseline, family physicians reported positive intention, attitude, subjective norm, and perceived behavioral control to advise patients about retinopathy screening suggesting limited opportunities for improvement in these constructs. There were no significant differences on intention, attitude, subjective norm, and perceived behavioral control following the intervention. Respondents also reported additional physician- and patient-related factors perceived to influence whether patients received retinopathy screening.

Conclusions

Lack of change in the primary and secondary theory-based outcomes provides an explanation for the lack of observed effect of the main OPEM trial. High baseline levels of intention to advise patients to attend retinopathy screening suggest that post-intentional and other factors may explain gaps in care. Process evaluations based on behavioral theory can provide replicable and generalizable insights to aid interpretation of randomized controlled trials of complex interventions to change health professional behavior.

Trial registration

ISRCTN72772651.

【 授权许可】

   
2014 Grimshaw et al.; licensee BioMed Central Ltd.

【 图 表 】

Figure 1.

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