Explaining the effects of an intervention designed to promote evidence-based diabetes care

a theory-based process evaluation of a pragmatic cluster randomised controlled trial

Jillian J Francis, Martin P. Eccles, Marie Johnston, Paula Whitty, Jeremy M Grimshaw, Eileen F. S. Kaner, Liz Smith, Anne Walker

Research output: Contribution to journalArticle

32 Citations (Scopus)
3 Downloads (Pure)

Abstract

Background: The results of randomised controlled trials can be usefully illuminated by studies of the processes by which they achieve their effects. The Theory of Planned Behaviour (TPB) offers a framework for conducting such studies. This study used TPB to explore the observed effects in a pragmatic cluster randomised controlled trial of a structured recall and prompting intervention to increase evidence-based diabetes care that was conducted in three Primary Care Trusts in England.
Methods: All general practitioners and nurses in practices involved in the trial were sent a postal questionnaire at the end of the intervention period, based on the TPB (predictor variables: attitude; subjective norm; perceived behavioural control, or PBC). It focussed on three clinical behaviours recommended in diabetes care: measuring blood pressure; inspecting feet; and prescribing statins. Multivariate analyses of variance and multiple regression analyses were used to explore changes in cognitions and thereby better understand trial effects.
Results: Fifty-nine general medical practitioners and 53 practice nurses (intervention: n = 55, 41.98% of trial participants; control: n = 57, 38.26% of trial participants) completed the questionnaire. There were no differences between groups in mean scores for attitudes, subjective norms, PBC or intentions. Control group clinicians had 'normatively-driven' intentions (i.e., related to subjective norm scores), whereas intervention group clinicians had 'attitudinally-driven' intentions (i.e., related to attitude scores) for foot inspection and statin prescription. After controlling for effects of the three predictor variables, this group difference was significant for foot inspection behaviour ( trial group x attitude interaction, beta = 0.72, p < 0.05; trial group x subjective norm interaction, beta = -0.65, p < 0.05).
Conclusion: Attitudinally-driven intentions are proposed to be more consistently translated into action than normatively-driven intentions. This proposition was supported by the findings, thus offering an interpretation of the trial effects. This analytic approach demonstrates the potential of the TPB to explain trial effects in terms of different relationships between variables rather than differences in mean scores. This study illustrates the use of theory-based process evaluation to uncover processes underlying change in implementation trials.

Original languageEnglish
Number of pages11
JournalImplementation Science
Volume3
Issue number50
DOIs
Publication statusPublished - 19 Nov 2008

Keywords

  • planned behavior
  • self-determination
  • subjective norms
  • intentions
  • attitudes
  • variables

Cite this

Explaining the effects of an intervention designed to promote evidence-based diabetes care : a theory-based process evaluation of a pragmatic cluster randomised controlled trial. / Francis, Jillian J; Eccles, Martin P.; Johnston, Marie; Whitty, Paula; Grimshaw, Jeremy M; Kaner, Eileen F. S.; Smith, Liz; Walker, Anne.

In: Implementation Science, Vol. 3, No. 50, 19.11.2008.

Research output: Contribution to journalArticle

Francis, Jillian J ; Eccles, Martin P. ; Johnston, Marie ; Whitty, Paula ; Grimshaw, Jeremy M ; Kaner, Eileen F. S. ; Smith, Liz ; Walker, Anne. / Explaining the effects of an intervention designed to promote evidence-based diabetes care : a theory-based process evaluation of a pragmatic cluster randomised controlled trial. In: Implementation Science. 2008 ; Vol. 3, No. 50.
@article{25cd5aaff27a49f98acd62d139f5561e,
title = "Explaining the effects of an intervention designed to promote evidence-based diabetes care: a theory-based process evaluation of a pragmatic cluster randomised controlled trial",
abstract = "Background: The results of randomised controlled trials can be usefully illuminated by studies of the processes by which they achieve their effects. The Theory of Planned Behaviour (TPB) offers a framework for conducting such studies. This study used TPB to explore the observed effects in a pragmatic cluster randomised controlled trial of a structured recall and prompting intervention to increase evidence-based diabetes care that was conducted in three Primary Care Trusts in England. Methods: All general practitioners and nurses in practices involved in the trial were sent a postal questionnaire at the end of the intervention period, based on the TPB (predictor variables: attitude; subjective norm; perceived behavioural control, or PBC). It focussed on three clinical behaviours recommended in diabetes care: measuring blood pressure; inspecting feet; and prescribing statins. Multivariate analyses of variance and multiple regression analyses were used to explore changes in cognitions and thereby better understand trial effects. Results: Fifty-nine general medical practitioners and 53 practice nurses (intervention: n = 55, 41.98{\%} of trial participants; control: n = 57, 38.26{\%} of trial participants) completed the questionnaire. There were no differences between groups in mean scores for attitudes, subjective norms, PBC or intentions. Control group clinicians had 'normatively-driven' intentions (i.e., related to subjective norm scores), whereas intervention group clinicians had 'attitudinally-driven' intentions (i.e., related to attitude scores) for foot inspection and statin prescription. After controlling for effects of the three predictor variables, this group difference was significant for foot inspection behaviour ( trial group x attitude interaction, beta = 0.72, p < 0.05; trial group x subjective norm interaction, beta = -0.65, p < 0.05). Conclusion: Attitudinally-driven intentions are proposed to be more consistently translated into action than normatively-driven intentions. This proposition was supported by the findings, thus offering an interpretation of the trial effects. This analytic approach demonstrates the potential of the TPB to explain trial effects in terms of different relationships between variables rather than differences in mean scores. This study illustrates the use of theory-based process evaluation to uncover processes underlying change in implementation trials.",
keywords = "planned behavior, self-determination, subjective norms, intentions, attitudes, variables",
author = "Francis, {Jillian J} and Eccles, {Martin P.} and Marie Johnston and Paula Whitty and Grimshaw, {Jeremy M} and Kaner, {Eileen F. S.} and Liz Smith and Anne Walker",
note = "Acknowledgements We are grateful to the health care professionals who participated in this study. This project was funded by the European Union as part of the ReBEQI project http://www.rebeqi.org. Jeremy Grimshaw holds a Canada Research Chair in Health Knowledge Transfer and Uptake. Eileen Kaner holds a Department of Health funded NHS Primary Care Career Scientist award.",
year = "2008",
month = "11",
day = "19",
doi = "10.1186/1748-5908-3-50",
language = "English",
volume = "3",
journal = "Implementation Science",
issn = "1748-5908",
publisher = "BioMed Central",
number = "50",

}

TY - JOUR

T1 - Explaining the effects of an intervention designed to promote evidence-based diabetes care

T2 - a theory-based process evaluation of a pragmatic cluster randomised controlled trial

AU - Francis, Jillian J

AU - Eccles, Martin P.

AU - Johnston, Marie

AU - Whitty, Paula

AU - Grimshaw, Jeremy M

AU - Kaner, Eileen F. S.

AU - Smith, Liz

AU - Walker, Anne

N1 - Acknowledgements We are grateful to the health care professionals who participated in this study. This project was funded by the European Union as part of the ReBEQI project http://www.rebeqi.org. Jeremy Grimshaw holds a Canada Research Chair in Health Knowledge Transfer and Uptake. Eileen Kaner holds a Department of Health funded NHS Primary Care Career Scientist award.

PY - 2008/11/19

Y1 - 2008/11/19

N2 - Background: The results of randomised controlled trials can be usefully illuminated by studies of the processes by which they achieve their effects. The Theory of Planned Behaviour (TPB) offers a framework for conducting such studies. This study used TPB to explore the observed effects in a pragmatic cluster randomised controlled trial of a structured recall and prompting intervention to increase evidence-based diabetes care that was conducted in three Primary Care Trusts in England. Methods: All general practitioners and nurses in practices involved in the trial were sent a postal questionnaire at the end of the intervention period, based on the TPB (predictor variables: attitude; subjective norm; perceived behavioural control, or PBC). It focussed on three clinical behaviours recommended in diabetes care: measuring blood pressure; inspecting feet; and prescribing statins. Multivariate analyses of variance and multiple regression analyses were used to explore changes in cognitions and thereby better understand trial effects. Results: Fifty-nine general medical practitioners and 53 practice nurses (intervention: n = 55, 41.98% of trial participants; control: n = 57, 38.26% of trial participants) completed the questionnaire. There were no differences between groups in mean scores for attitudes, subjective norms, PBC or intentions. Control group clinicians had 'normatively-driven' intentions (i.e., related to subjective norm scores), whereas intervention group clinicians had 'attitudinally-driven' intentions (i.e., related to attitude scores) for foot inspection and statin prescription. After controlling for effects of the three predictor variables, this group difference was significant for foot inspection behaviour ( trial group x attitude interaction, beta = 0.72, p < 0.05; trial group x subjective norm interaction, beta = -0.65, p < 0.05). Conclusion: Attitudinally-driven intentions are proposed to be more consistently translated into action than normatively-driven intentions. This proposition was supported by the findings, thus offering an interpretation of the trial effects. This analytic approach demonstrates the potential of the TPB to explain trial effects in terms of different relationships between variables rather than differences in mean scores. This study illustrates the use of theory-based process evaluation to uncover processes underlying change in implementation trials.

AB - Background: The results of randomised controlled trials can be usefully illuminated by studies of the processes by which they achieve their effects. The Theory of Planned Behaviour (TPB) offers a framework for conducting such studies. This study used TPB to explore the observed effects in a pragmatic cluster randomised controlled trial of a structured recall and prompting intervention to increase evidence-based diabetes care that was conducted in three Primary Care Trusts in England. Methods: All general practitioners and nurses in practices involved in the trial were sent a postal questionnaire at the end of the intervention period, based on the TPB (predictor variables: attitude; subjective norm; perceived behavioural control, or PBC). It focussed on three clinical behaviours recommended in diabetes care: measuring blood pressure; inspecting feet; and prescribing statins. Multivariate analyses of variance and multiple regression analyses were used to explore changes in cognitions and thereby better understand trial effects. Results: Fifty-nine general medical practitioners and 53 practice nurses (intervention: n = 55, 41.98% of trial participants; control: n = 57, 38.26% of trial participants) completed the questionnaire. There were no differences between groups in mean scores for attitudes, subjective norms, PBC or intentions. Control group clinicians had 'normatively-driven' intentions (i.e., related to subjective norm scores), whereas intervention group clinicians had 'attitudinally-driven' intentions (i.e., related to attitude scores) for foot inspection and statin prescription. After controlling for effects of the three predictor variables, this group difference was significant for foot inspection behaviour ( trial group x attitude interaction, beta = 0.72, p < 0.05; trial group x subjective norm interaction, beta = -0.65, p < 0.05). Conclusion: Attitudinally-driven intentions are proposed to be more consistently translated into action than normatively-driven intentions. This proposition was supported by the findings, thus offering an interpretation of the trial effects. This analytic approach demonstrates the potential of the TPB to explain trial effects in terms of different relationships between variables rather than differences in mean scores. This study illustrates the use of theory-based process evaluation to uncover processes underlying change in implementation trials.

KW - planned behavior

KW - self-determination

KW - subjective norms

KW - intentions

KW - attitudes

KW - variables

U2 - 10.1186/1748-5908-3-50

DO - 10.1186/1748-5908-3-50

M3 - Article

VL - 3

JO - Implementation Science

JF - Implementation Science

SN - 1748-5908

IS - 50

ER -