Motivational interviewingas a complex intervention Jim McCambridge ICMI-3 in Venice, June 19th 2012Improving health worldwidewww.lshtm.ac.uk
Outline1. Introduce complex interventions (CI) perspective and apply it to MI2. Propose value of systematic reviews & studies of heterogeneity - Play with ideas of simplicity and complexity (+ a little data)
2 UK MRC documents• http://www.mrc.ac.uk/Utilities/Documentrec ord/index.htm?d=MRC003372• http://www.mrc.ac.uk/Ourresearch/Research Initiatives/Methodologyresearch/documents/ index.htm
Definition CIs comprise “a number of separate elements which seem essential to the proper functioning of the interventions although the ‘active ingredient’ of the intervention that is effective is difficult to specify”
An alternative perspective• Alan Shiell & Penelope Hawe• Interventions conceptualised as events in complex systems.....which are adaptive and self-regulating
How is a CI different from asimple one?• Pragmatic distinction made according to what we want to find out – Aspirin, can be conceptualised as either – MI, ditto
Two suggestions• It may be useful to think of MI as a CI• Simplicity is often the best strategy for dealing with complexity
Shepperd et al. recommendations• Components, typologies of structural characteristics for mechanisms studies• Qualitative data• Quantitative data syntheses in systematic reviews• Narrative syntheses in systematic reviews
Beyond effectivenessestimates• Much unexplained variability in effectiveness of MI – effect sizes “disturbingly erratic”....Pandora’s box...• This will get much worse as large effectiveness trials, including more frequent null findings accumulate• Why do there appear to be differences in the effectiveness of MI?
Does medical settingmoderate outcome? No. O.R. K Hospital 1.15* 15 Physician office / clinic 1.37* 15 Emergency Department 1.40* 5 HIV Clinic with medical center 1.20* 3 Home Health 1.52* 2 Dentist 1.85* 1 Physical Therapy 1.92* 1
Does provider trainingmoderate outcome? No. O.R. K Mental health professional 1.43* 12 Mixture 1.14* 11 Nurse 1.27* 7 Dietician 1.32* 3 Physician 1.21* 2
Does measurement typemoderate outcomes? Yes. O.R. N Self-report 1.67* 226 Professionally kept records 1.48* 30 Biophysical indicators 1.22* 84 Self-report > Biophysical Records > Biophysical Note: N = number of effect sizes, not number of studies.
Did comparison groupmoderate outcome? No,suggesting M.I. is at least asgood as other programs O.R. K Waitlist 1.91* 7 Information only 1.54* 16 Treatment as usual 1.51* 31
Meta analysis is a statistical technique – does not requireconsideration of biasesSystematic review is a research design that provides astrategy for dealing with complexity to make valid inferencesWe need more systematic reviews of MI
Beyond systematic reviews1. Meta-epidemiological methods for resolving differences in meta-analytic findings2. Narrative methods also have the capacity to be sensitive to inference – reviews of reviews3. Both have capacity to generate new research questions
Take home messages• Getting to grips with complexity across studies as well as within them helps better understanding MI• We can do much more with what’s already been done• Answers relatively easy to get, asking the right research questions and choosing the right designs harder• Keep it all simple as far as possible!
Acknowledgements• Long term funding by the Wellcome Trust• Many many colleagues and friends for helping with development of ideas• Brad Lundahl and Jean Bernard Daeppen• Miller & Rollnick for presenting what is complex simply