Complex intervention trials need careful consideration of context, cost and management
Campbell et al 1 emphasise the importance of preliminary work in
understanding the context of a complex intervention prior to testing it in
a randomised controlled trial. However, whilst they indicate that, for a
behavioural intervention for people with cardiovascular disease, a
sufficient understanding may be achieved by reviewing literature, we found
additional value in primary research before a definitive trial.
Preliminary qualitative findings with the SPHERE Study2 helped define
context and understand particular behavioural influences within the
proposed study population – such as patients’ beliefs regarding the
relative risks of stress and smoking, their need for help in managing
stress and practitioners’ poor motivation for providing services for non-
compliant patients. Exploration of the proposed trial setting revealed
the variation in administrative support which practices would require.
Defining various levels of operation within the intervention helped
develop a theoretical framework but also heightened awareness of
monitoring treatment fidelity3 and possible contextual change during the
definitive trial – due to national initiatives to improve coronary heart
disease management, local initiatives to promote physical activity and
smoking legislation. Our findings will be interpreted in the context of
these.
Our preliminary work also revealed the significance of cost
implications of behaviour change for patients and practitioners. Though
omitted from Campbell et al’s discussion,1 we support suggestions4 that
cost considerations should be included in the modelling stages of design
of trials of complex interventions. Analysis of cost-benefits is
essential for meaningful evaluation of health services interventions.
There are obvious financial implications for funding bodies in
decisions regarding appropriate allocation of time and money for
preliminary work prior to a definitive trial. Reviewers should consider
whether applicants have sufficient knowledge of the context of proposed
trials to ensure that outcome data will provide meaningful conclusions
relevant to other health service settings.
Inevitably, following preliminary work a definitive trial may not
proceed either because the intervention is unlikely to be cost effective
or it is obvious that it should be implemented.1 This may cause employment
difficulties for research staff whose possible longer term funding depends
on outcomes of short term work. Allocating funding on a staged basis may
be best accommodated within a research network framework, such as recently
initiated through the UKRCN5 whereby a core staff of researchers can share
knowledge of factors influencing the implementation and evaluation of
complex interventions, within the context of both primary and secondary
care. Researchers’ skills may be transferred between projects with
greater flexibility than if employed directly for individual projects:
this should facilitate achievement of meaningful outcomes of trials,
particularly of complex interventions.
References
1. Campbell NC, Murray E, Darbyshire J, Emery J, Farmer A, Griffiths F,
Guthrie B, Lester H, Wilson P, Kinmonth AL. Designing and evaluating
complex interventions to improve health care. BMJ 2007;334:455-459
2. Corrigan M, Cupples ME, Smith SM, Byrne M, Leathem CS, Clerkin P,
Murphy AW. The contribution of qualitative research in designing a
complex intervention for secondary prevention of coronary heart disease in
two different healthcare systems BMC Health Services Research 2006;
6:90 doi:10.1186/1472-6963-6-90
3. Bellg, A.J., Borrelli, B., Resnick, B., Hecht, J., Sharp
Minicucci, D., Ory, M., Ogedegbe, G., Orwig, D., Ernest, D. &
Czajkowski, S. Enhancing Treatment Fidelity in Health Behavior Change
Studies: Best Practices and Recommendations from the NIH Behavior Change
Consortium.
Health Psychology 2004;23(5):443-451.
4. Eldridge S, Spencer A, Cryer C, Parsons S, Underwood M, Feder G.
Why modelling a complex intervention is an important precursor to trial
design: lessons from studying an intervention to reduce fall-elated
injuries in older people. J Health Serv Res Policy 2005;10(3):133-142
Rapid Response:
Complex intervention trials need careful consideration of context, cost and management
Campbell et al 1 emphasise the importance of preliminary work in
understanding the context of a complex intervention prior to testing it in
a randomised controlled trial. However, whilst they indicate that, for a
behavioural intervention for people with cardiovascular disease, a
sufficient understanding may be achieved by reviewing literature, we found
additional value in primary research before a definitive trial.
Preliminary qualitative findings with the SPHERE Study2 helped define
context and understand particular behavioural influences within the
proposed study population – such as patients’ beliefs regarding the
relative risks of stress and smoking, their need for help in managing
stress and practitioners’ poor motivation for providing services for non-
compliant patients. Exploration of the proposed trial setting revealed
the variation in administrative support which practices would require.
Defining various levels of operation within the intervention helped
develop a theoretical framework but also heightened awareness of
monitoring treatment fidelity3 and possible contextual change during the
definitive trial – due to national initiatives to improve coronary heart
disease management, local initiatives to promote physical activity and
smoking legislation. Our findings will be interpreted in the context of
these.
Our preliminary work also revealed the significance of cost
implications of behaviour change for patients and practitioners. Though
omitted from Campbell et al’s discussion,1 we support suggestions4 that
cost considerations should be included in the modelling stages of design
of trials of complex interventions. Analysis of cost-benefits is
essential for meaningful evaluation of health services interventions.
There are obvious financial implications for funding bodies in
decisions regarding appropriate allocation of time and money for
preliminary work prior to a definitive trial. Reviewers should consider
whether applicants have sufficient knowledge of the context of proposed
trials to ensure that outcome data will provide meaningful conclusions
relevant to other health service settings.
Inevitably, following preliminary work a definitive trial may not
proceed either because the intervention is unlikely to be cost effective
or it is obvious that it should be implemented.1 This may cause employment
difficulties for research staff whose possible longer term funding depends
on outcomes of short term work. Allocating funding on a staged basis may
be best accommodated within a research network framework, such as recently
initiated through the UKRCN5 whereby a core staff of researchers can share
knowledge of factors influencing the implementation and evaluation of
complex interventions, within the context of both primary and secondary
care. Researchers’ skills may be transferred between projects with
greater flexibility than if employed directly for individual projects:
this should facilitate achievement of meaningful outcomes of trials,
particularly of complex interventions.
References
1. Campbell NC, Murray E, Darbyshire J, Emery J, Farmer A, Griffiths F,
Guthrie B, Lester H, Wilson P, Kinmonth AL. Designing and evaluating
complex interventions to improve health care. BMJ 2007;334:455-459
2. Corrigan M, Cupples ME, Smith SM, Byrne M, Leathem CS, Clerkin P,
Murphy AW. The contribution of qualitative research in designing a
complex intervention for secondary prevention of coronary heart disease in
two different healthcare systems BMC Health Services Research 2006;
6:90 doi:10.1186/1472-6963-6-90
3. Bellg, A.J., Borrelli, B., Resnick, B., Hecht, J., Sharp
Minicucci, D., Ory, M., Ogedegbe, G., Orwig, D., Ernest, D. &
Czajkowski, S. Enhancing Treatment Fidelity in Health Behavior Change
Studies: Best Practices and Recommendations from the NIH Behavior Change
Consortium.
Health Psychology 2004;23(5):443-451.
4. Eldridge S, Spencer A, Cryer C, Parsons S, Underwood M, Feder G.
Why modelling a complex intervention is an important precursor to trial
design: lessons from studying an intervention to reduce fall-elated
injuries in older people. J Health Serv Res Policy 2005;10(3):133-142
5. http://www.ukcrn.org.uk/ accessed 2007-04-06
Competing interests:
None declared
Competing interests: No competing interests