Complex Interventions

Complex interventions are those that are made up of various interconnecting parts.  They are usually non-pharmacological interventions, for example interventions directed at health professionals’ behaviour, community based interventions (such as programs to prevent heart disease), group interventions (eg school based).  They can also be individual based interventions such as cognitive behavioural therapy.

The evaluation of complex interventions can be difficult because of problems of developing, identifying, documenting, and reproducing the intervention.  It can be useful to split the development and evaluation of such interventions into a number of phases.  Identifying your intervention; defining its components; defining a trial design and possibly piloting this design; carrying out a definitive, suitably powered trial; and finally, implementing the intervention in the long term.

Please see example papers and MRC guidance on the right.