Assessing the effectiveness of integrated interventions: terminology and approach.

Integrated care is a term that embraces several concepts, all of which imply that the target patients have complex or chronic illness. There is an assumption that such patients require integrated care and benefit from it. Attempts to test this hypothesis have produced evidence of only modest benefit, and much of the evidence is conflicting. Demonstration of effectiveness of integrated interventions in the clinical setting has been less convincing. Often, interventions are introduced uncritically and without adequate follow-up of their effectiveness. More rigorous research is required on definitions, theoretic constructs,outcome measures, the science of data synthesis, and translation to the clinical setting. Recent developments in theoretic constructs in these areas give promise of better answers to the question, "What works for whom in what context?". Qualitative methodology should form part of this research.