Table 3 Intervention vs. Implementation Trial Design Perspectives: A Hypothetical Example of the Use of Motivational Interviewing (MI) for Substance Use Disorders in the Homeless Population
From: An introduction to implementation science for the non-specialist
| Efficacy Design Principles | Effectiveness Design Principles | Implementation Design Principles | |
|---|---|---|---|
| Hypothesis | MI beats control | MI beats control | MI will be adopted and sustained |
| Population & setting | Exclude psychosis, bipolar, anxiety; any setting with cooperative patients | Include most comorbidities; typical setting is nonspecialized practice sites | Unit of observation may be patients, providers, or clinics; typical setting is nonspecialized practice sites |
| Outcome measures | Health outcomes, many: "just in case…" | Health outcomes, short & sweet | Emphasize MI adoption measures |
| Intervention: clinicians | PhDs, MSWs hired & trained by PI | Addiction counselors hired as study staff | Endogenous addiction counselors |
| Intervention: fidelity | Trained to criterion, audiotaped for fidelity | Trained to criterion, QI-type monitoring as in clinical system | Formative evaluation the focus |
| Context | Make sure that the trial is successful, at all costs | Work within “typical” conditions | Maintain typical conditions |
| Research support | Crypto-case management | Research support, but “firewalled” | Research support limited; e.g., only for training |
| Validity emphasis | Internal > > external | External > internal | Plan to optimize protocol in real time using formative evaluation, in violation of “traditional” considerations of internal validity, while systematically documenting adaptations |