Applying research to practice: does this evidence fit here?

Notions clés

Evidence-based practice in psychology

APA's policy defines it as integrating the best available research with clinical expertise in the context of patient characteristics, culture and preferences. Research is one of three elements; it informs judgment rather than replacing it.

External validity

Whether a trial's results can reasonably be applied to a definable group of patients in a particular setting. It depends on who was eligible or excluded, the setting, how the intervention was delivered and which outcomes were measured, details trial reports often describe poorly.

Efficacy versus effectiveness

Efficacy trials test an intervention under ideal, tightly controlled conditions with selected participants; effectiveness (pragmatic) trials test it in routine practice. Real trials fall along a continuum between the two, which tools such as PRECIS-2 help describe.

Transferability

The qualitative counterpart of generalizability: readers judge whether findings carry over to their own context by comparing it with the study's detailed description of its setting, participants and process.

Cultural adaptation

Changing an intervention's language, content or delivery to fit a cultural group. A meta-analysis of 78 studies found culturally adapted interventions more effective than unadapted versions of the same intervention, with a medium effect (g = .52).

Progress monitoring

Because group results do not guarantee any one person's response, clinicians can track each client's outcomes. In a meta-analysis, progress feedback produced a small improvement in symptom reduction (d = 0.15) and a small favorable effect on dropout.

Exemple commenté

A clinic director wants to adopt a 12-session treatment for adolescent depression. Its two supporting trials used therapists trained by the developers with weekly supervision, and excluded teens with suicidal thoughts or substance use. The clinic's therapists carry large caseloads, and many of its clients have one of those exclusions.

1. Classify the evidence: tightly controlled delivery and selected participants place these trials near the efficacy end of the continuum.
2. List the differences: the clinic's clients include groups the trials excluded, and its therapists lack the training and supervision the trials provided.
3. Look for closer evidence: search for pragmatic trials in routine settings or with clients like the clinic's before relying only on these results.
4. If the clinic adopts it, plan for the gap: arrange training and supervision for the core components, and track each client's outcomes with progress feedback to see whether it works locally.

Strong evidence from one setting is a starting point that has to be matched to, and tested in, the setting where it will be used.