Table 1 Summary of some distinguishing features among efficacy, effectiveness, and behavior change exercise trials.
From: Efficacy, effectiveness, and behavior change trials in exercise research
| Â | Efficacy Trial | Â | Â | |
|---|---|---|---|---|
| Â | Traditional | Contemporary | Effectiveness Trial | Behavior Change Trial |
Primary Outcome: | A health outcome | A health outcome | A health outcome | An exercise behavior outcome |
Secondary Outcomes: | Other health outcomes | Other health outcomes | Other health outcomes | Other behavior/health outcomes |
Protocol Deviations: | Not exercising | Not exercising/behavioral support | Not exercising/behavioral support | Not completing behavioral support |
Theoretical Model: | Outcome model needed | Outcome model needed | Outcome model needed | Outcome model not needed |
| Â | Behavior model not needed | Behavior model beneficial | Behavior model needed | Behavior model needed |
Participants: | Highly selected | Highly selected | Moderately selected | Variably selected |
| Â | Not exercising/limited exercise | Not exercising/limited exercise | Exercise levels reflective of practice | Variable exercise levels |
| Â | Lower generalizability | Lower generalizability | Higher generalizability | Higher generalizability |
Exercise Intervention: | Completely supervised | Completely/partially supervised | Unsupervised/partially supervised | NA (exercise is the outcome) |
| Â | Precise exercise type/volume | Partially flexible types/volumes | Flexible exercise types/volumes | Flexible exercise types/volumes |
| Â | Agree to exercise | Agree to exercise | Agree to exercise | Asked to exercise |
| Â | No/limited behavioral support | Agree to behavioral support | Agree to behavioral support | Agree to behavioral support |
Behavioral Support Intervention: | Minimal/informal | Extensive/comprehensive | Moderate/feasible for dissemination | Varied but systematic and feasible |
Comparison Intervention: | No exercise intervention | Minimal exercise intervention | Standard of care | At least exercise recommendation |
| Â | Agree not to exercise | Allowed to exercise | Allowed to exercise | Asked to exercise |
| Â | No behavioral support | No/limited behavioral support | Behavioral support as per standard care | Behavior support based on purpose |
Sample Size: | Powered for health outcome | Powered for health outcome | Powered for health outcome | Powered for behavioral outcome |
| Â | No allowance for nonadherence | Allowance for nonadherence | Allowance for nonadherence | No allowance for nonadherence |
Analysis: | Intention-to-treat | Intention-to-treat | Intention-to-treat | Intention-to-treat |
| Â | Prespecified subgroup analyses | Prespecified subgroup analyses | Prespecified subgroup analyses | Prespecified subgroup analyses |
Interpretation of Results: | ||||
Positive trial | Improves primary health outcome | Improves primary health outcome | Improves primary health outcome | Improve primary behavior outcome |
| Â | Adequate exercise adherence | Adequate exercise adherence | Adequate exercise adherence | Adequate support adherence |
| Â | Â | Support adherence not required | Support adherence not required | Â |
Negative trial | No change in health outcome | No change in health outcome | No change in health outcome | No change in behavioral outcome |
| Â | Adequate exercise adherence | Adequate exercise adherence | Adequate exercise adherence | Adequate support adherence |
| Â | Â | Support adherence not required | Support adherence not required | Â |
Inconclusive trial | No change in health outcome | No change in health outcome | No change in health outcome | No change in behavioral outcome |
| Â | Inadequate exercise adherence | Inadequate exercise adherence | Inadequate exercise adherence | Inadequate support adherence |
Nature of the Result: | ||||
Definitive | Negative trial | Negative trial | Positive trial | Negative trial |
| Â | No effect in practice is likely | No effect in practice is likely | Effect in practice is likely | No effect in practice is likely |
Ambiguous | Positive trial | Positive trial | Negative trial | Positive trial |
| Â | Effect in practice is unknown | Effect in practice is unknown | Effect under better conditions unknown | Effect on health outcomes unknown |
| Â | Â | Â | Â | (unless shown in trial or literature) |