Hybrid trials

Hybrid trials

Hybrid trials are studies that simultaneously evaluate both the clinical effectiveness of an intervention and the strategy used to implement it. These designs help accelerate the translation of research into practice by combining elements of effectiveness and implementation research within a single study.

When are they used?

Hybrid trials are used when there is:

• Evidence suggesting the intervention may be effective, but further testing is needed
• Interest in understanding how best to implement the intervention in real-world settings
• A need to shorten the time between efficacy research and practical application
• An opportunity to study both clinical and implementation outcomes in parallel

They are especially useful in applied health research where:

• Both outcome and delivery strategies are evolving
• Researchers wish to understand context, fidelity, and uptake
• Policy or practice decisions are imminent

Key Features

Hybrid trials incorporate:

• Simultaneous measurement of implementation and effectiveness outcomes
• Integration of implementation science frameworks (e.g., RE-AIM, CFIR)
• Often use mixed methods (quantitative and qualitative)
• Engage stakeholders (e.g., patients, providers, health systems) throughout the study
• Allow adaptive or tailored implementation strategies to be tested

Types of Hybrid Designs

Type 1

Primary focus on testing the effectiveness of a clinical intervention

Secondary focus on gathering information about implementation

Example: Testing a new diabetes care model and observing how it is adopted by clinics

Type 2

Equal focus on both effectiveness and implementation strategy

Simultaneous testing of the intervention and the implementation method

Example: Testing a smoking cessation program and comparing training models for delivery

Type 3

Primary focus on testing an implementation strategy

Intervention effectiveness is already well-established

Example: Comparing audit-and-feedback versus coaching to implement depression screening

Strengths

• Bridges the gap between research and practice
• Maximizes data collection efficiency by combining two objectives
• Provides early insights into implementation feasibility and barriers
• Enables faster scale-up if strategies are found effective

Limitations

• Increased complexity in design, analysis, and interpretation
• Requires expertise in both effectiveness and implementation science
• May demand more resources (e.g., larger teams, mixed methods, stakeholder input)
• Risk of diluting focus if objectives are not clearly prioritized

Example

A Type 2 hybrid trial might evaluate a new heart failure discharge intervention while also comparing two strategies to implement it: in-person nurse coaching vs. electronic reminders. The study would assess hospital readmissions (effectiveness) and fidelity to the coaching/reminder protocol (implementation).

Related Pages

• Implementation trials
• Pragmatic trials
• Cluster randomized trials
• Mixed methods research
• Stepped wedge trials

Bibliography

1. Curran GM, Bauer M, Mittman B, et al. Effectiveness-implementation hybrid designs. Medical Care. 2012;50(3):217–226.
2. Landes SJ, McBain SA, Curran GM. An introduction to effectiveness–implementation hybrid designs. Psychiatric Research and Clinical Practice. 2019;1(3):e33.
3. Lyon AR, Bruns EJ. User-centered redesign of evidence-based psychosocial interventions to enhance implementation—Hospitable soil or better seeds? JAMA Psychiatry. 2019;76(1):3–4.

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Adapted for educational use. Please cite relevant trial methodology sources when using this material in research or teaching.