3.5 Evidence-Informed Strategies and Intervention Mix

Choosing strategies that fit the problem and the setting

Evidence-informed planning does not mean copying a published program word for word. It means using the best available evidence together with assessment results, community preferences, resources, ethics, and local constraints. The competent CHES asks of any intervention: did it work, for whom, under what conditions, and which elements appear essential? That last question protects core components during adaptation.

Sources of evidence

Evidence comes from many places, and the exam treats community knowledge as legitimate evidence:

• Systematic reviews and clearinghouses such as The Community Guide (Guide to Community Preventive Services).
• Practice guidelines and professional standards.
• Peer-reviewed studies and surveillance reports.
• Evaluation findings from comparable programs and local pilot data.
• Community evidence — residents describing safety concerns, language barriers, distrust, or scheduling conflicts. This should shape the plan even when a journal article never mentions those conditions.

Strategy selection begins with the determinant

The determinant dictates the strategy:

• Limited knowledge → education may suffice.
• Low skill → demonstration, practice, and feedback.
• Access barrier → navigation, transportation, extended hours, cost reduction, or policy change.
• Social norm pressure → peer leaders and credible messengers.
• Environmental condition → individual counseling alone is too narrow; change the setting.

A strong intervention mix usually combines more than one strategy. A colorectal screening program might pair plain-language reminders, patient navigation, provider prompts, faith-community outreach, and a clinic workflow change — each with a purpose. The goal is not to pile on activities until the plan looks busy; it is to address the most important and changeable determinants within available resources.

Dose, reach, and cultural fit

Planners weigh dose (how much intervention each person receives — sessions, coaching minutes, reminders) against reach (how many and which members of the priority population participate). A high-dose program for a small group builds strong skills but misses many people; a broad media campaign reaches many but yields little practice. Match the choice to the objective.

Cultural fit is part of quality, not an add-on. Materials need appropriate language, reading level, examples, images, channels, and messengers. Strategies should build on community strengths and avoid blaming individuals for conditions shaped by social determinants of health. When adapting an evidence-based intervention, document what changed and why, and preserve core components — the behavior-change method, sequence, minimum dose, or skill practice — that made the original effective. Transcreation (recreating meaning for a culture) beats literal translation.

Feasibility screening and the exam pattern

Feasibility screening stops plans that look strong on paper but fail in practice. Ask: Do we have trained staff? Can partners deliver? Is there enough time in the school semester, grant period, or clinic workflow? Are costs covered? Is the site accessible? Are privacy and consent addressed? Can evaluation data be collected without overburdening participants?

The exam often describes constraints and asks for the best strategy. If transportation is the barrier, another lecture does not help. If literacy is low, a dense handout is weak. If the objective is policy adoption, individual knowledge change is not enough. Choose the answer that uses evidence and local fit together.

Key trap to memorize: when a stem says people already know a behavior matters but cannot act on it, the determinant is access or skill — not knowledge — so the correct answer rarely adds more education.

A spectrum of intervention types

The exam expects you to recognize categories of strategy and match them to determinants. Common types include health education and skill building, health communication and social marketing, policy, systems, and environmental (PSE) change, health-related community service such as screenings, community mobilization and coalition building, and support services such as navigation, transportation, or peer support. The Social Ecological Model implies that the strongest plans combine types across levels rather than relying on a single category.

• Education/skill building → low knowledge or low skill.
• Communication/social marketing → awareness, norms, and demand at scale.
• PSE change → access, environment, and durable, population-level barriers.
• Community service (screening, vaccination events) → reach and direct access gaps.
• Support services (navigation, interpreters, childcare) → logistical and structural barriers.

The hierarchy from individual to environmental

A useful planning principle is that upstream, environmental, and policy strategies tend to reach more people and last longer than one-time individual education, though they are harder to enact. When resources allow only one approach and the determinant is structural, the higher-leverage choice is usually the structural one. The exam rewards recognizing that a sidewalk-and-policy problem is not solved by another pamphlet, and that a sustainable referral workflow outlives a single workshop.

Documenting adaptation and protecting fidelity

When adapting an evidence-based program, the planner should record three things: the core components preserved (the active ingredients), the surface adaptations made for culture, language, or setting, and the fidelity plan describing how delivery will be checked against the original design. The exam treats casual, undocumented changes that strip core components as a threat to effectiveness, while thoughtful, documented adaptation that keeps the active ingredients is good practice. This is also where Area II planning hands off cleanly to Area III implementation, which monitors that fidelity during delivery.