Using Evidence to Improve Public Health Outcomes

January 24, 2019 | ASTHO Staff

As public health practitioners strive to achieve optimal health for all, they seek to implement proven and cost-effective policies and practices that maximize scarce resources. One method for determining what is effective entails assessing the evidence base for a particular approach. Because accessing and understanding research literature can require technical expertise in research methods, access to the literature, and considerable time investments, multiple registries have been developed that assess the research evidence and translate the findings so that policymakers and practitioners can identify evidence-based approaches—that is, programs, practices, and policies with evidence of favorable effects.

Highly credible information is provided by resources, such as the Agency for Healthcare Research and Quality’s EPC Evidence-Based Reports, the California Evidence-Based Clearinghouse for Child Welfare, the Cochrane Library, and CDC’s Guide to Community Preventive Services. “These registries have become an increasingly useful resource over the last two decades and are the initial ‘go to’ for many public health professionals working in the field,” says Marcus Plescia, ASTHO’s chief medical officer and liaison to CDC’s Community Guide.

In its role supporting state and territorial health agencies, offering technical assistance, and building capacity, ASTHO has committed to using these resources and research literature to verify the status of evidence for approaches that states are considering and implementing.

ASTHO ensures this support by a commitment to the following measures:

Adopting definitions for three evidence categories: evidence-based, evidence-informed, and experience-based.

ASTHO has reviewed the various definitions that evidence-based registries have utilized to qualify programs, practices, and policies as evidence-based. ASTHO’s three evidence categories capture the spectrum of evidence that exists for various approaches, from rigorous evaluation studies to reports drawing conclusions from anecdotal, correlational, or descriptive information.

Specifically, the definitions adopted by ASTHO include:

Evidence-based

At least one meta-analysis, randomized controlled trial (RCT), or high quality quasi-experimental design (QED) has linked the strategy to a reduced likelihood of an undesirable outcome or an increased likelihood of a favorable outcome.

Evidence-informed

At least one low-to-moderate quality QED has linked the strategy to a reduced likelihood of an undesirable outcome or an increased likelihood of a favorable outcome. Or, at least one meta-analysis, RCT, or high-quality QED has:

• Linked the strategy to a reduced likelihood of highly-correlated undesirable outcomes or an increased likelihood of highly-correlated favorable outcomes, or
• Linked a similar strategy to an impact on the outcome of interest, or
• Documented the causal links between risk and protective factors targeted by the strategy and the outcome(s) of interest.

Experience-based

Research to support this recommendation was not identified or is insufficient. However, the recommendation is (1) driven by sound data or theory, (2) has been found feasible in multiple settings, and (3) has no evidence of adverse or mixed effects.

Training ASTHO staff

ASTHO is investing in evidence-based public health training provided by Washington University. The training will focus on developing a concise statement for a public health problem, searching and summarizing the scientific literature to identity evidence-based policy and program interventions, prioritizing programmatic options, and communicating evidence to policymakers. This training will be complemented by in-house support by staff trained in assessing evidence for multiple evidence-based repositories.

Tracking the evidence category for activities implemented through ASTHO’s Capacity Building/Technical Assistance framework

Because what is measured is what gets done, ASTHO has developed measures to track the inclusion of evidence-based practice in its capacity building and technical assistance framework. For each activity and product, ASTHO staff must document whether it is evidence-based, evidence-informed, or experience-based. ASTHO tracks this metric on a quarterly and yearly basis. The goal is 75 percent, with the most recent quarter finding documentation at 31 percent (n=168).

Ultimately, multiple factors play an equally important role in the decisions that state and territorial health officials make—from the cost of potential approaches to the political feasibility of implementing one approach over another. Moreover, many issues lack guidance from the published literature. The development of the opioid epidemic, for instance, has required responses even as guidance and research have developed simultaneously.

In a conversation with Vermont’s health commissioner, Mark Levine, he reflected on the challenges of evidence-based practice in the field of public health: “Clearly it is time for public health to be an evidence-based discipline, but we have to look at when people are using evidence, how they’re using it, and how they are defining evidence-based.”

Often, the field must depend on evidence that may be based on one instance of a practice being effective when we lack knowledge about how successful that practice might be in other settings. Approaches touted as evidence-based may lack independent research studies to validate such claims. Levine also acknowledged the limitations of a state health agency, where members have full-time jobs and may not have the time or resources to explore the research literature on an ongoing basis.

“As a state health official, I try not to speak beyond my knowledge of the evidence,” says Levine, noting that actions must often be taken in the absence of research validation. For instance, Levine continues, while research shows that naloxone reverses opioid overdoses, “it is common sense rather than an evidence base that suggests that putting it in more hands will lower overdose rates.”

Given these realities, Levine enthusiastically endorsed ASTHO’s commitment to providing information to public health officials about the extent of research evidence. Moving forward, ASTHO will continue to assess the impact and utility to support evidence-based decisionmaking for improved health outcomes.