Evaluating diabetes health policies using natural experiments: the natural experiments for translation in diabetes study

Abstract

The high prevalence and costs of type 2 diabetes makes it a rapidly evolving focus of policy action. Health systems, employers, community organizations, and public agencies have increasingly looked to translate the benefits of promising research interventions into innovative policies intended to prevent or control diabetes. Though guided by research, these health policies provide no guarantee of effectiveness and may have opportunity costs or unintended consequences. Natural experiments use pragmatic and available data sources to compare specific policies to other policy alternatives or predictions of what would likely have happened in the absence of any intervention. The Natural Experiments for Translation in Diabetes (NEXT-D) Study is a network of academic, community, industry, and policy partners, collaborating to advance the methods and practice of natural experimental research, with a shared aim of identifying and prioritizing the best policies to prevent and control diabetes. This manuscript describes the NEXT-D Study group's multi-sector natural experiments in areas of diabetes prevention or control as case examples to illustrate the selection, design, analysis, and challenges inherent to natural experimental study approaches to inform development or evaluation of health policies.

Figure 1

Relationships of NEXT-D Research Projects across the Landscape of Stakeholders that Influence Diabetes Prevention and Control. Note: The framework shown is an adaptation of socio-ecological models, depicting the spectrum, levels, and reach of different health system, societal, industry, and governmental stakeholder policies that may influence diabetes incidence, progression, and outcomes. The dashed lines separating stakeholders convey bidirectional and fluid interactions across levels. Numbered indicators represent the positioning of different NEXT-D studies, specifically:

1. Kaiser Permanente Northern California evaluation of health plan detection, outreach, and incentives for preventive care.

2. University of California Los Angeles evaluation of a disease specific health plan for patients with prediabetes or diabetes offered by employers to reduce costs of care.

3. New York St. Luke's Roosevelt Hospital Center evaluation of the use of an electronic medical record system for diabetes risk detection and prevention in community health centers and other outpatient clinics.

4. Harvard University evaluation of the effects on diabetes outcomes of employer-mandated switching to a high deductible health plan.

5. Northwestern University evaluation of the reach, adoption, implementation, effectiveness, and costs of a commercial health payer policy to support diabetes prevention programs delivered in communities.