Introduction: The Navajo Nation is a large sovereign tribal nation. After several years of grassroots efforts and overcoming an initial presidential veto, the Navajo Nation passed the Healthy Diné Nation Act (HDNA) in 2014 to promote healthy behaviors in Navajo communities. This was the first such policy in the US and in any sovereign tribal nation worldwide.
Purpose and objectives: The objective of this study was to describe the process, implementation, and evaluation of the HDNA passage and its 2020 reauthorization and the potential for using existing and tribal-specific data to inform tribal policy making.
Intervention approach: The HDNA included a 2% tax on unhealthy foods sold on the Navajo Nation and waived a 6% sales tax on healthy foods. HDNA-generated funds were allocated to 110 local communities for wellness projects. No funds were allocated for enforcement or compliance.
Evaluation methods: We assessed HDNA tax revenue and tax-funded wellness projects in 110 chapters over time, by region and community size. The food store environment was assessed for fidelity of HDNA implementation, price changes since pretax levels, and shopper behaviors. HDNA revenue was cross-matched with baseline nutrition behaviors and health status through a Navajo-specific Behavioral Risk Factor Surveillance System survey.
Results: HDNA revenue decreased modestly annually, and 99% of revenue was disbursed to local chapters, mostly for the built recreational environment, education, equipment, and social events. Stores implemented the 2% tax accurately, and the food store environment improved modestly. Regions with high tax revenue also had high rates of diabetes, but not other chronic conditions. The HDNA was reauthorized in 2020.
Implications for public health: Sovereign tribal nations can drive their own health policy. Program evaluation can use existing data sources, tailored data collection efforts, and tribal-specific surveys to gain insight into feasibility, implementation, and impact.