Guidebook on Best Practices in Public Health

Executive summary

Countries face a range of public health challenges brought about by changes in lifestyle behaviours, environments, patterns of disease and population structure. These include increasing rates of non-communicable diseases and mental ill-health, air pollution and the rise of emerging infectious diseases such as antimicrobial resistance. Many of these trends worsened during the COVID‑19 pandemic, in particular mental ill-health and physical inactivity as a result of measures designed to reduce contact between people. For example, prevalence of anxiety and depression more than doubled during the pandemic among OECD countries with available data.

This OECD guidebook assists policy makers in addressing the greatest public health challenges by outlining the process for selecting, implementing and evaluating public health interventions. Such interventions may include health promotion actions delivered by primary care and other health care professionals, health literacy programs as well as policies to transform the environment in which people live. Real-world experiences from member countries appear throughout the document to support theoretical frameworks that underpin the guidebook.

Step 1: Identify public health interventions considered best practice and appropriate for transfer

The first part of the guidebook assesses public health interventions against five best practice criteria:

• Effectiveness: Extent to which the objectives of the intervention were achieved;

• Efficiency: Extent to which inputs were used to achieve desired outcomes;

• Equity: Extent to which the intervention reduces inequalities in society;

• Evidence‑based: The strength and validity of evidence used to develop or evaluate the intervention;

• Extent of coverage: Extent to which the intervention reached the target population.

For each criterion, the guidebook lists example indicators to assess performance, such as changes in quality-adjusted life years, life expectancy, and the cost-effectiveness or cost-benefit ratio.

Given the complexity of public health interventions, a best practice intervention in the original (“owner”) implementation setting will not necessarily be a best practice in a different “target” setting. For this reason, the guidebook includes a framework outlining four contextual factors that affect the successful transfer of an intervention:

• Population context: covers population characteristics such as sociodemographic factors as well as broader cultural considerations;

• Sector specific context: covers governance/regulation, financing, workforce, capital and access arrangements in the sector the intervention operates;

• Political context: political will from key decision-makers to implement the intervention;

• Economic context: the affordability of the intervention in the target setting.

A comparison of the owner and target setting against these four contextual factors helps policy makers decide whether to transfer the intervention, and if so, what adaptions are needed.

For both the best practice and transferability frameworks, the guidebook outlines indicators – both publically available and those that require primary research – to assist policy makers select a public health intervention suited to their local context. Example indicators include population health needs; workforce volume, skills and culture; regulations and legislation; infrastructure; political priorities; levels of stakeholder support; and implementation and operating costs.

Step 2: Plan for and monitor implementation

Once an intervention has been identified as best practice and appropriate for transfer, the next step is to implement it in a new target setting. Laying out a formal implementation process is crucial given successful public health interventions rely on co‑ordinated interactions between many people, tools and processes.

Step 2 of the guidebook provides a general framework for defining implementation in terms of “who does what, when”. During the implementation phase, the guidebook sets out how to identify people who actively contribute to implementation and all other stakeholders; select measurable objectives and relevant implementation indicators; assess resource needs against existing capacity and readiness; build human and institutional capacity; identify additional contextual factors to plan integration with existing processes and workflows, and define the scope for further adaptation; and draft the implementation protocol.

After implementing an intervention, policy makers should provide ongoing monitoring and assistance to ensure its success. For example, by identifying additional resource needs as well as disseminating positive results to reinforce motivation and foster continued stakeholder support.

Step 3: Rigorously evaluate public health interventions

There are many reasons to support rigorous intervention evaluations. In particular, evaluating a newly implemented intervention is crucial to understand whether it is successful and should therefore be continued, or if the intervention needs to be amended or even cancelled. Despite the importance of evaluations, they are not always included in project plans, for example due to a lack of expertise, time and resources, or a “blind” belief in the intervention’s success.

Developing an evaluation study should be undertaken once an intervention has been assessed as best practice and suitable for transfer. Designing the evaluation study at an early stage is necessary as it specifies the indicators and therefore the data needed to undertake an evaluation. To assist policy makers in this step, the types of indicators needed to measure effectiveness and efficiency are included, as well as tips on how to select those that are of high quality. Selected indicators were drawn from international databases, such as OECD Statistics and the World Health Organization’s Global Health Observatory and are therefore universally recognised. Example indicators include changes in body-mass index, litres of alcohol consumed and the number of cigarettes smoked daily. Indicators also extend beyond health and include measures of well-being as outlined within OECD’s Better Life Index such as life satisfaction. Finally, given it is not possible to rigorously evaluate all public health interventions, it is important at this stage to determine evaluation efforts based on intervention characteristics such as their size, significance and risk to population health.

Executing an evaluation study involves collecting primary and/or secondary sources of data to assess whether the intervention achieved its objectives. Data should be collected at the beginning and end of an intervention, and, if resources permit, a period after the intervention has concluded. Once collected, researchers must analyse the data, which includes choosing appropriate statistical methods to determine whether observed effects are due to the intervention or chance.

Results from the evaluation will guide follow-up action on whether to adopt, adapt or abandon the intervention. They should also be used to identify “lessons learnt”, which can then be applied to future implementations.