public health intervention wheel

public health intervention wheel

Public Health Interventions: A Comprehensive Guide

1. Introduction

In an ideal world, all public health decisions would be made after careful consideration of the best available evidence. In reality, some actions are taken without any evidence that they improve the public’s health. Going through the steps outlined in this book will enable you to make informed decisions about which interventions are best for your target community or population. The need for a scientific approach to public health interventions has been highlighted by professionals and academics in the field. Despite the fact that funding for public health programs often depends on their popularity rather than their effectiveness, it is becoming increasingly necessary to show that the actions taken to improve the public’s health are in fact doing so. There is now an expectation that problem identification and the design and implementation of interventions should be guided by research evidence of effectiveness. This applies to work done both within the public health sector and by other sectors that have an impact on the public’s health. An understanding of the developing science of intervention is essential to those who wish to be advocates for evidence-based action, as it provides the tools needed to apply existing knowledge to improve population health. This book is intended as an instructional guide for the design, implementation, and assessment of public health interventions to improve the health of a population. Though it is understood that public health professionals often have little influence over the formulations of programs designed to improve general health, the focus of this book is on interventions within the public health sector and within other sectors whose actions have an impact on the health of the public, as these are areas where evidence-based action is most necessary.

2. Understanding the Public Health Intervention Wheel

The Intervention Wheel was launched by the Minnesota Department of Health, field tested it, with feedback from many public health practitioners and an array of training programs. It is now used widely as a standardized language and a systematic approach to the practice of public health. Step by step, the Wheel defines the tasks, the assessment, the recommendations, and the practice of public health. The developers of the Wheel are continuing to refine it to make it even more user-friendly and responsive to health needs and to test its usefulness in diverse and changing health situations. They intend to field test or review cases in a variety of venues at local, state, and national levels, using the results to modify and improve the model.

The Intervention Wheel is a relatively new model for planning and organizing public health interventions. Despite its brief history, it is suggested as a useful guide to understanding all aspects of intervention, from the identification of a problem to the evaluation of the efforts. The Intervention Wheel, a synthesis of intervention models, provides a road map for the practice of public health and defines the field. It is a practical tool for matching interventions to problems, and it supports a full range of options for improving health. The Wheel uses an ecological perspective and a broad view of health determinants to move planners through a series of steps, beginning with social and public health problems, and ending with a set of interventions likely to improve the health of the populations at risk for the problem (community or systems level practice).

3. Key Components of the Public Health Intervention Wheel

As a whole, the Intervention Wheel is designed to define public health practice, incorporating a wide range of potential interventions, activities by diverse organizations, and many career paths, while promoting the value and contributions of public health.

Although implicit in the model and recognized recently, cultural competence is fundamental to the effectiveness of any or all interventions in the wheel. This model is not culture-based; it is a reflection of knowledge derived from many sciences and the evidence of practice. It follows that the wheel is relevant and adaptable to varied community and cultural needs.

There are the following five key components in the wheel: – The outer band of the Intervention Wheel is a graphic illustration of the complex, multi-dimensional practice of public health and the array of interventions available to achieve healthier populations. – The center oval symbolizes the scientific knowledge base of public health as the foundation for practice. This knowledge base is represented as three entities: public health/health promotion research, and evidence from research and best practice.

The Intervention Wheel is a classification model that portrays the range of methods used in public health practice. This wheel shows how public health interventions can be linked to practice standards or evidence.

4. Implementing Effective Public Health Interventions

Effectiveness and efficiency are maximized during the implementation stage of an intervention. Effectiveness is a measure of success in producing a desired result. On the other hand, efficiency is an often narrow concept usually measured by the amount of resources used in producing that result. An effective intervention will use its resources both effectively and efficiently. An intervention is said to be cost-effective when the resources used are not excessive in relation to the positive results produced. Correct and consistent implementation of intervention methods is crucial. The best results generally come from having a single well-defined method. This was shown in a study looking for a more effective means to encourage breast cancer screening in general practice. An intervention was prepared using a sponsored patient facilitation method which aimed at encouraging HCPs to invite their eligible patients to make an appointment during usual breast cancer awareness initiatives. This was the only method used in the study and it showed a 70% increase in screening rate in comparison to a 2% increase seen in a similar but more general study done using an implementation of a practice guideline for the frequency of screening mammography. This method will be measured by theory and actuality of the intervention are compared illustratively using a logic model. A logic model is a systematic and visual way to present and share your understanding of the relationships among the resources needed to operate an intervention, the activities that define the intervention, and the changes or results you hope to achieve. It can have many different forms, but mainly it is a simple pyramid usually consisting of a main goal at the top and a myriad of sub-goals in a wide bottom with very general to highly specific explanations of the exact ways these goals will be achieved.

During the planning stage, tentative goals are set to aim an intervention toward a specific need or epidemiological point. The population of interest must be defined and a suitable intervention strategy is chosen. A study undertaken on the efficacy of a rubella vaccination campaign showed that by targeting university students who had not been vaccinated or shown serological evidence of rubella immunity, the rate of adult women with congenital rubella syndrome living in the United States would decrease 25-30%.

A successful intervention has the potential to be a pivotal point in the course of a disease and can often change the course of an epidemic. With so much at stake, obtaining maximum effectiveness is crucial. Careful planning is required to ensure that interventions use resources efficiently and produce successful results. Four stages are involved in implementing an intervention: a planning stage, an implementation stage, a termination stage, and an evaluation stage. This is a continuous and cyclical process, not all studies will follow each of these stages and they are not always carried out in this order, but it is a conventional framework for evaluating a public health intervention.

5. Evaluating the Impact of Public Health Interventions

There are several reasons for evaluating the impact of an intervention on health outcomes. Outcome evaluation is the examination of the effects of a program against its objectives. Onward and Adams suggest that the purpose is to “assess the relevance, adequacy, and attainment of the objectives, and to identify factors that contributed to or impeded the achievement of the intended effects”. An effective program is one that has improved the health of a given population or has made a positive contribution to the health status. A successful program is one that has had its intended effects and demonstrated that these effects are due to the program itself. It is therefore important to measure effects and compare them against the original objectives. If an intervention is functionally a failure, it should be abandoned in favor of other more effective measures. This is gauged by comparing the costs and the effects of the intervention and contrasting them with alternative measures. Finally, it is often the case that because of political and social changes, the program may not have had its full effects. This is a way of demonstrating accountability and challenging the status quo.

In 1948, Winslow defined public health as: “the science and art of preventing disease, prolonging life, and promoting physical health and efficiency through organised community efforts for the sanitation of the environment, the control of community infections, the education of the individual in personal hygiene, the organisation of medical and nursing services for the early diagnosis and treatment of disease, and the development of social machinery which will ensure to every individual in the community a standard of living adequate for the maintenance of health”. Although these words are over fifty years old, they outline many public health activities very well. Ideally, one would wish to evaluate the impact of today’s public health interventions on the same areas that they are trying to promote. In reality, this is often difficult as they ascribe too closely to Winslow’s idealistic definition of health. It is often possible to evaluate the impact of specific interventions targeting a cause of ill health that is of interest to public health policy. An intervention to introduce low tar cigarettes in order to reduce the incidence of lung cancer and other respiratory diseases would be evaluated in the effects that it has on sales of the low tar cigarettes and their impact on lung cancer and respiratory disease rates.

The objectives of public health intervention often become lost as measures for reduced morbidity, mortality, or disability are recorded. Although these are the ultimate goals, they are not achievable in the short term and alternative measures are needed to assess progress in reaching them. It is useful to evaluate the impact of the intervention on intermediate outcomes.