Assessing Evidence to improve Population Health and Wellbeing

Carmen Aceijas, Carmen Aceijas

• Publisher: Learning Matters
• Year: 2011
• ISBN:
  9780857253903
• Edition: 1
• Topic: Medicine
• Subtopic: Public Health, Administration & Care

Written to support practitioners undertaking a Masters in public health, this book considers the main concepts, issues and methodologies of the second core competence of the Public Health Skills and Career Framework: ?Assessment of evidence of the effectiveness of interventions, programmes and services to improve population health and wellbeing?.

Coverage includes the theoretical definition of evidence and its use in public health, the role of critical appraisal methods and tools in evidence assessment and how Effectiveness, Efficiency and Quality inform evidence. The book is packed with case studies and activities to help link theory and practice and prompt personal reflection.

chapter 1
What is Meant by Evidence?

Carmen Aceijas and Amina Dilmohamed

Meeting the public health competences

Core area: Assessing the evidence of effectiveness of interventions, programmes and services to improve population health and wellbeing.

This chapter will help you to evidence the following competences for public health (Public Health Skills and Careers Framework):

• Level 5 (a): Knowledge of literature searching techniques
• Level 5 (d): Understanding of the purpose and methods of reviewing effectiveness in own area of work
• Level 6 (a): Understanding of how to search literature
• Level 6 (b): Knowledge of the principles of critical appraisal as applied to various studies, and its use in improving health and wellbeing
• Level 7 (a) Understanding of appraising the quality of primary and secondary research.

This chapter will also assist you in demonstrating the following National Occupational Standard(s) for public health:

• Reflect on and develop your practice – (HSC33)
• Encourage innovation in your area of responsibility – (M&L C2)
• Facilitate the clinical audit process – (HI124)
• Develop evidence based clinical guidelines – (HI127).

This chapter will also be useful in demonstrating Standard 4c and 4e and 7 of the Public Health Practitioner Standards.

• Standard 4. Continually develop and improve own and others’ practice in public health by:
  d. the application of evidence in improving own area of work
  e. objectively and constructively contributing to reviewing the effectiveness of own area of work.
• Standard 7. Assess the evidence of effective interventions and services to improve health and wellbeing – demonstrating:
  a. knowledge of the different types, sources and levels of evidence in own area of practice and how to access and use them
  b. the appraisal of published evidence and the identification of implications for own area of work practice.

Chapter overview

This chapter will help you to consider what evidence in public health is, and how it is related to evidence-based public health, its principles, why and when it is needed and its role in the decision making for programmes, interventions and services. Some discussion of its historical development is included to help you to understand how evidence became central to public health and to appreciate why all public health actions should be evidence based. This chapter will help you to develop your thinking about evidence in public health, and in particular the overall approach to the assessment of evidence for different interventions, programmes and services. Exercises in this chapter will focus on:

• developing clarity about the nature and origins of evidence in public health;
• developing a critical awareness of the importance of evidence-based public health for the public in general and, in particular, for stakeholders;
• understanding the key principles of evidence gathering and critical appraisal.

Public health professionals are regularly required to participate in the design and implementation of evidence-based projects and their evaluation. In order to help you to identify ways to identify evidence more effectively, in this chapter the key steps of the process will be explored. A number of useful tools that can be used at each stage are introduced here and further explored in following chapters.

After reading this chapter you will be able to:

• identify the nature and main features of evidence-based public health;
• appreciate and be aware of the origins of the concept;
• demonstrate familiarity with the basic process of gathering information and assessing evidence.

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What is evidence-based public health?

Evidence, at the most basic level, involves ‘the available body of facts or information indicating whether a belief or proposition is true or valid’ (Jewell and Abate, 2001) and from this definition we can start to understand that evidence-based public health is something that allows and aims for the production of a body of facts generated with robust systematically assessed or appraised system(s).

Evidence-based public health is an approach in public health that evolved from evidence-based medicine (EBM), which originated from an early plea to adopt an evidence-based approach in medicine. This plea was the work of the British epidemiologist Archie Cochrane (1909–1988), who in his seminal work Effectiveness and Efficiency: Random Reflections on Health Services (Cochrane, 1972), challenged the dominant medical authorities of his time to prove that what they did made any real difference. He further went on to criticise the lack of scientific methods in clinical practice: ‘It is surely a great criticism of our profession that we have not organised a critical summary, by speciality or subspecialty, updated periodically, of all relevant randomised controlled trials’ (Cochrane, 1979, pages 10–11).

Cochrane’s intuitive thoughts instigated the formation of the Cochrane Collaboration in 1992, an international network that synthesises what does and what does not work in health care or, in other words, supplements professional decisions with the latest research knowledge. As Cochrane pointed out many years ago, failing to conduct systematic, up-to-date reviews of controlled trials of health care may result in substantial adverse consequences for patients, practitioners, the health services, researchers and research funding bodies.

Perhaps the most cited author to define evidence-based medicine, however, is David Sackett. He defined evidence-based medicine as:

the conscientious, explicit and judicious use of current best evidence in making decisions about the care of individual patients. The practice of evidence-base medicine means integrating individual clinical expertise with the best available external clinical evidence from systematic research.

(Sackett et al., 1996, pages 71–72)

In the field of public health, a number of broad definitions of evidence-based public health have been formulated and the above statement on the origin of evidence-based public health from evidence-based medicine can be exemplified with the definition of evidence-based public health stated by Jenicek in 1997:

the conscientious explicit and judicious use of current best evidence in making decisions about the care of communities and populations in the domain of health protection, disease prevention, health maintenance and improvement.

(Jenicek, 1997, pages 187–197)

The similarities between Sackett’s definition of evidence-based medicine and Jenicek’s definition of evidence-based public health are obvious: ‘the conscientious explicit and judicious use of current best evidence in making decisions about the care of’. From there, Sackett declares the focus of interest as ‘individual patients’, while Jenicek states that it is ‘communities and populations’.

Similarities and differences between the two definitions could have hardly been better placed; both emphasise the dismissal of random or casual approaches. Both evidence-based medicine and evidence-based public health have to be conscientious and explicit. Nothing is left to chance, rather a systematic approach is clearly suggested. The focuses of interest are, however, very different: individual patients in evidence-based medicine versus communities and populations in evidence-based public health.

Jenicek went on to define evidence-based public health as the appropriate use of current best evidence to make decisions about the care of communities and population in the area of disease prevention and health promotion. He was astute to acknowledge that evidence-based public health had its own unique challenges because of its complex interventions and involvement with multiple communities and their societal issues.

Another definition portrays evidence-based public health as:

the development, implementation, and evaluation of effective programs and policies in public health through application of principles of scientific reasoning, including systematic uses of data and information systems, and appropriate use of behavioral science theory and program planning models.

(Brownson et al., 2003, page 4)

While Jenicek’s definition focuses on the need of evidence-based public health covering all the working areas of public health (protection, disease prevention, health maintenance and improvement), Brownson’s definition emphasises its applicability to all stages (design, implementation and evaluation) of public health interventions. Thus, the two definitions complete and complement each other. They share a common feature – the acknowledgement that evidence-based public health is the result of a conscious process guided by explicit and systematic reckoning aiming to analyse the strength of a given programme, intervention or service in an explicit and objective manner.

Nevertheless, a common error is made when assumptions about absolute degrees of certainty are attributed to programmes, interventions and so on, qualified as evidence based. It is worthwhile, then, clarifying that evidence-based public health looks for the best evidence currently available although this is not necessarily the final truth and that a large quantity of information does not necessarily mean we have sufficient evidence.

In other words, the...

Table of contents

• Cover
• Title
• Copyright
• Contents
• Foreword from the Series Editor
• Author Information
• Introduction
• Chapter 1 What is Meant by Evidence?
• Chapter 2 What are Sources of Evidence?
• Chapter 3 Making Sense of the Evidential Hierarchy Used to Judge Research Evidence
• Chapter 4 The Act/Art of Assessing: Critical Appraisal and its Relevance in Public Health
• Chapter 5 Assessing Evidence – the Quality of Primary and Secondary Research
• Chapter 6 Assessing Evidence – the Strengths and Weaknesses of Various Ways of Assessing Public Health Outcomes
• Chapter 7 Assessing Evidence – Cost-Effectiveness Analysis
• Chapter 8 Principles and Methods of Programme Evaluation
• Chapter 9 Assessing Quality and Effectiveness to Improve Public Health and Wellbeing
• Conclusion
• References
• Index