HEALTHY LIVING

Health Evidence Bulletins - Wales (logo)

Protocol Enhancement Project - Healthy Living

Introduction

The original Protocols for Investment in Health Gain were written in the early 1990s to suggest areas where the introduction, or more widespread use of, certain practices could lead to worthwhile improvements in health for the people of Wales. The documents also highlighted current practices that were of questionable value. This revision has been prepared by reviewing the earlier Protocol for Investment in Health Gain: Healthy Living1 to provide some clear, updated statements with a precise indication of the sources for each statement; and to introduce new statements arising from the literature.

In keeping with the original Protocols, it should be stressed that this document is designed primarily for those who commission health services, but it should also be useful to health practitioners wishing to know which health promoting interventions and activities have been shown to have the greatest impact on the health of individuals and populations. It should be read by those in a position to affect government policy towards taxation and legislative action which can lead to a reduction in health-harming behaviour.

The original Healthy Living protocol addressed the following areas:

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In the context of commissioning services for the NHS in the new century, and utilising the utilitarian principle of the greatest good to the greatest number, the Steering Group agreed that this bulletin should concentrate on the following topics:

The statements represent a methodical summary of the evidence in this area found through formal literature searches across a wide range of sources. The evidence has been critically appraised in a way that is appropriate for interventions that aim to promote healthy living, compiled into this document under the leadership of a public health physician and reviewed by a team of experts4.

Given the wide range of factors in society and the environment that impact on health and health-determining behaviour, and the complex nature of human motivation and actions, it is difficult to identify a simple causal chain which links a health promotion activity to changes in health status. It is therefore often inappropriate to use health status outcomes as primary measures of the success of health promotion intervention* . Instead, such evaluation has to be based on measurement of change in intermediate outcomes such as:

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For interventions designed to influence human behaviour and social interactions at the population level, classical experimental designs such as the randomised controlled trial are often impractical. They can place unrealistic restraints on the design of the intervention and make it impossible to manage that intervention (for example, in respect of the use of community networks) in ways that do not compromise the activity. It is also extremely difficult to maintain over the long time period often required for the measurement of changes in behaviour, organisational structures and social norms2. Other, complementary, research methods are therefore often used, such as qualitative ones, which can provide insights into people’s experiences and into the social contexts that strengthen, support or diminish health and health-determining behaviour3.

The convention used in this document to indicate the type of evidence is5:

‘Type I evidence’ - at least one good systematic review and meta-analysis (including at least one randomised controlled trial).
‘Type II evidence’ -
at least one good randomised controlled trial
‘Type III evidence’ - well designed interventional studies without randomisation
‘Type IV evidence’ - well designed observational studies
‘Type V evidence’ - expert opinion; influential reports and studies

The health gain notation (used to indicate the potential benefit to health) is6:

(1) ‘beneficial’ - effectiveness clearly demonstrated
(2) ‘likely to be beneficial’ - effectiveness not so firmly established
(3) ‘trade-off between beneficial and adverse effects’ - effects weighed according to individual circumstances
(4) ‘unknown’ - insufficient/inadequate for recommendation
(5)‘unlikely to be beneficial’ - ineffectiveness is not as clearly demonstrated as for (6)
(6) ‘likely to be ineffective or harmful’ - ineffectiveness or harm clearly demonstrated

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It should be stressed that these gradings, while aiming to be impartial, represent only the best advice of the professionals involved in preparing the Bulletin.

Despite the difficulties of obtaining and assessing evidence, there are a number of clear relationships between lifestyle factors and adverse health outcomes. In many of these, a plausible causative link can be established. What is more, it can be shown that altering some of these lifestyle factors can lead to a better health outcome. Other bulletins in this series, for example those on cardiovascular diseases, respiratory diseases and cancers, give details of the harm caused by many of the factors considered here. This bulletin concentrates on the actions that have been shown to be effective (or not) in producing change towards healthy living.


For a further discussion on evaluating health promotion activities see the Health Education Board for Scotland’s Research for a Healthier Scotland. Edinburgh: Health Education Board for Scotland, 1999.
http://www.hebs.scot.nhs.uk/research/strat/index.htm [accessed 1.6.00]

References:

  1. Welsh Health Planning Forum. Protocol for Investment in Health Gain. Healthy Living. Cardiff: Welsh Office, 1993
  2. Speller V, Learmonth A, Harrison D. The search for evidence of effective health promotion. British Medical Journal 1997; 315: 361-363
  3. Greenhalgh T, Taylor R. Papers that go beyond numbers (qualitative research). British Medical Journal 1997; 315: 740-743
  4. Barker J, Weightman AL and Lancaster J. Project for the Enhancement of the Welsh Protocols for Investment in Health Gain; Project Methodology 2. Cardiff: Duthie Library UWCM, 1997.
    http://hebw.cardiff.ac.uk/method/index.html [accessed 6.4.00 – Project Methodology 3 now available]
  5. This table is adapted from the Bandolier system (derived from the work at McMaster University, Canada) using the NHS Centre for Reviews and Dissemination criteria for a systematic review. See reference 2 or http://www.jr2.ox.ac.uk/Bandolier/band6/b6.5.html and the Database of Abstracts of Reviews of Effectiveness (DARE) in the Cochrane Library.
  6. This notation is modified from the tables used in Enkin M, Kierse MJNC, Renfrew M and Neilson J. A Guide to Effective Care in Pregnancy and Childbirth. 2nd ed. Oxford: Oxford University Press, 1995. pp. 389-390.

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Health Evidence Bulletins: Wales, Duthie Library, UWCM, Cardiff CF14 4XN. e-mail: weightmanal@cardiff.ac.uk