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Cochrane Consumer Network

Evidence-based health care

Using evidence to inform your decisions

Cochrane assesses the effects of healthcare treatments to provide important information on the benefits and risks of those interventions at a population level. These 'Cochrane Reviews' can be used to guide individual patients in making well-informed decisions about their own health care. Healthcare users differ in their values, circumstances and preferences which means that not everyone may decide to have a particular treatment; individuals make different treatment choices based on the same evidence. This has led to the development of decision aids to be used in partnership with healthcare providers:

See the Cochrane review Decision aids for people facing health treatment or screening decisions at www.cochrane.org/reviews/en/ab001431.html

Expert reports of clinical experiences are labelled as very low quality evidence, along with case reports and observational studies. Well-conducted, large randomised controlled trials provide high quality evidence, particularly if they are used to inform a systematic review. The latter provides the highest evidence.

Systematic reviews are based on clinical studies that carefully select their participants. As a result, more complex combinations of clinical problems and the social aspects of health care are not considered. The Cochrane Collaboration is working on how qualitative studies can be used to inform and add to the information obtained from the randomised controlled studies that mainly inform Cochrane reviews - where the outcomes are often measured in numerical terms (and so are termed quantitative studies). Qualitative measures include ‘quality of life’ and lifestyle changes. These may be obtained from detailed questionnaires. Qualitative studies can also use narrative interviews where participants are asked to talk about their experiences. Sets of semi-structured questions and prompts are used to explore the particular issues and information required for a study.

One system for developing recommendations from the clinical trials (from the evidence) is ‘Grading of Recommendations Assessment, Development and Evaluation’ or GRADE. The quality of the evidence is graded as: high, when it is considered that further research is very unlikely to change healthcare provider confidence in the estimate of effect; moderate, when further research is likely to have an important impact on confidence in the estimate of effect and may change the estimate; low, when further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate; and very low, when any estimate of effect obtained from existing clinical trials is very uncertain.

References: The Grading of Recommendations Assessment, Development and Evaluation (GRADE) www.gradeworkinggroup.org/  Introductory version in the British Medical Journal (BMJ 2008;336:924-926 (26 April), doi:10.1136/bmj.39489.470347.AD) www.bmj.com/cgi/content/full/336/7650/924

Why healthcare users in the systematic review process

In the Cochrane Consumer Network, we as healthcare users are involved in the process of preparing this one source of population-based evidence. We fulfill this role as ‘patient representatives’ and not as the individual.

Our intent is that our input, if suitable for the review and accepted, facilitates the implementation of systematic reviews and increases their applicability to health technology assessment and the development of clinical best practice guidelines. We bring with us the need adapt systematic reviews to meet the needs of individual patients and their preferences (based, for example, on culture, beliefs, age, sex, co-morbidities, genetic susceptibility, allergies and sensitivities, the personal situation at home).

"We have ‘knowledge’ that is based on expert opinion, an evidence base obtained from clinical trials, what we read in the media, and from our own experiential perceptions. Somewhere within all of that is the ‘reality’ (from discussions with Tom Jefferson, Cochrane review author).

Informed healthcare users want a system of patient-centred health care, where the community can trust that the care received is safe and of high quality, and where healthcare users are able to share in decision making.

Clinical Practice Guidelines

Guidelines are developed to provide information for practitioners and patients about the most effective treatments and interventions in a clinical situation, based as much as possible on research studies. Clinical guidelines set out to define clinical pathways and play an important role in helping the right treatment get to the right patient at the right time.

Systematic reviews are important sources of evidence to inform clinical practice guidelines. As clinical trials are not available to answer every question that comes up in the development of clinical practice guidelines, the guidelines and their recommendations may not always be based on strong evidence.

Health Technology Assessment

Health technology is a term that can be applied to many aspects of health care: prevention programmes, a diagnostic test, a device or piece of equipment, a drug or a procedure.

Health technology assessment is about the broad health system – whether the system can afford the healthcare intervention (or afford not to have it) in terms of its demonstrated effectiveness in changing health outcomes for a population. Other aspects are that the intervention is needed and the health system has the financial ability to provide the service.

Assessment is a form of policy research that examines the short and long-term consequences of using a healthcare technology. It is a multidisciplinary process that summarises information about the medical, social, economic and ethical issues related to the use of a health technology, done in a systematic and transparent way.

The types of considerations are: should the treatment be reimbursed in a healthcare system; for which patients and under what circumstances.

Economic evaluations (cost-effectiveness assessments) guide the decision-making process and any reimbursement and restricted access decisions.

Individual countries provide a different context to the use of the technology. It is the analysis of this context as well as the evidence that enables the health technology processes to make recommendations to policy makers in individual countries.

Why healthcare users in the process of developing evidence 

Users of health care need the tools to assess arguments for and against decisions made for their health care, and the use of evidence. Current themes are:

  • The publically held beliefs and perceptions about people's roles and responsibilities in health and health care
  • Development of communication skills and health information that can promote health literacy
  • Shared responsibility in health care and the continuity of that care
  • Promotion of safe and effective health care

Importantly, people still need hope, which may be the only ‘standby’ a person has.

Important questions: Does a healthcare intervention work in this healthcare setting, should we do it here? If so, how should it be used?

We are aware that the need for new or better treatment is best understood by the people living with an illness, and their caregivers. Their views should contribute to decisions about what health care should be provided. Yet within a health system the availability of resources are limited and must be allocated appropriately, based on affordability, effectiveness and meeting public or patient needs. By being involved, people will understand this better.

Page last updated: Sun 19th Aug 2012 8:02:32 CEST