W7 - Critical Appraisal - Development of Nutrition Recommendations & Guidelines Flashcards
Why is critical appraisal important?
To be able to translate scientific evidence to practise.
Give some examples of conflicting messages in nutrition
Fats give you heart diseases
Meat give you cancer
Carbs are bad for you
What are the common goals for nutrient reference standards
To meet physiological needs
Min risk of adverse effects
⬇️ risk of chronic diseases
UK has dietary reference values produced by who?
Public health England
Scientific advisory committee on nutrition
What comes under the DRV
EAR
RNI
LRNI
Safe intake
EAR
Estimated avg req
RNI
Ref nutrient intake
LRNI
Lower reference nutrient intake
What do nutrient recommendations focus on?
A single nutrient
i.e macro or micronutrients
What do dietary guidelines refer to?
Foods + dietary patterns
What do clinical practise guidelines do?
Personalise guidelines to the ind + translate the evidence base for the management of clinical conditions.
What regulates the health claims in marketing on the packaging of food products in Europe & the UK?
European Food Safety Authority
What came out in 2006
Regulations came out to ensure that any nutrition or health claim on food labels needs to be backed up by scientific evidence.
What are the 2 broad study designs used commonly in nutrition studies?
Experimental
Observational
What are case control studies good for in nutrition?
The impact of a specific nutrient or food intake/item/dietary pattern on the risk of developing a diseases between groups of people.
Observational studies
Association, not causation
Limited to responders, data collected/questions
Rely on self-report
Intervention studies (treatment vs control)
Not always possible/ethical
Limited time effect
Limited to group characteristics
Controlled env (lab)
Advantages to prospective cohort studies
Large sample
Long time-frame
Multiple measures at once
Cheaper + more feasible than RCT
Disadvantages to prospective cohort studies
Accuracy of data
Assumptions rather than certainty
Uncontrolled setting
What do evidence-based guidelines typically feature?
Explicit methodology
Systematic review of the evidence
Graded recommendations linked directly to the supporting evidence
State explicitly when recommendations are based on opinion.
What are the steps usually involved in guideline development
Specification of the topic + guideline development methodology
Systematic review of the evidence
Consideration of expert opinion
Public policy considerations
Drafting of the document
Peer review
What happens to supporting evidence?
Undergoes critical appraisal, incl, an assessment of the mag of the effect on outcomes observed in studies.
As well as health effects, guidelines can have secondary effects in other domains of daily life
Give examples
Family budgets
Shopping patterns
As well as health effects & secondary effects what can dietary guidelines also do?
Alter corporate dynamics w/in the commercial market place
i.e
Food industry
Restaurants
Retailing
Advertising
Why is comprehensiveness important?
To ensure all evidence is considered, avoiding any bias.
Why is critical appraisal carried out?
To examine strengths + weaknesses of the study designs so that judgement about the evidence can be linked to quality.
What influences where an ind will fall in the bell curve surrounding the mean?
Variety of effect modifiers
i.e risk factors, past medical history, lifestyle…
Limitations of evidence-based practise guidelines
Guidelines could be slightly wrong due to errors stemming from limitations in the science, I,e lack of data.
Recommendations that don’t give guidance on individualisation or that reduced complex decisions into simplistic algorithms may result in more harm than good.
