Evidence-Based%20Nutrition%20Practice

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Evidence-Based Nutrition Practice

• Applying the Concepts of EBP to Pediatric
  Nutrition Practice
• (with thanks to Donna Johnson)

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What evidence-based medicine is

• Evidence-based medicine is the conscientious,
  explicit and judicious use of current best
  evidence in making decisions about the care of
  individual patients.
• Sacket et al. BMJ 1996

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What evidence-based medicine is

• The practice of EBM requires the integration of
• individual clinical expertise
• with the
• best available external clinical evidence from
  systematic research.

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Two Principles for Evidence Based Practice

• Evidence alone is never enough to make a clinical
  decision (or a decision about guidelines or
  evidence)
• Decisions Recommendations should be guided by a
  hierarchy of strength of evidence

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• If no randomized trials have been carried out
  for our patients predicament, we follow the
  trail to the next best external evidence and go
  from there.
• 
  Sacket et al. BMJ 1996

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Why Evidence-Base Practice?

• Clinicians need information
• MDs said
• they need it twice a week,
• they get it from our text books journals.
• RDs said
• They need it 5 times a week
• They search the literature 5 times a month

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Clinicians really need information!

• If shadowed
• they need it up to 60 times per week but only
  actually find 30 of what they need
• and that comes from passers-by
• my textbooks are out of date
• my journals too disorganized

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Medical textbooks are out-of-date

• Fail to recommend Rx up to ten years after its
  been shown to be efficacious.
• Continue to recommend therapy up to ten years
  after its been shown to be useless.

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Many Traditional Interventions are Out of Date
Ex. Infant GERD
Effective?
Placing in elevated prone position No
Placing in infant seat No
Thickening formula with infant cereal No
Changing protein content of formula No
Use of pacifier Unclear
5 vs. 10 dextrose water Slightly
Carroll et al. Arch Ped Adoles Med. 2002
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Why dont RDs seek out the best evidence?

• Lack of time
• Lack of skills for critically appraising the
  literature
• Discomfort with going against traditional
  institutional practice

Thomas et al. J Hum Nutr Diet. 2003
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Three solutions

• Carefully research each clinical question that
  comes our way
• Seek and apply evidence-based medical summaries
  generated by others
• Accept evidence-based practice protocols
  developed by our colleagues.

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Process of EB Practice

• 1. Define the question
• 2. Plan and carry out search of the literature
• 3. Critically appraise the literature
• 4. Apply the results to your practice
• 5. Evaluate your performance

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Step 1 Define Question -- PICO

• P - Patient and disease
• I - Intervention
• C - Comparative intervention (optional)
• O - Outcome

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Step 2 Search for Evidence

• Translate PICO Question into a searchable
  question
• Establish a search strategy
• key concepts
• boolean operators
• synonyms
• prioritize
• limit

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Step 2 Search for Evidence
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Step 3 Critically Appraise

• Basic Introduction and Tutorial at
• http//healthlinks.washington.edu/hsl/classes/evid
  ence/

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ADA Quality Indicators

• Design appropriate to hypothesis
• Inclusion exclusion criteria
• Sample size
• Key quality indicators for each study design type
  (ex randomized trials or meta-analysis)

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Step 4 Apply Results

• Within context of individual patient preferences,
  values and rights (or population resources,
  values and culture)

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Evidence, Values, and Resources
Values
Evidence
Resources
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The Strength of the Evidence Depends on the Rigor
of the Studies

• Randomized Controlled Clinical Trial
• Cohort Study
• Case-control Study
• Cross Sectional Study
• Meta-analysis

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Randomized Controlled Clinical Trial

• Involves one or more test treatments and a
  control treatment
• Specified outcome measures for evaluating the
  intervention
• Bias free method for assigning treatment

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Randomized Controlled Clinical Trial
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Confounding Variable

• An extrinsic factor that is associated with the
  predictor variable and a cause of the outcome
  variable.
• Hulley and Cummings, Designing Clinical Research

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Cohort Study

• Identification of two groups
• one received exposure of interest
• one did not receive exposure
• Follow cohort through time to observe the outcome
  of interest

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Cohort Study
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Case-control Study

• Identify patients who have the outcome of
  interest (cases)
• Identify controls without the same outcome
• Look back to see if they had the exposure of
  interest

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Case-control Study
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Cross Sectional Study

• Observation of a defined population at a single
  point in time or time interval
• Exposures and outcomes determined at same time

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Cross Sectional Study
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Meta-analysis

• Quantitative method of combining the results of
  independent studies
• Larger sample size and stronger summaries and
  conclusions

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The Five Strengths of Evidence

• 1. Strong Evidence from at least one systematic
  review of multiple well-designed RCT
• 2. Strong evidence of at least one well designed
  RCT of appropriate size
• 3. Evidence from well designed trials without
  randomization, single group pre-post, cohort,
  time series or matched case control
• 4. Evidence from well designed non-experimental
  studies from more than one research group
• 5. Opinions of respected authorities based on
  clinical evidence, descriptive studies or reports
  of expert committees

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Systematic Reviews

• Identify problem area or area of uncertainty
• Formulate question
• Search for evidence
• Select relevant evidence
• Abstract findings and evaluate reports
• Form recommendations
• Summarize the strength of the evidence supporting
  the recommendation
• Disseminate the findings

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EB Review Example

• Huang R-C, Forbes DA, Davies MW Feed thickener
  for newborn infants with gastro-oesophageal
  reflux (Cochrane Review). In The Cochrane
  Library, Issue 2, 2004. Chichester, UK John
  Wiley Sons, Ltd.

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Background Gastro-oesophageal reflux (GOR) is
common in newborn infants. A common first line
management is the use of feed thickeners. The
prevalence of excessive GOR in children is
approximately 8, as diagnosed on 24 hour
ambulatory pH manometry studies in an unselected
healthy infant population. Symptomatic
regurgitation alone is more common and has been
found to occur in 18 of the general infant
population
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Step 1 Define Question

• P - Patient and disease
• I - Intervention
• C - Comparative intervention (optional)
• O - Outcome

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P Newborn infants with GOR preterm infants up
to 44 weeks I Thickeners of all types including
rice, gum, or flour based, added to all types of
milk including formula and human milk C
Non-thickened feeds O signs and symptoms of
reflux, 24 hour ambulatory pH monitoring and/or
oesophagitis on biopsy
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Step 2. Search for EvidenceWe searched MEDLINE
from 1966 to December 2001, the Cochrane
Controlled Trials Register, The Cochrane Library,
Issue 1, 2002. CINAHL from 1982 to December 2001,
and conference and symposia proceedings published
in Pediatric Research 1990 to 1994. We also
searched conference proceedings for the European
Society for Paediatric Gastroenterology and
Nutrition (ESPGAN) and the North American Society
for Pediatric Gastroenterology and Nutrition
(NASPGAN) from 1994 to December 2001. We did not
restrict the searches to the English language.
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Selection Criteria All randomised controlled
trials that examine the effects of thickening
formulas on treating gastro-oesophageal reflux in
neonates. The eligible studies were to compare
thickened feeds to no intervention (unthickened
feeds).
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Step 3. Critically appraise the literature

• Key Criteria
• blindness of randomisation
• blindness of intervention
• completeness of follow up
• blinding of outcome measurement
• For individual trials, mean differences (and 95
  confidence intervals) were reported for
  continuous variables
• For categorical outcomes the relative risk and
  risk difference (and 95 confidence intervals)
  were reported

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Data collection and analysis Two independent
reviewers identified potential studies from the
literature search. Quality was independently
assessed by two independent reviewers.
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Study Reason for exclusion
Bailey 1987  Patients' ages ranged from 4 days to 14 months. This was a cross over study in which each patient received both thickened and unthickened feeds, but it does not appear to be a randomised cross over trial. 
Carcassonne 1975  No control group was used. The age group ranged from 40 days to five years. The patients used had anatomical abnormalites, severe burns or brain tumours. 
Gouyon 1989  This study evaluated smectite in newborn infants with gastroesophageal reflux. It was rejected because of the lack of randomisation and use of further "thickeners" in some patients in both intervention and placebo group on the basis of undefined symptoms. Gouyon 1988 is an abbreviated report of the same study. 
Greally 1992  The study population was aged between 2 and 18 months. Infants were randomised to receive either cisapride or gaviscon/carobel. There was no placebo group. 
Khoshoo 2000  Age range was from 4 to 10 months. Not a RCT. 
Le Luyer 1992  The study group ranged in age from 2 weeks to 57 months. Not a RCT (no control group). Patients were divided into two groups using different doses of a thickener (sodium alginate) without randomisation. 
Miller 1999  This study was rejected on the basis of the age group encompassing 0 to 12 months. The outcome data for newborn infants could not be separated from the data of older infants. 
Orenstein 1987  Ages were between 4 to 34 weeks of age. This was a cross over study, not a RCT. Each patient received both thickened and unthickened feeds. 
Vandenplas 1994  Ages ranged from 1 week to 4 months old. The outcome data for newborn infants could not be separated from the data of older infants. 
Weldon 1972  Not a RCT. No control group. 
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Main Results No studies fulfilled the
requirements for inclusion in the systematic
review. Reviewers' conclusions There is no
evidence from randomised controlled trials to
support or refute the efficacy of feed thickeners
in newborn infants with GOR. Given the absence of
evidence, we cannot recommend using thickening
agents for management of GOR in newborn infants
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Step 4. Apply results Implications for
practiceAt present, there is no evidence from
randomised controlled trials to support or refute
the efficacy of feed thickeners in newborn
infants with GOR. Although thickening feeds is a
simple and cheap manoeuvre, there are some
theoretical side effects of this treatment such
as delayed gastric emptying with increased
caloric density of feed. Therefore, given the
absence of evidence, we do not recommend using
thickening agents for management of GOR in the
neonatal population.
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Medline

• http//www.ncbi.nlm.nih.gov/entrez/query.fcgi?dbP
  ubMed
• Under Limits can select
• Review
• Meta-analysis
• Practice Guidelines
• Randomized Controlled trial

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Cochran Database of Systematic Reviews

• http//www.update-software.com/clibng/cliblogon.ht
  m
• Can search and review abstracts for free
• Full text requires subscription

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Cochran Database of Systematic Reviews (examples
51 nutrition)

• Dietary interventions for PKU
• Carnitine supplementation of parenterally fed
  neonates
• Feed thickener for newborn infants with GER
• Vitamin A supplementation for preventing
  morbidity and mortality in very low birthweight
  infants
• Formula milk vs. preterm human milk for feeding
  preterm or LBW infants

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Cochran Database of Systematic Reviews (examples
51 nutrition)

• Growth monitoring in children
• Fat supplementation of human milk for promoting
  growth in preterm infants
• Gastrostomy feeding versus oral feeding alone for
  children with cerebral palsy
• Multicomponent fortified human milk for promoting
  growth in preterm infants
• Enteral nutritional therapy for induction of
  remission in Crohn's disease

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National Guideline Clearinghousehttp//www.guidel
ine.gov/
340 with nutrition 60 with peds nutrition

• examples
• Early discharge of the term newborn
• (bottle and breast-feeding National Assoc
  Neonatal Nurses)
• Nutrition practice guidelines for type 1 and type
  2 diabetes mellitus (ADA)
• Guidelines for the evaluation of food allergies
  (American Gastroenterological Association)
• Bariatric surgery for severely overweight
  adolescents concerns and recommendations. 

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National Guideline Clearinghousehttp//www.guidel
ine.gov/

• ADA currently has 12 guidelines here (ex.)
• chronic kidney disease
• gestational diabetes
• hyperlipidemia MNT
• type 1 and type 2 diabetes)
• hypertension older adults
• Most expected to be added in the future

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Haynes Haines, BMJ 1998