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Recommendations Summary

CF: Nutrition Screening: Pediatrics 2020

Click here to see the explanation of recommendation ratings (Strong, Fair, Weak, Consensus, Insufficient Evidence) and labels (Imperative or Conditional). To see more detail on the evidence from which the following recommendations were drawn, use the hyperlinks in the Supporting Evidence Section below.


  • Recommendation(s)

    CF: Frequency of Nutrition Screening, Less Than 2 Years of Age

    For infants and children with cystic fibrosis (CF) less than 2 years of age, it is reasonable to measure weight and length at each clinic visit and to screen for risk of impaired growth and other nutrition concerns at least monthly for the first six months of age, every other month from 6-12 months of age, and quarterly from 12-24 months of age to identify nutrition risk.

    Rating: Consensus
    Imperative

    CF: Method of Nutrition Screening, Less Than 2 Years of Age

    Infants and children with cystic fibrosis (CF) less than 2 years of age should be screened for nutrition risk by comparing weight-for-age, weight-for-length and length-for-age z-scores or percentiles to birthweight and to growth norms using WHO growth charts for the general population, since these parameters are longitudinally associated with lung function. Children who are not maintaining birthweight, weight-for-length, or length -for-age z-scores or who have depressed growth compared to the general population should be referred for full nutrition assessment by an RDN or international equivalent.

    Rating: Strong
    Imperative

    CF: Frequency of Nutrition Screening, 2-20 Years of Age

    For children and adolescents with cystic fibrosis (CF) ages 2-20 years, weight and height should be measured at each clinic visit and children should be screened for risk of impaired growth and other nutrition concerns at least quarterly or more frequently based on clinical condition to identify nutrition risk.

    Rating: Fair
    Imperative

    CF: Method of Nutrition Screening, 2-20 Years of Age

    Pediatric individuals with cystic fibrosis (CF) 2-20 years of age, should be screened for nutrition risk by comparing growth percentiles and z-scores to general population norms using Centers for Disease Control (CDC) growth charts for the general population, since these parameters are longitudinally associated with lung function. Children and adolescents who have a body mass index (BMI)-for-age <50th percentile and/or who have concerning trends in BMI-for-age, weight-for-age, or height-for-age z-scores should be referred for full nutrition assessment by an RDN or international equivalent.

    Rating: Strong
    Imperative

    • Risks/Harms of Implementing This Recommendation

      There are no obvious risks or harms associated with nutrition screening recommendations.

    • Conditions of Application

      RDN Judgement. These recommendations should be interpreted and implemented with consideration of client history and goals. Accurate, consistent anthropometric measurements are essential to growth monitoring. Recommendations regarding the criteria for referring pediatric clients for full nutrition assessment is based on research describing the inverse relationship between weight/growth and disease progression. However, by definition, half of children will naturally fall beneath the 50th percentile for weight and length/height. When monitoring clients, RDNs must use clinical judgement to determine if a child with z-scores under this cut-off are actually at nutrition risk or if they are stable on a lower growth curve and assessment is not needed. While increasing or decreasing z-scores will nearly always be an indication for full assessment, this process may or may not be possible depending on the other health concerns the client is managing at any given time.

      Healthcare Practitioner conducting Nutrition Screening. Though RDNs may not see or counsel individuals with CF and their families at every clinic visit, growth/weight status should be measured at each clinic visit, and RDNs, dietetic technicians registered (DTRs) or other qualified healthcare professionals should be responsible for monitoring trends in growth and weight to identify nutrition risk. If the RDN is not the individual screening for nutrition status, healthcare facilities should adopt a timely and reliable system for alerting RDNs when growth or weight measures warrant full nutrition assessment.

      Training. All persons conducting weight, height and length measures should be adequately trained using an institution-specific standardized protocol and measurement tools (scale and stadiometer, or infant scale and infantometer).

      WHO vs CDC growth curves: In accordance with recommendations for the general population, practitioners may use WHO growth standards for infants 0-24 months of age and begin using CDC growth charts at age two years (Grummer-Strawn et al 2010), though this is not currently specified in guidance for the CF population (Cystic Fibrosis Foundation 2019). For infants and children 0-24 months of age, WHO growth charts, compared to CDC growth charts, were less likely to define children as <50th percentile for weight-for-age (WFA) and weight-for-length (WFL) (Machogu et al 2015). Therefore, if practitioners use WHO growth charts to screen for growth, percentiles <70th percentile may be used to identify nutrition risk rather than the <50th percentile recommended when using CDC growth charts.

    • Potential Costs Associated with Application

      Measuring weight and height (or length) requires minimal resources (scale and stadiometer, or infant scale and infantometer) beyond those needed in any other standard practice. Equipment must be properly maintained and calibrated.  

    • Recommendation Narrative

      Evidence. Undernutrition is a common concern for individuals with CF due to increased energy expenditure and decreased nutrient absorption (Cystic Fibrosis Foundation Patient Registry 2017). In the systematic review of the literature, undernutrition demonstrated a clear longitudinal relationship with lung function decline (Academy of Nutrition and Dietetics 2019, Darrah et al 2016, Emerson et al 2002, Goss et al 2018, Keller et al 2003, Konstan et al 2007, Lai et al 2009, Machogu et al 2015, McPhail et al 2008, Sanders et al 2014, Sanders et al 2015, Sanders et al 2015, Sanders et al 2018, Usatin et al 2017, Welsh et al 2014, Woestenenk et al 2014, Yen et al 2013, Chamnan et al 2010, Stephenson et al 2015, Vieni et al 2017). In pediatric individuals with CF, regaining birthweight z-score by age two and maintaining BMI and height z-scores throughout childhood were associated with the highest FEV1% predicted later in life compared to those who did not regain and maintain z-scores in studies referencing CDC growth charts. Participants who maintained a weight, length, weight-for-length and BMI >50%ile from infancy and early childhood had higher FEV1% predicted values 4-16 years later, although there was no added improvement for those who maintained growth parameters >85%ile compared with >50%ile (Darrah et al 2016, Emersonet al 2002, Goss et al 2018, Kelle et al 2003, Konstan et al 2007, Lai et al 2009, Machogu et al 2015, McPhail et al 2008, Sanders et al 2014, Sanders et al 2015, Sanders et al 2015 P 2015, Sanders et al 2018, Usatin et al 2017, Welsh et al 2014, Woestenenk et al 2014, Yen et al 2013). Baseline FEV1% predicted was also associated with change in BMI over time (Goss et al 2018), so it is likely that the relationship between weight/growth parameters and lung function is bi-directional.

    • Recommendation Strength Rationale

      Recommendations for nutrition screening in pediatric individuals are based on Grade I, or strong, evidence indicating the longitudinal relationship between specific weight/growth parameters and lung function and mortality as well as clinical experience and norms in clinical practice (Cystic Fibrosis Foundation). The recommendation for adult participants is based off of Grade II, or fair, evidence as well as clinical experience and norms in clinical practice, guided by the Cystic Fibrosis Foundation.

    • Minority Opinions

      Consensus reached.