• About
    • Disclosure and Disclaimer Policy
  • Blog
  • Shop Ebooks
  • Recommended Products

Pediatric Feeding News

Dedicated to up to date pediatric feeding and dysphagia information

Welcome!

Hi, I'm Krisi Brackett, MS SLP/CCC this blog is dedicated to current information on pediatric feeding and swallowing issues. Email me at feedingnewsletter@gmail.com with questions.

Read More About Me Here...
  • Feeding Flock
    Research
  • For Parents
    & Caregivers
  • View The
    Resources
  • Pediatric Feeding
    & Dysphagia Newsletter
    • Volume 1
    • Volume 2
    • Volume 3
    • Volume 4
    • Volume 5
    • Volume 6
    • Volume 7
    • Volume 8
    • Volume 9
    • Volume 10
  • Workshops &
    Presentations
  • Ask Me A
    Question
  • Links
    We Like

Everything You Wanted to Know about Z Scores but were Afraid to Ask by Sharon Wallace MS RD CSP

December 6, 2015 by Krisi Brackett 6 Comments

feed 50 & 51I have been asked with increased frequency what a z score is and what is means when evaluating a growth curve. Z scores have been used as a research tool for many years to look at trends in growth in studies. However, now that many hospitals and physicians offices are moving towards an electronic health record, we are beginning to see them used more frequently as a nutrition evaluation tool to assess trends in growth as the scores are often provided as part of the plots on the computer generated growth curves in the chart.

What is a Z Score?

The score shows the standard deviation above or below the mean on the growth chart. If you have looked at a growth chart of a patient or your own child, you will recall it contains curve shaped lines with various percentiles on it. The middle line is the 50th%Ile and they extend out to the 97%ile percentile and 3rd%Ile. So, a z score of 0 is the equivalent of the 50th%ile or average of what you are measuring (weight, height, weight for height or BMI) for that age. A z score of +1 means your plots fall at the 15th%ile or 85th%Ile and a z score of +2 falls roughly at the 3rd or 97%Ile. z scores run positively (+1. +2.+3) or negatively (-1, -2. -3) and so on. A z score by itself would look like a bell curve (see figure 1).

zscore

What do they really mean? How do they help evaluate a pediatric patient?

The farther away a plot is from the median (again, a z score of 0=50th%Ile on the growth chart) in either direction, the higher likelihood that there is some sort of growth problem (obesity or undernutrition). Either of these issues can impact the decision making process regarding both nutrition and feeding goals. Obesity can exacerbate reflux symptoms and inhibit gross motor skills, which in turn can delay progression of feeding skills. Undernutrition can have significant impacts on all aspects of growth and development as well as place an infant or child at higher risk for lab abnormalities such as iron deficiency anemia. Degrees of pediatric malnutrition that are based on z scores are now developed by the ASPEN (American Society for Parenteral and Enteral Nutrition (ASPEN)) guidelines and are determined by z score trends (for example a five year old who’s BMI plots -1.5 for their z score would fall into a mild malnutrition category while a child who’s z score plots -3.2 would fall into a severe malnutrition category.

How do Registered Dietitians use these curves? What are the limitations?

Trends that the z score shows can track what impact adjustments in diet or tube feedings are having on their patient’s overall growth. The goal if a child has a negative z score is to adjust either the caloric density and/or volume of a formula or tube feeding and/or may affect what kind of foods are recommended in the diet. If the z score falls in the established ranges of malnutrition, oral feeding goals may need to be adjusted until the z score shifts in an upward direction (for example, that would not be the time to start cutting out a formula or tube feeding in efforts to improve appetite). If a z score is elevated (especially above +3), this may suggest obesity, and there may be more leverage regarding adjusting the food and/or formula intake and, if applicable, a tube feed schedule.

Certain limitations of the charts may include errors in weighing or measurement. Errors in measuring height are frequently made, especially if an infant or child has special health care needs or issues such as contractures which can make accurate measurement tricky. In addition, variations in weighing (naked vs fully clothed) especially in a young infant, can skew weights. Both of these inaccuracies will inadvertently affect a weight for height curve or BMI and in turn result in an inaccurate trend of z score.

Children who are stunted also may plot with a poor BMI curve and z score, but may not actually be malnourished. These scenarios are only a few of many factors that can make interpreting z scores challenging and because of this, decisions about how to utilize them should ideally be made with the guidance of a registered pediatric dietitian, who specializes in evaluating pediatric growth and nutrition issues.

* Sharon is a registered dietitian with a specialty in pediatrics. She works as one of the RD’s on the UNC pediatric feeding team.

Note: from Krisi. Because we treat our feeding team patients together as a team, I have been able to use the dietitian’s information including the z score to assist with getting insurance and medicaid approval for my feeding patients.

Share this:

  • Click to share on Twitter (Opens in new window)
  • Click to share on Facebook (Opens in new window)

Related

Filed Under: Nutrition Tagged With: dietician, feeding team, feeding therapy, growth chart, Z score

Comments

    Leave a Reply Cancel reply

    Your email address will not be published. Required fields are marked *

  1. here says

    March 30, 2020 at 2:28 pm

    ouc
    http://platansoft.ru/bitrix/rk.php?goto=https://headspaceglass.com/collections/toro-glass fef

    Reply
  2. Unblocked says

    March 7, 2021 at 5:32 pm

    Thanks for any other informative web site. The place else could I get that
    type of info written in such an ideal method?
    I have a challenge that I’m simply now operating on, and I’ve been on the look out for
    such information.

    Reply
  3. usa news says

    May 13, 2021 at 10:35 pm

    Thanks for any other informative blog. The place else may just I get that type of info written in such an ideal means?

    I have a venture that I am just now operating on, and I have been on the look out for
    such information.

    Reply
  4. click here says

    June 5, 2021 at 2:07 am

    An outstanding share! I’ve just forwarded this onto a co-worker
    who was doing a little homework on this. And he in fact bought me dinner due to the fact
    that I stumbled upon it for him… lol. So let me reword
    this…. Thanks for the meal!! But yeah, thanx for spending time to discuss this matter here on your web site.

    Reply
  5. putlocker says

    July 21, 2021 at 11:12 am

    Good blog you have here.. It’s hard to find quality writing like yours these days.
    I really appreciate people like you! Take care!!

    Reply
  6. ymovies says

    July 27, 2021 at 10:33 pm

    Great post! We are linking to this great post on our site.
    Keep up the great writing.

    Reply

Cart

Products

  • When Your Child Can't Or Won't Eat
    Rated 1.00 out of 5
    $10.00

Recent Posts

  • Happy New Year 2023!
  • Baby-Led Bottle Feeding – Free Ebook Promotion for 4 Days
  • UNC Feeding Team presents:  Avoiding Mealtime Stress in Pediatric Feeding Disorders:  Interdisciplinary Approaches to Address Food Selectivity, Oral Aversion and Food Refusal
  • A Formula Shortage How Policy, Societal Pressure Impact Babies & Parents
  • Feeding Research: Looking for Parents of 6-12 month olds

Recent Comments

  • Sue Marolf on Feeding Flock – Feeding Assessment Tools
  • Kelsey on Hypersensitive Gag Reflex and Pediatric Feeding Delays By Donna Scarborough Ph.D., CCC-SLP, BCS-S Miami University, Oxford, OH scarbod@muohio.edu
  • Elaine Egbert on Aversive Feeding Behavior: Getting full mouth opening for the spoon and why it’s worth the trouble
  • Krisi Brackett on Feeding Flock – Feeding Assessment Tools
  • prabha on Feeding Flock – Feeding Assessment Tools

search

Categories

Archives

My Account | Shop | Shopping Cart
Copyright ©2023, Pediatric Feeding News. All Rights Reserved. Custom design by Pixel Me Designs
 

Loading Comments...