Growth Screening Flag Checker

Introduction

Healthy growth is judged by pattern, not by a single dot on a chart. A child's height, weight, or body mass index can sit inside a familiar percentile band while the visit history shows a new slowdown, a sharp change from the child's previous channel, or a weight pattern that deserves another look.

Pediatric growth screening compares measurements with children of the same sex and similar age. Percentiles make that comparison easier to read, but they can also hide important context. A child near the 10th percentile may be growing normally for their family and history, while a child who falls from a much higher channel may need review even before crossing a very low cutoff.

Several details change the meaning of a growth visit. Infants and toddlers are commonly read with weight-for-length before body mass index becomes the usual adiposity measure. Preterm children may need corrected age during early follow-up. Parent heights can make a short stature pattern less surprising, or make it more concerning when the child's projected height sits well below the family range. Measurement quality matters too, because a small height error across a short interval can create a false height velocity warning.

Four questions usually decide whether a visit series needs attention:

• Is the latest height or weight unusually low or high for the child's age and sex?
• Has the child's percentile position fallen enough to cross major growth channels?
• Is recent height velocity slower than expected for the age range and visit spacing?
• Do corrected age, adiposity measure, or family height change how the pattern should be read?

Screening flags are not diagnoses. They are prompts to verify the measurements, review the visit timeline, and decide whether routine surveillance, near-term reassessment, or professional clinical review is appropriate.

How to Use This Tool:

Enter a chronological visit series first, then refine the reference and follow-up settings only when the default assumptions do not match the child or program.

1. Set Sex to the same sex used for the growth chart series. The comparison curves, adiposity routing, and family-height context all depend on this choice.
2. Paste at least two rows into Visit data rows as age_months,height_cm,weight_kg. Keep one visit per line. If the tool reports an invalid row or says it needs at least two rows, check for missing commas, nonnumeric text, or a row with fewer than three values.
3. Choose Risk tolerance, Guidance follow-up interval, Intervention urgency, and Catch-up priority for the guidance wording and timing. These settings help shape the recommendation rows after the growth checks are calculated.
4. Open Advanced when you need to change Reference policy, Gestational age at birth, or Corrected-age window. Auto routing uses a WHO-style lens under 24 months and a CDC-style lens from 24 months onward.
5. Add Mother height and Father height when family-height context is useful. Set Parent height unit first, then choose the Family target band that should count as an acceptable range around the mid-parental target.
6. Adjust the alert thresholds only when you have a program reason to do so. Band crossing alert, Percentile-shift alert, High adiposity alert, Adiposity persistence, Height velocity guardrail, and Velocity persistence control when critical or watch findings appear.
7. Read the summary and Flag Ledger first. Use Visit Audit to check each visit, Alert Ladder to see the triage counts, and the Growth Flag Map or Height Velocity Guardrail charts when a visual check helps explain the pattern.

For a first pass, leave the reference and threshold settings at their defaults, paste a clean visit series, and focus on the Overall screening status, Top signal, and Verify items rows before changing sensitivity.

Interpreting Results:

The most important fields are Screening lane, Top signal, Critical flags, Watch flags, Verify items, Triage score, and Suggested follow-up interval. Treat them as a triage summary, then inspect the Flag Ledger evidence before deciding what to do next.

A high Triage score means the visit series has more reasons for review. It does not identify a cause. A low score does not prove that growth is normal if the source data are wrong, puberty timing is unusual, symptoms are present, or a clinician has other concerns.

Technical Details:

Growth screening combines attained size with change over time. Attained size compares the current measurement with an age- and sex-specific reference. Change over time compares the child's own earlier visits with the latest visit. The tool uses built-in reference anchors and adjustment rules to create a practical screening estimate, so exact values can differ from official CDC or WHO chart software.

Age routing is central. Under 24 months of screening age, adiposity is read as weight-for-length. From 24 months onward, adiposity is read as BMI-for-age. If gestational age is below 40 weeks and the visit falls inside the selected correction window, screening age is reduced before the percentile estimates and routing rules are applied.

Formula Core:

These equations show the main quantities used for BMI, reference comparison, corrected age, height velocity, family target height, and the composite triage score.

In the triage score, C is the number of critical flags, W is the number of watch flags, and Q is 1 when any verify item is present. Height velocity is annualized in cm/year, so short intervals need extra caution.

Rule Core:

Reference and Boundary Notes:

• Reference policy changes the screening lens. Auto routing uses WHO-style behavior before 24 months and CDC-style behavior afterward, while fixed WHO, fixed CDC, and hybrid modes keep one reference style across the series.
• Corrected age is only applied when prematurity is present and the visit is inside the selected correction window. Older visits return to chronological age.
• Adiposity routing uses weight-for-length before 24 months and BMI-for-age from 24 months onward, so the same weight and height can be described with different clinical language depending on age.
• Visit normalization keeps the latest row for duplicate ages, which prevents duplicate age entries from being counted twice but also creates a verify item.

Limitations and Privacy Notes:

This is an informational screening aid for growth-pattern review. It is not a diagnosis, treatment recommendation, or replacement for official chart plotting, clinical history, physical examination, or professional judgment.

• The built-in reference anchors are simplified screening estimates, not exact CDC or WHO LMS chart tables.
• Head circumference, pubertal stage, symptoms, medications, chronic illness, nutrition history, and measurement technique are outside the calculation.
• The calculation works from numeric rows in the browser. Do not enter names, record numbers, addresses, or notes that are not needed for the row format.
• Copied results, downloaded files, charts, and shared page data can contain the measurements you entered, so handle them as health-related information.

Worked Examples:

FAQ:

Glossary:

Percentile

A same-age, same-sex ranking that shows where a measurement sits compared with a reference group.

z-score

A standard-deviation score showing how far the observed value is from the reference median.

Corrected age

Chronological age reduced by weeks born before 40 weeks of gestation, used only inside the selected correction window.

Height velocity

The annualized rate of height gain between two visits, expressed in cm/year.

Weight-for-length

An infant and toddler adiposity comparison that relates weight to length before BMI-for-age is used.

BMI-for-age

Body mass index interpreted against age- and sex-specific child reference percentiles.

Mid-parental target

A family-height estimate calculated from mother and father heights with a sex-specific adjustment.

Triage score

A weighted summary where critical flags count most, watch flags count next, and any verify item adds one point.

References:

• Use and Interpretation of the WHO and CDC Growth Charts for Children from Birth to 20 Years in the United States, Centers for Disease Control and Prevention, May 2013.
• CDC Growth Charts, Centers for Disease Control and Prevention, last reviewed September 2, 2024.
• Child and Teen BMI Categories, Centers for Disease Control and Prevention, June 28, 2024.
• Child Growth Standards, World Health Organization, 12 February 2025.