Assess Fetal, Newborn, and Child Growth with International Standards
- Package: gigs
- Version: 0.0.7
- Generated: 2024-05-16T17:17:08
- Author(s): Bartosz Jablonski ([email protected]), Simon Parker ([email protected]), Linda Vesel, Eric Ohuma ([email protected])
- Maintainer(s): Bartosz Jablonski ([email protected])
- License: GNU General Public License v3.0
- File SHA256:
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for this version - Content SHA256:
C*A3084D73E2B717E303A1F97AEE11E8D43E5C07738C2B0EB3C59BB741DB84B6FF
for this version
Produced as part of the Guidance for International Growth Standards (GIGS)
project at the London School of Hygiene & Tropical Medicine,
gigs
provides a single, simple interface for working with
the WHO Child Growth standards and outputs from the
INTERGROWTH-21st project. You will find functions for
converting from anthropometric measures (e.g. weight or length) to
z-scores and centiles, and the inverse. Also included are functions for
classifying newborn and infant growth according to literature-based
cut-offs.
gigs
is of use to anyone interested in fetal and child growth, including
child health researchers, policymakers, and clinicians. This package is best
suited to growth data where the gestational age (GA) of each child is known, as
the use of the growth standards included in gigs
is GA-dependent.
We recommend you check out the
available standards section to
see if your anthropometric measurements can be converted to z-scores/centiles by
gigs
. We recommend using gigs
to generate continuous or categorical
measures of fetal/newborn/child growth, which can then be used in downstream
analyses.
gigs
works with the SAS Packages Framework (SPF), so installing gigs
requires
that the SPF is installed. First, create a directory where the SPF and
packages will be stored. This can be at any directory you choose, for example:
D:\SAS_Packages
/home/myuser/myPackages
SPF is designed in such a way that this directory you've made must be refered
to by fileref packages
. In your SAS session (preferably at the beginning), you
should run the following code:
filename packages "/path/to/packages/directory";
Installing an SPF package, "in a nutshell", means copying SPFinit.sas
(from
packagename.zip
) file into the packages directory. This can be done
automatically or manually.
To install gigs
automatically, your SAS session must have access to the
internet.
The following code will install the SAS Packages Framework, gigs
,
and macroArray
(required for gigs
to work). You only need to execute
this code once:
filename packages "/path/to/packages/directory";
filename SPFinit url
"https://raw.githubusercontent.com/yabwon/SAS_PACKAGES/main/SPF/SPFinit.sas";
%include SPFinit;
%installPackage(SPFinit gigs macroArray)
filename SPFinit clear;
After running this code, check the log to see if the process was successful.
If your SAS session does not have access to the internet but you can copy
files manually to your packages directory, you can install gigs
like so:
Once downloaded, copy these files manually to your SAS packages directory.
To use gigs
in a new SAS session, you must enable the SAS Packages Framework, then
load gigs
with %loadPackage
:
filename packages "/path/to/packages/directory";
%include packages(SPFinit.sas);
%loadPackage(gigs)
The macroArray
package will be loaded automatically when gigs
is loaded.
If using gigs
often in your work, the most convenient/practical way to load gigs
is
to put those three lines of code in your autoexec.sas
file.
The SAS Packages Framework (SPF)
Location of the SAS Packages Repository
gigs
operates with anthropometric measurements, and can convert between these and
z-scores/centiles. Z-scores and centiles represent the location of a
measurement within a normal distribution of values, such that:
- A z-score is the number of standard deviations from the mean for a given anthropometric measurement (e.g. height or weight).
- A centile represents the proportion of measurements in some distribution
which we would expect to be lower than a measurement we've taken. In
gigs
, these are represented as a value between0
and1
. For example,0.5
corresponds to the 50th centile (i.e. the mean), whereas0.75
corresponds to the 75th centile.
In growth data, z-scores and centiles represent the size a fetus, newborn, or child relative to its peers. Its size is considered relative to some standardising variable, which is usually age but could also be another variable such as their length. By tracking a child's relative size as they grow, you can see if they are achieving their growth potential or not. If not, this may indicate underlying issues such as ill health or undernutrition.
gigs
facilitates the proper use of international growth standards, which
are growth charts developed using international samples of healthy singleton
children born to mothers that had their health needs met during pregnancy.
They represent an international standard of 'optimal' growth. gigs
implements
international growth standards from the WHO and INTERGROWTH-21st
project:
-
ig_nbs
- INTERGROWTH-21st Newborn Size standards (including very preterm)Component standards
Acronym Description Unit gest_days
rangewfga
weight-for-GA kg 168 to 300 days lfga
length-for-GA cm 168 to 300 days hcfga
head circumference-for-GA cm 168 to 300 days wlrfga
weight-to-length ratio-for-GA kg/cm 168 to 300 days ffmfga
fat-free mass-for-GA kg 266 to 294 days bfpfga
body fat percentage-for-GA % 266 to 294 days fmfga
fat mass-for-GA kg 266 to 294 days -
ig_png
- INTERGROWTH-21st Postnatal Growth of Preterm Infants standardsComponent standards
Acronym Description Unit x
rangewfa
weight-for-age kg 27 to ≤64 exact weeks lfa
length-for-age cm 27 to ≤64 exact weeks hcfa
head circumference-for-age cm 27 to ≤64 exact weeks wfl
weight-for-length kg 35 to 65 cm -
ig_fet
- INTERGROWTH-21st Fetal standardsComponent standards
Acronym Description Unit x
rangehcfga
head circumference-for-GA mm 98 to 280 days bpdfga
biparietal diameter-for-GA mm 98 to 280 days acfga
abdominal circumference-for-GA mm 98 to 280 days flfga
femur length-for-GA mm 98 to 280 days ofdfga
occipito-frontal diameter for-GA mm 98 to 280 days efwfga
estimated fetal weight-for-GA g 154 to 280 days sfhfga
symphisis-fundal height-for-GA mm 112 to 294 days crlfga
crown-rump length-for-GA mm 58 to 105 days gafcrl
GA-for-crown-rump length days 15 to 95 mm gwgfga
gestational weight gain-for-GA kg 98 to 280 days pifga
pulsatility index-for-GA 168 to 280 days rifga
resistance index-for-GA 168 to 280 days sdrfga
systolic/diastolic ratio-for-GA 168 to 280 days tcdfga
transcerebellar diameter-for-GA mm 98 to 280 days tcdfga
GA-for-transcerebellar diameter mm 98 to 280 days poffga
parietal-occipital fissure-for-GA mm 105 to 252 days sffga
Sylvian fissue-for-GA mm 105 to 252 days avfga
anterior horn of the lateral ventricle-for-GA mm 105 to 252 days pvfga
atrium of the posterior horn of the lateral ventricle-for-GA mm 105 to 252 days cmfga
cisterna magna-for-GA mm 105 to 252 days hefwfga
Hadlock estimated fetal weight-for-GA g 126 to 287 days -
who_gs
- WHO Child Growth Standards for term infantsComponent standards
Acronym Description Unit x
rangewfa
weight-for-age kg 0 to 1856 days bfa
BMI-for-age kg/m2 0 to 1856 days lhfa
length/height-for-age cm 0 to 1856 days hcfa
head circumference-for-age cm 0 to 1856 days wfl
weight-for-height kg 45 to 110 cm wfh
weight-for-length kg 65 to 120 cm acfa
arm circumference-for-age cm 91 to 1856 days ssfa
subscapular skinfold-for-age mm 91 to 1856 days tsfa
triceps skinfold-for-age mm 91 to 1856 days
Bill & Melinda Gates Foundation
Required SAS Components:
- Base SAS Software
Required SAS Packages:
- macroArray (1.2.6)
SAS package generated by SAS Package Framework, version 20240423