2014 WHO Growth Charts for Canada (Set 2): Boys 2-19 years
In September 2014, the Public Health Agency of Canada and their Collaborative Committee on national growth charts released a revised set of 'WHO Growth Charts Adapted for Canada' (Set 2) intended to address concerns raised by chart users. Weight-for-age reference curves were extended to ages 10-19y based on re-analysis by the Canadian Pediatric Endocrine Group (CPEG) of the 'core data' from the US National Center for Health Statistics, collected by NCHS from 1963-1975 and used by the WHO to develop their 2007 reference curves. In addition, granularity was added in the normal range (-2 to +2 SD) through restoration of the 7 centiles familiar to long-time CDC chart users, important in the application of conventional diagnostic criteria for failure to thrive, hypertension, and FASD. Potentially misleading extreme centiles were also dropped or de-emphasized, consistent with the published CPEG re-analysis.
For optimal viewing, you may wish to widen the browser window so that you can see each data entry line separately, with two adjacent plots. An HTML5 compliant browser is required to use this plotter, which takes advantage of the HTLM5 canvas graphics i.e. No Internet Explorer
Set 2 Charts (released by PHAC in September, 2014)
Enter date of birth: In Safari and Firefox, dates are entered as yyyy/mm/dd e.g. 2000/01/15. Chrome also uses a slightly different date format (yyyy-mm-dd e.g. 2000-01-15).
Enter date of visit using the same date format
Enter height in centimeters (cm)
Enter weight in kilograms (kg)
Click "Plot Visit", the button to the right of the data entry fields.
To plot height, weight, and body mass index (BMI), you will need to provide some data, including date of birth, date of visit (when the measurements were taken), height, and weight. To respect patient privacy laws, none of these data are shared with the server hosting this application, and all calculations are done locally in your browser.
Date of birth: In Safari and Firefox, dates are entered as yyyy/mm/dd e.g. 2000/01/15 for January 1, 2000. In some browsers (e.g. Chrome), a calendar date picker may also be used. Chrome also uses a slightly different date format (yyyy-mm-dd e.g. 2000-01-15 for January 1 2000), which will be specified in the data entry field.
Date of visit: Using the same date format, this refers to the date on which the measurements were actually made.
Height should be entered in centimeters (cm) and weight in kilograms (kg).
Once you have entered these data, click on "Plot Visit", the button to the right of the data entry fields.
Clicking on this button instructs your browser to calculate the following results, which appear to the right of the data entry fields:
Body mass index Z-score
In addition, height, weight, and body mass index are plotted on the 2014 WHO growth charts for Canada. Several additional buttons allow you to further modify or save these plots.
Toggle Size: Prepares large, high resolution versions of the height-weight and BMI charts for viewing. The Save/Get button (below) allows you to save these images to your local hard drive.
Clear Plot: Clears the plots, but retains the data you've entered
Plot All: Re-plots all of the data you've entered
Plot Options: Brings up a panel of options that allow you to change the color and size of the plot symbol. After changing the symbol, you can re-plot all visits by clicking the "Plot All" button or revise a single visit clicking the adjacent "Plot Visit" button.
Color: Select a different color for the plot symbol.
Radius: Select a different size for the plot symbol.
Hide options: Hide this panel again.
Reset: Erases both the plots and all data you've entered.
Save/Get: Brings up a panel of options for saving plots and data (for subsequent re-use).
Save Data: Current HTML5 security standards prohibit web browsers from saving data to your local hard drive. To respect these 'best practices' while still allowing you to revisit your work, this button will save the data to your local browser cache, a secure area where browsers are allowed to store 'cookies'. This allows you to temporarily save all the data you've entered in the secure browser cache, where it will remain until the cache is emptied (typically once a year unless you've changed your browser defaults. These defaults can be revised at any time by visiting your browser preferences). You will be given the opportunity to specify a name for the data file e.g. the hospital chart number, etc. Again, these data are not shared with the server hosting the application and are accessible only to the browser used to create the cookie in the first place.
Get Data: This will cause another panel to appear. From the drop-down list on the right, choose a data file previously saved to the local browser cache. The "Retrieve" button will allow you to retrieve these data (re-plotting them in the process). The "Delete" button can be used to delete this particular cookie, and "Hide" button will conceal the panel again.
Save Plot 1 and Save Plot 2: These buttons produce high resolution, publication quality JPEG images of the height/weight-for-age (Plot 1) or the BMI-for-age charts (Plot 2). These can be saved on your own hard drive, where they can be viewed, edited, printed or added to a presentation in applications like Word or PowerPoint. For security reasons, web browsers are not allowed to save images to your hard drive without permission. So when you click this button, you will be given instructions on how to save the JPEG file for future use (right-click and save).
Sponsored by Canadian Paediatric Endocrine Group Working Committee for National Growth Charts
Celia Rodd MD MSc, Winnipeg Children's Hospital
Daniel L. Metzger MD, BC Children’s Hospital
Elizabeth Cummings MD, IWK Health Centre
Jean-Pierre Chanoine MD, BC Children’s Hospital
Sarah Lawrence MD, Children’s Hospital of Eastern Ontario
Mark Palmert MD PhD, Hospital for Sick Children
Atul Sharma MD MSc, Biostatistical Consulting Unit, University of Manitoba
OBJECTIVES: To promote body mass index in older children, weight-for-age is omitted after age 10y in the new WHO reference charts for ages 5–19y, which are based on ‘core data’ from the US National Center for Health Statistics (NCHS). Canadian health providers have expressed concerns about this omission and the selection of centiles. We therefore sought to extend weight-for-age reference curves from 10 to 19y by applying WHO exclusion criteria and curve fitting methods to NCHS data and to revise the choice of displayed centiles.
METHODS: Based on WHO exclusion criteria, 314 girls and 304 boys were omitted for ‘unhealthy’ weights-for-height. By applying WHO global deviance and information criteria, optimal Box-Cox power exponential models were used to fit smoothed weight-for-age centiles. Bootstrap resampling was used to assess the precision of centile estimates. For all charts, additional centiles in the healthy range were included, and centiles 3 and 97% were substituted for the more extreme WHO 0.1 and 99.9%.
RESULTS: In addition to weight-for-age beyond 10y, our charts provide more granularity in the centiles in the healthy range –2 to +2 SD (3-97%). For both weight and BMI, the bootstrap confidence intervals for the 99.9th centile were at least an order of magnitude wider than the corresponding 50th centile values.
CONCLUSIONS: These charts complement existing WHO charts by allowing weight-for-age to be plotted concurrently with height in older children. The additional centiles permit a more precise assessment of normal growth and earlier detection of aberrant growth as it crosses centiles.