WHO height charts can be safely substituted when calculating BP Z-scores in a North American clinic setting

The Public Health Agency of Canada has officially adopted growth charts from the World Health Organization (WHO); nevertheless, North American blood pressure (BP) Z-scores and percentiles still depend on height Z-scores based on growth charts from the US Centers for Disease Control (CDC), which may differ significantly, particularly in toddlers. Since many practitioners simply replace CDC height scores with WHO equivalents for diagnosing hypertension, we explore the impact of this substitution on BP Z-scores in real-world BPs measured on more than 22,000 children aged 2 to 18 years.