Cardiovascular Disease

1. Prevalence of Hypertension in
Children:
Comparison Between Task Force
Recommendations and Average of Multiple
Measurements over 2 or 4 years

2. Authors
Kenneth F. Adams Emily D. Parker
Alan R. Sinaiko Louise C Greenspan
Joan C. Lo Karen L. Margolis
David J. Magid Nancy E. Sherwood
Elyse O. Kharbanda Nicole K. Schneider
Matthew F. Daley Patrick J. O’Connor
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3. Institutions
 HealthPartners
 Kaiser Permanente Colorado
 Kaiser Permanente Northern California
 University of Minnesota
 Funding: NHLBI 1R01HL093345-01
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4. Background: Childhood Hypertension
 Hypertension in adults is an asymptomatic
physiologic condition that predicts long term
adverse conditions
 Hypertension may also be a sign of current
pathologic conditions (e.g., kidney disease)
 Hypertension in children is associated with pre-
clinical cardiovascular disease in adulthood (carotid
intimal media thickness, left ventricular hypertrophy)
 Tracking: Elevated BP in childhood is a risk factor
for hypertension in adulthood
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5. Background: Childhood Hypertension
 NHBPEP 4th Working Group prescribed an approach
to assessing hypertension
 Gender, age, & height-specific BP percentiles based
on normative data collected from school studies
 Mimics adult hypertension guidelines
 Measurement should be repeated on separate
occasions (Stage 1)
 Various classifications
 Pre-HTN, Stage 1, Stage 2
 Providers should measure BP at all routine clinic visits
 Prospective orientation
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6. Background: Current clinical
environment
 Electronic medical records (EMR) allow provider to
track blood pressure over time
 Several years of retrospective data may be available
 Conversion from BP (as mm Hg) to age, gender, and
height-specific BP percentiles can be automated
 But interpretation of retrospective BP data may not be
straight-forward
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7. Methods
 Source population: Children and adolescents
(3-17 years); patient at one of 3 sites
 Analysis cohort is a subset of the source population
 Inclusion: Children having ≥ 3 BP measures (height
must be available)
 Exclusion: Pregnant at any time during follow-up
 Subjects are censored at time of HTN diagnosis or
claim for anti-HTN drug
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8. Results: Prevalence of hypertension
and other intermediate categories
By Working Group Classification Frequency
n %
HTN * 3,210 2.63
Pre-HTN and other intermediate categories † 36,285 29.63
Normal: All BP <90th % 82,832 67.74
Total 122,273 100.00
* Includes 3+ consecutive BP measures ≥ 95th % (Stage 1 HTN),
or 1+ BP measure >99th % + 5 mm Hg (Stage 2 HTN)
† Intermediate categories include BP 90th to 95th % (pre-HTN),
1-2 BP ≥ 95th %, or 3+ non-consecutively elevated BP measures
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9. Results: Cross-Tabulation of Working
Group Definitions with Avg BP ≥ 95th %
Average BP Percentile
Working Group Classification < 95th * ≥ 95th Total
n % % %
3+ consecutive BP measures ≥ 95th % 2,728 1.96 0.27 2.23
1+ BP measure >99th % + 5 mm Hg 477 0.29 0.10 0.39
Not hypertensive 119,068 97.20 0.18 97.38
Total 122,273 99.45 0.55 100.00
* cell percentages
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10. Results: Hypertension Prevalence By
Look-back Duration
HTN Prevalence Using 3 Definitions
Look-back Time Unique 3+ 1 or more Average
Period subjects consecutive BP >99th % BP ≥ 95th
BP ≥ 95th % + 5 mm Hg percentile
n % % %
Up to 4 years 122,273 2.63 1.00 0.55
Most recent 3 years 117,696 2.55 0.99 0.56
Most recent 2 years 98,648 2.45 0.97 0.58
Most recent 1 year 60,773 2.57 1.09 0.74
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11. Results: Hypertension Prevalence By
Number of BP Measures Available
HTN Prevalence Using 3 Definitions
Number of BP Unique 3+ 1 or more Average
Measures Available subjects consecutive BP >99th % BP ≥ 95th
BP ≥ 95th % + 5 mm Hg percentile
n % % %
3 41,139 1.28 0.18 0.92
4-5 39,648 1.63 0.28 0.49
≥6 41,486 3.75 0.72 0.24
Total 122,273 2.23 0.39 0.55
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12. Comments (1)
 These preliminary data show
 Prevalence of hypertension in overall pediatric
population is low by all 3 measures
 4th Working Group definitions have only limited
correspondence with hypertension defined by
average BP percentile ≥ 95th percentile
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13. Comments (2)
 These preliminary data show
 Duration of follow-up (1-4 years) is not related to
prevalence of any of the 3 BP measures
 Prevalence of Stage 1 and Stage 2 hypertension
increases with the number of BP measures available
 Prevalence of average BP≥ 95th percentile
decreases with number of BP measures available
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14. Comments (3)
 Potential significance
 Differences in subjects identified by the 3
hypertension definitions suggests lack of persistence
and indicates further research is needed
 Clinical usefulness of diagnosing hypertension in
pediatric patients using these criteria is unclear
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