Derivation and validation of age and temperature specific reference values and centile charts to predict lower

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Published on: August 7, 2017

R G Nijman1, M Thompson, M van Veen

  • 1Department of General Paediatrics, Erasmus MC-Sophia Children's Hospital, 3015 GJ Rotterdam, Netherlands.

BMJ (Clinical Research Ed.)
|July 5, 2012
PubMed

Insights

New reference values for respiratory rate in febrile children were developed using age and temperature-dependent centile charts. These charts improve the detection of lower respiratory tract infections (LRTI) compared to existing thresholds.

Area of Science:

  • Pediatric Medicine
  • Respiratory Physiology
  • Infectious Diseases

Background:

  • Accurate respiratory rate assessment is crucial for diagnosing lower respiratory tract infections (LRTI) in children.
  • Existing respiratory rate thresholds lack precision in identifying LRTI in febrile children.
  • Age and body temperature significantly influence respiratory rate, necessitating context-specific reference values.

Purpose of the Study:

  • To establish age- and temperature-dependent reference values and centile charts for respiratory rate in children.
  • To evaluate the predictive accuracy of these new reference values for identifying LRTI in febrile children.
  • To compare the diagnostic performance of new thresholds against existing guidelines.

Main Methods:

  • A prospective observational study involving febrile children aged 1 month to 16 years.
  • Development of respiratory rate centile charts (50th, 75th, 90th, 97th) using a derivation population (n=1555).
  • Validation of diagnostic performance using a separate validation population (n=671) and multivariable regression analysis.

Main Results:

  • Respiratory rate increased by 2.2 breaths/min per 1°C rise, independent of age.
  • The 97th centile cut-off values demonstrated higher specificity (0.94) and positive likelihood ratio (3.66) for LRTI detection.
  • New centile cut-offs outperformed existing thresholds (e.g., Advanced Pediatrics Life Support) but could not differentiate between pneumonic and non-pneumonic LRTI.

Conclusions:

  • Age- and temperature-dependent centile charts provide novel reference values for respiratory rate in febrile children.
  • The 97th centile cut-off values are more effective in detecting the presence of LRTI than current respiratory rate thresholds.
  • These findings support the use of new reference values for improved LRTI diagnosis in pediatric emergency settings.
Abstract

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