Variability in Peak Expiratory Flow Does Not Classify Asthma According to Severity

Pérez-Yarza, Eduardo G.; Cobos, Nicolás; de la Cruz, Juan José

doi:10.1016/S1579-2129(07)60124-4

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Abstract

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Objective

The aim of this study was to determine whether variability in peak expiratory flow (PEF) could be used to classify the level of severity of asthma in children.

PATIENTS AND METHODS

We studied 387 boys and girls diagnosed with asthma and classified severity according to clinical criteria (Spanish Society of Pediatric Pneumology). PEF variability was determined using a portable mini- Wright peak flow meter (Clement Clarke International, London, UK; range, 50 L/min–800 L/min) over a 14-day period, with no changes in normal treatment. The following indices were used to calculate PEF variability: 1) difference between morning PEF and nighttime PEF, expressed as a percentage of the mean value of the PEF measurements taken on that day; 2) minimum PEF rate during a week, expressed as a percentage of the highest value recorded during that week; 3) difference between the highest and the lowest PEF values, expressed as a percentage of the highest value; and 4) the 10th percentile of PEF values recorded during a week, expressed as a percentage of the highest value recorded during that week. We assessed agreement between clinical classification and PEF variability using the weighted [.kappa] coefficient. We also analyzed the sensitivity and specificity of PEF variability indices for episodic and persistent asthma.

RESULTS

The analysis of levels of agreement between clinical classification of asthma and formulas 1, 2, 3, and 4 gave quadratic weighted κ coefficients of 0.494, 0, 0.488, and 0.346, respectively. The results were similar when patients were grouped and analyzed by type of asthma (episodic or persistent asthma).

CONCLUSIONS

The monitoring of PEF variability, a recommendation common in national and international guidelines on the management of asthma in children, is not valid for classifying severity of asthma in children.

Key words:

Asthma

Classification

Severity

Peak expiratory flow

Variability

Children

Objetivo

El objetivo de este estudio ha sido estudiar si la variabilidad del flujo espiratorio máximo (FEM) permite clasificar el asma en niños por niveles de gravedad.

PACIENTES Y MÉTODOS

Se ha estudiado a 387 niños y niñas diagnosticados de asma, cuya gravedad se clasificó atendiendo a criterios clínicos (Sociedad Española de Neumología Pediátrica). Se determinó la variabilidad del FEM con un medidor portátil (Mini Wright Peak Flow Meter Clement, Clarke International Ltd., Londres, Reino Unido; escala 50-800 l/min) en los 14 días siguientes, sin modificar los tratamientos habituales, según los índices de variabilidad del FEM: 1) diferencia entre el FEM de la mañana y el de la noche, expresado como porcentaje del valor medio de las medidas del FEM durante el día; 2) mínimo valor del FEM durante una semana, expresado como porcentaje del mejor FEM durante esa semana; 3) diferencia del mejor sobre el peor FEM, como porcentaje sobre el mejor, y 4) percentil 10 de los valores del FEM durante una semana, expresado como porcentaje del mejor FEM durante esa semana. Se analizó el grado de acuerdo entre la clasificación clínica y la variabilidad del FEM mediante el estudio de la concordancia (índice kappa ponderado). También se efectuó un análisis de sensibilidad y especificidad para el asma episódica y el asma persistente en relación con la variabilidad del FEM.

RESULTADOS

Los niveles de acuerdo entre la clasificación clínica del asma y las fórmulas 1, 2, 3 y 4 mostraron índices kappa ponderados bicuadrados de 0,494, 0, 0,488 y 0,346, respectivamente. Los resultados fueron similares cuando los pacientes se agruparon en asma episódica y asma persistente.

CONCLUSIONES

La medida de la variabilidad del FEM, recomendación común de las guías nacionales e internacionales para el manejo del asma en niños, no es válida para clasificar el asma en niños por niveles de gravedad.

Palabras clave:

Asma

Clasificación

Gravedad

Flujo espiratorio máximo

Variabilidad

Niños

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REFERENCES

[1]

National Asthma Education and Prevention Program. Expert Panel Report. Guidelines for the Diagnosis and Management of Asthma. National Institutes of Health. National Heart, Lung and Blood Institute. Update on selected topics 2002. NIH Publication n.º 025074, 2003. Available from: http:/www. nhlbi.nih.gov/guidelines/asthma/ index.htm. Accessed September19, 2006

[2]

J Sirvent Gómez, E González Pérez-Yarza.

Fisiopatología, diagnóstico y evaluación del paciente asmático.

Tratado de Neumología Infantil, pp. 577-598

[3]

Grupo de Respiratorio de Atención Primaria, Sociedad Española de Medicina Rural y Generalista, Sociedad Española de Neumología y Cirugía Torácica, Sociedad Española de Neumología Pediátrica y Associació Asmatológica Catalana. Guía Española para el Manejo del Asma (GEMA).Available from: www.gemesama.com. Accessed September19, 2006

[4]

National Heart, Lung, and Blood Institute, National Institutes of Health. International consensus report on diagnosis and treatment of asthma. Bethesda: NHLBI/NIH; 1992 [publication 92-3091].

[5]

National Asthma Education and Preventing Program. Expert Panel Report. Guidelines for the diagnosis and management of asthma. National Institutes of Health. National Heart, Lung and Blood Institute. NIH Publication No. 97-4051, 1997. Available from: http:/www.nhlbi.nih.gov/guidelines/asthma/index.htm. Accessed September 19, 2006.

[6]

Global Initiative for asthma. Global strategy for asthma management and prevention. NHLBI/WHO Workshop Report. Bethesda: National Heart, Lung and Blood Institute. National Institutes of Health; 2005. Available from: http:/www.ginasthma.org. Accessed September 19, 2006.

[7]

The British Thoracic Society and the Scottish Intercollegiate Guidelines Network. British guideline on the management of asthma. A national clinical guideline, 2005. Available from: http:/www.sing.ac.uk/ guideline/fulltext/63/index.html. Accessed September 19, 2006.

[8]

RM Busquets Monge, A Escribano Montaner, M Fernández Benitez, L García-Marcos, J Garde Garde, M Ibero Iborra, et al.

Consenso sobre tratamiento del asma en Pediatría.

An Pediatr (Barc), 64 (2006), pp. 365-378

[9]

M Merino, J Aranguren, M Callén, J Elorz, A Etxeberría, JB Galdiz, et al.

Guía de práctica clínica sobre asma (1.ª parte).

An Pediatr (Barc), 64 (2006), pp. 557-572

[10]

M Merino, J Aranguren, M Callén, J Elorz, A Etxeberría, JB Galdiz, et al.

Guía de práctica clínica sobre asma (2.ª parte).

An Pediatr (Barc), 65 (2006), pp. 51-66

[11]

Global Strategy for Asthma Management and Prevention. Revised 2006. Available from: http:/www.ginasthma.org. Accessed November 30, 2006.

[12]

B Higgins, JR Britton, S Chinn, TD Jones, D Jenkinson, PG Buerney, et al.

The distribution of peak expiratory flow variability in a population sample.

Am Rev Respir Dis, 140 (1989), pp. 1368-1372

http://dx.doi.org/10.1164/ajrccm/140.5.1368 | Medline

[13]

JE Gern, PA Eggleston, KC Schuberth, ND Eney, EO Goldstein, ME Weiss, et al.

Peak flow variation in childhood asthma: a three year analysis.

J Allergy Clin Immunol, 93 (1994), pp. 706-716

Medline

[14]

HC Siersted, HS Hansen, NCG Hansen, N Hyldebrandt, G Mostgaard, H Oxhoy.

Evaluation of peak expiratory flow variability in an adolescent population sample: the Odense schoolchild study.

Am J Respir Crit Care Med, 149 (1994), pp. 598-603

http://dx.doi.org/10.1164/ajrccm.149.3.8118624 | Medline

[15]

HK Reddel, CM Salome, JK Peat, AJ Woolcock.

Which index of peak expiratory flow is most useful in the management of stable asthma?.

Am J Respir Crit Care Med, 151 (1995), pp. 1320-1325

http://dx.doi.org/10.1164/ajrccm.151.5.7735580 | Medline

[16]

JL Fleiss.

Statistical methods for rates and proportions, 2nd ed., pp. 38-48

[17]

G Polgar, V Promadhat.

Pulmonary function testing in children: techniques and standards, Saunders, (1971),

[18]

Standardisation of Spirometry.

ATS/ERS Task Force: standardisation of lung function testing.

Eur Respir J, 26 (2005), pp. 319-338

http://dx.doi.org/10.1183/09031936.05.00034805 | Medline

[19]

PH Quanjer, GJ Borsboom, B Brunekreff, M Zach, G Forche, JE Cotes, et al.

Spirometric reference values for white European children and adolescents: Polgar revisited.

Pediatr Pulmonol, 19 (1995), pp. 135-142

Medline

[20]

DG Altman.

Practical statistics for medical research, Chapman and Hall, (1991),

[21]

TCJ Li.

Home peak expiratory flow rate monitoring in patients with asthma.

Mayo Clin Proc, 70 (1995), pp. 649-656

http://dx.doi.org/10.1016/S0025-6196(11)63916-5 | Medline

[22]

T Frischer, R Meinert, R Urbanek, J Kuehr.

Variability of peak expiratory flow rate in children: short and long term reproducibility.

Thorax, 50 (1995), pp. 35-39

Medline

[23]

LP Malmberg, K Nikander, AS Pelkonen, P Syvänen, T Koljonen, T Haahtela, et al.

Acceptability, reproducibility, and sensitivity of forced expiratory volumes and peak expiratory flow during bronchial challenge testing in asthmatic children.

Chest, 120 (2001), pp. 1843-1849

Medline

[24]

AC Ferguson.

Persisting airway obstruction in asymptomatic children with asthma with normal peak expiratory flow rates.

J Allergy Clin Immunol, 82 (1988), pp. 19-22

Medline

[25]

PD Sly, P Cahill, K Willet, P Burton.

Accuracy of mini peak flow meters in indicating changes in lung function in children with asthma.

BMJ, 308 (1994), pp. 572-574

Medline

[26]

N Eid, B Yandell, L Howell, M Heddy, S Sheikh.

Can peak expiratory flow predict airflow obstruction in children with asthma?.

Pediatrics, 105 (2000), pp. 354-358

Article | Medline

[27]

JB Clough, JD Williams, ST Holgate.

Effect of atopy on the natural history of symptoms, peak expiratory flow, and bronchial responsiveness in 7 and 8 year old children with cough and wheeze.

Am Rev Respir Dis, 143 (1991), pp. 755-760

http://dx.doi.org/10.1164/ajrccm/143.4_Pt_1.755 | Medline

[28]

EEM van Essen-Zandvliet, MD Hugues, HJ Waalkens, EG Duiverman, SJ Pocock, KF Kerrebijn.

Effects of 22 months of treatment with inhaled corticosteroids and/or beta-2-agonists on lung function, airway responsiveness, and symptoms in children with asthma. The Dutch Chronic Non-specific Lung Disease Study Group.

Am Rev Respir Dis, 148 (1993), pp. 818-893

http://dx.doi.org/10.1164/ajrccm/148.3.818 | Medline

[29]

HAM Kerstjens, PLP Brnad, PM de Jong, GH Köeter, DS Postma, Dutch CNSLD Study Group.

Influence of treatment on peak expiratory flow and its relation to airway hyperresponsiveness and symptoms.

Thorax, 49 (1994), pp. 1109-1115

Medline

[30]

G Ryan, KM Latimer, J Dolovich, FE Hargreave.

Bronchial responsiveness to histamine: relationship to diurnal variation of peak flow rate, improvement after bronchodilator, and airway calibre.

Thorax, 37 (1982), pp. 423-429

Medline

[31]

WR Douma, HAM Kerstjens, CM Roos, GH Koëter, DS Postma, Dutch Chronic Non-specific Lung Disease study group.

Changes in peak expiratory flow indices as a proxy for changes in bronchial hyperresponsiveness.

Eur Respir J, 16 (2000), pp. 220-225

Medline

[32]

JJ den Otter, GMW Reijnen, WJHM van den Bosch, CP van Schayck, J Molema, C van Weel.

Testing bronchial hyper-responsiveness: provocation or peak expiratory flow variability?.

Br J Gen Pract, 47 (1997), pp. 487-492

Medline

[33]

MF Goldstein, BA Veza, EH Dunsky, DJ Dvorin, GA Belecanech, IC Haralabatos.

Comparisons of peak diurnal expiratory flow variation, postbronchodilator FEV1 responses, and methacholine inhalation challenges in the evaluation of suspected asthma.

Chest, 119 (2001), pp. 1001-1010

Medline

[34]

PLP Brand, EJ Duiverman, DS Postma, HJ Waalkens, KF Kerrebijn, EEM van Essen-Zandvliet, et al.

Peak flow variation in childhood asthma: relationship to symptoms, atopy, airways obstruction and hyperresponsiveness.

Eur Respir J, 10 (1997), pp. 1242-1247

Medline

[35]

G Sawyer, J Miles, S Lewis, P Fitzharris, N Pearce, R Beasley.

Classification of asthma severity: should the international guidelines be changed?.

Clin Exp Allergy, 28 (1998), pp. 1565-1570

Medline

[36]

MH Vargas, HH Ruiz-Gutiérrez, C Espinosa-Serafín, G Zuñiga-Vázquez, ME Furuya.

Underestimation of the peak flow variability in asthmatic children: evaluation of a new formula.

Pediatr Pulmonol, 39 (2005), pp. 325-331

http://dx.doi.org/10.1002/ppul.20196 | Medline

[37]

AL Fuhlbrigge, ST Weiss, KM Kuntz, AD Paltiel, for the CAMP Research Group.

Pediatrics, 118 (2006), pp. 247-355

[38]

LB Bacharier, RC Strunk, D Mauger, D White, RF Lemanske Jr, CA Sorkness.

Classifying asthma severity in children.

Am J Respir Crit Care Med, 170 (2004), pp. 426-432

http://dx.doi.org/10.1164/rccm.200308-1178OC | Medline

[39]

PLP Brand, RJ Roorda.

Usefulness of monitoring lung function in asthma.

Arch Dis Child, 88 (2003), pp. 1021-1025

Medline

This study was partially funded by a GlaxoSmithKline (GSK) Spain research grant to the Asthma Working Group of the Spanish Society of Pediatric Pneumology (SENP). GSK Spain did not participate in the design of the study, data analysis, results, or conclusions. The data are the property of the Asthma Working Group of the SENP.

*

The researchers who participated in this study are listed at the end of the article.

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