What constitutes an obstructive ventilatory impairment in a pediatric population? A study design.

There is no clear consensus as to what constitutes an obstructive ventilatory impairment (OVI) in pediatric populations. To determine the percentage of children/adolescents having an OVI among those addressed for spirometry after taking into account the definitions advanced by some international scholarly societies [British Columbia (BC), British thoracic-society (BTS), Canadian thoracic society (CTS), European respiratory society and American thoracic society (ERS-ATS), global initiative for asthma (GINA), Irish college of general practitioners (ICGP), national asthma council (NAC), national institute of clinical excellence (NICE), Société de pneumologie de langue française, Société pédiatrique de pneumologie et allergologie (SPLF-SP2A), and South African thoracic society (SATS)]. This bi-centric cross-sectional study involves two medical structures in Sousse/Tunisia, and will encompass children/adolescents aged 6-18 years. A medical questionnaire will be administered, clinical and anthropometric data will be collected, and the spirometric data will be measured by two spirometers. The following six definitions of OVI will be applied: i) GINA: Forced expiratory volume in 1 second (FEV1) < 80% and a FEV1/forced vital capacity (FVC) ≤ 0.90; ii) ICGP: FEV1/FVC < 0.70; iii) ERS-ATS or BTS or SATS or SPLF-SP2A or NAC: FEV1/FVC z-score < -1.645; iv) NICE: FEV1/FVC < 0.70 or FEV1/FVC z-score < -1.645; v) CTS: FEV1/FVC < 0.80 or a FEV1/FVC z-score < -1.645; and vi) ERS: "FEV1 z-score or FEV1/FVC z-score" < -1.645 or "FEV1 or FEV1/FVC" < 0.80. The percentage of children/adolescents having an OVI will significantly vary between the six definitions. The frequency of OVI in a pediatric population will depend on the definition chosen.