Applicability of commonly used Caucasian and Multi ethnic

Applicability of commonly used Caucasian and Multi ‐ethnic reference prediction equations for spirometry interpretation in Tunisian adult’s population Ben Saad H, Maatoug C, Thabet H, Amimi S, Rouatbi S, Hadj Mabrouk K Groupement du Médecine du Travail du Gouvernorat de Sousse INTRODUCTION The applicability of Caucasian prediction equations described by the European Community for Coal and Steel (ECCS 1983) [1] and currently used in Tunisia, or the recent Multi‐ethnic reference values derived by the Global Lungs Initiative (GLI 2012) [2] in interpreting spirometry data in Tunisian subjects has not been studied. AIMS To evaluate if Caucasian, Multi-ethnic and Tunisian prediction equations can be used interchangeably while interpreting routine spirometric data. POPULATION AND METHODS Population: 38 Tunisian adults: 19 healthy lifelong non-smokers (8 ♂/11 ♀) and 19 smokers (12 ♂/7 ♀) Spirometry measurements: done according recent international guidelines (ATS/ERS 2005). Applied spirometric reference equations: Tunisian reference equations [Tunisia 1995] [3], ECCS 1983 [1], GLI 2012 [2]. Measured/calculated spirometric data: predicted values and lower limit of normal (LLN), according each reference equations, for the following spirometric parameters: 1 st forced expiratory volume (FEV 1), forced vital capacity (FVC), FEV 1/FVC ratio, maximum mid expiratory flow (MMEF) and expiratory flow when 75% of FVC has been exhaled (FEF 75%). Applied definition: large airway obstructive ventilatory defect (AOVD): FEV 1/FVC < LLN. Small AOVD: FVC > LLN and MMEF < LLN. Tendency through a restrictive ventilatory defect (TRVD): FEV 1 and FVC < LLN and FEV 1/FVC> LLN. The spirometric profile of each subject was determined according the three reference equations [1 -3]. Statistical analysis: A non parametric test was applied to compare the measured/calculated spirometric data expressed as a percentage of predicted values (%pred) and the LLN calculated from the 3 reference equations [1 -3]. CONCLUSION The use of Caucasian or Multhi-ethnic prediction equations resulted in misinterpretation of spirometry data in a significant proportion of subjects. REFERENCES 1. Quanjer Ph. H (ed. ). Standardized lung function testing. Bull Europ Physiopathol Respir 1983; 19 (supll 5): 195. 2. Quanjer PH et al. Multi-ethnic reference values for spirometry for the 3 -95 year age range. Report of the Global Lungs Initiative, ERS t. Task force to establish improved lung function reference values. ERJ Express. Published on June 27, 2012 as doi: 10. 1183/09031936. 00080312. 3. . Tabka Z et al. Spirometric reference values in a Tunisian population. Tunis Med. 1995; 73: 125 -31. RESULTS