There is a vast literature of normal population studies, many of which have deficiencies in sample size, ethnicity, definition of normality, inclusion of smokers and choice of equipment. In the absence of population-specific reference values, measurements for patients of mainly European origin are better predicted by European values while those for patients of mainly British and Irish origin are better predicted by North American values.

The following tables provide mean predicted values for Caucasians of both sexes for FEV₁, FVC, FEV₁/FVC, FEF_25–75% and PEF. The tables are based on a large and well-conducted study in asymptomatic, lifelong non-smokers aged 8 to 80 years who participated in the National Health and Nutrition Examination Survey (NHANES III).^2,3 It is not recommended to extrapolate beyond the age and height range of the population used to obtain the reference equations.

Age is shown in years, height is shown in centimetres.

Respiratory function tables

From the National Asthma Council Australia. Asthma Management Handbook 2006. Melbourne: National Asthma Council Australia, 2006. Used with permission.

• Male
• Female
• Male children
• Female children

Content updated 28 March, 2008