https://ogma.newcastle.edu.au/vital/access/ /manager/Index en-au 5 https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:17502 , FVC and FEF25-75% from 11654 white males and 11113 white females, aged 3-94 years, routinely tested in the pulmonary function laboratories of four tertiary hospitals. FEF75% was available in 8254 males and 7407 females. Predicted values and lower limits of normal, defined as the fifth percentile, were calculated for FEV1, FVC, FEV1/FVC ratio, FEF25-75% and FEF75% using prediction equations from the Global Lung Function Initiative. There was very little discordance in classifying test results. FEF25-75% and FEF75% were below the normal range in only 2.75% and 1.29% of cases, respectively, whereas FEV1, FVC and FEV1/FVC ratio were within normal limits. Airways obstruction went undetected by FEF25-75% in 2.9% of cases and by FEF75% in 12.3% of cases. Maximum mid-expiratory flow and flow towards the end of the forced expiratory manoeuvre do not contribute usefully to clinical decision making over and above information from FEV1, FVC and FEV1/FVC ratio.]]> Sat 24 Mar 2018 08:04:05 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:16918 1)/(forced) vital capacity ((F)VC) ratio below the fifth percentile and graded the severity of pulmonary function impairment using z-scores for FEV₁, which signify how many standard deviations a result is from the mean predicted value. Using the lower limit of normal for FEV₁/(F)VC and z-scores for FEV₁ of -2, -2.5, -3 and -4 to delineate severity grades of airflow limitation leads to close agreement with ATS/ERS severity classifications and removes age, sex and height related bias. The new classification system is simple, easily memorised and clinically valid. It retains previously established associations with clinical outcomes and avoids biases due to the use of per cent predicted FEV₁. Combined with the Global Lung Function prediction equations it provides a worldwide diagnostic standard, free of bias due to age, height, sex and ethnic group.]]> Sat 24 Mar 2018 08:00:32 AEDT ]]>