What are the sensitivity and the specificity of pre and post shift changes in lung function in the diagnosis of occupational asthma?

The following references have been associated with this question by users of this website. They do not form part of the BOHRF occupational asthma guidelines.

burgeps	Park 2009	This paper shows that In workers with challenge positive occupational asthma the mean change across shift of pef is very small in workers on a day or morning shift. (about 5 litres/min) because the PEF usually increases after waking due to spontaneous diurnal variation. Using a cut off of 5 litres/min gives a sensitivity of 50% and a specificity of 91%. Using Oasys analysis of the same record an Oasys score >2.5 had a sensitivity of 83% and a specificity of 91%. The Area Between th Curves (ABC) score had a sensitivity of 67% and a specificity of 100%. There is clear benefit from 2-hourly PEF records over pre and post shift changes.
burgeps	BURGE 1979	FEV1 fell by more than 10% over a working shift in 33% of cases of occupational asthma and 5% of the similarly exposed asymptomatic controls