What are the sensitivity and the specificity of a normal measurement of non-specific reactivity while at work 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 Labrecque 2004 1/2 workers with positive challenge had normal NSBR before and after challenge (but no very recent exposure before the challenge) An extract of pork mean illicited an immediate asthmatic reaction in one, the other had a positive workplace challenge
burgeps Hannu 2007 Sensitivity 71% against specific challenge
burgeps Beach 2007 Non-specific hyper-responsibeness sensitivity 79.3% (68-88) High MW;66.7% (58-74) Low MW. Specificity 51.3% (35-67) high MW, 63.9% (56-71) Low MW
burgeps Yacoub 2007 1/40 had normal methacholine reactivity (>16mg/ml at diagnosis)
burgeps Dufour 2009 The individual sults of NSBR e not given, but the mean methacholine Pc20 was 3.5 mg/ml (0.02-112) ffor low w allegens pre challenge and 2.7 mg/ml (0.04-128) or high mw agents The cchages post challege wwere sall (LMW 1.8 +/- 2.3, HMW 0.8 +/- 1.8). The changes following immediate reactions (were lower than those following late reations as expected) but only for high MW agents
burgeps Munoz 2004 sensitivity 75%, specificity 12.5%
burgeps Sauni 2010 Study of cobalt asthma in a refinery with cases defined by specific inhaltion challenge to cobalt dust. Normal NSBR in 5/22 (23%) at diagnosis
burgeps Malo 2011 This is an interesting paper, but all the analysis is retrospective and requires prospective validation. Although there was a relationship between sputum eosinophilia, NSBR and occupatiuonal asthma both together and separately, the negative combination is not enough to exclude occupational asthma (negative predictive value 58% when compared with non-occupational asthma. NSBR (methacholine >16mg/ml) normal in 35/129 challenge positive oa
burgeps Labrecque 2011 42% of the 22 with challenge positive OA had normal NSBR (interval from last exposure not stated)
burgeps Beretta 2017 Methacholine >16mg/ml in 13% of a predominantly high MW group
burgeps Engel 2019
burgeps Lipinska-Ojrzanowska 2020 Normal NSBR was found pre SIC in 45% of reactors to high molecular weight allergens and 19% reactors to low MW agents. A 3 fold increase in NSBR followed LMW reactors in 83% and High MW reactors in 66%.
burgeps Abramson 2020 Pre-employment increase non-specific reactivity was not predictive of future occupational asthma symptoms or accelerated FEV1 loss in aluminium foundry workers and was not recommended

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