Table 3

Features reflecting asthma severity among those with diisocyanate OA versus other causes of OA, 1980–3

Diisocyanate OAOther OAp Value
*Number with information in the file.
n425419
Using inhaled steroids (n (%))29% of 373*43% of 386*0.001
FEV1 % predicted (mean (SD (median)))97.6 (21.8 (99.35))93.2 (25.3 (94.35))0.01
VC % (mean (SD (median)))102.5 (18 (103.5))99.3 (19.4 (99.9))0.02
FEF50 % (mean (SD (median)))84.3 (36 (84.8))75.8 (37.8 (74.7))0.01
FEF25 % (mean (SD (median)))73.3 (46 (63.1))70.1 (44 (59.6))NS
Actual FEV1/VC (mean (SD (median)))75.6 (10.8 (77.45))73.6 (13.6 (75.29))0.03
Methacholine PC20 during work period (mean (SD (median)))4.6 (11.5 (0.9)) (n=101)2.8 (6.7 (1.1)) (n=107)NS
Methacholine PC20 off work (mean (SD (median)))18.4 (23.5 (7.7)) (n=239)*17.4 (24.1 (4.3)) (n=199)*NS
At least one hospital admission for asthma up to 1996 (n (%))5.3% of 414*11.1% of 396*0.003