Table 2
Relationship between airway obstruction as assessed by FEV
1
and PEF
FEV
1
< FEV
1
pred
− 1.64RSD
FEV
1
⩾ FEV
1
pred
− 1.64RSD
Total
PEF < PEFpred − 1.64RSD
40
46
86
PEF ⩾ PEFpred − 1.64RSD
8
146
154
Total
48
192
240
p = 0.0001 (χ
2
test).