Table 2

Comparison of respiratory symptoms (%) between cotton and silk textile workers

Cumulative incidence*Persistence of report†Intermittent symptom‡
OnceTwice3 or 4 times
*Among those who were asymptomatic for each particular symptom at baseline.
†Among cotton and silk workers participating in all four surveys.
‡Among those who participated in all four surveys and reported a particular symptom one or more times.
95% confidence limits shown in parentheses.
Byssinosis
Cotton24.2 (20.0 to 28.7)23.1 (18.4 to 27.9)9.9 (6.5 to 13.3)1.3 (0.3 to 2.6)51.0 (41.0 to 60.9)
Silk0.00.00.00.00.0
p value<0.0001<0.0001
Chest tightness
Cotton22.5 (18.5 to 26.9)20.8 (16.2 to 25.4)7.3 (4.3 to 10.2)1.3 (0.3 to 2.6)83.1 (72.9 to 93.9)
Silk9.9 (7.3 to 13.1)8.9 (5.7 to 12.2)1.7 (2.3 to 3.2)0.083.9 (72.1 to 93.7)
p value<0.0001<0.00010.99
Chronic bronchitis
Cotton9.1 (6.5 to 12.2)14.2 (10.3 to 18.1)5.9 (3.3 to 8.6)5.9 (3.8 to 8.6)69.6 (58.3 to 79.5)
Silk7.1 (4.6 to 10.4)10.7 (7.1 to 14.2)3.1 (1.1 to 5.1)1.7 (0.2 to 3.2)82.2 (67.9 to 92.0)
p value0.32<0.010.07
Chronic cough
Cotton9.0 (6.5 to 12.2)14.5 (10.6 to 18.5)5.0 (2.5 to 7.4)5.3 (2.8 to 7.8)74.7 (63.3 to 84.0)
Silk6.6 (4.3 to 9.8)9.3 (5.9 to 12.6)4.5 (2.1 to 6.8)1.7 (0.2 to 3.2)86.7 (73.2 to 95.0)
p value0.22<0.010.20
Dyspnoea (+2)
Cotton27.7 (23.1 to 32.6)24.1 (19.3 to 28.9)9.2 (6.0 to 12.5)7.3 (4.3 to 10.2)67.5 (58.5 to 75.7)
Silk26.4 (22.3 to 30.8)23.4 (18.5 to 28.2)5.8 (3.2 to 8.5)1.4 (0.4 to 2.7)71.9 (61.4 to 80.9)
p value0.68<0.0010.08