A Cohort Study on Self-Reported Respiratory Symptoms of Toner-Handling Workers: Cross-Sectional and Longitudinal Analysis from 2003 to 2008

Table 6

Relationship between %FEV_1.0 and breathlessness.

	1st survey	2nd survey	3rd survey	4th survey	5th survey	6th survey
Toner-handling group	24 (21.6%)	7 (8.1%)	11 (15.1%)	6 (9.1%)	9 (15.3%)	8 (14.8%)
Never-toner-handling group	2 (9.1%)	4 (25.0%)	0 (0.0%)	1 (7.7%)	2 (20.0%)	1 (14.3%)
𝑃 value^#	0.24	0.07	0.34	1.00	0.66	1.00

^#𝑃 value of chi-square test; ^∗𝑃<0.05 and ^∗∗𝑃<0.01.
The percentage in the table was calculated by the following formula; the number of subjects with %FEV_1.0 < 80% * 100/the number of subjects with breathlessness.