Table 2.

Subjective symptoms and results of the urine cotinine test (>5 ng/mL)

	Total	Less working	More working	p
	Mean ± SD, N(%)	Mean ± SD, N(%)	Mean ± SD, N(%)
	(n = 171)	(n = 83)	(n = 88)
Respiratory symptom	123(71.93)	55(66.27)	68(77.27)	0.1525
Muscular symptom	102(59.65)	53(63.86)	49(55.68)	0.3509
Nervous symptom	171(100.0)	58(100.0)	113(100.0)	–
Psychological symptom	12(7.02)	0(0.00)	12(13.64)	0.0003
Positivity of urine cotinine sampling (>5 ng/mL)	165(96.49)	83(100.0)	82(93.18)	0.0289

SD, standard deviation.