Table 4

Comparison of nerve conduction study results for chlorpyrifos (CPF) and referent subjects at the one year examination and change over one year from baseline

	Group	n	One year		Change
	Group	n	Mean (SD)	p value*	Mean (SD)	p value*
*t test for difference in means (adjusted for unequal variance between groups).
CV, conduction velocity.
Median sensory
Amplitude (μv)	CPF	53	32 (12.8)	0.52	2.1 (3.8)	0.91
	Referent	58	33 (13.6)		2.0 (5.2)
Terminal CV (m/s)	CPF	53	52.9 (7.0)	0.74	−1.9 (4.2)	0.93
	Referent	58	53.3 (6.7)		−1.9 (4.5)
Distal latency (ms)	CPF	53	3.5 (0.5)	0.69	0.2 (0.22)	0.84
	Referent	58	3.5 (0.5)		0.2 (0.21)
Ulnar sensory
Amplitude (μv)	CPF	53	30 (12.3)	0.68	3.0 (6.0)	0.65
	Referent	58	31 (14.5)		3.6 (7.1)
Terminal CV (m/s)	CPF	53	55.3 (5.5)	0.75	−2.2 (4.4)	0.71
	Referent	58	54.9 (5.2)		−2.5 (4.2)
Distal latency (ms)	CPF	53	3.3 (0.3)	0.97	0.1 (0.2)	0.80
	Referent	58	3.3 (0.3)		0.1 (0.2)
Sural sensory
Amplitude (μv)	CPF	53	20 (8.2)	0.20	2.1 (6.2)	0.09
	Referent	58	18 (6.8)		0.1 (6.4)
Terminal CV (m/s)	CPF	53	48.6 (4.7)	0.34	−1.8 (5.1)	0.70
	Referent	58	47.7 (4.7)		−2.2 (4.1)
Distal latency (ms)	CPF	53	3.7 (0.3)	0.50	0.2 (0.3)	0.82
	Referent	58	3.7 (0.3)		0.2 (0.3)
Median motor
Amplitude (mv)	CPF	53	10.9 (3.2)	0.81	1.5 (2.7)	0.08
	Referent	58	10.7 (3.4)		0.6 (2.5)
Forearm CV (m/s)	CPF	53	55.5 (3.9)	0.63	−1.2 (3.4)	0.18
	Referent	58	55.1 (3.6)		−2.0 (3.5)
Distal latency (ms)	CPF	53	3.8 (0.6)	0.57	0.3 (0.3)	>0.99
	Referent	58	3.7 (0.6)		0.3 (0.3)
F wave latency (ms)	CPF	53	28.3 (2.1)	0.92	0.5 (0.9)	0.69
	Referent	58	28.3 (2.5)		0.6 (1.4)
Peroneal motor
Amplitude (mv)	CPF	53	6.3 (2.7)	0.83	−1.0 (2.1)	0.81
	Referent	58	6.4 (2.4)		−1.1 (1.7)
Distal latency (ms)	CPF	52	4.9 (0.8)	0.07	0.2 (0.6)	0.18
	Referent	58	4.6 (0.6)		0.1 (0.3)
F wave latency (ms)	CPF	50	49.2 (3.8)	0.22	0.7 (1.9)	0.18
	Referent	58	50.3 (5.2)		1.4 (2.9)