Table 3.

Potential predictor variables of HPD use and differences in reporting by method

Variable	All		Survey, HPD use >50% %	Activity card, HPD use >50% %	Difference (survey activity) %
	n	%
All	251	100	55	41	14
Site
Site A	33	13	70*	42	28
Site B	31	12	58	32	26
Site C	25	10	40	24	16
Site D	37	15	68	43	25
Site E	31	12	68	58	10
Site F	38	15	53	45	8
Site G	29	12	31	45	−14
Site H	27	11	41	30	11
Trade
Cement mason	6	2	83*	50*	33
Plumber	16	6	81	50	31
Electrician	22	9	73	32	41
Operating engineer	7	3	43	14	29
Pipefitter	16	6	63	50	13
Sheet metal	14	6	57	57	0
Ironworker	17	7	41	6	35
Carpenter	113	45	45	41	4
Laborer	40	16	60	50	10
Years in construction
<10 years	83	33	55	39	16
10–20 years	89	35	58	43	15
>20 years	77	31	48	39	9
Education
<HS	18	7	28*	33	−5
HS, GED	145	58	54	42	12
>HS, trade school	87	35	60	40	20
Hearing status
Good	108	43	62	47*	15
Fair	120	48	50	38	12
Poor	19	8	47	16	31
Percent shift above 85 dBA
<25%	102	41	62	31	31
25–50%	104	41	53	50	3
>50%	45	18	42	40	2

χ²: *P ≤ 0.05; **P ≤ 0.01.