Hearing effects from intermittent and continuous noise exposure in a study of Korean factory workers and firefighters

Table 6 Coefficients and confidence intervals for all covariates using multiple regression for the first year of observations (2006).

	2006
	β	Confidence Interval
Age	0.458	0.15-0.767
Work duration	0.004	-0.02-0.028
Smoking status (no/yes)*	0.983	-1.695-3.661
Group (Firefighter/Factory worker)**	12.544	9.196-15.892

Age and group (firefighter or farm machinery factory worker) remained significant in the final model

ISSN: 1471-2458