Table 2.

Individual and group ICCs by industry and assessment round

Industry/round	Mean of all ratingsa (SD)	${\sigma }_{\text{T}}^{\text{2}}$b	ICCindc (95% CI)			ICCgrpc (95% CI)
			All raters (n = 6)	Industrial hygienists (n = 3)	Occupational physicians (n = 3)	All raters (n = 6)	Industrial hygienists (n = 3)	Occupational physicians (n = 3)
Foundry (n = 72)
OH  round	2.8 (0.8)	0.70	0.63 (0.54–0.72)	0.64 (0.52–0.74)	0.61 (0.49–0.72)	0.91 (0.88–0.94)	0.84 (0.76–0.90)	0.82 (0.74–0.89)
OH/IQ  round	2.8 (0.9)	0.88	0.57 (0.47–0.67)	0.61 (0.49–0.72)	0.53 (0.40–0.65)	0.89 (0.84–0.92)	0.83 (0.74–0.89)	0.78 (0.67–0.85)
Textile (n = 74)
OH  round	2.4 (0.9)	0.81	0.55 (0.45–0.65)	0.52 (0.39–0.64)	0.69 (0.58–0.78)	0.88 (0.83–0.92)	0.76 (0.66–0.84)	0.87 (0.81–0.91)
OH/IQ  round	2.6 (1.0)	1.02	0.44 (0.34–0.55)	0.39 (0.25–0.53)	0.68 (0.57–0.77)	0.83 (0.76–0.88)	0.65 (0.50–0.77)	0.86 (0.80–0.91)

CI, confidence interval; n, number of subjects; SD, standard deviation.

^aMean of all six raters and all subjects, e.g. for the foundry industry, the mean is based on 6 × 72 ratings.

^b${\sigma }_{\text{T}}^{\text{2}}$ is the total variance from two-way random effects analysis of variance model.

^cSince the magnitude of ICC_ind and ICC_grp is influenced by the between-subject variability of the study population and the prevalence of the intensity ratings, comparisons of ICC between groups that have different total variances should be made cautiously.