. Author manuscript; available in PMC: 2015 Jul 16.

Published in final edited form as: Am J Ind Med. 2014 Sep 15;57(12):1398–1412. doi: 10.1002/ajim.22372

TABLE V.

Post-hoc Analysis Results Dividing Affected Employee Workers’ Compensation Claim Frequency Into (a) Yearly and (b) Quarterly Rates^a

	Study period	Claim rate^a RR^c (95% CI)	Cost per FTE^b RR^d (95% CI)	Geometric mean cost per claim^b RR^e (95% CI)
a.
Pre-Intervention	2nd year	1.03 (0.89, 1.20)	0.96 (0.7, 1.32)	1.01 (0.85, 1.21)
Post-Intervention	3rd year	0.50 (0.32, 0.79)^*	0.28 (0.16, 0.5)^*	0.67 (0.51, 0.88)^*
	4th year	0.31 (0.14, 0.66)^*	0.15 (0.07, 0.34)^*	0.79 (0.56, 1.1)
b.
Pre-Intervention	2nd year	1.03 (0.89, 1.20)	0.96 (0.7, 1.32)	1.01 (0.85, 1.21)
Post-Intervention	3rd year, 1st quarter	0.62 (0.41, 0.91)^*	0.26 (0.14, 0.47)^*	0.67 (0.46, 0.97)^*
	3rd year, 2nd quarter	0.52 (0.28,0.96)^*	0.28 (0.1, 0.76)^*	0.71 (0.48, 1.03)
	3rd year, 3rd quarter	0.52 (0.33, 0.82)^*	0.42 (0.16, 1.06)	0.60 (0.39, 0.94)^*
	3rd year, 4th quarter	0.39 (0.20, 0.78)^*	0.22 (0.09, 0.52)^*	0.68 (0.46, 1.02)
	4th year, 1st quarter	0.51 (0.24, 1.07)	0.33 (0.13, 0.84)^*	0.86 (0.56, 1.32)
	4th year, 2nd quarter	0.29 (0.15, 0.58)^*	0.12 (0.05, 0.34)^*	0.65 (0.39, 1.07)
	4th year, 3rd quarter	0.21 (0.08, 0.54)^*	0.07 (0.02, 0.22)^*	0.67 (0.38, 1.17)
	4th year, 4th quarter	0.26 (0.10, 0.70)^*	0.14 (0.05, 0.39)^*	0.92 (0.56, 1.53)

Note: All regression models control for time trend. Rate ratios are in reference to the first year of the pre-intervention data.

Total number of claims (medical-only and lost-time) per 100 full-time equivalents (FTEs).

Paid 30-month nominal cost.

Poisson regression.

Two-part regression model- refer to Methods and Online Appendix.

Linear regression.

Significant difference, P <.05.