Table 3.

Safety climate measures by current versus past general contractor project, stratified by general contractor size

	Outcomes	Surveys n	Current Project mean (CI)*	Past Project‡ mean (CI)*	P*
Large General Contractor	n		3	5
	General Contractor Safety	586	77.8 (74.2–81.4)	64.9 (59.1–70.7)	<0.0001
	Subcontractor Safety	583	83.0 (80.4–85.6)	79.3 (74.6–84.0)	0.04
	Coworker Safety	580	82.8 (80.3–85.4)	76.6 (71.9–81.2)	0.0005
	Self Safety	575	82.7 (80.5–84.9)	79.4 (75.4–83.4)	0.03
	Crew Safety	575	84.8 (82.4–87.1)	82.0 (78.0–86.1)	0.07
Small General Contractor	n		3	22
	General Contractor Safety	524	69.8 (65.6–74.0)	70.5 (66.7–74.3)	0.68
	Subcontractor Safety	520	80.4 (77.2–83.5)	79.3 (76.3–82.2)	0.43
	Coworker Safety	517	78.3 (75.3–81.4)	79.6 (76.7–82.5)	0.37
	Self Safety	519	81.6 (78.9–84.4)	81.8 (79.3–84.3)	0.92
	Crew Safety	519	82.0 (79.2–84.9)	81.1 (78.5–83.7)	0.42

^*Means, confidence intervals and P values derived from hierarchical linear models, where safety score is the outcome variable, project (current versus past), general contractor size and interaction of project by general contractor size are the independent variables (fixed effects).

Interaction P values for general contractor safety (P<0.0001) and coworker safety (P=0.001) indicate the relationship between project and these safety scores vary by general contractor size. Interaction P values for other safety scores (0.09 to 0.38) were not significant.

^‡155 surveys in past project not included, due to general contractor size not obtained

Random intercepts for subcontractor and participant nested within subcontractor included to account for within group clustering