TABLE 4.

Estimation by quartile regression of amniotic fluid proinflammatory mediators following intraamniotic infection and azithromycin treatment

		Control			IAI			IAI+AZI			P valuea
Mediator	Quartile	Estimate	Lower	Upper	Estimate	Lower	Upper	Estimate	Lower	Upper	IAI vs Con	IAI+AZI vs Con
TNF-α	25% quartile	0.47	−∞	0.47	0.47	0.47	44.92	20.50	−∞	116.33	.0155	.0821
	50% quartile	0.47	0.47	0.47	54.20	18.25	266.45	84.70	24.79	211.68	<.0001	.0006
	75% quartile	0.47	0.47	∞	323.60	74.21	1681.11	202.00	116.17	∞	<.0001	<.0001
IL-1β	25% quartile	0.17	−∞	0.17	0.17	0.17	6.21	0.40	−∞	20.06	.0155	.0821
	50% quartile	0.17	0.17	0.17	11.60	1.26	119.23	17.30	0.51	152.35	<.0001	.0006
	75% quartile	0.17	0.17	∞	145.60	27.40	468.69	24.00	20.04	∞	<.0001	<.0001
IL-6	25% quartile	1.38	−∞	1.38	1.38	1.38	13638.74	1.38	−∞	1382.55	.0216	.0989
	50% quartile	1.38	1.38	1.38	14281.60	57.88	40579.90	1598.20	0.95	76125.50	<.0001	.0010
	75% quartile	1.38	1.38	∞	47130.60	25674.59	60766.71	45858.60	1483.25	∞	<.0001	<.0001
PGE2	25% quartile	15.00	−∞	15.00	15.00	15.00	187.41	−0.14	−∞	−0.08	.0278	.2736
	50% quartile	15.00	15.00	88.68	196.70	15.91	1006.35	−1.19	−∞	∞	<.0001	.0363
	75% quartile	15.00	15.00	∞	1134.60	368.62	3258.51	−0.14	−∞	∞	<.0001	.0001
PGF2α	25% quartile	10.00	−∞	10.00	10.00	10.00	90.52	0.10	−∞	216.79	.0216	.2636
	50% quartile	10.00	10.00	10.00	176.00	−∞	567.37	0.10	−∞	∞	<.0001	.0183
	75% quartile	10.00	10.00	∞	596.80	270.47	912.72	173.80	3.36	In	<.0001	<.0001

P<.05 was considered significant.

AZI, azithromycin treatment group; IAI, intraamniotic infection; IL, interleukin; ND, not detectable; PG, prostaglandin; TNF, tumor necrosis factor.

^aBased on rank tests. Normal, Wilcoxon, and sign functions are implemented and suitable for iid error models, and tau score function is implemented and appropriate for non-iid error models.