Table 2. Maximum Transverse Diameter and Volume of Abdominal Aortic Aneurysms by Treatment Assignment.

	Doxycycline (n = 129)	Placebo (n = 125)	Difference (95% CI)	P valuea
Full analysis population
Maximum transverse diameter, cm
6 mo, No. of patients	119	116
Mean (SD)	4.40 (0.44)	4.40 (0.43)	0 (−0.12 to 0.11)	.94
1 y, No. of patients	119	113
Mean (SD)	4.49 (0.48)	4.48 (0.44)	0.02 (−0.10 to 0.13)	.80
2 y, No. of patients	96	101
Mean (SD)	4.61 (0.52)	4.61 (0.53)	0 (−0.15 to 0.15)	.99
Baseline to 2-y change
No. of patients b	96	101
Mean (SD)	0.36 (0.21)	0.36 (0.28)	0 (−0.07 to 0.07)	.93
Volume, cm3
6 mo, No. of patients	119	116
Mean (SD)	102.90 (26.19)	100.40 (26.27)	2.52 (−4.22 to 9.26)	.46
1 y, No. of patients	119	113
Mean (SD)	106.00 (29.13)	105.00 (28.28)	0.95 (−6.48 to 8.38)	.80
2 y, No. of patients	96	101
Mean (SD)	113.60 (34.91)	111.20 (33.14)	2.41 (−7.16 to 11.97)	.62
Baseline to 2-y change
No. of patientsb	96	101
Mean (SD)	18.60 (14.38)	19.16 (15.75)	−0.56 (−4.81 to 3.68)	.79
Per-protocol population
Maximum transverse diameter, cm
6 mo, No. of patients	64	71
Mean (SD)	4.35 (0.47)	4.42 (0.41)	−0.07 (−0.21 to 0.08)	.38
1 y, No. of patients	66	72
Mean (SD)	4.44 (0.49)	4.51 (0.42)	−0.07 (−0.23 to 0.08)	.35
2 y, No. of patients	61	67
Mean (SD)	4.54 (0.55)	4.66 (0.50)	−0.12 (−0.30 to 0.06)	.21
2-y to Baseline, No. of patients b	61	67
Mean (SD)	0.33 (0.22)	0.36 (0.26)	−0.03 (−0.12 to 0.05)	.47
Volume, cm3
6 mo, No. of patients	64	71
Mean (SD)	96.70 (25.95)	101.60 (23.48)	−4.89 (−13.31 to 3.52)	.25
1 y, No. of patients	66	72
Mean (SD)	100.70 (28.79)	105.60 (25.64)	−4.93 (−14.10 to 4.23)	.29
2 y, No. of patients	61	67
Mean (SD)	106.80 (35.67)	114.00 (31.98)	−7.22 (−19.06 to 4.61)	.23
2-y to Baseline, No. of patients b	61	67
Mean (SD)	15.78 (13.95)	19.16 (16.18)	3.38 (−8.69 to 1.93)	.21

^aTwo-sample t test P values.

^bMean changes in measured maximum transverse diameter and volume based on patients for whom computed tomographic scans were available.