Table 2.

Ki-67 index: Characteristics and modulation by treatment group^*

	Placebo (n = 74)		13-cis-RA + AT (n = 77)		9-cis-RA (n = 74)
Epithelial layer	Mean (95% CI)	Median (range)	Mean (95% CI)	Median (range)	Mean (95% CI)	Median (range)
Basal layer
Baseline†	2.41 (1.85 to 2.97)	1.70 (0 to 15.03)	2.22 (1.79 to 2.65)	1.78 (0 to 11.16)	2.34 (1.71 to 2.97)	1.58 (0 to 18.17)
3 months†	2.93 (2.22 to 3.65)	2.32 (0 to 14.53)	2.19 (1.64 to 2.74)	1.75 (0 to 11.62)	2.39 (1.41 to 3.37)	1.54 (0.23 to 23.16)
Modulation‡	0.39 (−0.41 to 1.18)	0.10 (−12.12 to 11.14)	0.07 (−0.67 to 0.81)	−0.23 (−9.87 to 9.7)	0.11 (−1.27 to 1.48)	−0.01 (−17.88 to 22.45)
P value§	.24		.66		.94
Parabasal layer
Baseline†	6.10 (4.64 to 7.57)	3.96 (0.76 to 33.62)	5.46 (4.31 to 6.62)	3.57 (0 to 27.70)	5.81 (4.33 to 7.28)	3.41 (0 to 31.58)
3 months†	7.16 (5.12 to 9.20)	4.59 (0 to 38.10)	4.24 (3.28 to 5.21)	3.44 (0 to 20.23)	4.03 (3.01 to 5.05)	2.77 (0.28 to 15.40)
Modulation‡	0.67 (−1.55 to 2.89)	0.08 (−29.77 to 22.78)	−1.08 (−2.65 to 0.48)	−0.81 (−23.11 to 17.34)	−1.65 (−3.48 to 0.19)	−0.34 (−31.31 to 8.26)
P value§	.59		.13		.24

^*RA = retinoic acid; AT = α-tocopherol; CI = confidence interval. Ki-67 index is expressed as the mean (95% CI) and the median (range).

^†The statistics for baseline (n = 73 in the placebo group, n = 75 in the 13-cis-RA group, and n = 73 in the 9-cis-RA group) and 3-month (n = 56 in the placebo group, n = 64 in the 13-cis-RA group, and n = 49 in the 9-cis-RA group) measurements were based on all available samples.

^‡Modulation of Ki-67 index (n = 55 in placebo group, n = 62 in 13-cis-RA group, and n = 48 in 9-cis-RA group) was calculated only on participants who had both baseline and 3-month measurements (Ki-67 at 3 months – Ki-67 at baseline); shown as mean (95% CI) and median (range).

^§Wilcoxon signed rank test was performed to test the statistical significance of the change in the median Ki-67 modulation in each treatment group. All statistical tests were two-sided.