. Author manuscript; available in PMC: 2016 Apr 15.

Published in final edited form as: N Engl J Med. 2015 Oct 15;373(16):1519–1530. doi: 10.1056/NEJMoa1500409

Table 2.

Risk Ratios for Colorectal Adenoma Outcomes According to Treatment Assignment.^*

Treatment Assignment	One or More Adenomas^†		One or More Advanced Adenomas^‡
	No. of Patients/ Total No. (%)	Risk Ratio (95% CI)^§	No. of Patients/ Total No. (%)	Risk Ratio (95% CI)^§
Vitamin D vs. no vitamin D
No vitamin D	442/1035 (42.7)	Reference	98/1042 (9.4)	Reference
Vitamin D	438/1024 (42.8)	0.99 (0.89–1.09)	98/1032 (9.5)	0.99 (0.75–1.29)
Calcium vs. no calcium
No calcium	362/761 (47.6)	Reference	77/764 (10.1)	Reference
Calcium	345/762 (45.3)	0.95 (0.85–1.06)	81/773 (10.5)	1.02 (0.76–1.38)
Calcium plus vitamin D vs. calcium alone
Calcium	259/655 (39.5)	Reference	63/662 (9.5)	Reference
Calcium plus vitamin D	259/643 (40.3)	1.01 (0.88–1.15)	56/648 (8.6)	0.89 (0.63–1.26)
Calcium plus vitamin D vs. neither agent
Neither calcium nor vitamin D	183/380 (48.2)	Reference	35/380 (9.2)	Reference
Calcium plus vitamin D	174/381 (45.7)	0.93 (0.80–1.08)	37/387 (9.6)	0.99 (0.63–1.56)

The analyses of vitamin D versus no vitamin D included all participants who underwent randomization. The analyses of calcium versus no calcium and of vitamin D plus calcium versus neither agent were restricted to participants who underwent full factorial randomization. The analyses of vitamin D plus calcium versus calcium did not include participants who underwent full factorial randomization and were assigned to receive placebo or vitamin D alone.

^†

P values, calculated with the use of a chi-square contingency-table test, are as follows: vitamin D versus no vitamin D, P = 0.98; calcium versus no calcium, P = 0.37; vitamin D plus calcium versus calcium, P = 0.79; and vitamin D plus calcium versus neither agent, P = 0.49.

^‡

Denominators differ between adenomas and advanced adenomas because of missing data for lesion size and an assumption that small lesions (<6 mm) with missing pathological data are not advanced adenomas (see the Supplementary Appendix).

^§

Risk ratios were adjusted for age, clinical center, anticipated surveillance interval (3 or 5 years), a three-level variable for sex and type of randomization (male, female and two-group randomization, female and full factorial randomization), and number of baseline adenomas (1, 2, or ≥3).