Table 3. Mean scores on knowledge subscales.

	Marks available	Intervention n = 203	Control n = 197	Difference (95% CI)	p-value a
Knowledge subscale
Breast cancer mortality benefit
Conceptual	3	2.57	2.3	0.26 (0.13, 0.4)	< 0.001
Numerical	5	2.38	0.85	1.53 (1.16, 1.9)	< 0.001
Total	8	4.95	3.15	1.79 (1.38, 2.2)	< 0.001
False-positive screening results
Conceptual	1	1	0.95	0.04 (0.01, 0.07)	0.019
Numerical	3	1.34	0.35	0.99 (0.75, 1.24)	< 0.001
Total	4	2.34	1.3	1.04 (0.78, 1.29)	< 0.001
Overdiagnosis
Conceptual	7	4.52	2.88	1.64 (1.35, 1.93)	< 0.001
Numerical	3	1.49	0.49	1 (0.78, 1.22)	< 0.001
Total	10	6.01	3.37	2.64 (2.24, 3.04)	< 0.001
All subscales
Conceptual	11	8.08	6.14	1.94 (1.56, 2.32)	< 0.001
Numerical	11	5.22	1.69	3.53 (2.78, 4.27)	< 0.001
Total	22	13.3	7.83	5.47 (4.5, 6.44)	< 0.001

^a The Student’s t tests for quantitative variables were adjusted for clustering using the Rao-Scott correction.