Table 2.

Summary of studies that evaluated CRC risk prediction models

StudyModel evaluatedSampleFeatures evaluatedKey findings
Kim and colleagues (85)Harvard Caner Risk Index (63)A prospective cohort of 38,953 men aged 40 to 70 years (Health Professionals Follow-up Study); follow-up from 1986 to 1996; 230 incident CRC cases. A prospective cohort of 52,668 women aged 40 to 70 years (Nurses' Health Study); follow-up from 1984 to 1994; 244 incident CRC cases.Calibration, discrimination, and utilityOverestimated the number of CRC for men within “much below average risk” and “very much below average risk” risk categories. Well calibrated for women. Modest discrimination: c = 0.71 (95% CI, 0.68–0.74) for men and 0.67 (95%CI, 0.64–0.70) for women.
Emmons and colleagues (86)Harvard Caner Risk Index (63)In-depth cognitive interviews with 9 individuals from the general population; and 9 focus groups (6 females and 3 males) aged ≥40 yearsMeaning of risk, perceptions about cancer, and interpretation of the results66% extremely/very satisfied, 32% somewhat satisfied with the model format. 86% extremely/very satisfied, 13% somewhat satisfied with the information provided in the model. 3% not at all satisfied with the model. Some dissatisfied because exposures that they believed to be important were not included (e.g., poverty, toxic waste, air pollution) Difficult for participants in completing the HCRI in its paper-and-pencil form.
Emmons and colleagues (87)Harvard Colorectal Cancer Risk Assessment and Communication Tool for Research (HCCRACT-R; ref. 63)A randomized control trial on 159 men and 194 women aged 40 to 70 years without previous personal history of cancer. Intervention groups: those receiving (i) presentation of both absolute and relative risk (ii) presentation of absolute risk only Control group: those without receiving any personal risk informationAccuracy of risk perception, and, level of worry and satisfactionSignificant changes in risk perception accuracy for both relative risk (P = 0.01) and absolute risk (P = 0.001) across intervention groups. Of those with inaccurate absolute risk perception at baseline, 54% of the participants in the group who received presentation of both absolute and relative risk, and 64% of those in the group who received presentation of absolute risk only, had correct absolute risk perception at post-test, compared with only 12% of the control group. 13% less worried, 17% more worried about getting CRC after completing the HCCRACT-R.
Imperiale and colleagues (84)Imperiale (84)A cross-sectional study on 1,031 asymptomatic individuals aged ≥50 years undergoing first-time screening colonoscopy between 1999 and 2001DiscriminationModest discrimination: c = 0.74 (SD = 0.06)
Park and colleagues (88)Freedman (64)A prospective cohort of 155,345 men and 108,057 women aged 50 to 71 years (American Association of Retired Persons—diet and health study); follow-up from 1995 to 2003 (mean, 6.9 y); 2,092 male and 965 female incident CRC cases.Calibration and discriminationWell calibrated for men (E/O = 0.99; 95% CI, 0.95–1.04) and for women (E/O = 1.05; 95% CI, 0.98–1.11) overall. Overestimated risk for men with one affected relative (E/O = 1.35; 95% CI, 1.17–1.55); women with one affected relative (E/O = 1.20; 95% CI, 1.00–1.45); men with 2 affected relatives (E/O = 1.48; 95% CI, 1.00–2.19); and men who had a history of screening and polyps (E/O = 1.42; 95% CI, 1.24–1.63). Underestimated risk for men who had a history of screening with no polyps (E/O = 0.67; 95% CI, 0.62–0.72). Modest discriminatory accuracy: c = 0.61 (95% CI, 0.60–0.62) for men and 0.61 (95% CI, 0.59–0.62) for women
Ma and colleagues (83)Ma (83)A prospective cohort of 18,256 men aged 40 to 59 years (Japan Public Health Center-based study—Cohort I); follow-up from 1990 to 2005 (mean, 10.1 y); 389 incident CRC cases.Calibration and discriminationUnderestimation for colon cancer: O/E = 1.19 (95% CI, 1.03–1.37). Well calibrated for rectal cancer (O/E = 0.94; 95% CI, 0.78–1.12) and for CRC overall (O/E = 1.09; 95% CI, 0.98–1.23) Modest discriminatory accuracy: c = 0.64 (95% CI, 0.61–0.67) for CRC, 0.66 (95% CI, 0.62–0.70) for colon cancer, 0.62 (95% CI, 0.57–0.66) for rectal cancer

Abbreviations: c, concordance statistic; E, expected; O, observed.