Table 2.
Distribution and accuracy of perceived risk by breast cancer risk categorya
| Characteristic | Average risk (n=481) | High risk (n=19) | Total sample (n=500) |
|---|---|---|---|
|
| |||
| n (%) | n (%) | n (%) | |
| Perceived Absolute Riskb | |||
| Low risk | 267 (55.5) | 4 (21.1) ** | 271 (54.2) |
| Average risk | 148 (30.8) | 5 (26.3) | 153 (30.6) |
| High risk | 66 (13.7) | 10 (52.6) | 76 (15.2) |
| Overestimate | 66 (13.7) | n/a | 66 (13.2) |
| Accurate | 415 (86.3) | 10 (52.6) | 425 (85.0) |
| Underestimate | n/a | 9 (47.4) | 9 (1.8) |
| Perceived Comparative Riskb | |||
| Lower risk | 184 (38.3) | 4 (21.1) ** | 188 (37.6) |
| Equal risk | 189 (39.3) | 4 (21.1) | 193 (38.6) |
| Higher risk | 108 (22.4) | 11 (57.9) | 119 (23.8) |
| Overestimate | 108 (22.5) | n/a | 108 (21.6) |
| Accurate | 373 (77.5) | 11 (57.9) | 384 (76.8) |
| Underestimate | n/a | 8 (42.1) | 8 (1.6) |
| Mean (s.e.) | Mean (s.e.) | Mean (s.e.) | |
| Perceived Numeric Risk (%)c | 33.1 (1.3) | 70.0 (20.0) | 33.2 (1.3) |
| Risk Comprehensiond | n/a | n/a | n (%) |
| Overestimate | 335 (67.0) | ||
| Accurate | 163 (32.6) | ||
| Underestimate | 2 (0.4) | ||
Notes: s.e. = standard error; n.a. = not applicable.
Participants’ breast cancer risk category based on the National Cancer Institute’s Breast Cancer Risk Assessment Tool (BCRAT).
For Perceived Absolute Risk and Perceived Comparative Risk, participants were categorized based on their BCRAT 5-year absolute risk of developing breast cancer, with high risk defined as BCRAT five-year risk ≥1.67% (n=19) and average as BCRAT five-year risk<1.67% (n=481). For both absolute and comparative risk estimates, women at high risk of breast cancer could not overestimate their risk and women at average risk could not understimate their risk, since the BCRAT only categorizes as high risk or average risk; accordingly, these categories were not applicable for analysis.
For Perceived Numeric Risk, participants were categorized based on their BCRAT lifetime absolute risk of developing breast cancer, with high risk defined as BCRAT lifetime risk ≥20% (n=2) and average risk as BCRAT lifetime risk<20% (n=498); the BCRAT lifetime risk estimate was used to categorize participants, since the question on numeric risk asked women about their perceived risk of developing breast cancer over their lifetime.
Since the BCRAT lifetime absolute risk was used in calculating risk estimate, we did not stratify by BCRAT lifetime absolute risk estimate and present the risk comprehension for the entire study sample.
p<0.01. All estimates are based on participants who have a valid (non-missing) response to each variable.