Background
Methods
Design
Participants
Procedure
Measures
Outcome variables
Determinants
Statistical analyses
Results
Participant characteristics
All women N = 942 | Low risk N = 236 | Average risk N = 228 | Moderate risk N = 239 | High risk N = 239 | ||||||
---|---|---|---|---|---|---|---|---|---|---|
Age (years), mean (SD) | 59.0 | (6.3) | 58.7 | (6.3) | 58.6 | (6.5) | 58.9 | (5.9) | 59.8 | (6.3) |
Education level, n (%) | ||||||||||
Lower education | 249 | (26.4) | 65 | (27.6) | 58 | (25.4) | 63 | (26.4) | 63 | (26.4) |
Higher secondary education | 372 | (39.5) | 82 | (34.7) | 97 | (42.5) | 96 | (40.2) | 97 | (40.6) |
Higher vocational qualification | 321 | (34.1) | 89 | (37.7) | 73 | (32.1) | 80 | (33.4) | 79 | (33.0) |
Marital status, n living with partner (%) | 729 | (77.3) | 187 | (79.2) | 180 | (78.9) | 188 | (78.7) | 174 | (72.8) |
First-degree family history breast cancer, n yes (%) | 204 | (21.7) | 47 | (19.9) | 52 | (22.8) | 47 | (19.7) | 58 | (24.3) |
Body mass index (kg/m2), mean (SD)a | 26.3 | (4.8) | 26.5 | (4.9) | 26.1 | (4.6) | 26.6 | (5.5) | 26.0 | (4.1) |
Medical condition, n ≥ 2 diagnosed (%)b | 424 | (45.0) | 119 | (50.4) | 96 | (42.1) | 103 | (43.1) | 106 | (44.4) |
Current medication use, n yes (%) | 391 | (41.5) | 109 | (46.2) | 85 | (37.3) | 91 | (38.1) | 106 | (44.4) |
Current MHTc use, n yes (%) | 33 | (3.5) | 9 | (3.8) | 5 | (2.2) | 12 | (5.0) | 7 | (3.0) |
Benign breast disease, n yes (%) | 272 | (28.9) | 79 | (33.5) | 64 | (28.1) | 68 | (28.5) | 61 | (25.5) |
Perceived breast cancer risk (%) | ||||||||||
Low | 182 | (19.3) | 48 | (20.3) | 44 | (19.3) | 47 | (19.7) | 43 | (18.0) |
Below average | 186 | (19.7) | 45 | (19.1) | 49 | (21.5) | 40 | (16.7) | 52 | (21.8) |
Average | 498 | (52.9) | 126 | (53.4) | 121 | (53.1) | 130 | (54.4) | 121 | (50.6) |
Moderate | 54 | (5.7) | 10 | (4.2) | 10 | (4.4) | 16 | (6.7) | 18 | (7.5) |
High | 5 | (0.5) | 2 | (0.8) | 1 | (0.4) | 1 | (0.4) | 1 | (0.4) |
Missing value | 17 | (1.8) | 5 | (2.1) | 3 | (1.3) | 5 | (2.1) | 4 | (1.7) |
General health score, mean (SD) | 82.1 | (14.2) | 81.3 | (14.4) | 81.7 | (15.5) | 83.8 | (12.8) | 81.5 | (13.9) |
Life events, n ≥ 2 (%)d | 264 | (28.0) | 74 | (31.4) | 64 | (28.1) | 63 | (26.4) | 63 | (26.4) |
HLOCe, n (%) | ||||||||||
Internal | 300 | (31.8) | 78 | (33.1) | 69 | (30.3) | 73 | (30.5) | 80 | (33.5) |
Physician | 67 | (7.1) | 11 | (4.7) | 11 | (4.8) | 27 | (11.3) | 18 | (7.5) |
Chance | 447 | (47.5) | 115 | (48.7) | 111 | (48.7) | 107 | (44.8) | 114 | (47.7) |
No clear preference | 113 | (12.0) | 29 | (12.3) | 34 | (14.9) | 27 | (11.3) | 23 | (9.6) |
Missing value | 15 | (1.6) | 3 | (1.3) | 3 | (1.3) | 5 | (2.1) | 4 | (1.7) |
Belief in medicines, mean (SD) | ||||||||||
Harm | 9.0 | (2.5) | 9.0 | (2.5) | 9.2 | (26.7) | 9.0 | (2.5) | 9.0 | (2.5) |
Overuse | 11.5 | (3.3) | 11.6 | (3.3) | 11.6 | (3.4) | 11.6 | (3.3) | 11.3 | (3.3) |
Health anxiety, mean (SD) | 7.7 | (4.0) | 7.6 | (4.1) | 7.7 | (3.8) | 7.6 | (3.8) | 7.8 | (4.2) |
Risk-based screening and prevention preferences
All women N = 942 | Low risk N = 236 | Average risk N = 228 | Moderate risk N = 239 | High risk N = 239 | ||||||
---|---|---|---|---|---|---|---|---|---|---|
Want to know breast cancer risk, n (%)a | ||||||||||
Yes | 756 | (80.3) | ||||||||
No | 70 | (7.4) | ||||||||
Don’t know | 99 | (10.5) | ||||||||
Missing value | 17 | (1.8) | ||||||||
Willing to get mammogram, n (%) | 727 | (96.2) | ||||||||
Willing to complete questionnaire, n (%) | 725 | (95.9) | ||||||||
Willing to provide blood sample, n (%) | 738 | (97.6) | ||||||||
Risk result in letter, n acceptable (%)a | 621 | (67.1) | 199 | (86.1) | 160 | (70.2) | 144 | (61.5) | 118 | (50.2) |
Need for consultation, n yes (%)a | 722 | (76.6) | 131 | (56.7) | 158 | (70.2) | 214 | (91.5) | 219 | (93.2) |
Preferred risk counsellor, n (%)b | ||||||||||
General practitioner | 539 | (57.2) | 91 | (38.6) | 126 | (55.3) | 169 | (70.7) | 153 | (64.0) |
Oncologist | 293 | (31.1) | 38 | (16.1) | 58 | (25.4) | 94 | (39.3) | 103 | (43.1) |
Nurse | 93 | (9.9) | 21 | (8.9) | 24 | (10.5) | 24 | (10.0) | 24 | (10.0) |
Geneticist | 77 | (8.2) | 14 | (5.9) | 10 | (4.4) | 29 | (12.1) | 24 | (10.0) |
Radiologist | 64 | (6.8) | 11 | (4.7) | 15 | (6.6) | 24 | (10.0) | 14 | (5.9) |
Radiographer | 63 | (6.7) | 15 | (6.4) | 18 | (7.9) | 19 | (7.9) | 11 | (4.6) |
Use website, n yes (%)c | 730 | (79.0) | 167 | (72.6) | 172 | (76.4) | 203 | (86.8) | 188 | (80.0) |
Supplemental screening, n yes (%)c | 370 | (39.3) | 63d | (27.4) | 89e | (39.6) | 117e | (50.0) | 101f | (43.0) |
Preferred screening interval low risk | ||||||||||
2-year | 116 | (50.7) | ||||||||
3-year | 30 | (13.1) | ||||||||
4-year | 30 | (13.1) | ||||||||
5-year | 13 | (5.7) | ||||||||
Don’t know | 18 | (7.8) | ||||||||
Other | 22 | (9.6) | ||||||||
Preferred screening start age low risk | ||||||||||
50 years | 64 | (27.9) | ||||||||
51 years | 3 | (1.3) | ||||||||
52 years | 12 | (5.2) | ||||||||
53 years | 8 | (3.5) | ||||||||
54 years | 7 | (3.1) | ||||||||
55 years | 37 | (16.2) | ||||||||
56 years | 3 | (1.3) | ||||||||
57 years | 3 | (1.3) | ||||||||
58 years | 3 | (1.3) | ||||||||
59 years | 1 | (0.4) | ||||||||
60 years | 13 | (5.7) | ||||||||
Other | 43 | (18.8) | ||||||||
Don’t know | 32 | (14.0) | ||||||||
Preferred screening interval high risk | ||||||||||
6-month | 31 | (30.7) | ||||||||
1-year | 51 | (50.5) | ||||||||
18-month | 1 | (1.0) | ||||||||
2-year | 4 | (4.0) | ||||||||
Don’t know | 6 | (5.9) | ||||||||
Other | 8 | (7.9) | ||||||||
Preferred screening start age high risk | ||||||||||
40 years | 60 | (59.4) | ||||||||
42 years | 1 | (1.0) | ||||||||
45 years | 5 | (5.0) | ||||||||
50 years | 2 | (2.0) | ||||||||
Other | 22 | (21.8) | ||||||||
Don’t know | 11 | (10.9) | ||||||||
Increased breast self-exam (% yes)g | 597 | (64.7) | 65 | (28.4) | 132 | (58.7%) | 204 | (87.2) | 196 | (83.4) |
Change diet (%)h | ||||||||||
Yes | 445 | (47.2) | 101 | (42.8) | 91 | (39.9) | 129 | (54.0) | 124 | (51.9) |
No | 9 | (1.0) | 6 | (2.5) | 0 | (−) | 1 | (0.4) | 2 | (0.8) |
No, not required | 362 | (38.4) | 98 | (41.5) | 105 | (46.1) | 78 | (32.6) | 81 | (33.9) |
Don’t know | 40 | (4.2) | 8 | (3.4) | 11 | (4.8) | 8 | (3.3) | 13 | (5.4) |
Other | 61 | (6.5) | 14 | (5.9) | 15 | (6.6) | 18 | (7.5) | 14 | (5.9) |
Change exercise habits (%)h | ||||||||||
Yes | 307 | (32.6) | 64 | (27.1) | 71 | (31.1) | 86 | (36.0) | 86 | (36.0) |
No | 119 | (12.6) | 42 | (17.8) | 30 | (13.2) | 25 | (10.5) | 22 | (9.2) |
No, not required | 332 | (35.2) | 86 | (36.4) | 83 | (36.4) | 78 | (32.6) | 85 | (35.6) |
Don’t know | 84 | (8.9) | 17 | (7.2) | 19 | (8.3) | 26 | (10.9) | 22 | (9.2) |
Other | 75 | (8.0) | 18 | (7.6) | 19 | (8.3) | 19 | (7.9) | 19 | (7.9) |
Change alcohol consumption (%)h | ||||||||||
Yes | 277 | (29.4) | 58 | (24.6) | 59 | (25.9) | 71 | (29.7) | 89 | (37.2) |
No | 55 | (5.8) | 25 | (10.6) | 12 | (5.3) | 10 | (4.2) | 8 | (3.3) |
No, not required | 531 | (56.4) | 130 | (55.1) | 142 | (62.3) | 136 | (56.9) | 123 | (51.5) |
Don’t know | 30 | (3.2) | 9 | (3.8) | 4 | (1.8) | 10 | (4.2) | 7 | (2.9) |
Other | 24 | (2.5) | 5 | (2.1) | 5 | (2.2) | 7 | (2.9) | 7 | (2.9) |
Willing to consider medication (% yes)i | 241 | (58.2) | 112 | (53.8) | 129 | (62.6) | ||||
Tamoxifen preference, n (%)j | ||||||||||
Pill | 171 | (35.7) | 90 | (37.7) | 81 | (33.9) | ||||
Cream | 125 | (26.2) | 59 | (24.7) | 66 | (27.6) | ||||
No preference | 93 | (19.5) | 42 | (17.6) | 51 | (21.3) | ||||
Neither | 47 | (9.8) | 26 | (10.9) | 21 | (8.8) | ||||
Don’t know | 32 | (6.7) | 17 | (7.1) | 15 | (6.3) | ||||
Anecdotal knowledge of tamoxifen (% yes)j | 55 | (11.8) | 22 | (9.4) | 33 | (14.1) |
Acceptability of risk-based breast cancer screening
Characteristic | Acceptability of risk-based breast cancer screening | |||||
---|---|---|---|---|---|---|
Interest in risk | Interest in supplemental screening | Interest in breast self-examination | ||||
Unadjusted | Multi-adjustedc | Unadjusted | Multi-adjustedc | Unadjusted | Multi-adjustedc | |
OR (95% CI) | OR (95% CI) | OR (95% CI) | OR (95% CI) | OR (95% CI) | OR (95% CI) | |
Risk scenario | ||||||
Low | n/ad | n/ad | 0.58 (0.39, 0.86) | 0.61 (0.41, 0.92) | 0.28 (0.19, 0.41) | 0.28 (0.19, 0.42) |
Average | n/ad | n/ad | REF | REF | REF | REF |
Moderate | n/ad | n/ad | 1.53 (1.01, 2.21) | 1.59 (1.09, 2.34) | 4.79 (3.01, 7.64) | 5.26 (3.25, 8.52) |
High | n/ad | n/ad | 1.15 (0.79, 1.67) | 1.23 (0.84, 1.81) | 3.54 (2.29, 5.47) | 4.32 (2.72, 6.86) |
Agee | 0.94 (0.91, 0.96) | 0.94 (0.91, 0.97) | 1.00 (0.97, 1.02) | 0.99 (0.97, 1.02) | 1.01 (0.99, 1.03) | 1.00 (0.97, 1.03) |
Education | ||||||
Lower | REF | REF | REF | REF | REF | REF |
Higher secondary | 1.68 (1.11, 2.55) | 1.21 (0.76, 1.90) | 0.79 (0.57, 1.09) | 0.72 (0.51, 1.03) | 1.08 (0.77, 1.53) | 1.00 (0.65, 1.53) |
Higher vocational | 1.34 (0.89, 2.03) | 1.04 (0.66, 1.61) | 0.62 (0.44, 0.88) | 0.58 (0.40, 0.84) | 0.81 (0.57, 1.14) | 0.66 (0.43, 1.01) |
FDRb breast cancer | ||||||
No | REF | REF | REF | REF | REF | REF |
Yes | 1.09 (0.72, 1.65) | 0.97 (0.61, 1.53) | 1.34 (0.98, 1.85) | 1.28 (0.90, 1.81) | 0.95 (0.69, 1.32) | 1.00 (0.67, 1.52) |
Benign breast disease | ||||||
No | REF | REF | REF | REF | REF | REF |
Yes | 1.20 (0.82, 1.75) | 1.25 (0.83, 1.88) | 1.02 (0.77, 1.37) | 0.98 (0.72, 1.34) | 1.03 (0.77, 1.39) | 1.24 (0.86, 1.78) |
General healthf | 0.99 (0.98, 1.00) | 1.00 (0.98, 1.01) | 1.00 (0.99, 1.01) | 1.00 (0.99, 1.01) | 1.01 (0.99, 1.01) | 1.00 (0.99, 1.01) |
Risk perception | ||||||
Below average | n/ad | n/ad | 0.79 (0.60, 1.05) | 0.90 (0.67, 1.22) | 1.50 (1.12, 1.99) | 1.83 (1.28, 2.60) |
Average | n/ad | n/ad | REF | REF | REF | REF |
Above average | n/ad | n/ad | 1.75 (1.01, 3.02) | 1.49 (0.82, 2.70) | 1.23 (0.69, 2.17) | 0.84 (0.42, 1.68) |
Health anxietyg | 1.05 (1.00, 1.09) | 1.04 (0.99, 1.10) | 1.03 (0.99, 1.06) | 1.02 (0.99, 1.06) | 1.01 (0.97, 1.04) | 1.03 (0.98, 1.08) |
Health locus of control | ||||||
No preference | REF | REF | REF | REF | REF | REF |
Internal | 1.00 (0.55, 1.80) | 0.85 (0.44, 1.64) | 0.84 (0.54, 1.30) | 0.98 (0.61, 1.56) | 1.24 (0.79, 1.95) | 1.17 (0.67, 2.03) |
Physician | 0.56 (0.26, 1.18) | 0.51 (0.22, 1.17) | 0.74 (0.40, 1.37) | 0.63 (0.32, 1.24) | 2.86 (1.38, 5.94) | 2.09 (0.87, 5.03) |
Chance | 0.79 (0.45, 1.38) | 0.74 (0.39, 1.39) | 0.80 (0.52, 1.21) | 0.87 (0.56, 1.37) | 1.00 (0.65, 1.53) | 0.82 (0.49, 1.39) |
Acceptability of risk-based breast cancer prevention
Characteristic | Acceptability of risk-based prevention | |||||||
---|---|---|---|---|---|---|---|---|
Change diet | Increase exercise | Limit alcohol intake | Consider medication | |||||
Unadjusted | Multi-adjustedc | Unadjusted | Multi-adjustedc | Unadjusted | Multi-adjustedc | Unadjusted | Multi-adjustedc | |
OR (95% CI) | OR (95% CI) | OR (95% CI) | OR (95% CI) | OR (95% CI) | OR (95% CI) | OR (95% CI) | OR (95% CI) | |
Risk scenario | ||||||||
Low | 1.12 (0.76, 1.66) | 1.10 (0.73, 1.68) | 0.80 (0.52, 1.21) | 0.76 (0.49, 1.18) | 0.98 (0.64, 1.50) | 1.08 (0.69, 1.68) | n/a | n/a |
Average | REF | REF | REF | REF | REF | REF | n/a | n/a |
Moderate | 1.88 (1.27, 2.80) | 1.95 (1.27, 2.98) | 1.33 (0.88, 2.01) | 1.30 (0.84, 2.00) | 1.27 (0.84, 1.92) | 1.32 (0.86, 2.04) | REF | REF |
High | 1.72 (1.16, 2.56) | 1.95 (1.28, 2.97) | 1.28 (0.85, 1.93) | 1.37 (0.89, 2.09) | 1.77 (1.19, 2.65) | 2.02 (1.33, 3.08) | 1.44 (0.97, 2.13) | 1.57 (1.03, 2.37) |
Agef | 0.98 (0.96, 1.00) | 0.99 (0.96, 1.01) | 0.98 (0.96, 1.00) | 0.99 (0.96, 1.01) | 1.01 (0.98, 1.03) | 1.00 (0.98, 1.03) | 0.98 (0.95, 1.01) | 0.99d (0.96, 1.03) |
Education | ||||||||
Lower | REF | REF | REF | REF | REF | REF | REF | REF |
Higher secondary | 1.21 (0.86, 1.72) | 1.16 (0.79, 1.71) | 1.86 (1.27, 2.73) | 1.81 (1.20, 2.74) | 1.41 (0.97, 2.06) | 1.35 (0.90, 2.03) | 1.33 (0.80, 2.19) | 1.26 (0.73, 2.16) |
Higher vocational | 0.97 (0.68, 1.38) | 1.06 (0.71, 1.56) | 1.93 (1.31, 2.85) | 1.93 (1.27, 2.91) | 2.03 (1.38, 2.97) | 1.81 (1.21, 2.70) | 1.38 (0.82, 2.32) | 1.56 (0.89, 2.74) |
BMIg | 1.13 (1.09, 1.17) | 1.12 (1.08, 1.17) | 1.02 (0.99, 1.05) | 1.02 (0.98, 1.05) | 0.94 (0.91, 0.97) | 0.95 (0.92, 0.98) | 1.04 (1.00, 1.08) | 1.03 (0.99, 1.08) |
FDRb breast cancer | ||||||||
No | REF | REF | REF | REF | REF | REF | REF | REF |
Yes | 0.72 (0.51, 1.00) | 0.63 (0.43, 0.93) | 0.58 (0.40, 0.85) | 0.55 (0.36, 0.84) | 0.84 (0.59, 1.20) | 0.90 (0.61, 1.33) | 1.53 (0.94, 2.47) | 1.31 (0.76, 2.25) |
Benign breast disease | ||||||||
No | REF | REF | REF | REF | REF | REF | REF | REF |
Yes | 0.72 (0.53, 0.98) | 0.88 (0.63, 1.23) | 0.83 (0.60, 1.14) | 0.86 (0.61, 1.22) | 1.06 (0.77, 1.44) | 0.99 (0.71, 1.38) | 1.16 (0.74, 1.83) | 1.26 (0.78, 2.04) |
Co-morbidity | ||||||||
0–1 | REF | REF | REF | REF | REF | REF | REF | REF |
≥ 2 | 1.13 (0.86, 1.49) | 1.00 (0.73, 1.38) | 1.14 (0.85, 1.53) | 1.20 (0.87, 1.66) | 0.79 (0.59, 1.05) | 0.90 (0.65, 1.24) | 1.23 (0.83, 1.82) | 1.06 (0.69, 1.65) |
General healthh | 0.99 (0.98, 1.00) | 0.99 (0.98, 1.01) | 0.99 (0.98, 1.00) | 0.99 (0.98, 1.00) | 1.00 (0.99, 1.01) | 1.00 (0.99, 1.01) | 0.98 (0.97, 1.00) | 0.99d (0.97, 1.01) |
Life events | ||||||||
0–1 | REF | REF | REF | REF | REF | REF | REF | REF |
≥ 2 | 1.15 (0.84, 1.56) | 1.08 (0.78, 1.51) | 1.01 (0.72, 1.40) | 1.00 (0.70, 1.41) | 0.92 (0.67, 1.26) | 0.93 (0.66, 1.30) | 1.06 (0.68, 1.66) | 1.05 (0.65, 1.69) |
Risk perception | ||||||||
Below average | 0.86 (0.65, 1.15) | 0.92 (0.67, 1.26) | 0.96 (0.71, 1.30) | 0.97 (0.70, 1.34) | 1.16 (0.86, 1.56) | 1.04 (0.75, 1.43) | 0.56 (0.37, 0.85) | 0.65 (0.41, 1.01) |
Average | REF | REF | REF | REF | REF | REF | REF | REF |
Above average | 1.96 (1.04, 3.68) | 1.72 (0.85, 3.50) | 1.23 (0.67, 2.27) | 1.40 (0.71, 2.77) | 1.04 (0.56, 1.90) | 0.88 (0.45, 1.72) | 1.21 (0.54, 2.69) | 1.00 (0.41, 2.46) |
Health anxietyi | 1.05 (1.02, 1.09) | 1.04 (1.00, 1.08) | 1.03 (0.99, 1.06) | 1.01 (0.97, 1.05) | 1.02 (0.98, 1.06) | 1.03 (0.99, 1.07) | 1.04 (0.99, 1.09) | 1.02 (0.96, 1.08) |
Health locus of control | ||||||||
No preference | REF | REF | REF | REF | REF | REF | REF | REF |
Internal | 0.96 (0.60, 1.51) | 0.94 (0.57, 1.55) | 1.13 (0.70, 1.82) | 1.05 (0.63, 1.75) | 1.47 (0.91, 2.39) | 1.50 (0.89, 2.53) | 1.01 (0.50, 2.08) | 0.98 (0.46, 2.09) |
Physician | 2.25 (1.12, 4.50) | 1.77 (0.82, 3.80) | 2.23 (1.14, 4.36) | 2.05 (0.99, 4.25) | 1.24 (0.62, 2.46) | 1.44 (0.68, 3.03) | 1.23 (0.50, 3.04) | 1.23 (0.46, 3.29) |
Chance | 0.93 (0.60, 1.44) | 1.01 (0.63, 1.64) | 1.14 (0.72, 1.81) | 1.19 (0.73, 1.95) | 1.20 (0.75, 1.92) | 1.27 (0.76, 2.10) | 0.75 (0.38, 1.49) | 0.66 (0.31, 1.38) |
Current medication use | ||||||||
No | REF | REF | ||||||
Yes | 1.33 (0.89, 1.98) | 1.00e (0.63, 1.59) | ||||||
Beliefs about medicinesj | ||||||||
Harm | 0.87 (0.80, 0.94) | 0.89d (0.82, 0.98) | ||||||
Overuse | 0.86 (0.81, 0.92) | 0.87d (0.81, 0.93) |