Table 3. Primary and secondary outcomes for the DCIS cohort (Unadjusted results shown).
| Outcome | DA mean (s.d.) | Control mean (s.d.) | Difference (95% CI) | P-value | Standardised effect |
|---|---|---|---|---|---|
| Decisional conflict (DCS; max 100) |
20.7 (25.4) |
11.9 (10.9) |
8.8 (−2.4, 20.0) |
0.1 |
0.42 |
| Knowledge of clinical trials (max 7) |
5.56 (1.4) |
5.14 (1.8) |
0.41 (−0.52, 1.35)a |
0.3 |
0.26 |
| Objective knowledge of IBIS-II (max 100) |
77.6 (16.5) |
63.8 (22.2) |
13.9 (3.7, 24.0)a,b |
0.008 |
0.69 |
| Subjective knowledge of IBIS-II (QuIC-B; max 100) |
88.9 (12.5) |
83.2 (25.6) |
5.7 (−3.3, 14.6)a |
0.2 |
0.29 |
| Anxiety (STAI-S; max 80) |
29.6 (8.7) |
36.7 (10.9) |
−7.1 (−14.7, 0.6)b |
0.07 |
−0.70 |
| Attitude towards IBIS-II (max 100) |
76.0 (15.3) |
83.2 (11.8) |
−7.1 (−17.2, 2.9) |
0.2 |
−0.51 |
| Decisional regret at 3 months (DRS; max 50) |
16.9 (17.4) |
20.5 (12.1) |
−3.5 (−14.6, 7.4) |
0.5 |
−0.24 |
| Decisional satisfaction at 3 months (SWD; max 5) |
4.40 (0.7) |
4.39 (0.4) |
0.01 (−0.41, 0.41) |
1.0 |
0.01 |
| Intended to participate in IBIS-II |
65% |
73% |
−9 (−41, 23) |
0.6 |
−0.09 |
| Actual enrolment in IBIS-II |
58% |
64% |
−6 (−40, 27) |
0.7 |
−0.13 |
| Dropout from IBIS-IIc | 4/11=36% | 2/9=22% | 14 (−25, 53)b | 0.4 | 0.30 |
Abbreviations: CI= confidence interval; DCS= decisional conflict scale; DRS= Decisional Regret Scale; IBIS-II= International Breast Cancer Intervention Study-II; QuIC-B= Quality of Informed Consent scale – Part B; STAI-S= State-Trait Anxiety Inventory state scale; SWD= Satisfaction with Decision scale.
a
P<0.05 for main effect of cohort, indicating a difference in levels between Prevention and DCIS cohorts.
b
P<0.05 for main effect of cohort x group, indicating a difference in intervention effect between Prevention and DCIS cohorts.
c
Among those who enrolled.