Method: Longitudinal, multi-site survey of breast cancer (BC) patients, with measurements at 1 month and 1 year after surgery. Patients completed the BC Surgery Decision Quality Instrument to assess knowledge, goals and involvement in decision-making. Total knowledge and involvement scores were scaled from 0-100% with higher scores indicating higher knowledge and involvement. We tested several hypotheses: (1) knowledge scores would decline (2) the decline would be greater for quantitative items than qualitative items, (3) involvement scores would decline and (4) goals (e.g. desire to keep breast, remove breast for peace of mind and avoid radiation) would become more aligned with choices over time. Changes in scores were examined using paired t-tests.
Result:
267/444 (60%) completed 1 month and 229/267 (86%) completed 1-year assessment. The mean total knowledge score did not change (69.2% (SD16.6%) 1-month versus 69.4% (SD17.7%) 1-year, p=0.86). Patients scored the same on quantitative items (61.3% 1-month versus 59.8% 1-year, p=0.65). The reports of involvement did not change (66.8% (SD24.7%) versus 65.2% (SD26.1%), p=0.31). Only one of the goals, avoid radiation, changed significantly and became less important for all patients over time (for lumpectomy patients, mean difference=-0.44, p=0.03 and for mastectomy patients, mean difference=-0.93, p=0.05). Despite the minimal change in mean scores, many respondents had knowledge scores (116/229, 50%) or involvement scores (163/229, 70%) change by >10% with increases balancing out decreases.
Conclusion: Contrary to our hypotheses, we did not find differences in the mean scores for knowledge, involvement or goals. For population-level assessments, it may be reasonable to survey BC patients up to a year after the decision, greatly increasing feasibility of measurement. However, scores changed markedly for many at the individual-level and additional studies are needed to examine factors associated with these changes and to confirm these results for other decisions.