The purpose of the Breast Cancer Surgery Decision Quality Instrument is to provide a comprehensive assessment of the extent to which patients make informed decision and receive treatments that match their goals. The knowledge score had good retest reliability and was able to discriminate between providers and patients. The concordance score provides an assessment of how well treatments matched patients’ goals. The goals used in calculating the concordance score had good retest reliability. Patients were able to complete the BCS-DQI on their own, with low rates of missing items indicating that it was feasible.
The knowledge items cover content that the majority of providers feel is very important for patients to know before making a decision. Patients had some gaps in knowledge, e.g. only 57% correctly answering that survival is the same for mastectomy and lumpectomy with radiation. It was surprising that the knowledge scores of the healthy controls were similar to those of the breast cancer survivors. This result could be due to the fact that the controls were more knowledgeable generally (due to working in health care environment), or that survivors’ breast cancer knowledge had decreased over time. Other studies have found similarly low levels of knowledge for patients surveyed much closer to the time of diagnosis, which suggests that timing may not fully explain the lack of knowledge for this sample [14
Three of the goals and concerns, importance of keeping the breast, removing the breast for peace of mind, and avoiding radiation, met the criteria for retest reliability and also discriminated between the options. The first two goals may appear to be simply two ends of the same issue, and although they are negatively correlated, they are not redundant (Pearson
−0.46). Similar concerns have been found to be related to treatment choices in other breast cancer studies [16
]. Clinicians seeking to elicit patients’ preferences should, at a minimum, discuss how patients feel about keeping or losing their breast and how they feel about radiation.
The concordance score was high, indicating that most patients received treatments that matched their goals. Patients who preferred mastectomy were somewhat less likely to receive it (82%) compared to those who preferred lumpectomy (92%). Contrary to our hypotheses, we did not find evidence that respondents who received treatments that matched their goals had higher confidence or less decisional regret. This was possibly due to a ceiling effect with these items, as all patients had very high confidence and low regret. Several studies have found a positive relationship between decision making processes, such as being offered a choice of breast surgery and matching preferred level of involvement in decision making, with health outcomes including body image, psychological adjustment, and satisfaction [18
]. It will be important to examine associated between concordance and these other outcomes in prospective studies.
The definition for concordance used here requires that the treatments received match patients’ goals. There are a growing number of studies that are reporting this metric, although the studies define and measure concordance differently [28
]. The multidimensional measure of informed choice is one approach that combines knowledge and value concordance into a single measure [34
]. It was developed to measure the quality of decision about prenatal testing and has been adapted for use in genetic testing for cancer [34
]. The ability to reliably document that the treatments received, or the care delivered, reflects patients’ goals, needs and wants will be important.
The BCS-DQI was designed to audit the quality of decisions and to compare performance of providers or breast cancer centers on how well they inform their patients and how well they tailor treatments to patients’ goals. Clinicians have requested a short version that could be used in routine practice as a screening tool to assess patients’ knowledge and goals before the visit so that they could address any gaps. A short version, the BCS-DQI Screener, includes 5 knowledge items and 5 goals. Since there are fewer items, it might miss knowledge gaps or key goals that patients have. The purpose is to stimulate conversation between patients and providers about options, outcomes and goals, but not to limit content to only those items included.
Collins et al. (2009) surveyed newly diagnosed patients with an earlier version of the BCS-DQI Screener after patients had viewed a decision aid and before they saw their surgeon. They found high patient knowledge scores, for example, 98% of respondents answered the question about survival equivalence of the treatments correctly compared to 57% from the retrospective sample reported here [37
]. In general, the patients’ knowledge scores in their study (86%) were comparable to the providers’ scores (87%). Further, in the Collins study, the same three goals were significant in the multivariable treatment model, suggesting the concordance model may hold for newly diagnosed patients who are actively making the treatment decision [37
The current study has several limitations that should be noted. First, it was a retrospective study and patients were surveyed about 2 ½
years after the decision during which time their knowledge, goals and concerns likely changed. The survey relies on patient report and may not fully reflect what information was conveyed by clinicians during the decision making process. The sample was from four academic, National Cancer Institute-designated comprehensive cancer centers, and the performance may be different in community settings. Non-white patients had a lower response rate than white patients which raise questions about acceptability across diverse populations. Several studies have documented lower response rates and lower participation in research studies for non-white participants [38
]. Further, the content validity was established on the full set of items and it is possible that the reduced set and the 5-item screener would not be reviewed as highly. It will be important to further test the BCS-DQI in order to understand the acceptability and performance of the instrument across more diverse populations and practice settings, and with patients at the time of the decision.