Validity of standard gamble utilities in patients referred for aortic valve replacement

Value assessment frameworks: who is valuing the care in healthcare?

Many healthcare agencies are producing evidence-based guidance and policy that may determine the availability of particular healthcare products and procedures, effectively rationing aspects of healthcare. They claim legitimacy for their decisions through reference to evidence-based scientific method and the implementation of just decision-making procedures, often citing the criteria of 'accountability for reasonableness'; publicity, relevance, challenge and revision, and regulation. Central to most decision methods are estimates of gains in quality-adjusted life-years (QALY), a measure that combines the length and quality of survival. However, all agree that the QALY alone is not a sufficient measure of all relevant aspects of potential healthcare benefits, and a number of value assessment frameworks have been suggested. I argue that the practical implementation of these procedures has the potential to lead to a distorted assessment of value. Undue weight may be ascribed to certain attributes, particularly those that favour commercial or political interests, while other attributes that are highly valued by society, particularly those related to care processes, may be omitted or undervalued. This may be compounded by a lack of transparency to relevant stakeholders, resulting in an inability for them to participate in, or challenge, the decisions. The makes it likely that costly new technologies, for which inflated prices can be justified by the current value frameworks, are displacing aspects of healthcare that are highly valued by society.

Patient-centered benefit-risk analysis of transcatheter aortic valve replacement

Background: Aortic stenosis (AS) treatments include surgical aortic valve replacement (SAVR) and transcatheter aortic valve replacement (TAVR). Choosing between SAVR and TAVR requires patients to trade-off  benefits and risks. The objective of this research was to determine which  TAVR and SAVR outcomes patients consider important, collect quantitative data about how patients weigh benefits and risks, and evaluate patients' preferences for SAVR or TAVR. Methods: Patients  were recruited from advocacy organization databases. Patients self-reported as being diagnosed with AS, and as either having received AS treatment or as experiencing AS-related physical activity limitations. An online adapted swing weighting (ASW) method - a pairwise comparison of attributes - was used to elicit attribute trade-offs from 219 patients. Survey data were used to estimate patients' weights for AS treatment attributes, which were incorporated into a quantitative benefit-risk analysis (BRA) to evaluate patients' preferences for TAVR and SAVR. Results: On average, patients put greater value on attributes that favored TAVR than SAVR. Patients' valuation of the lower mortality rate, reduced procedural invasiveness, and quicker time to return to normal quality of life associated with TAVR, offset their valuation of the time over which SAVR has been proven to work. There was substantial heterogeneity in patients' preferences. This was partly explained by age, with differences in preference observed between patients <60 years to those ≥60 years. A Monte Carlo Simulation found that 79.5% of patients prefer TAVR. Conclusions: Most AS patients are willing to tolerate sizable increases in clinical risk in exchange for the benefits of TAVR, resulting in a large proportion of patients preferring TAVR to SAVR. Further work should be undertaken to characterize the heterogeneity in preferences for AS treatment attributes. Shared decision-making tools based on attributes important to patients can support patients' selection of the procedure that best meets their needs.

Patient-centered benefit-risk analysis of transcatheter aortic valve replacement

Background: Aortic stenosis (AS) treatments include surgical aortic valve replacement (SAVR) and transcatheter aortic valve replacement (TAVR). Choosing between SAVR and TAVR requires patients to trade-off  benefits and risks. The objective of this research was to determine which  TAVR and SAVR outcomes patients consider important, collect quantitative data about how patients weigh benefits and risks, and evaluate patients’ preferences for SAVR or TAVR.

Methods: Patients  were recruited from advocacy organization databases. Patients self-reported as being diagnosed with AS, and as either having received AS treatment or as experiencing AS-related physical activity limitations. An online adapted swing weighting (ASW) method – a pairwise comparison of attributes – was used to elicit attribute trade-offs from 219 patients. Survey data were used to estimate patients’ weights for AS treatment attributes, which were incorporated into a quantitative benefit-risk analysis (BRA) to evaluate patients’ preferences for TAVR and SAVR.

Results: On average, patients put greater value on attributes that favored TAVR than SAVR. Patients’ valuation of the lower mortality rate, reduced procedural invasiveness, and quicker time to return to normal quality of life associated with TAVR, offset their valuation of the time over which SAVR has been proven to work. There was substantial heterogeneity in patients’ preferences. This was partly explained by age, with differences in preference observed between patients <60 years to those ≥60 years. A Monte Carlo Simulation found that 79.5% of patients prefer TAVR.

Conclusions: Most AS patients are willing to tolerate sizable increases in clinical risk in exchange for the benefits of TAVR, resulting in a large proportion of patients preferring TAVR to SAVR. Further work should be undertaken to characterize the heterogeneity in preferences for AS treatment attributes. Shared decision-making tools based on attributes important to patients can support patients’ selection of the procedure that best meets their needs.

Patient values and preferences on transcatheter or surgical aortic valve replacement therapy for aortic stenosis: a systematic review

OBJECTIVE

To investigate patients' values and preferences regarding aortic valve replacement therapy for aortic stenosis.

SETTING

Studies published after transcatheter aortic valve insertion (TAVI) became available (2002).

PARTICIPANTS

Adults with aortic stenosis who are considering or have had valve replacement, either TAVI or via surgery (surgical aortic valve replacement, SAVR).

OUTCOME MEASURES

We sought quantitative measurements, or qualitative descriptions, of values and preferences. When reported, we examined correlations between preferences and objective (eg, ejection fraction) or subjective (eg, health-related quality of life) measures of health.

RESULTS

We reviewed 1348 unique citations, of which 2 studies proved eligible. One study of patients with severe aortic stenosis used a standard gamble study to ascertain that the median hypothetical mortality risk patients were willing to tolerate to achieve full health was 25% (IQR 25-50%). However, there was considerable variability; for mortality risk levels defined by current guidelines, 130 participants (30%) were willing to accept low-to-intermediate risk (≤8%), 224 (51%) high risk (>8-50%) and 85 (19%) a risk that guidelines would consider prohibitive (>50%). Study authors did not, however, assess participants' understanding of the exercise, resulting in a potential risk of bias. A second qualitative study of 15 patients identified the following factors that influence patients to undergo assessment for TAVI: symptom burden; expectations; information support; logistical barriers; facilitators; obligations and responsibilities. The study was limited by serious risk of bias due to authors' conflict of interest (5/9 authors industry-funded).

CONCLUSIONS

Current evidence on patient values and preferences of adults with aortic stenosis is very limited, and no studies have enrolled patients deciding between TAVI and SAVR. On the basis of the data available, there is evidence of variability in individual values and preferences, highlighting the importance of well-informed and shared decision-making with patients facing this decision.

TRIAL REGISTRATION NUMBER

PROSPERO CRD42016041907.

Eliciting Patient Risk Willingness in Clinical Consultations as a Means of Improving Decision-Making of Aortic Valve Replacement

BACKGROUND

Treatment decisions for aortic valve replacement (AVR) should be sensitive to patient preferences. However, we lack knowledge of patient preferences and how to obtain them.

METHODS AND RESULTS

We assessed the mortality risk patients were willing to accept when undergoing AVR by using the Standard Gamble method and aimed to show how this risk willingness was affected by level of disease burden. We report findings from 439 patients, aged >18 years with severe aortic stenosis who were referred for evaluation of AVR to our institution. The vast majority of patients accepted a mortality risk regarded as high or prohibitive according to current guidelines. Of the 439 patients, 51% patients were willing to forego surgery with high mortality risk (8-50%) and 19% were willing accept a prohibitive mortality risk (>50%) as defined in current guidelines. However, the risk willingness varied considerably. Acceptance of prohibitive risk willingness (>50%) was associated with reporting of 3 to 5 different restricting symptoms, with an odds ratio of 4.07 (95% CI 1.56-10.59) opposed by increasing score on EuroQol-Visual Analog Scale, with an odds ratio of 0.99 (95% CI 0.97-1.00). The poor ability to predict risk willingness based on available clinical variables and health status suggests that other factors may be important advocating the need for tools for soliciting patient's preferences individually.

CONCLUSION

When undergoing AVR, patients were willing to accept considerably higher perioperative risk than what is considered acceptable in current guidelines and practice. Patient preferences varied considerably, and they should be directly assessed and taken into account in decision-making and guidelines.

CLINICAL TRIAL REGISTRATION

URL: https://clinicaltrials.gov/. Unique identifier: NCT01794832.