A protocol for a discrete choice experiment: understanding patient medicine preferences for managing chronic non-cancer pain

Which Factors Are Considered by Patients When Considering Total Joint Arthroplasty? A Discrete-choice Experiment

BACKGROUND

TKA and THA are major surgical procedures, and they are associated with the potential for serious, even life-threatening complications. Patients must weigh the risks of these complications against the benefits of surgery. However, little is known about the relative importance patients place on the potential complications of surgery compared with any potential benefit the procedures may achieve. Furthermore, patient preferences may often be discordant with surgeon preferences regarding the treatment decision-making process. A discrete-choice experiment (DCE) is a quantitative survey technique designed to elicit patient preferences by presenting patients with two or more hypothetical scenarios. Each scenario is composed of several attributes or factors, and the relative extent to which respondents prioritize these attributes can be quantified to assess preferences when making a decision, such as whether to pursue lower extremity arthroplasty.

QUESTIONS/PURPOSES

In this DCE, we asked: (1) Which patient-related factors (such as pain and functional level) and surgery-related factors (such as the risk of infection, revision, or death) are influential in patients' decisions about whether to undergo lower extremity arthroplasty? (2) Which of these factors do patients emphasize the most when making this decision?

METHODS

A DCE was designed with the following attributes: pain; physical function; return to work; and infection risks, reoperation, implant failure leading to premature revision, deep vein thrombosis, and mortality. From October 2021 to March 2022, we recruited all new patients to two arthroplasty surgeons' clinics who were older than 18 years and scheduled for a consultation for knee- or hip-related complaints who had no previous history of a primary TKA or THA. A total of 56% (292 of 517) of new patients met the inclusion criteria and were approached with the opportunity to complete the DCE. Among the cohort, 51% (150 of 292) of patients completed the DCE. Patients were administered the DCE, which consisted of 10 hypothetical scenarios that had the patient decide between a surgical and nonsurgical outcome, each consisting of varying levels of eight attributes (such as infection, reoperation, and ability to return to work). A subsequent demographic questionnaire followed this assessment. To answer our first research question about the patient-related and surgery-related factors that most influence patients' decisions to undergo lower extremity arthroplasty, we used a conditional logit regression to control for potentially confounding attributes from within the DCE and determine which variables shifted a patient's determination to pursue surgery. To answer our second question, about which of these factors received the greatest priority by patients, we compared the relevant importance of each factor, as determined by each factor's beta coefficient, against each other influential factor. A larger absolute value of beta coefficient reflects a relatively higher degree of importance placed on a variable compared with other variables within our study. Of the respondents, 57% (85 of 150) were women, and the mean age at the time of participation was 64 ± 10 years. Most respondents (95% [143 of 150]) were White. Regarding surgery, 38% (57 of 150) were considering THA, 59% (88 of 150) were considering TKA, and 3% (5 of 150) were considering both. Among the cohort, 49% (74 of 150) of patients reported their average pain level as severe, or 7 to 10 on a scale from 0 to 10, and 47% (71 of 150) reported having 50% of full physical function.

RESULTS

Variables that were influential to respondents when deciding on lower extremity total joint arthroplasty were improvement from severe pain to minimal pain (β coefficient: -0.59 [95% CI -0.72 to -0.46]; p < 0.01), improvement in physical function level from 50% to 100% (β: -0.80 [95% CI -0.9 to -0.7]; p < 0.01), ability to return to work versus inability to return (β: -0.38 [95% CI -0.48 to -0.28]; p < 0.01), and the surgery-related factor of risk of infection (β: -0.22 [95% CI -0.30 to -0.14]; p < 0.01). Improvement in physical function from 50% to 100% was the most important for patients making this decision because it had the largest absolute coefficient value of -0.80. To improve physical function from 50% to 100% and reduce pain from severe to minimal because of total joint arthroplasty, patients were willing to accept a hypothetical absolute (and not merely an incrementally increased) 37% and 27% risk of infection, respectively. When we stratified our analysis by respondents' preoperative pain levels, we identified that only patients with severe pain at the time of their appointment found the risk of infection influential in their decision-making process (β: -0.27 [95% CI -0.37 to -0.17]; p = 0.01) and were willing to accept a 24% risk of infection to improve their physical functioning from 50% to 100%.

CONCLUSION

Our study revealed that patients consider pain alleviation, physical function improvement, and infection risk to be the most important attributes when considering total joint arthroplasty. Patients with severe baseline pain demonstrated a willingness to take on a hypothetically high infection risk as a tradeoff for improved physical function or pain relief. Because patients seemed to prioritize postoperative physical function so highly in our study, it is especially important that surgeons customize their presentations about the likelihood an individual patient will achieve a substantial functional improvement as part of any office visit where arthroplasty is discussed. Future studies should focus on quantitatively assessing patients' understanding of surgical risks after a surgical consultation, especially in patients who may be the most risk tolerant.

CLINICAL RELEVANCE

Surgeons should be aware that patients with the most limited physical function and the highest baseline pain levels are more willing to accept the more potentially life-threatening and devastating risks that accompany total joint arthroplasty, specifically infection. The degree to which patients seemed to undervalue the harms of infection (based on our knowledge and perception of those harms) suggests that surgeons need to take particular care in explaining the degree to which a prosthetic joint infection can harm or kill patients who develop one.

Societal Preferences for Meningococcal B Vaccination in Children: A Discrete Choice Experiment in Spain

INTRODUCTION

Immunization is the most effective strategy for the prevention of invasive meningococcal disease caused by Neisseria meningitidis serogroup B (MenB); however, parents need to weigh the risk-benefit and financial impact of immunizing their children against MenB in the absence of a national immunization program (NIP). This study aimed to explore societal preferences (of parents and pediatricians) regarding the attributes of a MenB vaccine in Spain.

METHODS

A discrete choice experiment (DCE) based on cross-sectional surveys was carried out to determine preferences. A literature review and scientific committee determined the six attributes related to the MenB vaccine included in the DCE: vaccination age, cost, duration, percentage of protection, adverse events probability, and expert/authority recommendation. Data were analyzed using a mixed logit model. Relative importance (RI) of attributes was calculated and compared between parents and pediatricians.

RESULTS

A total of 278 parents [55.8% female, mean age 40.4 (standard deviation, SD 7.3) years] and 200 pediatricians [73.0% female, mean age 45.8 (SD 12.9) years] answered the DCE. For parents, the highest RI was attributed to vaccine cost, expert/authority recommendation, and percentage of protection (26.4%, 26.1%, and 22.9%, respectively), while for pediatricians the highest RI was assigned to percentage of protection, expert/authority recommendation, and vaccination age (27.2%, 23.7%, and 22.6%, respectively). Significant differences between parents and pediatricians were found in the RI assigned to all attributes (p < 0.001), except for vaccine recommendation.

CONCLUSION

In the decision regarding MenB vaccination, cost was a driver in parental decision-making but had a low RI for pediatricians and, conversely, vaccination age was highly valued by pediatricians but was the attribute with least importance for parents. Despite these differences, expert/authority recommendation and percentage of protection were essential criteria for both groups. These results provide relevant information about MenB vaccination, highlighting the importance of considering societal preferences for NIP inclusion.

Importance of attributes and willingness to pay for oral anticoagulant therapy in patients with atrial fibrillation in China: A discrete choice experiment

BACKGROUND

Adherence to oral anticoagulant therapy in patients with atrial fibrillation (AF) in China is low. Patient preference, one of the main reasons for discontinuation of oral anticoagulant therapy, is an unfamiliar concept in China.

METHODS AND FINDINGS

A discrete choice experiment (DCE) was conducted to quantify patient preference on 7 attributes of oral anticoagulant therapy: antidote (yes/no), food-drug interaction (yes/no), frequency of blood monitoring (no need, every 6/3/1 month[s]), risk of nonfatal major bleeding (0.7/3.1/5.5/7.8[%]), risk of nonfatal stroke (ischemic/hemorrhagic) or systemic embolism (0.6/3.2/5.8/8.4[%]), risk of nonfatal acute myocardial infarction (AMI) (0.2/1.0/1.8/2.5[%]), and monthly out-of-pocket cost (0/120/240/360 RMB) (0 to 56 USD). A total of 16 scenarios were generated by using D-Efficient design and were randomly divided into 2 blocks. Eligible patients were recruited and interviewed from outpatient and inpatient settings of 2 public hospitals in Beijing and Shenzhen, respectively. Patients were presented with 8 scenarios and asked to select 1 of 3 options: 2 unlabeled hypothetical treatments and 1 opt-out option. Mixed logit regression model was used for estimating patients' preferences of attributes of oral anticoagulants and willingness to pay (WTP) with adjustments for age, sex, education level, income level, city, self-evaluated health score, histories of cardiovascular disease/other vascular disease/any stroke/any bleeding, and use of anticoagulant/antiplatelet therapy. A total of 506 patients were recruited between May 2018 and December 2019 (mean age 70.3 years, 42.1% women). Patients were mainly concerned about the risks of AMI (β: -1.03; 95% CI: -1.31, -0.75; p < 0.001), stroke or systemic embolism (β: -0.81; 95% CI: -0.90, -0.73; p < 0.001), and major bleeding (β: -0.69; 95% CI: -0.78, -0.60; p < 0.001) and were willing to pay more, from up to 798 RMB to 536 RMB (124 to 83 USD) monthly. The least concerning attribute was frequency of blood monitoring (β: -0.31; 95% CI: -0.39, -0.24; p < 0.001). Patients had more concerns about food-drug interactions even exceeding preferences on the 3 risks, if they had a history of stroke or bleeding (β: -2.47; 95% CI: -3.92, -1.02; p < 0.001), recruited from Beijing (β: -1.82; 95% CI: -2.56, -1.07; p < 0.001), or men (β: -0.96; 95% CI: -1.36, -0.56; p < 0.001). Patients with lower educational attainment or lower income weighted all attributes lower, and their WTP for incremental efficacy and safety was minimal. Since the patients were recruited from 2 major hospitals from developed cities in China, further studies with better representative samples would be needed.

CONCLUSIONS

Patients with AF in China were mainly concerned about the safety and effectiveness of oral anticoagulant therapy. The preference weighting on food-drug interaction varied widely. Patients with lower educational attainment or income levels and less experience of bleeding or stroke had more reservations about paying for oral anticoagulant therapies with superior efficacy, safety, and convenience of use.

Patient Preferences to Assess Value IN Gene Therapies: Protocol Development for the PAVING Study in Hemophilia

Introduction: Gene therapies are innovative therapies that are increasingly being developed. However, health technology assessment (HTA) and payer decision making on these therapies is impeded by uncertainties, especially regarding long-term outcomes. Through measuring patient preferences regarding gene therapies, the importance of unique elements that go beyond health gain can be quantified and inform value assessments. We designed a study, namely the Patient preferences to Assess Value IN Gene therapies (PAVING) study, that can inform HTA and payers by investigating trade-offs that adult Belgian hemophilia A and B patients are willing to make when asked to choose between a standard of care and gene therapy.

Methods and Analysis: An eight-step approach was taken to establish the protocol for this study: (1) stated preference method selection, (2) initial attributes identification, (3) stakeholder (HTA and payer) needs identification, (4) patient relevant attributes and information needs identification, (5) level identification and choice task construction, (6) educational tool design, (7) survey integration, and (8) piloting and pretesting. In the end, a threshold technique survey was designed using the attributes “Annual bleeding rate,” “Chance to stop prophylaxis,” “Time that side effects have been studied,” and “Quality of Life.”

Ethics and Dissemination: The Medical Ethics Committee of UZ KU Leuven/Research approved the study. Results from the study will be presented to stakeholders and patients at conferences and in peer-reviewed journals. We hope that results from the PAVING study can inform decision makers on the acceptability of uncertainties and the value of gene therapies to patients.