Patient preferences among third agent HIV medications: a US and German perspective

Understanding Treatment Preferences Among People Living with HIV in Australia: A Discrete Choice Experiment

Purpose

To better understand what is most important to people living with human immunodeficiency virus (PLWH) when choosing their treatment. We assessed how PLWH trade off the potential risks and benefits of oral and long acting injectable (LAI) treatments.

Participants and Methods

Firstly, in-depth interviews were conducted with 11 PLWH to develop a holistic understanding of experiences and determine attributes that contribute to treatment decision-making. Secondly, a discrete choice experiment (DCE) was used to understand the treatment preferences for PLWH with n = 99 PLWH aged 18 years or over with a diagnosis of human immunodeficiency virus (HIV) and who were currently using anti-retroviral therapy (ART). Study participants were presented with 12 scenarios and asked to select their preferred treatment among two hypothetical injectable treatment alternatives, "injection 1" and "injection 2" and their current oral ART treatment. The DCE data were modelled using a latent class model (LCM).

Results

The model revealed significant heterogeneity in preferences for treatment attributes among study participants. Two segments/classes of PLWH were identified. The first segment expressed a strong preference for their current oral treatment; the second segment showed strong preference for the injection treatment and for it to be administered in a GP clinic. Overall, out-of-pocket cost was the most important attribute for participants. One-third of PLWH were willing to switch to an LAI.

Conclusion

Not all PLWH valued the same treatment attributes equally. Overall, out-of-pocket costs for treatments were considered by respondents as the most determining factor in making treatment choices. Results have important implications for healthcare policy and will serve to better inform patients and stakeholders involved in the treatment decision-making process about the treatment preferences of PLWH. Clinicians are encouraged to consider shared decision-making to establish the treatment course that best aligns with PLWH's treatment goals.

The Role of Web-Based Adaptive Choice-Based Conjoint Analysis Technology in Eliciting Patients' Preferences for Osteoarthritis Treatment

OBJECTIVE

To assess the feasibility of using adaptive choice-based conjoint (ACBC) analysis to elicit patients' preferences for pharmacological treatment of osteoarthritis (OA), patients' satisfaction with completing the ACBC questionnaire, and factors associated with questionnaire completion time.

METHODS

Adult patients aged 18 years and older with a medical diagnosis of OA, experiencing joint pain in the past 12 months, and living in the Northeast of England participated in the study. The participants completed a web-based ACBC questionnaire about their preferences regarding pharmaceutical treatment for OA using a touchscreen laptop independently, and accordingly, the questionnaire completion time was measured. Moreover, the participants completed a pen-and-paper feedback form about their experience in completing the ACBC questionnaire.

RESULTS

Twenty participants aged 40 years and older, 65% females, 75% had knee OA, and suffering from OA for more than 5 years participated in the study. About 60% of participants reported completing a computerized questionnaire in the past. About 85% of participants believed that the ACBC task helped them in making decisions regarding their OA medications, and 95% agreed or strongly agreed that they would be happy to complete a similar ACBC questionnaire in the future. The average questionnaire completion time was 16 min (range 10-24 min). The main factors associated with longer questionnaire completion time were older age, never using a computer in the past, and no previous experience in completing a questionnaire.

CONCLUSIONS

The ACBC analysis is a feasible and efficient method to elicit patients' preferences for pharmacological treatment of OA, which could be used in clinical settings to facilitate shared decision-making and patient-centered care. The ACBC questionnaire completion consumes a significantly longer time for elderly participants, who never used a computer, and never completed any questionnaire previously. Therefore, the contribution of patients and public involvement (PPI) group in the development of the ACBC questionnaire could facilitate participants' understanding and satisfaction with the task. Future research including patients with different chronic conditions may provide more useful information about the efficiency of ACBC analysis in eliciting patients' preferences for osteoarthritis treatment.

A world of choices: preference elicitation methods for improving the delivery and uptake of HIV prevention and treatment

PURPOSE OF REVIEW

Despite the growing availability of effective HIV prevention and treatment interventions, there are large gaps in their uptake and sustained use across settings. It is crucial to elicit and apply patients' and stakeholders' preferences to maximize the impact of existing and future interventions. This review summarizes quantitative preference elicitation methods (PEM) and how they can be applied to improve the delivery and uptake of HIV prevention and treatment interventions.

RECENT FINDINGS

PEM are increasingly applied in HIV implementation research; however, discrete choice experiments (DCEs) have predominated. Beyond DCEs, there are other underutilized PEM that may improve the reach and effectiveness of HIV prevention and treatment interventions among individuals by prioritizing their barriers to engagement and determining which attributes of interventions and delivery strategies are most valued. PEM can also enhance the adoption and sustained implementation of strategies to deliver HIV prevention and treatment interventions by assessing which attributes are the most acceptable and appropriate to key stakeholders.

SUMMARY

Greater attention to and incorporation of patient's and stakeholders' preferences for HIV prevention and treatment interventions and their delivery has the potential to increase the number of persons accessing and retained in HIV prevention and treatment services.

Divergent preferences for enhanced HIV testing options among high-risk populations in northern Tanzania: a short report

To achieve the UNAIDS target of diagnosing 95% of all persons living with HIV, enhanced HIV testing services with greater attractional value need to be developed and implemented. We conducted a discrete choice experiment (DCE) to quantify preferences for enhanced HIV testing features across two high-risk populations in the Kilimanjaro Region in northern Tanzania. We designed and fielded a survey with 12 choice tasks to systematically recruited female barworkers and male mountain porters. Key enhanced features included: testing availability on every day of the week, an oral test, integration of a general health check or an examination for sexually transmitted infections (STI) with HIV testing, and provider-assisted confidential partner notification in the event of a positive HIV test result. Across 300 barworkers and 440 porters surveyed, mixed logit analyses of 17,760 choices indicated strong preferences for everyday testing availability, health checks, and STI examinations. Most participants were averse to oral testing and confidential partner notification by providers. Substantial preference heterogeneity was observed within each risk group. Enhancing HIV testing services to include options for everyday testing, general health checks, and STI examinations may increase the appeal of HIV testing offers to high-risk populations.Trial registration: ClinicalTrials.gov identifier: NCT02714140.

Dynamics of Patient-Based Benefit-Risk Assessment of Medicines in Chronic Diseases: A Systematic Review

BACKGROUND

A critical gap exits in understanding the dynamics of patient-based benefit-risk assessment (BRA) of medicines in chronic diseases during the disease journey.

PURPOSE

To systematically review and synthesize current evidence on the changes of patients' preferences about the benefits and risks of medicines during their disease journey including the influence of disease duration and severity, and previous treatment experience.

METHODS

A systematic review of studies identified in PubMed and Embase, from inception to November 2020, was conducted in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement. Articles were eligible if they analyzed adult patient-based BRA of medicines with a chronic disease, based on at least one of the pre-specified dimensions: disease severity, disease duration, or previous treatment experience.

RESULTS

A total of 26,228 articles were identified and 105 were eligible for inclusion. Of these, 85 detected a variation in patient-based BRA of medicines with at least one of the pre-specified criteria. Patients with higher disease severity and more treatment experience have increased risk tolerance. It remains inconclusive whether disease duration directly affects the relative importance of a patient's preference.

CONCLUSION

Factors important for patients' BRA of their medicines during a chronic disease journey vary more with their clinical situation and previous treatment experience than with time since diagnosis. Due to the importance of these factors on patients' perspectives and potential impact on their decision-making and eventually their clinical outcomes, there is a need for more studies to assess the dynamics of patients' BRA in every disease.

What factors influence HIV testing? Modeling preference heterogeneity using latent classes and class-independent random effects

Efforts to eliminate the HIV epidemic will require increased HIV testing rates among high-risk populations. To inform the design of HIV testing interventions, a discrete choice experiment (DCE) with six policy-relevant attributes of HIV testing options elicited the testing preferences of 300 female barworkers and 440 male Kilimanjaro mountain porters in northern Tanzania. Surveys were administered between September 2017 and July 2018. Participants were asked to complete 12 choice tasks, each involving first- and second-best choices from 3 testing options. DCE responses were analyzed using a random effects latent class logit (RELCL) model, in which the latent classes summarize common participant preference profiles, and the random effects capture additional individual-level preference heterogeneity with respect to three attribute domains: (a) privacy and confidentiality (testing venue, pre-test counseling, partner notification); (b) invasiveness and perceived accuracy (method for obtaining the sample for the HIV test); and (c) accessibility and value (testing availability, additional services provided). The Bayesian Information Criterion indicated the best model fit for a model with 8 preference classes, with class sizes ranging from 6% to 19% of participants. Substantial preference heterogeneity was observed, both between and within latent classes, with 12 of 16 attribute levels having positive and negative coefficients across classes, and all three random effects contributing significantly to participants' choices. The findings may help identify combinations of testing options that match the distribution of HIV testing preferences among high-risk populations; the methods may be used to systematically design heterogeneity-focused interventions using stated preference methods.

Patients' preferences for antiretroviral therapy service provision: a systematic review

Background

Achieving global targets of adherence to treatment, retention in care, and treatment success remains a challenge. Health system investment to make antiretroviral therapy services more responsive to patients’ needs and values could address these impediments. Appropriate resource allocation to implement differentiated HIV treatment services demands research evidence. This study aimed to provide an overview of the patients’ preferences for antiretroviral therapy service delivery features.

Methods

Electronic databases (PubMed, Web of Science, Embase, and CINAHL) and search engines (Google and Google Scholar) were searched. This review has followed a convergent segregated approach to synthesis and integration. Data from the included studies were systematically extracted, tabulated, and summarised in a narrative review. Studies that analysed preferences for antiretroviral therapy regardless of the method used and published in the English language in any year across the world and HIV positive clients who were 15 years and above on 4th February 2021 were included for this review. The quality of the included studies was assessed using the mixed methods appraisal tool. A thematic synthesis of the data from the findings section of the main body of the qualitative study was undertaken. ATLAS.ti software version 7 was used for qualitative synthesis.

Results

From the 1054 retrieved studies, only 23 studies (16 quantitative, three qualitative, and four mixed-methods) fulfilled the inclusion criteria. The median number of attributes used in all included quantitative studies was 6 (Inter Quartile Range 3). In this review, no study has fulfilled the respective criteria in the methodological quality assessment. In the quantitative synthesis, the majority of participants more valued the outcome, whereas, in the qualitative synthesis, participants preferred more the structure aspect of antiretroviral therapy service. The thematic analysis produced 17 themes, of which ten themes were related to structure, three to process, and four to outcome dimension of Donabedian’s quality of care model. The findings from individual quantitative and qualitative syntheses complement each other.

Conclusions

In this review, participants’ value for antiretroviral therapy service characteristics varied across included studies. Priorities and values of people living with HIV should be incorporated in the policy, practice, research, and development efforts to improve the quality of antiretroviral therapy service hence avoid poor patient outcomes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12962-021-00310-7.

Using discrete choice experiments to design interventions for heterogeneous preferences: protocol for a pragmatic randomised controlled trial of a preference-informed, heterogeneity-focused, HIV testing offer for high-risk populations

INTRODUCTION

Approximately one million undiagnosed persons living with HIV in Southern and Eastern Africa need to test for HIV. Novel approaches are necessary to identify HIV testing options that match the heterogeneous testing preferences of high-risk populations. This pragmatic randomised controlled trial (PRCT) will evaluate the efficacy of a preference-informed, heterogeneity-focused HIV counselling and testing (HCT) offer, for improving rates of HIV testing in two high-risk populations.

METHODS AND ANALYSIS

The study will be conducted in Moshi, Tanzania. The PRCT will randomise 600 female barworkers and 600 male Kilimanjaro mountain porters across three study arms. All participants will receive an HIV testing offer comprised of four preference-informed testing options, including one 'common' option-comprising features that are commonly available in the area and, on average, most preferred among study participants-and three options that are specific to the study arm. Options will be identified using mixed logit and latent class analyses of data from a discrete choice experiment (DCE). Participants in Arm 1 will be offered the common option and three 'targeted' options that are predicted to be more preferred than the common option and combine features widely available in the study area. Participants in Arm 2 will be offered the common option and three 'enhanced' options, which also include HCT features that are not yet widely available in the study area. Participants in Arm 3, an active control arm, will be offered the common option and three predicted 'less preferred' options. The primary outcome will be uptake of HIV testing.

ETHICS AND DISSEMINATION

Ethical approval was obtained from the Duke University Health System IRB, the University of South Carolina IRB, the Ethics Review Committee at Kilimanjaro Christian Medical University College, Tanzania's National Institute for Medical Research, and the Tanzania Food & Drugs Authority (now Tanzania Medicines & Medical Devices Authority). Findings will be published in peer-reviewed journals. The use of rigorous DCE methods for the preference-based design and tailoring of interventions could lead to novel policy options and implementation science approaches.

TRIAL REGISTRATION NUMBER

NCT02714140.

Heterogeneous Patient Preferences for Modern Antiretroviral Therapy: Results of a Discrete Choice Experiment

OBJECTIVE

Limited data describe patient preferences for the growing number of antiretroviral therapies (ARTs). We quantified preferences for key characteristics of modern ART deemed relevant to shared decision making.

METHODS

A discrete choice experiment survey elicited preferences for ART characteristics, including dosing (frequency and number of pills), administration characteristics (pill size and meal requirement), most bothersome side effect (from diarrhea, sleep disturbance, headaches, dizziness/difficulty thinking, depression, or jaundice), and most bothersome long-term effect (from increased risk of heart attacks, bone fractures, renal dysfunction, hypercholesterolemia, or hyperglycemia). Between March and August 2017, the discrete choice experiment was fielded to 403 treatment-experienced persons living with human immunodeficiency virus (HIV), enrolled from 2 infectious diseases clinics in the southern United States and a national online panel. Participants completed 16 choice tasks, each comparing 3 treatment options. Preferences were analyzed using mixed and latent class logit models.

RESULTS

Most participants were male (68%) and older (interquartile range: 42-58 years), and had substantial treatment experience (interquartile range: 7-21 years). In mixed logit analyses, all attributes were associated with preferences. Side and long-term effects were most important, with evidence of substantial preference heterogeneity. Latent class analysis identified 5 preference classes. For classes 1 (40%), 2 (24%), and 3 (21%), side effects were most important, followed by long-term effects. For class 4 (10%), dosing was most important. Class 5 (4%) was largely indifferent to ART characteristics.

CONCLUSION

Overall, treatment-experienced persons living with HIV valued minimizing side effects and long-term toxicities over dosing and administration characteristics. Preferences varied widely, highlighting the need to elicit individual patient preferences in models of shared antiretroviral decision making.

A Conjoint Analysis of the Acceptability of Targeted Long-Acting Injectable Antiretroviral Therapy Among Persons Living with HIV in the U.S

With long-acting injectable antiretroviral therapy likely to be a treatment option for people living with HIV (PLWH), it is critical to assess its acceptability among potential end-users. Based on formative qualitative work and our own ongoing development of targeted long-acting products in nanosuspension formulations, we created eight hypothetical medication scenarios varying along six dichotomous attributes: administration location (home versus [vs.] clinic), dosing frequency (every 2 weeks vs. 1 week), injections per dose (one vs. two), injection pain (mild vs. moderate), injection site reaction (mild vs. moderate), and effectiveness (better vs. same as pills). PLWH from three outpatient care clinics in Seattle, WA and Riverside, CA rated acceptability (i.e., willingness to try each hypothetical medication) from 0 (very unlikely) to 100 (very likely). In conjoint analyses, we examined level and correlates of acceptability, the impact of each attribute on overall acceptability, and moderators of this effect. Participants (median age 52 years; 71% male, 34% White, 36% Black/African American, 20% Hispanic) rated acceptability of the 8 scenarios from 47.8 (standard deviation [SD] = 37.0) to 68.8 (SD = 34.1), with effectiveness (impact score = 7.3, SD = 18.7, p = 0.005) and dosing frequency (impact score = 5.7, SD = 19.6, p = 0.034) the only attributes with a significant impact on acceptability. There were no statistically significant differences in overall acceptability according to any participant socio-demographic or other characteristic; however, gender, education, employment status, and experience with and hatred/avoidance of injections moderated some effects. Overall acceptability for targeted long-acting antiretroviral treatment as proposed was modest, with superior effectiveness and lower dosing frequency most impactful on acceptability. Future acceptability research should continue to evaluate specific products in development with a full range of conjoint analytic and other techniques.

Stated-preference research in HIV: A scoping review

Discrete choice experiments (DCE), conjoint analysis (CA), and best-worst scaling (BWS) are quantitative techniques for estimating consumer preferences for products or services. These methods are increasingly used in healthcare research, but their applications within the field of HIV research have not yet been described. The objective of this scoping review was to systematically map the extent and nature of published DCE, CA, and BWS studies in the field of HIV and identify priority areas where these methods can be used in the future. Online databases were searched to identify published HIV-related DCE, CA and BWS studies in any country and year as the primary outcome. After screening 1,496 citations, 57 studies were identified that were conducted in 26 countries from 2000-2017. The frequency of published studies increased over time and covered HIV themes relating to prevention (n = 25), counselling and testing (n = 10), service delivery (n = 10), and antiretroviral therapy (n = 12). Most studies were DCEs (63%) followed by CA (37%) and BWS (4%). The median [IQR] sample size was 288 [138-496] participants, and 74% of studies used primary qualitative data to develop attributes. Only 30% of studies were conducted in sub-Saharan Africa where the burden of HIV is highest. Moreover, few studies surveyed key populations including men who have sex with men, transgender people, pregnant and postpartum women, adolescents, and people who inject drugs. These populations represent priorities for future stated-preference research. This scoping review can help researchers, policy makers, program implementers, and health economists to better understand the various applications of stated-preference research methods in the field of HIV.

Discrete choice experiments in health economics: a review of the literature

BACKGROUND

Discrete choice experiments (DCEs) are increasingly used in health economics to address a wide range of health policy-related concerns.

OBJECTIVE

Broadly adopting the methodology of an earlier systematic review of health-related DCEs, which covered the period 2001-2008, we report whether earlier trends continued during 2009-2012.

METHODS

This paper systematically reviews health-related DCEs published between 2009 and 2012, using the same database as the earlier published review (PubMed) to obtain citations, and the same range of search terms.

RESULTS

A total of 179 health-related DCEs for 2009-2012 met the inclusion criteria for the review. We found a continuing trend towards conducting DCEs across a broader range of countries. However, the trend towards including fewer attributes was reversed, whilst the trend towards interview-based DCEs reversed because of increased computer administration. The trend towards using more flexible econometric models, including mixed logit and latent class, has also continued. Reporting of monetary values has fallen compared with earlier periods, but the proportion of studies estimating trade-offs between health outcomes and experience factors, or valuing outcomes in terms of utility scores, has increased, although use of odds ratios and probabilities has declined. The reassuring trend towards the use of more flexible and appropriate DCE designs and econometric methods has been reinforced by the increased use of qualitative methods to inform DCE processes and results. However, qualitative research methods are being used less often to inform attribute selection, which may make DCEs more susceptible to omitted variable bias if the decision framework is not known prior to the research project.

CONCLUSIONS

The use of DCEs in healthcare continues to grow dramatically, as does the scope of applications across an expanding range of countries. There is increasing evidence that more sophisticated approaches to DCE design and analytical techniques are improving the quality of final outputs. That said, recent evidence that the use of qualitative methods to inform attribute selection has declined is of concern.

A descriptive review on methods to prioritize outcomes in a health care context

BACKGROUND

Evidence synthesis has seen major methodological advances in reducing uncertainty and estimating the sizes of the effects. Much less is known about how to assess the relative value of different outcomes.

OBJECTIVE

To identify studies that assessed preferences for outcomes in health conditions.

METHODS

SEARCH STRATEGY

we searched MEDLINE, EMBASE, PsycINFO and the Cochrane Library in February 2014.

INCLUSION CRITERIA

eligible studies investigated preferences of patients, family members, the general population or healthcare professionals for health outcomes. The intention of this review was to include studies which focus on theoretical alternatives; studies which assessed preferences for distinct treatments were excluded.

DATA EXTRACTION

study characteristics as study objective, health condition, participants, elicitation method, and outcomes assessed in the study were extracted.

MAIN RESULTS

One hundred and twenty-four studies were identified and categorized into four groups: (1) multi criteria decision analysis (MCDA) (n = 71), (2) rating or ranking (n = 25), (3) utility eliciting (n = 5) and (4) studies comparing different methods (n = 23). The number of outcomes assessed by method group varied. The comparison of different methods or subgroups within one study often resulted in different hierarchies of outcomes.

CONCLUSIONS

A dominant method most suitable for application in evidence syntheses was not identified. As preferences of patients differ from those of other stakeholders (especially medical professionals), the choice of the group to be questioned is consequential. Further research needs to focus on validity and applicability of the identified methods.

Primary-care patients' trade-off preferences with regard to antidepressants

BACKGROUND

Antidepressants are frequently prescribed but results regarding their efficacy have been equivocal for different spectra of the severity continuum and their side-effects are often burdensome. Non-adherence is a likely consequence. The objective was therefore to examine patients' trade-offs between the efficacy, side-effects and other drawbacks of antidepressants and whether these trade-offs predicted non-adherence.

METHOD

Trade-offs from 225 antidepressant users, recruited through community pharmacies, were assessed with an Adaptive Conjoint Analysis (ACA) choice task that was customized to each individual patient. From the estimated utilities, relative importance scores of treatment properties were calculated. Non-adherence was measured through self-report and pharmacy refill data.

RESULTS

Relapse prevention and symptom relief were on average equally important. Side-effects were as important and the side-effect stomach and intestine complaints was on average even slightly more important than relapse prevention and symptom relief. Additional treatment with psychotherapy was preferred by 61% of the patients. A benefit/drawback ratio revealed that 18% of the patients did not consider the efficacy to outweigh the drawbacks. A higher benefit/drawback ratio was associated with a decreased odds of intentional non-adherence [odds ratio (OR) 0.2, 95% confidence interval (CI) 0.07-0.7, Wald = 6.7, p = 0.01).

CONCLUSIONS

For nearly one in five patients, the efficacy of antidepressants does not outweigh their drawbacks. Knowing patients' trade-offs is likely to aid both physicians and patients to identify important treatment preferences, to improve adherence and to make more deliberate decisions on whether or not to continue treatment.

Patient preferences for chemotherapies used in breast cancer

BACKGROUND

Therapies for invasive breast cancer may be associated with an incremental survival advantage that should be weighed against the risk of toxicities when making treatment decisions. The objective of this study was to elicit patient preferences for a comprehensive profile of attributes associated with chemotherapies for breast cancer.

METHODS

This was a cross-sectional study of 121 patients with stage I-IV breast cancer who completed an internet-based conjoint survey that assessed the following attributes: ten grade III/IV toxicities, survival advantage, and administration regimen. Literature and expert input were used to identify descriptions for each attribute and respective levels (eg, different risks of toxicities). Subjects rated the attribute levels on a series of scales and indicated preferences in pair-wise comparisons of two hypothetical treatments differing in attribute levels. Ordinary least-squares regression was used to calculate utilities (preference weights) for each attribute level.

RESULTS

Of the twelve attributes, survival was the most important; specifically, a survival advantage of 3 months versus no survival advantage was most influential in the perceived value of chemotherapy. Among toxicities, the differences in the risks of neutropenia with hospitalization, diarrhea, nausea, and fatigue had the most impact on preferences; the risk differences of myalgia, stomatitis, and hand-foot syndrome had the least. In general, a more convenient administration regimen was less important than a 13% chance or more of severe toxicities, but more important than a 10%-12% chance of severe toxicities.

CONCLUSION

Breast cancer patients place high value on small incremental survival advantages associated with treatment despite the risk of serious toxicities.

Methodologic evaluation of adaptive conjoint analysis to assess patient preferences: an application in oncology

BACKGROUND

Adaptive conjoint analysis (ACA) is an individually tailored preferences elicitation technique that mimics actual decision-making processes by asking participants to make trade-offs between the various dimensions that underlie decision problems. ACA is increasingly applied in patient preferences assessments but formal evaluation of its validity and reliability is lacking.

OBJECTIVE

To investigate ACA's validity and reliability in elicitation of treatment outcome preferences.

METHODS

Sixty-eight disease-free rectal cancer patients, treated with surgery with or without preoperative radiotherapy were asked to complete exercises to assess their preferences for radiotherapy [using the treatment trade-off method (TTM)] and for key outcomes associated with radiotherapy (using ACA). We assessed (i) rank ordering of ACA-derived outcome-probability utilities, (ii) compensatory decision making, (iii) ACA test-retest reliability, and (iv) concordance of ACA- and TTM-based preferences.

RESULTS

All participants completed the TTM and 66 completed the ACA questionnaire, in 15 min on average. Outcome utilities were rank ordered in agreement with probabilities from best to worst in most participants, except for sexual dysfunction. Most participants were willing to trade survival and their most important outcome. Mean importance ratings were similar at retest. ACA- and TTM-based preferences differed. TTM-based preferences were related to past treatment, ACA-based preferences were not.

CONCLUSIONS

ACA assesses group-level preferences reliably over time and captures individual preferences independently from treatment experience in treated cancer patients. ACA seems a valid treatment outcome preference elicitation method in a context in which trade-offs between cure and quality of life need to be considered.

Adaptive choice-based conjoint analysis: a new patient-centered approach to the assessment of health service preferences

Conjoint analysis (CA) has emerged as an important approach to the assessment of health service preferences. This article examines Adaptive Choice-Based Conjoint Analysis (ACBC) and reviews available evidence comparing ACBC with conventional approaches to CA. ACBC surveys more closely approximate the decision-making processes that influence real-world choices. Informants begin ACBC surveys by completing a build-your-own (BYO) task identifying the level of each attribute that they prefer. The ACBC software composes a series of attribute combinations clustering around each participant's BYO choices. During the Screener section, informants decide whether each of these concepts is a possibility or not. Probe questions determine whether attribute levels consistently included in or excluded from each informant's Screener section choices reflect 'Unacceptable' or 'Must Have' simplifying heuristics. Finally, concepts identified as possibilities during the Screener section are carried forward to a Choice Tournament. The winning concept in each Choice Tournament set advances to the next choice set until a winner is determined.A review of randomized trials and cross-over studies suggests that, although ACBC surveys require more time than conventional approaches to CA, informants find ACBC surveys more engaging. In most studies, ACBC surveys yield lower standard errors, improved prediction of hold-out task choices, and better estimates of real-world product decisions than conventional choice-based CA surveys.

Preferences for characteristics of antiretroviral therapy provision in Johannesburg, South Africa: results of a conjoint analysis

A survey was administered to HIV-infected patients and a sample in Soweto and the Johannesburg inner city to measure preferences for antiretroviral therapy (ART) provision. The 25 to 49-year-old male and female respondents viewed 20 sets of three hypothetical ART clinic choices after reading information on ART. Each set had a permutation of four levels of: monthly ART price, clinic waiting times, HIV clinic branding and clinic staff attitudes. For each set, respondents selected the preferred mix of characteristics and indicated if they would pay for it. For every ZAR 100 (USD PPP 25) increase in price, the average probability of selecting a clinic decreased by 2.8 and 3.0% in the HIV patient and household samples, respectively. Cost as well as staff attitude, wait time, and clinic branding may constitute important barriers to ART uptake and adherence in resource-poor settings.

Adaptive Conjoint Analysis as individual preference assessment tool: feasibility through the internet and reliability of preferences

OBJECTIVE

Patient values are not routinely assessed in clinical practice. Adaptive Conjoint Analysis (ACA) is increasingly applied in studies assessing treatment preferences, and could provide a means to routinely assess individual patients' treatment preferences.

METHODS

An ACA-questionnaire was administered three times (7-10 days apart) to 98 long-term rectal cancer survivors either on a portable computer or through internet, to assess whether (a) responses differ according to administration mode, (b) relative importances of rectal cancer treatment outcomes (survival, local control, incontinence, sexual problems) consolidate over time, (c) ACA-outcomes are sufficiently reliable (ICC) for use in individual decision-making. We also evaluated patients' acceptance of ACA.

RESULTS

Mode did not affect ACA-completion or evaluation. Importance scores did not consolidate over time. ICCs were poor for sexual problems and fair for the other outcomes, and were at least equal or higher from first to second retest. Most participants valued completing the ACA-questionnaire and learning their results.

CONCLUSION

Values did not show consolidation over time. ACA-derived preferences should not determine which treatment patients should choose.

PRACTICE IMPLICATIONS

Findings extend ACA-validation studies to the health care setting and suggest that ACA-questionnaires might be appreciated as adjuncts to treatment decision-making in newly diagnosed patients.

Once-daily atazanavir/ritonavir versus twice-daily lopinavir/ritonavir, each in combination with tenofovir and emtricitabine, for management of antiretroviral-naive HIV-1-infected patients: 48 week efficacy and safety results of the CASTLE study

BACKGROUND

Atazanavir/ritonavir is as effective as lopinavir/ritonavir, with a more favourable lipid profile and less gastrointestinal toxicity, in treatment-experienced HIV-1-infected patients. We compared these two combinations directly in treatment-naive patients.

METHODS

In this open-label, international non-inferiority study, 883 antiretroviral-naive, HIV-1-infected patients were randomly assigned to receive atazanavir/ritonavir 300/100 mg once daily (n=440) or lopinavir/ritonavir 400/100 mg twice daily (n=443), in combination with fixed-dose tenofovir/emtricitabine 300/200 mg once daily. Randomisation was done with a computer-generated centralised randomisation schedule and was stratified by baseline levels of HIV RNA (viral load) and geographic region. The primary endpoint was the proportion of patients with viral load less than 50 copies per mL at week 48. The main efficacy analysis was done by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00272779.

FINDINGS

At week 48, 343 (78%) of 440 patients receiving atazanavir/ritonavir and 338 (76%) of 443 patients receiving lopinavir/ritonavir had achieved a viral load of less than 50 copies per mL (difference 1.7%, 95% CI -3.8 to 7.1). Mean increases from baseline in CD4 cell count were similar (203 cells per muL in the atazanavir/ritonavir group vs 219 cells per muL in the lopinavir/ritonavir group). 25 (6%) patients in the atazanavir/ritonavir group and 26 (6%) in the lopinavir/ritonavir group were virological failures by week 48. Only two patients, both in the atazanavir/ritonavir group, had non-polymorphic protease inhibitor resistance mutations emerge on treatment, which conferred phenotypic resistance to atazanavir in one patient. Serious adverse events were noted in 51 (12%) of 441 patients in the atazanavir/ritonavir group and in 42 (10%) of 437 patients in the lopinavir/ritonavir group. Fewer patients in the atazanavir/ritonavir group than in the lopinavir/ritonavir group experienced grade 2-4 treatment-related diarrhoea (10 [2%] vs 50 [11%]) and nausea (17 [4%] vs 33 [8%]). Grade 2-4 jaundice was seen in 16 (4%) of 441 patients in the atazanavir/ritonavir group versus none of 437 patients in the lopinavir/ritonavir group; grade 3-4 increases in total bilirubin were seen in 146 (34%) of 435 patients on atazanavir/ritonavir and in one (<1%) of 431 patients on lopinavir/ritonavir.

INTERPRETATION

In treatment-naive patients, atazanavir/ritonavir once-daily demonstrated similar antiviral efficacy to lopinavir/ritonavir twice-daily, with less gastrointestinal toxicity but with a higher rate of hyperbilirubinaemia.