Exploring patient preference heterogeneity for pharmacological treatments for chronic pain: A latent class analysis

The Evolving Landscape of Discrete Choice Experiments in Health Economics: A Systematic Review

INTRODUCTION

Stakeholder preference evaluations are increasingly emphasized in healthcare policy and health technology assessment. Discrete choice experiments (DCEs) are the most common method for quantifying preferences among patients, the public, and healthcare professionals. While prior reviews (1990-2017) have examined DCE trends, no comprehensive synthesis exists for studies published since 2018. This updated review (2018-2023) provides critical insights into evolving methodologies and global trends in health-related DCEs.

METHODS

A systematic search (2018-2023) of Medline, Embase, and Web of Science identified relevant studies. Studies were screened for inclusion and data were extracted, including details on DCE design and analysis. To enable trend comparisons, the search strategy and extraction items aligned with previous reviews.

RESULTS

Of 2663 identified papers, 1279 met the inclusion criteria, reflecting a significant rise in published DCEs over time. DCEs were conducted globally, with a remarkable increase in publications from Asia and Africa compared with previous reviews. Experimental designs and econometric models have advanced, continuing prior trends. Notably, most recent DCEs were administered online.

DISCUSSION

The rapid growth of DCE applications underscores their importance in health research. While the methodology is advancing rapidly, it is crucial that researchers provide full transparency in reporting their methods, particularly in detailing experimental designs and validity tests, which are too often overlooked. Key recommendations include improving reporting of experimental designs, applying validity tests, following good practices for presenting benefit-risk attributes, and adopting open science practices. Ensuring methodological rigor will maximize the impact and reproducibility of DCE research in health economics.

Examining national health insurance fund members' preferences and trade-offs for the attributes of contracted outpatient facilities in Kenya: A discrete choice experiment

Patient choice of health facilities is increasingly gaining recognition for potentially enhancing the attainment of health system goals globally. In Kenya, National Health Insurance Fund (NHIF) members are required to choose an NHIF-contracted outpatient facility before accessing care. Understanding their preferences could support resource allocation decisions, enhance the provision of patient-centered care, and deepen NHIF's purchasing decisions. We employed a discrete choice experiment to examine NHIF members' preferences for attributes of NHIF-contracted outpatient facilities in Kenya. We developed a d-efficient experimental design with six attributes, namely availability of drugs, distance from household to facility, waiting time at the facility until consultation, cleanliness of the facility, attitude of health worker, and cadre of health workers seen during consultation. Data were then collected from 402 NHIF members in six out of 47 counties. Choice data were analysed using panel mixed multinomial logit and latent class models. NHIF members preferred NHIF-contracted outpatient facilities that always had drugs [β=1.572], were closer to their households [β=-0.082], had shorter waiting times [β=-0.195], had respectful staff [β=1.249] and had either clinical officers [β=0.478] or medical doctors [β=1.525] for consultation. NHIF members indicated a willingness to accept travel 17.8km if drugs were always available, 17.7km to see a medical doctor for consultation, and 14.6km to see respectful health workers. Furthermore, NHIF members indicated a willingness to wait at a facility for 8.9 hours to ensure the availability of drugs, 8.8 hours to see a doctor for consultation, and 7.2 hours to see respectful health workers. Understanding NHIF member preferences and trade-offs can inform resource allocation at counties, service provision across providers, and purchasing decisions of purchasers such as the recently formed social health insurance authority in Kenya as a move towards UHC.

Evaluating the balance of benefits and harms in chronic pain clinical trials: prioritizing individual participants over individual outcomes

BACKGROUND

Randomized clinical trials (RCTs) generally assess efficacy and safety separately, with the conclusion of whether a treatment is beneficial based solely on the efficacy endpoint. However, assessing and combining efficacy and safety domains, using a single composite outcome measure, can provide a more comprehensive assessment of the overall effect of a treatment. Furthermore, composite outcomes can incorporate information regarding the relationship between the individual outcomes. In fact, such outcomes have been suggested in the clinical trials literature for at least 15 years.

OBJECTIVES

To (1) identify whether recent primary publications of chronic pain RCTs from major pain journals included a composite outcome measure of benefits and harms and (2) discuss the potential benefits of such outcomes in various stages of treatment development, including as outcome measures in RCTs, and to support decisions of Data and Safety Monitoring Boards and ordering of treatments in the context of treatment guidelines.

EVIDENCE REVIEW

RCTs published in 6 major pain journals published between 2016 and 2021 that investigated interventions for chronic pain were reviewed.

FINDINGS

Of 73 RCTs identified, only 2 included a composite outcome measure of benefits and harms. Both of these articles compared 2 active treatments.

CONCLUSIONS

Composite outcomes of benefits and harms are underutilized in chronic pain RCTs. The advantages and challenges of using such outcomes are discussed.

Engagement in Integrative and Nonpharmacologic Pain Management Modalities Among Adults with Chronic Pain: Analysis of the 2019 National Health Interview Survey

Objective

To examine variables associated with engagement in (1) integrative health and medicine (IHM) and (2) nonpharmacologic modalities rather than opioids among United States adults with chronic pain.

Methods

Using the 2019 National Health Interview Survey, we examined sociodemographic, pain, and mental health predictors of (1) the sum of IHM modalities (ie, chiropractic care, yoga/Tai Chi, massage, or meditation/guided imagery) used to manage pain and (2) exclusive engagement in nonpharmacologic pain management modalities (ie, IHM, a chronic pain self-management program, support groups, or physical, rehabilitative, occupational, or talk therapy) or opioids in the past 3 months.

Results

Metropolitan residency, higher family income, higher education levels, increased number of pain locations, and increased frequency of pain limiting life/work activities were associated with increased odds of IHM engagement. Older age, male sex, non-Hispanic Black/African American race/ethnicity, and daily opioid use were associated with decreased odds of IHM engagement. Older age, male sex, and increased depressive symptoms were associated with decreases in the count of IHM modalities used to manage pain. Metropolitan residency, higher family income, and higher education levels were associated with increased odds of exclusive nonpharmacologic modality engagement. Older age and increasing frequency of pain limiting life/work activities were associated with decreased odds of exclusive nonpharmacologic modality engagement.

Conclusions

We identified several contrasts between factors prevalent among individuals with chronic pain and factors associated with engagement in nonpharmacologic and IHM modalities. These results support efforts to address barriers to accessing these modalities among subpopulations of adults with chronic pain (eg, older adults, individuals identifying as Black/African American, rural residents, and those with lower levels of education and income).

Acceptability, values, and preferences of older people for chronic low back pain management; a qualitative evidence synthesis

BACKGROUND

Chronic primary low back pain (CPLBP) and other musculoskeletal conditions represent a sizable attribution to the global burden of disability, with rates greatest in older age. There are multiple and varied interventions for CPLBP, delivered by a wide range of health and care workers. However, it is not known if these are acceptable to or align with the values and preferences of care recipients. The objective of this synthesis was to understand the key factors influencing the acceptability of, and values and preferences for, interventions/care for CPLBP from the perspective of people over 60 and their caregivers.

METHODS

We searched MEDLINE, CINAHL and OpenAlex, for eligible studies from inception until April 2022. We included studies that used qualitative methods for data collection and analysis; explored the perceptions and experiences of older people and their caregivers about interventions to treat CPLBP; from any setting globally. We conducted a best fit framework synthesis using a framework developed specifically for this review. We assessed our certainty in the findings using GRADE-CERQual.

RESULTS

All 22 included studies represented older people's experiences and had representation across a range of geographies and economic contexts. No studies were identified on caregivers. Older people living with CPLBP express values and preferences for their care that relate to therapeutic encounters and the importance of therapeutic alliance, irrespective of the type of treatment, choice of intervention, and intervention delivery modalities. Older people with CPLBP value therapeutic encounters that validate, legitimise, and respect their pain experience, consider their context holistically, prioritise their needs and preferences, adopt a person-centred and tailored approach to care, and are supported by interprofessional communication. Older people valued care that provided benefit to them, included interventions beyond analgesic medicines alone and was financially and geographically accessible.

CONCLUSIONS

These findings provide critical context to the implementation of clinical guidelines into practice, particularly related to how care providers interact with older people and how components of care are delivered, their location and their cost. Further research is needed focusing on low- and middle-income settings, vulnerable populations, and caregivers.

Patient preferences in the treatment of chronic musculoskeletal pain: a systematic review of discrete choice experiments

ABSTRACT

Chronic musculoskeletal pain (CMP) is a preference-sensitive condition for which numerous treatment options are available, each with benefits and risks. Thus, patient preferences play a critical role in decision making. This study summarized evidence from discrete choice experiments (DCEs) to quantify patient preferences for CMP treatment and identified important treatment attributes. A systematic review of DCEs on patient preferences for CMP treatment was conducted. Studies were included if they used DCE to determine patient preferences for CMP. A previously described methodological assessment tool was used to assess the risk of bias. The treatment attributes were summarized and sorted according to the frequency of citation and relative weight. Subgroup analyses were conducted to explore the intervention-specific attributes. A total of 15 eligible studies with 4065 participants were included. We identified "capacity to realize daily life activities," "risk of adverse events," "effectiveness in pain reduction," and "out-of-pocket cost" as important attributes. Although "treatment frequency" and "onset of treatment efficacy" were less frequently mentioned, they were also important attributes. The attribute of "risk of adverse events" was especially important for drug treatment. The "out-of-pocket cost" and "treatment location and mode" were important attributes of exercise therapy. The attributes identified in this review will inform the design of future DCE studies, facilitate the translation of measurement-based care to value-based care, and provide the rationale to promote shared decision making and patient-centered care.

Preferences of patients with chronic low back pain about nonsurgical treatments: Results of a discrete choice experiment

INTRODUCTION

This study aimed to assess patients' preferences of nonsurgical treatments for chronic low back pain (CLBP).

METHOD

We conducted a discrete choice experiment (DCE) in Quebec, Canada, in 2018. Seven attributes were included: treatment modality, pain reduction, the onset of treatment efficacy, duration effectiveness, difficulties with daily activities, sleep problems, and knowledge of the patient's body and pain location. Treatment modalities were corticosteroid injections, supervised body-mind physical activities, supervised sports physical activities, physical manipulations, self-management courses, and psychotherapy. Utility levels were estimated using a logit model, a latent class model and a Bayesian hierarchical model.

RESULTS

Analyses were conducted on 424 $424$ individuals. According to the Bayesian hierarchical model, the conditional relative importance weights of attributes were as follows: (1) treatment modality (34.79%), (2) pain reduction (18.73%), (3) difficulties with daily activities (11.71%), (4) duration effectiveness (10.06%), (5) sleep problems (10.05%), (6) onset of treatment efficacy (8.60%) and (7) knowledge of the patient's body and pain location (6.06%). According to the latent class model that found six classes of respondents with different behaviours (using Akaike and Bayesian criteria), the treatment modality was the most important attribute for all classes, except for class 4 for which pain reduction was the most important. In addition, classes 2 and 5 refused corticosteroid injections, while psychotherapy was preferred only in class 3.

CONCLUSION

Given the preference heterogeneity found in the analysis, it is important that patient preferences are discussed and considered by the physicians. This will help to improve the patient care pathway in a context of a patient-centred model for a disease with growing prevalence.

PATIENT OR PUBLIC CONTRIBUTION

A small group of patients was involved in the conception, design and interpretation of data. Participants in the DCE were all CLBP patients.

Considerations Around Coding the Membership Probability Function in a Latent Class Analysis: Renewed Insights

This technical note discusses how dummy and effects coding of categorical respondent characteristics in a class membership probability function should be interpreted by researchers employing a latent class analysis to explore preference heterogeneity in a discrete-choice experiment. Previous work highlighted issues arising from such coding when interpreting an alternative specific constant that represents an opt-out alternative or current situation in a discrete-choice experiment and did not fully address how this coding impacts the interpretation of parameters resulting from the membership probability function in a latent class analysis. Although latent class membership probability could be predicted separately for each respondent or subgroup of respondents, conclusions are often drawn directly from the model estimation using the full sample, which requires correctly interpreting the estimated parameters. In these cases, the misinterpretation that may arise if the problem is ignored could impact the policy conclusions and recommendations drawn based on the discrete-choice experiment results. This note provides an example comparing dummy and effects coding used to model respondent characteristics in the membership probability function in a discrete-choice experiment aimed to explore preferences for the treatment of chronic pain in the USA.