Patientenpräferenzen in der medikamentösen Therapie von Diabetes Mellitus Typ 2: Systematische Klassifizierung und Metavergleich der Patientenpräferenzstudien

Quantified patient preferences for lifestyle intervention programs for diabetes prevention-a protocol for a systematic review

BACKGROUND

The 20-70% participation of diabetes patients in lifestyle interventions (LSI) worldwide seems to be rather sub-optimal, in spite of all intents of such interventions to delay further progress of the disease. Positive effects through LSI are expected in particular for patients who suffer less from diabetes-related limitations or other chronic diseases. Seeing that diabetes prevalence and with it mortality are increasing, LSI have become an inherent part of diabetes treatment standards. Various qualitative studies have been carried out to identify participation barriers for LSI. However, these have not resulted in more detailed knowledge about the relative importance of factors with an inhibiting impact on participation. Since it cannot be assumed that all of the influencing factors have equivalent values, it is necessary to investigate their individual importance with regard to a positive or negative decision about participating. There are no systematic reviews on patient preferences for LSI programs in diabetes prevention. As a result, the main objectives of this systematic review are to (i) identify existing patient preference elicitation studies related to LSI for diabetic patients, (ii) summarize the methods applied and findings, and (iii) appraise the reporting and methodological quality of such studies.

METHODS

We will perform systematic literature searches to identify suitable studies from 14 electronic databases. Retrieved study records will be included based on predefined eligibility criteria as defined in this protocol. We will run abstract and full-text screenings and then extract data from all selected studies by filling in a predefined data extraction spreadsheet. We will undertake a descriptive, narrative synthesis of findings to address the study objectives, since no pooling for quantified preferences is for methodological reasons implementable. We will pay special attention to aspects of methodological quality of preference elicitation by applying established evaluation criteria of the ISPOR and some own developed criteria for different elicitation techniques. All critical stages within the screening, data extraction, and synthesis processes will be conducted by two pairs of authors. This protocol adheres to PRISMA and PRISMA-P standards.

DISCUSSION

The proposed systematic review will provide an overview of the methods used and current practice in the elicitation and quantification of patients' preferences for diabetes prevention lifestyle interventions. Furthermore, the methodological quality of the identified studies will be appraised as well.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42018086988.

Conducting a Discrete-Choice Experiment Study Following Recommendations for Good Research Practices: An Application for Eliciting Patient Preferences for Diabetes Treatments

OBJECTIVES

To consolidate and illustrate good research practices in health care to the application and reporting of a study measuring patient preferences for type 2 diabetes mellitus medications, given recent methodological advances in stated-preference methods.

METHODS

The International Society for Pharmacoeconomics and Outcomes Research good research practices and other recommendations were used to conduct a discrete-choice experiment. Members of a US online panel with type 2 diabetes mellitus completed a Web-enabled, self-administered survey that elicited choices between treatment pairs with six attributes at three possible levels each. A D-efficient experimental design blocked 48 choice tasks into three 16-task surveys. Preference estimates were obtained using mixed logit estimation and were used to calculate choice probabilities.

RESULTS

A total of 552 participants (51% males) completed the survey. Avoiding 90 minutes of nausea was valued the highest (mean -10.00; 95% confidence interval [CI] -10.53 to -9.47). Participants wanted to avoid low blood glucose during the day and/or night (mean -3.87; 95% CI -4.32 to -3.42) or one pill and one injection per day (mean -7.04; 95% CI -7.63 to -6.45). Participants preferred stable blood glucose 6 d/wk (mean 4.63; 95% CI 4.15 to 5.12) and a 1% decrease in glycated hemoglobin (mean 5.74; 95% CI 5.22 to 6.25). If cost increased by $1, the probability that a treatment profile would be chosen decreased by 1%.

CONCLUSIONS

These results are consistent with the idea that people have strong preferences for immediate consequences of medication. Despite efforts to produce recommendations, ambiguity surrounding good practices remains and various judgments need to be made when conducting stated-preference studies. To ensure transparency, these judgments should be described and justified.

What matters in type 2 diabetes mellitus oral treatment? A discrete choice experiment to evaluate patient preferences

AIMS

The aim of this empirical study is to evaluate patient preferences for different characteristics of oral type 2 diabetes mellitus (T2DM) treatment. As T2DM treatment requires strict adherence, patient needs and preferences should be taken into consideration.

METHODS

Based on a qualitative and quantitative analysis, a discrete choice experiment (DCE) was applied to identify patient preferences. Apart from six identical attributes (adjustment of glycated hemoglobin [HbA1c], prevention of hypoglycemia, risk of genital infection, risk of gastrointestinal problems, risk of urinary tract infection, and weight change), one continuous variable of either "additional healthy life years" (AHY) or "additional costs" attribute (AC) was included. The DCE was conducted using a fractional factorial design, and the statistical data analysis used random effect logit models.

RESULTS

In total, N = 626 (N = 318 AHY + N = 308 AC) T2DM patients participated in the survey. The estimation revealed a clear dominance for prevention of hypoglycemia (coefficient 0.937) and adjustment of HbA1c (coefficient 0.541). The attributes, "additional healthy life years" (coefficient 0.458) or "additional costs" (coefficient 0.420), were in the middle rank and both of significant impact. The side effects, risk of genital infection (coefficient 0.301), risk of gastrointestinal problems (coefficient 0.296), and risk of urinary tract infection (coefficient 0.241) followed in this respective order. Possible weight change (coefficient 0.047) was of less importance (last rank) to the patients in this evaluation.

CONCLUSIONS

These survey results demonstrate how much a (hypothetical) T2DM oral treatment characteristic affects the treatment decision. The preference data can be used for risk-benefit assessment, cost-benefit assessment, and the establishment of patient-oriented evidence. Understanding how patients perceive and value different aspects of diabetes oral treatment is vital to the optimal design and evaluation of treatment options. The present results can be an additional source of information for design, assessment, and decision in T2DM treatment regimes. As such, more effective and efficient care of patients can be achieved, thereby increasing adherence.