Advancing stated-preference methods for measuring the preferences of patients with type 2 diabetes

Transcription

1 Advancing stated-preference methods for measuring the preferences of patients with type 2 diabetes Second DAB Meeting November 20, 2014 Baltimore, MD

2 Development of the Preference Tasks

3 Section Outline Stated-preference methods in diabetes von Arx Research question/vignette Janssen Attributes and levels Janssen Preference elicitation Bridges 2014, Johns Hopkins University. All rights reserved.

4 Stated preference methods in diabetes Lill-Brith von Arx University of Southern Denmark, COHERE Novo Nordisk A/S, Dep. of Epidemiology 4 Date Presentation title

5 Agenda Background Systematic Review Project aim Discrete Choice Experiment

6 The patient perspective in drug development Patient-centred development how is it realised? Research Development Commercialisation Phase 1 Phase 1-2 Phase 3 Phase 4 Research project approval Assessment of patient unmet medical needs First human dose Development candidate selection Clinical proof of concept Phase 3 Stop/go decision Marketing authorisation Product launch LCM Pricing & reimbursement PROs Anthropological methods/qualitative research Stated preference methods

7 Presentation title Date 7 Priorities in drug development Diabetes self- management Quality- of- life Health outcome Efficacy A1c Safety Ease of use Cost Clinical development Decision makers Cost- Effec.veness Pa.ents

8 Date 8 Project idea Examine patient preference towards insulin treatment defining patient-important outcomes in diabetes research In an era where diabetes research goes beyond lifesaving therapies (glucose lowering efficacy) what patient segments benefit the most from innovative products? Is there a social gradient in benefit gained from innovation?

9 Date 9 Aim of the systematic review To provide an overview of the current application of stated preference methods in diabetes care examine how stated preference methods are applied in diabetes (pharmaceutical diabetes treatments) evaluate the value of this information in developing the patient perspective in clinical and policy decisions. von Arx LB. Kjaer T. The Patient Perspective of Diabetes Care: A Systematic Review of Stated Preference Research. Patient 2014;7(3):

10 Funding of DCE studies (n=11) Date 10

11 Date 11 Rationale provided in articles for study conduct Key aspect Rationale provided in the articles Shared decision making (n=7) To foster patient-caregiver concordance To enhance treatment outcome To improve adherence To reduce health care costs Product differentiation (n=9) To inform a choice between distinct treatment alternatives (e.g. oral versus. injectable medication) To differentiate between similar products (e.g. insulin analogues)

12 Date 12 Efficacy Glycemic control Attribute selection Adverse events Hypoglycemia Nausea Weight control CVD (treatment inherent risk) Product ease of use Mode and timing of administration

13 Date 13 Efficacy measure HbA1c PPG/FPG Blood sugar/glucose control HbA1c: % change Post-prandial glucose/fasting-plasma glucose: mmol/l or generic Blood sugar/glucose control: generic description (optimal, poor)

14 Date 14 Summary Although the rationale for conducting a DCE is patient-centered the attribute selection in most applications are based on clinical outcome measures Clear definition of the attribute levels describing the choice scenarios (e.g. severity of hypoglycaemic events) Supporting the choice task with relevant respondent health information Paucity in SP research examining health outcomes beyond what is examined during the development programme Applications of current DCEs could be for pricing-and reimbursement decisions Therapeutic application Glycemic control preferred over avoiding minor hypo glycemic events, but not nighttime or severe hypos.

15 Date 15 Project aim To examine patient preference towards the benefits and risks of insulin treatment To evaluate the effect benefit-risk tradeoffs of presenting benefit is an actual health outcome rather than a surrogate measure To examine individual predictors of preference General- and diabetes specific health status Socioeconomic status and labour market attachment Health behaviour and risk aversion

16 Presentation title Date 16 Survey design of the DCE Benefit Risk Surrogate A 1c % Questionnaire A A 1c % + guidance B A 1c % + cheap talk Weight Heart attack Minor Hypos Major Hypos C Health benefit Reduced risk of longterm complications D

17 Presentation title Date 17 DCE choice task 8.5 % 8.5 % (moderate) 8.5 % +

18 Date 18 Source data Self-administered questionnaire (postal) DCE choice task Health literacy (diabetes/hba1c) Health behaviour/time preference/risk aversion Sociodemographics Diabetes registry 3300 type 2 diabetes pts using insulin Health and diabetes status Long term complications General health status (incl. CVD)

19 Date 19 Follow- up project Qualitative study Examining patient understanding of A1c and long-term sequalae risk Mathilde L.M. Eriksen, MSc stud, RN, SDU & NN Helle Ploug Hansen, professor, SDU Lill-Brith von Arx, MSc, PhD stud, SDU & NN

20 Thank you! Date 20

21 Identification of the research question, vignette, and attributes Ellen Janssen, BA PhD Student Department of Health Policy and Management Johns Hopkins Bloomberg School of Public Health 21

22 Presentation Outline Background Research Question Vignette Attributes and levels 2014, Johns Hopkins University. All rights reserved.

23 Background Many different types of medications for type 2 diabetes Oral medications Subcutaneous medications Insulin Metformin generally first line treatment Considered safe 5% of patients that initiate metformin treatment need to switch medications due to severe gastro-intestinal side effects 2014, Johns Hopkins University. All rights reserved.

24 Research Question Objective: quantify the relative preferences of adults with type 2 diabetes for diabetes medication related attributes Research question: What are the treatment preferences for patients with type 2 diabetes who have recently been diagnosed and need to switch medications due to a metformin intolerance? 2014, Johns Hopkins University. All rights reserved.

25 Vignette Imagine that you were recently diagnosed with type 2 diabetes. Your doctor prescribed you metformin. You have been taking metformin for the past three months and are experiencing severe side effects. These side effects include continuous diarrhea, nausea, and abdominal bloating. You are now talking to your doctor about switching medications. Out of the two medications below, which one would you prefer? 2014, Johns Hopkins University. All rights reserved.

26 Attributes Eight attributes identified 1. Glycemic control 2. Hypoglycemia 3. Weight Changes 4. Heart Attack 5. Gastrointestinal side effects 6. Glucose monitoring 7. Dosage and administration 8. Cost 2014, Johns Hopkins University. All rights reserved.

27 Attributes Detailed Attribute Definition Level Glycemic control Hypoglycemia Weight Changes Heart Attack HbA1c levels Symptoms of hypoglycemia: nausea, rapid pulse, shakiness, blurred vision, hunger, fatigue, pallor Weight loss in first six months since starting medication Additional medication related risk of a heart attack HbA1C levels at 9% (poor) HbA1C levels at 7.5% (suboptimal) HbA1C levels at 6.5% (optimal) No events 4 events in a month 8 events in a month 20% of people gain weight 10% of people gain weight 10% of people lose weight No additional person will have a heart attack 1 additional person out of 1000 (0.1%) will have a heart attack 10 additional patients out of 1000 (1.0%) will have a heart attack 2014, Johns Hopkins University. All rights reserved.

28 Attributes Detailed Cont d Attribute Definition Level Gastrointestinal Side Effects Glucose Monitoring Dosage Cost Percent of people who will suffer from medication related risk of diarrhea, nausea, and abdominal bloating How often your doctor recommends that you monitor your blood glucose How often you will need to take the medication Out of pocket costs 0% no risk of diarrhoea, upset stomach and/or nausea 10% 20% Three times a day Once a day Once a week Injection once a day in relation to meal Oral medication once a day in relation to meal Oral medication once a day irrespective of meal $25/month $50/month $75/month 2014, Johns Hopkins University. All rights reserved.

29 Ques.ons Relevance of attributes Number of attributes Framing of attributes Denominator Severe side effect 29

30 The Preference Elicitation Task John F.P. Bridges, Ph.D Principle Investigator Associate Professor Department of Health Policy and Management Johns Hopkins Bloomberg School of Public Health 30

31 Presentation Outline Randomized Experiments Statistical efficient design vs Bayesian Optimal Design DCE vs. BWS 2014, Johns Hopkins University. All rights reserved.

32 Randomized Experiment Design two different preference elicitation tasks Randomly assign respondents to the different preference elicitation tasks Motivation: Paucity of research comparing different preference elicitation methods or different experimental designs Use of a randomized trial will increase ability to draw inferences from results Fill in evidence gaps in stated-preference methods Advance measurement of patients and stakeholders values Introduce stakeholders to innovative stated-preference methods 2014, Johns Hopkins University. All rights reserved.

33 Comparisons Original experiment: Statistically D-efficient design to Bayesian optimal design Proposed experiment: Compare Discrete Choice Experiment (DCE) to Best-Worst Scaling Case 2 (BWS Case 2) 2014, Johns Hopkins University. All rights reserved.

34 Original Experiment: Statistically Efficient vs. Bayesian Optimal Design Traditional experimental designs for conjoint analysis have focused on orthogonality and statistical efficiency, Prone to scale biases. Modern experimental design techniques employ Bayesian techniques to maximize respondent efficiency. No direct comparison of results from a statisticallyefficient experimental design and respondent-efficient experimental design. 2014, Johns Hopkins University. All rights reserved.

35 DCE and BWS Case 2 DCE and BWS make use of treatment profiles that consist of attributes at different levels DCE: two distinct treatment profiles at a time Select treatment profile that is preferred BWS case 2: one treatment profile at a time. Select best attribute and worst attribute 2014, Johns Hopkins University. All rights reserved.

36 DCE Profile Medication Feature Medication A Medication B AJribute HbA 1c change Number of hypoglycemic events per month From 8.5 to 8.3* (poor blood glucose control) From 8.5 to 6.5* (optimal blood glucose control) 1 to 2 More than 2 Water retention Yes No Weight gain in first 6 months None Mild stomach upset Chance of a heart attack Which medication would you choose? Mild nausea and vomiting or diarrhea that continues as long as you take the medicine No additional person (0%) will have a heart attack I would choose Medication A ** Attributes cited from Hauber et al. (2009) 6 with adjustment. 10 pounds No stomach problems 10 additional people out of 1,000 (1.0%) will have a heart attack I would choose Medication B Level 2014, Johns Hopkins University. All rights reserved.

37 Best-Worst Scaling (Case 2) Best Medication features Worst HbA1c changed from 8.5 to 8.3* (poor blood glucose control) 1 to 2 hypoglycemic events per month Experience water retention Profile No weight gain in first 6 months Mild nausea and vomiting or diarrhea that continues as long as you take the medicine No additional person (0%) will have a heart attack AJribute with level Imagine you were offered this oral diabetes medication. Tick the medication feature that is the best and the medication feature that is the worst. ** Attributes cited from Hauber et al. (2009) 6 with adjustment. 2014, Johns Hopkins University. All rights reserved.

38 Proposed experiment: DCE vs. BWS Case 2 DCE well established One of the most popular stated-preference methods Technical, many requirements on study design BWS not as well established Requires less questions for same amount of information Less burdensome Concordance/discordance of DCE and BWS case 2 still needs to get established 2014, Johns Hopkins University. All rights reserved.

39 Reasons for Switching Experiments Design experiment was highly technical Not very relevant to patients and other stakeholders Comparison of DCE and BWS case 2 more relevant to patient engagement Easier to communicate and understand for patient and stakeholder groups Will provide more concrete advise/methods for (patient) groups new to stated-preferences 2014, Johns Hopkins University. All rights reserved.

40 Protecting Health, Saving Lives Millions at a Time