Research Triangle Institute The Use of Conjoint Analysis to Elicit Patient Preferences in Selecting Treatment Endpoints F. Reed Johnson, PhD Distinguished Fellow and Principal Economist Research Triangle Institute Integrating Stakeholder Preferences in Comparative Effectiveness Research August 27, 2012 www.rti.org RTI International is a trade name of Research Triangle Institute. 1
RTI International Research Triangle Institute Comparative Effectiveness Research Compares the benefits and harms of alternative interventions Assists patients, physicians, and regulators to make informed decisions Institute of Medicine, 2009 2
RTI International Research Triangle Institute Comparisons for whom? Comparing benefits and harms and making informed decisions requires identifying relevant endpoints Increased concern about patient involvement in protocol development “When asking the public to assist in determining health priorities, we should use techniques that allow people to reveal their true preferences. If not, why bother asking them at all?” Gafni, Social Science and Medicine, 1995 3
RTI International Research Triangle Institute Types of Self-Reported Data Patient- Stated Health-State Reported Preferences Utilities Outcomes Standard Elicitation Discrete Choice Likert Scale Gamble/Time Formats Tradeoff Example Tailored SF-36 EQ-5D Tariffs Instruments Preference Metrics Weights, HTE, HRQoL Scores QALYs MAR, MAB, WTP CEA, CBA, licensing, Uses CEA, CEA, licensing adherence, clinical reimbursement guidelines 4
RTI International Research Triangle Institute Health-State Utility versus Preference Utility: Determinants HEALTH-STATE UTILITY PREFERENCE UTILITY Clinical outcomes Clinical Outcomes Duration Duration Treatment factors – Side Effects/Tolerability – Dosage Method/Frequency – Cost Process factors – Health-Care Setting Physician interactions – Personal factors – Age, gender, education, etc. – Health history Financial circumstances – 5
RTI International Research Triangle Institute Labels Conjoint (consider jointly) analysis Discrete-choice experiments Stated-choice surveys 6 6
RTI International Research Triangle Institute Choice-Experiment Methods Treatment alternatives consist of combinations of features. Preferences among treatment alternatives depend on the relative importance of features. Respondents state preferences for series of constructed, hypothetical treatment alternatives. Statistical model estimates preference weights consistent with observed choices. Preference weights quantify relative importance as the willingness to accept tradeoffs. 7 7 7
RTI International Research Triangle Institute Example Benefit-Risk Tradeoff Question Osteoarthritis Which treatment would you choose if these were the only options available? Feature Treatment A Treatment B PAIN Efficacy No Pain Extreme Pain No Pain Extreme Pain STIFFNESS No Stiffness Extreme Stiffness No Stiffness Extreme Stiffness Side Effects Moderate Occasional mild symptoms. Frequent moderate symptoms. STOMACH PROBLEMS Treat with over - the - counter medicines Treat with a prescription medicine Mild- 1 patient out of 5 patients out of RISK OF Side-Effect 100 (1 %) will BLEEDING 100 (5 %) will have have a bleeding ULCER Serious a bleeding ulcer ulcer Risks RISK OF 5 patients out of 15 patients out of HEART 100 ( 5 %) will 100 ( 15 %) will ATTACK or have a stroke have a heart attack STROKE page 8 8
RTI International Research Triangle Institute Why are T2DM patients inadherent? 1.00 1.0 = +0.28 0.8 0.72 0.6 0.4 0.2 0.0 "Best" "Satisfactory" 1/day 2/day Glucose control 9 9 9
RTI International Research Triangle Institute Why are T2DM patients inadherent? 1.00 1.0 0.89 = +0.28 0.8 0.72 = -0.61 0.6 0.4 0.28 0.2 0.0 "Best" "Satisfactory" 1/day 2/day Glucose control Number of Injections Hauber AB, Mohamed AF, Johnson FR, Falvey H. Treatment preferences and medication adherence of people with type 2 diabetes using oral glucose-lowering agents. Diabet Med. 2009;26:416-24. 10 10 10
RTI International Research Triangle Institute Physician Versus Patient Preferences Hepatitis B Lescrauwaet B, Mohamed AF, Johnson FR, Hauber AB. Do patients and physicians have similar preferences for health care decisions involving uncertain outcomes for chronic hepatitis B in Germany and Turkey? Poster presented at the International 11 Society for Pharmacoeconomics and Outcomes Research 16th Annual International Meeting; May 2011. Baltimore, MD.
RTI International Research Triangle Institute Physician Versus Patient Preferences Hepatitis B Lescrauwaet B, Mohamed AF, Johnson FR, Hauber AB. Do patients and physicians have similar preferences for health care decisions involving uncertain outcomes for chronic hepatitis B in Germany and Turkey? Poster presented at the International Society for Pharmacoeconomics and Outcomes Research 12 16th Annual International Meeting; May 2011. Baltimore, MD.
RTI International Research Triangle Institute Physician Versus Patient Preferences Hepatitis B Most important Least important German patients Renal toxicity Weight of evidence German physicians Efficacy Weight of evidence Turkish patients Weight of evidence Fracture risk Turkish physicians Renal toxicity Fracture risk Lescrauwaet B, Mohamed AF, Johnson FR, Hauber AB. Do patients and physicians have similar preferences for health care decisions involving uncertain outcomes for chronic hepatitis B in Germany and Turkey? Poster presented at the International Society for Pharmacoeconomics and Outcomes Research 13 16th Annual International Meeting; May 2011. Baltimore, MD.
RTI International Research Triangle Institute Maximum Acceptable Risk Calculation Renal Cell Carcinoma Wong MK, Mohamed AF, Hauber AB, Yang J-C, Liu Z, Rogerio J, et al. Patients rank toxicity against progression-free survival in second-line 14 treatment of advanced renal cell carcinoma. J Med Econ. 2012 Jul 3. doi: 10.3111/13696998.2012.708689. [Epub ahead of print].
RTI International Research Triangle Institute Maximum Acceptable Risk Calculation Renal Cell Carcinoma = +0.84 Wong MK, Mohamed AF, Hauber AB, Yang J-C, Liu Z, Rogerio J, et al. Patients rank toxicity against progression-free survival in second-line 15 treatment of advanced renal cell carcinoma. J Med Econ. 2012 Jul 3. doi: 10.3111/13696998.2012.708689. [Epub ahead of print].
RTI International Research Triangle Institute Maximum Acceptable Risk Calculation Renal Cell Carcinoma = +0.84 = 0.84 Wong MK, Mohamed AF, Hauber AB, Yang J-C, Liu Z, Rogerio J, et al. Patients rank toxicity against progression-free survival in second-line 16 treatment of advanced renal cell carcinoma. J Med Econ. 2012 Jul 3. doi: 10.3111/13696998.2012.708689. [Epub ahead of print].
RTI International Research Triangle Institute Maximum Acceptable Breast-Cancer Risk Vasomotor Symptoms 0.025 Absolute Risk Maximum Acceptable Risk 0.020 Relative Risk 0.015 0.010 0.005 0.000 Severe to Severe to Severe to no symptoms mild symptoms moderate symptoms Johnson FR, Ozdemir S, Hauber AB, Kauf T. Women's willingness to accept risk for perceived vasomotor symptom relief. J Womens Health. 2007;16(7):1028-40. 17
RTI International Research Triangle Institute Maximum Acceptable Breast-Cancer Risk Vasomotor Symptoms 0.025 Absolute Risk Maximum Acceptable Risk 0.020 Relative Risk 0.015 0.010 0.005 WHI Risk 0.000 Severe to Severe to Severe to no symptoms mild symptoms moderate symptoms Johnson FR, Ozdemir S, Hauber AB, Kauf T. Women's willingness to accept risk for perceived vasomotor symptom relief. J Womens Health. 2007;16(7):1028-40. 18
RTI International Research Triangle Institute Some Methodological Challenges Hypothetical bias Inexperience with condition – Socially acceptable responses – – Stated preference/revealed preference experiments Cognitive challenges – Effective description of clinical endpoints Surrogate markers – Risk concepts – Consensus among researchers – Experimental design – Statistical analysis 19 19
RTI International Research Triangle Institute Discussion Effective incorporation of patient perspectives in protocol development requires quantification. Idea of treating patient-preference measures as evidence is novel for most clinicians. DCE methods offer methods for quantifying relative values of health endpoints. Good validity and reliability for relatively simple trade-off problems. Applications to more difficult problems is an active area of research. 20
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