VALUE IN HEALTH 14 (2011) 1153–1157 Available online at www.sciencedirect.com journal homepage: www.elsevier.com/locate/jval Elicitation of Informed General Population Health State Utility Values: A Review of the Literature Helen McTaggart-Cowan, PhD* Canadian Centre for Applied Research in Cancer and British Columbia Cancer Agency, Vancouver, BC, Canada A B S T R A C T Objective: Within a health-care decision-making context, whose health state utility values (HSUVs) should be used is constantly debated. This discussion is important because patient and general population utilities can differ. These discrepancies may be due to the general population not being informed about the health states. This article investigates approaches used to inform the general population about the health states that they are valuing. Methods: Studies reporting methods to obtain informed general population HSUVs were identified, outlined, and critically appraised. Results: Fourteen studies were identified: seven used information sessions, two used simulation methods, two used reflection and deliberation techniques, and three used adaptation exercises. Conclusions: This review demonstrated a range of Introduction Cost-utility analysis (CUA) is increasingly being used to guide decision makers regarding the allocation of health-care resources. In CUA, health benefits are quantified using quality-adjusted lifeyears (QALYs) [1], a measure that combines both duration and quality of life (QOL) into a single index. QOL information is obtainable from respondents in the form of health state utility values (HSUVs). Whether patients or members of the general population should provide HSUV to be incorporated into a CUA is currently under debate [2]. Although patients may be better at valuing their own health [3], most agencies that use QALYs have advocated that HSUVs should be obtained from the general population [4 – 6]. This is because general population utilities are better suited to inform policy decisions in publicly funded health-care systems. Rational citizens, operating behind a “veil of ignorance,” provide HSUVs unbiased by specific interests. General population respondents are asked to envision life in the health state and then provide a utility value for it. A drawback to using general population HSUVs, however, is that health state descriptions are brief. As such, respondents may not fully comprehend life with the impaired health state, leading to decisions that do not maximize societal health benefits. The debate on whose HSUVs to use is important because previous studies have shown significant discrepancies between patient and general population utilities [7,8]. Generally, patient utilities tend to be higher than those of the general population’s. This approaches to elicit informed general population HSUVs. The majority of the studies indicated that informing the respondents significantly affected their opinions of the health states and hence their HSUVs. This suggests that the utilities that are currently used to guide health-care resource allocation decisions may not represent the general population’s preferences for specific health states. This could result in decisions that do not maximize societal health benefits. Keywords: adaptation, general population, health states, informed utilities, review. Copyright © 2011, International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. may be a result of misinterpreting the same health state or incorporating differing levels of disease adaptation into the valuations; for a further discussion, refer to Ubel et al. [9], Brazier et al. [10], and Stiggelbout and de Voel-Voogt [11]. This difference can have significant ramifications when incorporated into a CUA [9]. To ensure that general population utilities are relevant, HSUVs provided by respondents informed about the health condition may be a better approach [4,10,12]. The informing process allows the respondents to incorporate all available information regarding the health condition into their own assessment. Thus, the current challenge is to refine the health state elicitation method such that respondents are informed and able to formulate their HSUVs. This article synthesizes the results from studies that informed the general population when valuing health states. Methods PubMed, EMBASE, and PsycINFO databases were searched to identify empirical studies that informed the general population about the health states that they are valuing. The search was restricted to articles in English dated 2009 or earlier. The search keywords were general population, public, health state$, inform$, and utility. The references of retrieved articles were searched to trace potentially relevant articles. Peer-reviewed published studies were selected for review if they used written or other audiovisual techniques to describe the * Address correspondence to: Helen McTaggart-Cowan, Canadian Centre for Applied Research in Cancer Control, 675 West 10th Avenue, Vancouver, BC Canada V5Z 1L3. E-mail: hcowan@bccrc.ca. 1098-3015/$36.00 – see front matter Copyright © 2011, International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. doi:10.1016/j.jval.2011.05.046 1154 Table 1 – Characteristics of the reviewed studies. No. Study Design Sample Country of study Type Size Bramlett et al., 2006 [16] SI GP (r) 75 US 2 Briggs et al., 2008 [17] SI GP (c) 75 UK 3 Clarke et al., 1997 [18] SI GP (c) 39 Canada, US 4 Cunningham and Hunt, 2000 [19] SI GP (c) 57 UK 5 Happich and von Lengerke, 2005 [20] SI GP (r) 210 6 Lee et al., 2000 [21] SI GP (r) 20 USA 7 Lenert et al., 2004 [22] SI GP (c) 620 USA 8 Aballéa and Tsuchiya, 2007 [23] SI GP (r) 38 Germany UK Pre- and posttests Health state valued Valuation method Information to enrich the health state descriptions No Mild stuttering SG TTO Rating Moderate stuttering SG TTO Rating Severe stuttering SG TTO Rating No No Stable schizophrenia TTO Relapsed schizophrenia TTO Yes (patient) No Gaucher’s disease (low blood SG counts) TTO Risk-risk trade-off Gaucher ‘s disease (bone pain) SG TTO Risk-risk trade-off Gaucher ‘s disease (enlarged SG abdomen) TTO Risk-risk trade-off Yes No Dentofacial deformities SG TTO VAS Yes (patient) No Tinnitus SG TTO VAS Yes (patient) No Mild schizophrenia SG VAS Moderate schizophrenia SG VAS No No Mild schizophrenia SG Moderate schizophrenia (type 1) SG Moderate schizophrenia (type 2) SG Severe schizophrenia (type 1) SG Severe schizophrenia (type 2) SG Severe schizophrenia (type 3) SG Severe schizophrenia (type 4) SG Extremely severe SG No Simulation to reproduce symptoms of the health state descriptions No No Mild visual impairment TTO Severe visual impairment TTO Postoperative vision TTO Mean informed HSUVs Pretest Posttest Control N/A 0.96 0.93 0.80 0.91 0.85 0.65 0.81 0.63 0.44 0.87 0.48 0.94 0.87 0.32 0.94 0.86 0.29 0.92 0.82 0.24 0.73 0.67 54.3 0.81 0.79 0.34 0.88 0.64 0.83 0.54 0.88 0.76 0.75 0.65 0.66 0.56 0.63 0.43 N/A N/A N/A N/A N/A N/A N/A N/A 0.76 0.50 0.55 N/A 0.94 0.87 0.55 0.81 0.81 0.40 0.90 0.80 0.45 0.79 0.72 59.5 0.80 0.77 0.35 0.92 0.70 0.92 0.64 N/A N/A (continued on next page) VALUE IN HEALTH 14 (2011) 1153–1157 1 Control group Table 1 (continued). No. Study Design Sample Country of study Control group Pre- and posttests No Type Size 9 Czoski-Murray et al., 2009 [24] SI GP (c) 104 UK No 10 Shiell et al., 2003 [25] SI GP (r) 233 Australia Yes Health state valued Reading limit Legal blindness Untreated age-related macular degeneration Reflection and deliberation techniques Yes EQ-5D state 11222 EQ-5D state 11213 Stein et al. 2006, [26] SI GP (c) 15 12 Damschroder et al., 2005 [27] SQ GP (c) 359 13 Damschroder et al., 2008 [28] SI GP (r) 1117 UK No USA Yes USA No Yes Multiple sclerosis state 1 Multiple sclerosis state 2 Gaucher’s disease EQ-5D state 1 EQ-5D state 2 EQ-5D state 3 Heart failure state 1 Heart failure state 2 Moderate eczema Severe eczema Osteoarthritis state 1 Osteoarthritis state 2 Osteoarthritis state 3 Osteoarthritis state 4 Exercises to evoke adaptation to the health states No Preexisting paraplegia Yes SQ GP (c) 852 698 USA Yes Yes Control 0.71 0.59 0.36 N/A SG TTO SG TTO SG SG SG SG SG SG SG SG SG SG SG SG SG SG 0.71 0.75 0.58 0.55 0.75 0.94 0.88 0.97 0.30 0.75 0.84 0.51 0.782 0.70 0.96 0.83 0.96 0.98 0.68 0.72 0.53 0.53 0.83 0.93 0.88 0.98 0.30 0.75 0.84 0.50 0.786 0.69 0.96 0.83 0.97 0.98 0.66 0.61 0.57 0.52 N/A PTO N/A Below-the-knee amputation SG TTO SG TTO SG TTO SG TTO VAS VAS Paraplegia Ubel et al., 2005 [29] Posttest N/A PTO Colostomy 14 Pretest TTO TTO TTO New-onset paraplegia Severe back pain Paraplegia Paraplegia Mean informed HSUVs N/A 47.0 50.6 Saving the lives of 100 patients ⫽ saving the lives of 100 healthy people Saving the lives of 102 patients ⫽ saving the lives of 100 healthy people 0.76 0.89 0.73 0.83 0.64 0.81 0.63 0.79 51.6 58.5 Saving the lives of 100 patients ⫽ saving the lives of 102 healthy people Saving the lives of 1000 patients ⫽ saving the lives of 100 healthy people 0.76 0.90 0.72 0.86 0.67 0.81 0.67 0.80 62.2 52.7 VALUE IN HEALTH 14 (2011) 1153–1157 11 Valuation method EQ-5D, EuroQoL; GP (c), general population (convenient sample); GP (r), general population (representative sample); HSUVs, health state utility values; N/A, not applicable; PTO, person trade-off; SG, standard gamble; SI, structured interview; SQ, self-completed questionnaire; TTO, time trade-off; VAS, visual analog scale. 1155 1156 VALUE IN HEALTH 14 (2011) 1153–1157 health states to the respondents. Studies were excluded if the respondents did not value distinct health states. After a critical review of titles and abstracts, 14 full-text articles met the inclusion criteria. Extracted information included design, type of sample and size, country of study, presence of a control group, pre- and post-tests used, health state labels, valuation techniques used, and mean informed HSUVs. Results Table 1 summarizes the identified empirical studies. Interventions used to inform the general population were categorized into information to enrich the health state descriptions (n ⫽ 7); simulation to reproduce the symptoms of the health state (n ⫽ 2); opportunity to reflect and deliberate on the health state descriptions (n ⫽ 2); and exercises to evoke adaptation to the health state (n ⫽ 3). More information about the reviewed studies is available in Appendix A found at doi: 10.1016/j.jval.2011.05.046. The majority of the identified studies provided respondents with additional information through the use of audio recordings and videos. The drawback of this approach is that the respondents are not able to properly envision themselves in the health state that they are being asked to value. One method to overcome this limitation is to use devices to enhance the effect of the health state (e.g., spectacles to replicate different severities of visual impairment). Such simulation techniques can help the respondents to better imagine life in the health state; however, they are not applicable to all disease states. Deliberation and adaptation techniques explicitly encourage respondents to consider broader life aspects in relation to the health state. The deliberation approach may replicate the way in which “real-life” decisions are made, whereas adaptation exercises inform the respondents about the possibility of adapting to an impaired health state over time. Discussion This review aimed to gain an understanding of the methods currently being used to inform the general population when valuing health states. Conventionally, health states in valuation studies tend to be described as varying levels of a limited number of different domains. They may not, however, provide enough sensitivity for general population respondents to familiarize themselves with the health state and provide a meaningful valuation. By providing additional information, alongside the descriptions, focusing illusion effect—an inattention to broad life domains and overestimation of the emotional impact of an event [13]—may be reduced. Specifically, general population respondents may disproportionately focus on certain activities that could be negatively affected by the impaired health state and ignore other aspects of life (e.g., personal and spiritual relationships) that may be unaffected by a changed state of health [14]. These influences could cause respondents to under- or overestimate their HSUVs, biasing the outcome of a CUA. Although informing the respondents does not ensure that all start at exactly the same knowledge point, it should eliminate complete unawareness of the health state. This review’s ability to determine the most effective method to inform the general population is limited because most studies did not include either independent control groups or pre- and posttest measurements. Without these specific components, the impact of the information on HSUVs cannot be directly assessed. Only seven studies included controls; of these, three used patients as “controls”. Of the seven, only studies 10 and 14 included preand posttest measurements (Table 1). As a result, the impact of informing the general population on their HSUVs cannot be generalized in this review. Although both of these studies revealed that the informed HSUVs were not significantly different from those of the controls, these are too few from which to draw a meaningful conclusion. The majority of studies had general population respondents value disease-specific health states rather than generic ones. The use of disease-specific states may enable respondents to better imagine the impact of the health state on their QOL; however, this prevents comparison across diseases. As a result, it would be more beneficial to understand how to best inform them about generic health states [4 – 6]. However, there is concern that the value currently attached to the QOL of these generic states may be determined by unengaged and uninformed members of the general population. Future work could involve the recalculation of tariffs (e.g., EuroQoL 5D) that are currently being used to generate population HSUVs for use in economic evaluation with respondents who are informed about the health states that they are valuing to assess whether there was a difference between the uninformed and informed HSUVs. By doing this, wider use of the QALY as a health outcomes measure may be established [15]. Another way to inform the general population is to provide them with patient HSUVs; this was not explored in any of the reviewed studies. The drawback of this method is that patient HSUVs needs to be collected at different time points to describe a series of events, including at disease onset, during adaptation, and after a period of time living with the condition [10]. For this approach, however, the QALY model will need to be reconsidered. By calculating individual QALYs for each time point, duration and QOL can no longer be regarded as utility independent. This could significantly affect the standard practice of using valuation sets in economic evaluation of health-care technologies. Despite the recommendation to use informed general population values in decision making [4 – 6], this review demonstrates that relatively few studies have aimed at informing the general population about the health states that they are being asked to value; this may be a result of there being no guidance on how to construct HSUVs of this type. Due to limitations within the designs of the reviewed work (i.e., absence of independent control groups or pre- and posttest measurements), there is no clear indication of which methods for informing respondents are appropriate and whether these methods would vary for different disease states. The majority of the reports, however, indicated that informing the respondents significantly affected their opinions of the health states and hence their HSUVs. This suggests that the utilities that are currently used to guide health-care resource allocation decisions may not represent the general populations’ preferences for the health states. This could potentially result in decisions that do not maximize societal health benefits. Given these important policy implications, further research to develop an appropriate method for informing general population values is needed. Acknowledgments The author thanks the editor and the two anonymous reviewers for their valuable suggestions, as well as Aki Tsuchiya and Stuart Peacock for comments on earlier versions of this article. At the time that this review was conducted, the author was a doctoral candidate at the University of Sheffield and was supported by a doctoral research award from the Canadian Institutes for Health Research. The usual disclaimer applies. 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