The reliability and internal consistency of an Internet-capable computer program for measuring utilities

Direct Assessment of Health Utilities Using the Standard Gamble Among Patients With Primary Intracerebral Hemorrhage

BACKGROUND

Standard gamble (SG) directly measures patients' valuation of their health state. We compare in-hospital and day-90 SG utilities (SGU) among intracerebral hemorrhage patients and report a 3-way association between SGU, EuroQoL-5 dimension, and modified Rankin Scale at day 90.

METHODS AND RESULTS

Patients with intracerebral hemorrhage underwent in-hospital and day-90 assessments for the modified Rankin Scale, EuroQoL-5 dimension, and SG. SG provides patients a choice between their current health state and a hypothetical treatment with varying chances of either perfect health or a painless death. Higher SGU (scale, 0-1) indicates lower risk tolerance and thus higher valuation of the current health state. Logistic regression was used to estimate the likelihood of low SGU (≤0.6), and Wilcoxon paired signed-rank test compared in-hospital and day-90 SGU. In-hospital and day-90 SG was obtained from 381 and 280 patients, respectively, including 236 paired observations. Median (interquartile range) in-hospital and day-90 SGUs were 0.85 (0.40-0.98) and 0.98 (0.75-1.00; P<0.001). In-hospital SGUs were lower with advancing age (P=0.007), higher National Institutes of Health Stroke Scale, and intracerebral hemorrhage scores (P<0.001). Proxy-based assessments resulted in lower SGUs; median difference (95% CI), -0.2 (-0.33 to -0.07). After adjustment, higher National Institutes of Health Stroke Scale and proxy assessments were independently associated with lower SGU, along with an effect modification of age by race. Day-90 SGU and modified Rankin Scale were significantly correlated; however, SGUs were higher than the EuroQoL-5 dimension utilities at higher modified Rankin Scale levels.

CONCLUSIONS

Divergence between directly (SGU) and indirectly (EuroQoL-5 dimension) assessed utilities at high levels of functional disability warrant careful prognostication of intracerebral hemorrhage outcomes and should be considered in designing early end-of-life care discussions with families and patients.

Valuation of EQ-5D-5L health states: a comparison of seven Asian populations

Objectives: To compare the time trade-off (TTO) utility values of EQ-5D-5L health states elicited from different general populations in Asia. Methods: We analyzed the TTO data from seven Asian EQ-5D-5L valuation studies in which utility values of 86 EQ-5D-5L health states were elicited from general population samples. An eight-parameter multiplicative regression model including five dimension parameters (mobility [MO], self-care, usual activities [UA], pain/discomfort, anxiety/depression) and three level parameters (level 2 [L2], level 3 [L3], and level 4 [L4]) was used to model the data from each of the populations. The model coefficients were compared to understand how the valuations of EQ-5D-5L health states differ. Results: For dimension parameters, Korea and Indonesia generally had the highest and lowest values among the populations, respectively; UA and MO commonly had the highest and lowest values among the parameters, respectively. For level parameters, Singapore and Korea generally had the highest and lowest values, respectively; L2 showed less variance compared to L3 and L4. Koreans, Indonesians, and Singaporeans appeared to have different health preferences compared with other populations. Conclusion: Utility values of EQ-5D-5L health states differ among Asian populations, suggesting that each health system should establish and use its own value set.

Feasibility, comparability, and reliability of the standard gamble compared with the rating scale and time trade-off techniques in Korean population

PURPOSE

The standard gamble (SG) method is the gold standard for valuing health states as a utility, although it is accepted that it is difficult to valuate health states. This study was conducted in order to compare the SG with the rating scale (RS) and time trade-off (TTO) techniques in terms of their feasibility, comparability, and reliability in a valuation survey of the general Korean population.

METHODS

Five-hundred members of the general Korean population were recruited using a multi-stage quota sampling method in Seoul and its surrounding areas, Korea. Respondents evaluated 9 EQ-5D-5L health states using a visual analogue scale (VAS), SG, and TTO during a personal interview. Feasibility was assessed in aspects of the level of difficulty, administration time, and inconsistent responses. Comparability was evaluated using intraclass correlation coefficient (ICC) and the Bland-Altman approach. Test-retest reliability was analyzed using the ICC.

RESULTS

Of the three methods, VAS was the easiest and quickest method to respond. The SG method did not differ significantly compared to the TTO method in administration time as well as the level of difficulty. The SG and TTO values were highly correlated (r = 0.992), and the average mean difference between the SG and the TTO values was 0.034. The ICCs of the VAS, SG, and TTO scores were 0.906, 0.841, and 0.827, respectively.

CONCLUSIONS

This study suggests that the SG method compared with the VAS and TTO method was feasible and offered a reliable tool for population-based, health state valuation studies in Korea.

A Review and Meta-Analysis of Prostate Cancer Utilities

Background. Health-related quality of life is a key issue in prostate cancer (PC) management. The authors summarized published utilities for common health-related quality of life outcomes of PC and determined how methodological factors affect them. Methods. In their systematic review, the authors identified 23 articles in English, providing 173 unique utilities for PC health states, each obtained from 2 to 422 respondents. Data were pooled using linear mixed-effects modeling with utilities clustered within the study, weighted by the number of respondents divided by the variance of each utility. Results. In the base model, the estimated utility of the reference case (scenario of a metastatic PC patient with severe sexual symptoms, rated by non-PC patients using time tradeoff) was 0.76. Disease stage, symptom type and severity, source of utility, and scaling method were associated with utility differences of 0.10 to 0.32 (P < 0.05). Utilities from PC patients rating their own health were 0.14 higher than those from the reference case, but utilities from PC patients rating scenarios were lowest. Time tradeoff yielded the highest utilities. Computer administration yielded lower utilities than personal interview (P = 0.02). Neither the scale's high anchor nor study purpose had significant effects on utilities. Conclusions. This study provides pooled utility estimates for common PC health states and describes how clinical and methodological factors can significantly affect these values. When possible, utility estimates for a modeling application should be derived similarly. Formal data synthesis methods might be useful to researchers integrating utility data from heterogeneous sources. Further exploration of these methods for this purpose is warranted.

Time Trade-Off as a Measure of Health-Related Quality of Life: Long Bone Nonunions Have a Devastating Impact

BACKGROUND

Long bone nonunions have an important impact on a patient's quality of life. The purpose of this study was to compare long bone nonunions with use of the Time Trade-Off direct measure to compute utility scores and to determine which nonunion anatomic location had the lowest health-related quality of life. The Time Trade-Off assesses the percentage of a patient's remaining life that the patient would be willing to trade for perfect health.

METHODS

Eight hundred and thirty-two consecutive long bone nonunions with Time Trade-Off data were identified and were retrospectively studied from a prospectively collected patient database. Nonunions with infections and those involving the articular portion of the bone were recorded. Time Trade-Off utility scores were obtained for all nonunion cases upon their initial clinical evaluation by a single surgeon specializing in reconstructive trauma.

RESULTS

The mean utility score of our nonunion cohort was 0.68 and it differed significantly by long bone (p = 0.037). Nonunions of the forearm had the lowest utility score (0.54), followed by the clavicle (0.59), femur (0.68), tibia or fibula (0.68), and humerus (0.71). Post hoc tests showed that patients with nonunions of the forearm had significantly lower utility scores (p = 0.031) compared with all other bones.

CONCLUSIONS

Patients diagnosed with a long bone nonunion have a very low health-related quality of life. We found that this single cohort's mean utility score was 0.68. This result is well below that of illnesses such as type-I diabetes mellitus (0.88), stroke (0.81), and acquired immunodeficiency syndrome (0.79). We found that patients with forearm nonunions had the lowest utility scores.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

The Trojan Lifetime Champions Health Survey: development, validity, and reliability

CONTEXT

Self-report questionnaires are an important method of evaluating lifespan health, exercise, and health-related quality of life (HRQL) outcomes among elite, competitive athletes. Few instruments, however, have undergone formal characterization of their psychometric properties within this population.

OBJECTIVE

To evaluate the validity and reliability of a novel health and exercise questionnaire, the Trojan Lifetime Champions (TLC) Health Survey.

DESIGN

Descriptive laboratory study.

SETTING

A large National Collegiate Athletic Association Division I university.

PATIENTS OR OTHER PARTICIPANTS

A total of 63 university alumni (age range, 24 to 84 years), including former varsity collegiate athletes and a control group of nonathletes.

INTERVENTION(S)

Participants completed the TLC Health Survey twice at a mean interval of 23 days with randomization to the paper or electronic version of the instrument.

MAIN OUTCOME MEASURE(S)

Content validity, feasibility of administration, test-retest reliability, parallel-form reliability between paper and electronic forms, and estimates of systematic and typical error versus differences of clinical interest were assessed across a broad range of health, exercise, and HRQL measures.

RESULTS

Correlation coefficients, including intraclass correlation coefficients (ICCs) for continuous variables and κ agreement statistics for ordinal variables, for test-retest reliability averaged 0.86, 0.90, 0.80, and 0.74 for HRQL, lifetime health, recent health, and exercise variables, respectively. Correlation coefficients, again ICCs and κ, for parallel-form reliability (ie, equivalence) between paper and electronic versions averaged 0.90, 0.85, 0.85, and 0.81 for HRQL, lifetime health, recent health, and exercise variables, respectively. Typical measurement error was less than the a priori thresholds of clinical interest, and we found minimal evidence of systematic test-retest error. We found strong evidence of content validity, convergent construct validity with the Short-Form 12 Version 2 HRQL instrument, and feasibility of administration in an elite, competitive athletic population.

CONCLUSIONS

These data suggest that the TLC Health Survey is a valid and reliable instrument for assessing lifetime and recent health, exercise, and HRQL, among elite competitive athletes. Generalizability of the instrument may be enhanced by additional, larger-scale studies in diverse populations.

Health outcomes of delayed union and nonunion of femoral and tibial shaft fractures

INTRODUCTION

Knowledge about the functional consequences of lower limb long bone fractures is helpful to inform patients, clinicians and employers about their recovery process and prognosis. This study aims to describe the epidemiology and health outcomes of femoral and tibial shaft fractures treated at two level I trauma centres, by comparing the differences between patients with delayed union or nonunion and patients with union.

PATIENTS AND METHODS

An analysis of registry data over two years, supplemented with medical record review, was conducted. Fracture healing was retrospectively assessed by clinical and radiological evidence of union, and the need for surgical intervention. SF-12 scores, and work and pain status were prospectively recorded at six and twelve months post injury.

RESULTS

285 fractures progressed to union and 138 fractures developed delayed union or nonunion. There was a significant difference between the two cohorts with regards to the mechanism of injury, association with multi-trauma, open fractures, grade of Gustilo classification, patient fund source, smoking status and presence of comorbidities. The SF-12 physical component score was less than 50 at both six and twelve months with improvement in the union group, but not in the delayed union or nonunion group. 72% of patients with union had returned to work at one year, but 54% continued to have pain. The difference compared to patients with delayed union or nonunion was significant.

DISCUSSION

Even patients whose fractures unite in the expectant time-frame will have residual physical disability. Patients with delayed union or nonunion have still poorer outcomes, including ongoing problems with returning to work and pain. It is important to educate patients about their injury so that they have realistic expectations. This is particularly relevant given that the patients most likely to sustain femoral or tibial shaft fractures are working-age healthy adults, and up to a third of fractures may develop delayed union or nonunion.

CONCLUSION

Despite modern treatment, the patient-reported outcomes of lower limb long bone shaft fractures do not return to normal at one year. Patients with delayed union or nonunion can expect poorer outcomes.

A Review and Meta-analysis of Colorectal Cancer Utilities

OBJECTIVE

To perform a systematic review of utility weights for colorectal cancer (CRC) health states reported in the scientific literature and to determine the effects of disease factors, patient characteristics, and utility methods on utility values.

METHODS

We identified 26 articles written in English and published from January 1980 to January 2013, providing 351 unique utilities for CRC health states elicited from 6546 unique respondents. The CRC utility data were analyzed using linear mixed-effects models with CRC type, stage, time to or from initial care, utility measurement instrument, and administration method as independent variables.

RESULTS

In the base case model, the estimated utility for a patient with stage I to III CRC more than 1 year after surgery, rated using a self-administered time tradeoff instrument, was 0.90. Stage, time to or from initial care, and utility measurement instrument were associated with statistically significant utility differences ranging from -0.19 to 0.02. Utilities for patients with stage IV cancer were 0.19 lower (P < 0.001) than for those with stage I to III cancer. Utilities elicited at more than 1 year after surgery were 0.05 higher than those elicited at 3 months after surgery (P = 0.008). Estimates of differences between utility measurement instruments were sensitive to how repeated scores in the same patient group were treated, and other findings were sensitive to how the disease stage was modeled and method of administration.

CONCLUSIONS

Variations in reported utilities are associated with factors such as cancer stage, time to or from initial care, and utility measurement instrument. More research is needed to study why apparently similar patients report different quality of life.

Qualitative and Quantitative Analysis of Interviewer Help Answering the Time Tradeoff

OBJECTIVES

The time tradeoff (TTO) is an important method to directly obtain health utilities. Challenges of the TTO are, among others, "nontraders" and illogical answers. In TTO interviews, these challenges are resolved by the interviewer. In web-based TTOs, training procedures and logical checks are used based on the views of the researchers. As web-based TTOs will be used more often in the future, we investigated how respondents arrive at their ratings to determine the help they require.

METHODS

In 2 earlier studies performed by this research group, respondents valued 6 EQ-5D states on a TTO. Respondents were asked to think out loud, and all interviews were audiotaped. A random selection of these interviews were transcribed and double-coded by two independent raters, using a priori and inductive coding until saturation was reached. Based on the retrieved mistakes and comments, a list of frequently asked questions (FAQ) was developed.

RESULTS

In total, 91 interviews were coded. In all, 85% made at least 1 mistake, 41% made a misreading/miscalculation, 70% misunderstood the tradeoff, 27% misunderstood the EQ-5D dimensions, 29% misunderstood the scenario, 45% made a comment about the TTO, and 43% expressed frustration. More misunderstandings were reported in the Peeters study, which was performed in a realistic setting, whereas the van Osch study was conducted in a more ideal setting. Misunderstandings of the scenario were mosly reported by patients.

CONCLUSIONS

Almost all respondents need interviewer help. This may have implications for the validity of interviewer-based TTO elicitations when social acceptability bias is an issue or with explicit hypothesis and the interviewer is not blinded. The FAQ list can be used to standardize interviewer help or as a help function in a web-based TTO.

Emerging adults' stress and health: the role of parent behaviors and cognitions

Although parent behaviors and cognitions are important for stress/health outcomes throughout development, little research examines whether cognitions mediate the relationship between parent behaviors and stress/health outcomes. As a result, the current study examined the reports of 160 emerging adults regarding their mothers' and fathers' behaviors (via the Parental Bonding Instrument and Alabama Parenting Questionnaire), their cognitions (via the Stress Appraisal Measure, Negative Mood Regulation Scale, Life Orientation Test-Revised, General Self-Efficacy Scale, and Ruminative Response Scale-Abbreviated), and their stress/health outcomes (via the Perceived Stress Scale and Short-Form Health Survey). Results of this study suggested that emerging adults' cognitions partially mediated the relationship between their mothers' behaviors and their stress/health outcomes and fully mediated the relationship between their fathers' behaviors and their stress/health outcomes. Future research should examine parent behaviors as important distal variables in emerging adults' stress/health outcomes but should examine cognitions as more salient, immediate predictors of their stress/health outcomes.

Ordering errors, objections and invariance in utility survey responses: a framework for understanding who, why and what to do

BACKGROUND

Utilities are the quantification of the perceived quality of life associated with any health state. They are used to calculate QALYs, the outcome measure in cost-utility analysis. Generally measured through surveys of individuals, utilities often contain apparent or unapparent errors that can bias resulting values and QALYs calculated from these values.

OBJECTIVE

The aim of this study was to improve direct health utility elicitation methodology through the identification of the types of survey responses that indicate errors and objections, and the reasons underlying them.

METHODS

We conducted a systematic review of the medical (PubMed), economics (EconLit) and psychology (PsycINFO) literature from 1975 through June 2010 for articles describing the types and frequency of errors and objections in directly elicited utility survey responses, and strategies to address these responses. Primary data were collected through an internet-based utility survey (standard gamble) of community members to identify responses that indicate error or objections. A qualitative telephone survey was conducted among a subset of respondents with these types of responses using an open-ended protocol to elicit rationales for them.

RESULTS

A total of 11 papers specifically devoted to errors, objections and invariance in utility responses have been published since the mid-1990s. Error/objection responses can be broadly categorized into ordering errors (which include illogical and inconsistent responses) and objections/invariance (which include missing data, protest responses and refusals to trade time or risk in utility questions). Reported frequencies of respondents making ordering errors ranged from 5% to 100%, and up to 35% of respondents have been reported as objecting to the survey or task in some manner. Changes in the design, administration and analysis of surveys can address these potentially problematic responses. Survey data (n = 398) showed that individuals who provided invariant responses (n = 26) reported the lowest level of difficulty with the survey and often identified as religious (23% of invariant responders found the survey difficult vs 63% of all responders, and 77% of invariant responders identified as religious compared with 56% of entire sample; p < 0.05 for both). Respondents who provided illogical responses (n = 50) were less likely to be college educated (56% of illogical responders vs 73% of entire sample; p < 0.05), and less likely to be confident in their responses (62% vs 75% of entire sample; p < 0.05). Qualitative interviews (n = 42) following the survey revealed that the majority of ordering errors were a result of confusion, lack of attention or difficulty in responding to the survey on the part of the respondent, while invariant responses were often considered and thoughtful reactions to the premise of valuing health using the standard gamble task.

CONCLUSIONS

Rationales for error/objection responses include difficulty in articulating preferences or misunderstanding with a complex survey task, and also thoughtful and considered protestations to the task. Mechanisms to correct unintentional errors may be useful, but cannot address intentional responses to elements of the measurement task. Identification and analysis of the prevalence of errors and objections in responses in utility data sets are essential to understanding the accuracy and precision of utility estimates and analyses that depend thereon.

Willingness to pay for a QALY based on community member and patient preferences for temporary health states associated with herpes zoster

BACKGROUND AND OBJECTIVES

A clear sense of what society is willing to pay for a QALY could enhance the usefulness of cost-effectiveness analysis as a field. Scant information exists on willingness to pay (WTP) for a QALY based on direct elicitation of preferences from community members or patients. We had the opportunity to evaluate WTP per QALY using data from a survey on temporary health outcomes related to herpes zoster. Our aims were to (i) describe how much community members are willing to pay to save a QALY based on scenarios describing temporary health states; (ii) evaluate how WTP per QALY varies based on experience with the disease being described and with demographic variables; and (iii) evaluate how the duration and intensity of pain in a scenario influences WTP per QALY.

METHODS

Community members drawn from a nationally representative survey research panel (n = 478) completed an Internet-based survey using time trade-off (TTO) and WTP questions to value a series of scenarios that described herpes zoster cases of varying pain intensity (on a scale of 0-10) and duration (30 days to 1 year). Patients with shingles (n = 354) or postherpetic neuralgia (PHN; n = 120) [defined as having symptoms for 90 days or more] from two large healthcare systems completed telephone interviews with similar questions. Mean and median WTP per QALY values were calculated by dividing the WTP amount by the discounted time traded for each scenario. Responses with a WTP value of more than zero and a TTO value of zero (which would have resulted in an undefined value) were excluded. TTO values were discounted by 3% per year. WTP per QALY means were calculated after trimming the top and bottom 2.5% of responses. Multivariate analyses were conducted using generalized linear mixed models that assumed a negative binomial distribution.

RESULTS

Among all respondents, the WTP per QALY ranged from a median of $US7000 to $US11,000 and a trimmed mean of $US26 000 to $US45,000 (year 2005 values), depending on the scenario described. WTP per QALY values varied significantly with respondent characteristics, as well as among respondents with similar characteristics. In multivariate analyses, the mean WTP per QALY was higher among respondents who were younger, male or had higher educational or income levels. After adjusting for these demographic variables, patients who had experienced shingles gave responses with the highest WTP per QALY values. Patients who had experienced PHN gave the lowest values, and community members gave values intermediate to the shingles and PHN groups. In multivariate models that evaluated the effects of pain and duration of the hypothetical zoster scenario, lower duration was associated with higher WTP per QALY. This effect appeared to be due to people increasing the amounts of time they would be willing to trade as duration increased, without proportional increases in the amounts of money they would be willing to pay.

CONCLUSIONS

Community members and patients gave mean WTP per QALY values that varied significantly based on age, sex, socioeconomic status, experience with shingles and duration of the health state evaluated. The variability in WTP per QALY suggests that it may be difficult to define a unitary threshold of dollars per QALY for policy making based on cost-effectiveness analyses.

Community and patient values for preventing herpes zoster

OBJECTIVES

The US Advisory Committee on Immunization Practices has recently recommended a new vaccine against herpes zoster (shingles) for routine use in adults aged > or =60 years. However, estimates of the cost effectiveness of this vaccine vary widely, in part because of gaps in the data on the value of preventing herpes zoster. Our aims were to (i) generate comprehensive information on the value of preventing a range of outcomes of herpes zoster; (ii) compare these values among community members and patients with shingles and post-herpetic neuralgia (PHN); and (iii) identify clinical and demographic characteristics that explain the variation in these values.

METHODS

Community members drawn from a nationally representative survey research panel (n = 527) completed an Internet-based survey using time trade-off and willingness-to-pay questions to value a series of scenarios that described cases of herpes zoster with varying pain intensities (on a scale of 0 to 10, where 0 represents no pain and 10 represents the worst imaginable pain) and duration (30 days to 1 year). Patients with shingles (n = 382) or PHN (n = 137) [defined as having symptoms for > or =90 days] from two large healthcare systems completed telephone interviews with similar questions to the Internet-based survey and also answered questions about their current experience with herpes zoster. We constructed generalized linear mixed models to evaluate the associations between demographic and clinical characteristics, the length and intensity of the health states and time trade-off and willingness-to-pay values.

RESULTS

In time trade-off questions, community members offered a mean of 89 (95% CI 24, 182) discounted days to avoid the least severe scenario (pain level of 3 for 1 month) and a mean of 162 (95% CI 88, 259) discounted days to avoid the most severe scenario (pain level of 8 for 12 months). Compared with patients with shingles, community members traded more days to avoid low-severity scenarios but similar numbers of days to avoid high-severity scenarios. Compared with patients with PHN, community members traded fewer days to avoid high-severity scenarios. In multivariate analyses, older age was the only characteristic significantly associated with higher time trade-off values. In willingness-to-pay questions, community members offered a mean of $US450 (95% CI 203, 893) to avoid pain of level 3 for 1 month and a mean of $US1384 (95% CI 873, 2050) [year 2005 values] to avoid pain of level 8 for 12 months. Community members traded less money than patients with either shingles or PHN to avoid both low- and high-severity scenarios (p-values <0.05 to <0.001). In multivariate models, male gender, higher income and having experienced shingles or PHN were associated with higher willingness to pay to avoid herpes zoster. When patients were asked to assign a value to avoiding their own case of herpes zoster, those with shingles assigned a mean of 67 days or $US2319, while those with PHN assigned a mean of 206 days or $US18 184. Both the time and monetary value traded were associated with the maximum intensity of the pain the individual had experienced, but neither was associated with the duration of the pain.

CONCLUSIONS

We believe that this study provides the most comprehensive information to date on the value individuals place on preventing herpes zoster, and it includes the only such valuation from nationally representative community members as well as patients with herpes zoster. Community members would trade substantial amounts of time or money to avoid herpes zoster, even in the least severe scenarios. The time trade-off results in this study may differ from those in other studies because of important differences in methods of assessing health utilities. Consideration of both community and patient perspectives is crucial to help decision makers fully determine the implications of their policies now that a vaccine against herpes zoster is available.

An Examination of Fulfilled Housing Preferences and Quality of Life among Homeless Persons with Mental Illness and/or Substance Use Disorders

This study examined the types of housing features considered important to a sample of homeless persons diagnosed with a mental illness and/or substance use disorder and the relationship between the degree to which important features were obtained in subsequent housing and subjective quality of life, clinical and housing outcomes at 3-month and 1-year follow-up periods. After controlling for significant clinical and sociodemographic covariates, results from regression analyses indicate that the degree to which a client's individual housing preferences were realized in dwellings is significantly associated with greater quality of life in the future, but not clinical outcomes or housing tenure.

Health utility ratings for a spectrum of alcohol-related health states

BACKGROUND

Preference-based utility ratings for health conditions are important components of cost-utility analyses and population burden of disease estimates. However, utility ratings for alcohol problems have not been determined.

OBJECTIVES

The objectives of this study were to directly measure utility ratings for a spectrum of alcohol-related health states and to compare different methods of utility measurement.

DESIGN, SETTING, AND SUBJECTS

The authors conducted a cross-sectional interview of 200 adults from a clinic and community sample.

METHODS

Subjects completed computerized visual analog scale (VAS), time tradeoff (TTO), and standard gamble (SG) utility measurement exercises for their current health, a blindness scenario, and for 6 alcohol-related health state scenarios presented in random order. The main outcome measures were the utility ratings, scaled from 0 to 1, and anchored by death (0) and perfect health (1).

RESULTS

The 200 subjects were middle-aged (mean, 41 +/- 14 years), 61% women, and racially diverse (48% black, 43% white). Utility ratings decreased as the severity of the alcohol-related health state increased, but differed significantly among the VAS, TTO, and SG methods within each health state. Adjusted mean (95% confidence interval) utility ratings for alcohol dependence (VAS, 0.38 [0.34-0.41]; TTO, 0.54 [0.48-0.60]; SG, 0.68 [0.63-0.73]) and alcohol abuse (VAS, 0.53 [0.49-0.56]; TTO, 0.71 [0.65-77]; SG, 0.76 [0.71-0.81]) were significantly lower than utility ratings for nondrinking, moderate drinking, at-risk drinking, current health, and blindness.

CONCLUSIONS

Utility ratings for alcohol-related health states decrease as the severity of alcohol use increases. The low utility ratings for alcohol abuse and alcohol dependence are similar to those reported for other severe chronic medical conditions.

Valuations of EQ-5D health states: are the United States and United Kingdom different?

PURPOSE

We sought to compare directly elicited valuations for EQ-5D health states between the US and UK general adult populations.

METHODS

We analyzed data from 2 EQ-5D valuation studies where, using similar time trade-off protocols, values for 42 common health states were elicited from representative samples of the US and UK general adult populations. First, US and UK population mean valuations were estimated and compared for each health state. Second, random-effect models were used to compare the US and UK valuations while adjusting for known predictors of EQ-5D valuations (ie, age, sex, health state descriptors) and to investigate whether and how the valuations differ.

RESULTS

Population mean valuations of the 42 health states ranged from -0.38 to 0.88 for the United States and from -0.54 to 0.88 for the United Kingdom, with the US mean scores being numerically higher than the UK for 39 health states (mean difference: 0.11; range: -0.01 to 0.25). After adjusting for the main effects of known predictors, the average difference in valuations was 0.10 (P < 0.001). The magnitude of the difference in the US and UK valuations was not constant across EQ-5D health states; greater differences in valuations were present in health states characterized by extreme problems.

CONCLUSIONS

Meaningful differences exist in directly elicited TTO valuations of EQ-5D health states between the US and UK general populations. Therefore, EQ-5D index scores generated using valuations from the US general population should be used for studies aiming to reflect health state preferences of the US general public.

Improving patient safety through informatics tools for shared decision making and risk communication

This paper describes how informatics tools can support shared decision making and risk communication and thereby play an important role in enhancing patient safety. Using preference elicitation techniques and knowledge on risk communication, such tools can help patients understand their treatment options and associated short- and long-term benefits and risks, assist in the elicitation of patient preferences, and help patients and clinicians in making treatment choices with the highest likelihood of achieving desired patient outcomes. Important features of such tools are proposed, including: (1) Interactive tutorials to improve risk comprehension and prepare patients and clinicians for the decision making task; (2) choices between different presentation modes to meet patients' individual reading levels and presentation preferences; (3) risk calculations that account for individual risk profiles; (4) performance of necessary calculations to reach the actual decision; (5) automatic updates of evidence; and (6) the use of different preference-elicitation techniques.

The validity of person tradeoff measurements: randomized trial of computer elicitation versus face-to-face interview

Can person tradeoff (PTO) value judgments be elicited by a computer, or is a face-to-face interview needed? The authors randomly assigned 95 subjects to interview or computer methods for the PTO, a valuation measure that is often difficult for subjects. They measured relative values of foot numbness, leg paralysis, and quadriplegia (all 3 pairs) at 2 reference group sizes (10 or 100). Relative values did not differ between computer and interview. Overall, 21% of responses were equality responses, 13% were high extreme values, and 5% violated ordinal criteria. The groups did not differ in these measures. The authors also assessed consistency across reference group size (10 v. 100). Although relative values were significantly lower for 100 than for 10, mode did not influence the size of this effect. Subjects made, on average, equally consistent judgments for the 3 comparisons. A computerized PTO elicitation protocol produced results of similar quality to that of a face-to-face interview.

iMPACT3: Internet-based development and administration of utility elicitation protocols

iMPACT3 (Internet Multimedia Preference Assessment Instrument Construction Tool, version 3) is a software development environment that helps researchers build Internet-capable multimedia utility elicitation software programs. The program is a free, openly accessible Web site (http.// preferences.ucsd.edu/impact3/asp). To develop a utility elicitation software program using iMPACT3, a researcher selects modular protocol components from a library and custom tailors the components to the details of his or her research protocol. iMPACT3 builds a Web site implementing the protocol and downloads it to the researcher's computer. In a study of 75 HIV-infected patients, an iMPACT3-generated protocol showed substantial evidence of construct validity and good internal consistency (logic error rates of 4% to 10% and procedural invariance error rates of 10% to 28%, depending on the elicitation method) but only fair 3- to 6-week test-retest reliability (intraclass correlation coefficient= 0.42 to 0.55). Further work may be needed on specific utility assessment procedures, but this study's results confirm iMPACT3's feasibility in facilitating the collection of health state utility data.

Representing patient preference-related concepts for inclusion in electronic health records

In recent years shared decision making between patients and their health care providers and the inclusion of patient preferences in patient care have been, in theory, embraced as models for good clinical practice. Patients' experiences, values, and preferences are increasingly acknowledged as important pieces of evidence for appropriate health care decision making. To effectively use information about patient preferences in patient care, this information, which is gathered through a process of preference elicitation, needs to be integrated with other types of information, e.g., diagnoses, treatments, and patient status indicators within the context of a longitudinal electronic health record. This integration requires that patient preference-related concepts be represented nonambiguously and in a manner that renders them suitable for computer rather than human processing. In this article, the authors describe important patient preference-related concepts and illustrate the use of the LOINC semantic structure as a terminology model to create fully specified names for a sample of 15 preference elicitations from 8 published research articles.