Vahram Ghushchyan

Preference-Based EQ-5D Index Scores for Chronic Conditions in the United States:

Background. The Panel on Cost-Effectiveness in Health and Medicine has called for an “off-the-shelf” catalogue of nationally representative, community-based preference scores for health states, illnesses, and conditions. A previous review of cost-effectiveness analyses found that 77% did not incorporate community-based preferences, and 33% used arbitrary expert or author judgment. These results highlight the necessity of making a wide array of appropriate, community-based estimates more accessible to cost-effectiveness researchers. Objective. To provide nationally representative EQ-5D index scores for chronic ICD-9 codes. Methods. The nationally representative Medical Expenditure Panel Survey (MEPS) was pooled (2000–2002) to create a data set of 38,678 adults. Ordinary least squares (OLS), Tobit, and censored least absolute deviations (CLAD) regression methods were used to estimate the marginal disutility of each condition, controlling for age, comorbidity, gender, race, ethnicity, income, and education. Results. Most chronic conditions, age, comorbidity, income, and education were highly statistically significant predictors of EQ-5D index scores. Homoskedasticity and normality assumptions were rejected, suggesting only CLAD estimates are theoretically unbiased. The magnitude and statistical significance of coefficients varied by analytic method. OLS and Tobit coefficients were on average 60% and 143% greater than CLAD, respectively. The marginal disutility of 95 chronic ICD-9 codes as well as unadjusted mean, median, and 25th and 75th percentiles are reported.Conclusion. This research provides nationally representative, communitybased EQ-5D index scores associated with a wide variety of chronic ICD-9 codes that can be used to estimate quality-adjusted life-years in cost-effectiveness analyses.

A National Catalog of Preference-based Scores for Chronic Conditions in the United States

Background:The variability in preferences used in quality-adjusted life-years estimation jeopardizes the comparability of cost-effectiveness analyses and has led the Panel on Cost-Effectiveness in Health and Medicine (the PCEHM) to call for a catalog of “off-the-shelf” preference weights associated with conditions that can be used by health researchers without the burden of collecting primary data. Objective:The current research responds to the call by developing a nationally representative catalog of preference-based scores for chronic conditions and associated sociodemographic characteristics. Methods:The authors report the EQ-5Dindex scores of chronic conditions and associated sociodemographic characteristics in the nationally representative Medical Expenditure Panel Survey (MEPS). Chronic conditions were coded using “quality priority conditions” (QPC) and clinical classification categories (CCC). OLS, Tobit, and censored least absolute deviations (CLAD) regression models were used to provide condition estimates adjusted for age, comorbidity, gender, race, ethnicity, income, and education. Results:Unadjusted and adjusted EQ-5Dindex scores for each QPC and CCC code are presented. EQ-5Dindex scores for older age categories were lower than younger categories, female scores were lower than males, certain racial groups had lower scores than others, and EQ-5Dindex scores were higher for individuals with higher education and income levels. Conclusion:The preference-based chronic condition scores reported in this research are nationally representative and may be useful to researchers to calculate quality-adjusted life-years for cost-effectiveness analyses and population-based burden of illness studies without the difficulty of primary data collection. Further research is necessary to validate these scores in condition-specific studies.

Catalogue of EQ-5D Scores for the United Kingdom

Background. The National Institute for Health and Clinical Excellence (NICE) has issued guidance on cost-effectiveness analyses, suggesting that preference-based health-related quality of life (HRQL) weights or utilities be based on UK community preferences, preferably using the EQ-5D; ideally all analyses would use the same system for deriving HRQL weights, to encourage consistency and comparability across analyses. Development of a catalogue of EQ-5D scores for a range of health conditions based on UK preferences would help achieve many of these goals. Objective. To provide a UK-based catalogue of EQ-5D index scores. Methods. Methods were consistent with the previously published catalogue of EQ-5D scores for the US. Community-based UK preferences were applied to EQ-5D descriptive questionnaire responses in the US-based Medical Expenditure Panel Survey (MEPS). Ordinary least squares (OLS), Tobit, and censored least absolute deviations (CLAD) regression methods were used to estimate the ‘marginal disutility’ of each condition controlling for covariates. Results. Pooled MEPS files (2000-2003) resulted in 79,522 individuals with complete EQ-5D scores. Marginal disutilities for 135 chronic ICD-9 and 100 CCC codes are provided. Unadjusted descriptive statistics including mean, median, 25th and 75th percentiles are also reported. Conclusion. This research provides community-based EQ-5D index scores for a wide variety of chronic conditions that can be used to estimate QALYs in cost-effectiveness analyses in the UK. Although using EQ-5D questionnaire responses from the US-based MEPS is less than ideal, the estimates approximate HRQL guidelines by NICE and provide an easily accessible“off-the-shelf” resource for cost-effectiveness and publichealth applications.

Mapping the EQ-5D Index from the SF-12: US General Population Preferences in a Nationally Representative Sample:

Background Health status measures provide a numeric score representing a profile of health status across several domains, such as physical and mental health. The SF-12 and its longer form, the SF-36, are examples of generic health status measures. Although these Background. Previous mapping algorithms estimating EQ-5D index scores from the SF-12 were based on preferences from a UK community sample. However, preferences based on the general US population are most appropriate for costeffectiveness analyses done from the societal perspective in the United States. Objective. To provide a mapping algorithm for estimating EQ-5D index scores from the SF-12 based on a nationally representative sample and using preferences based on the general US population.Methods. The Medical Expenditure Panel Survey (MEPS) 2002 and 2000 data were used as independent derivation and validation sets to estimate the relationship between SF-12 scores and EQ-5D index scores, controlling for sociodemographic characteristics and comorbidity burden. Prediction equations for end-users who only have access to SF-12 scores were derived and compared. The empirical performance of censored least absolute deviations (CLAD), Tobit, and ordinary least squares (OLS) analytic methods were compared by calculating the mean prediction error in the validation set.Results. The fully specified CLAD model resulted in the lowest mean prediction error, followed by OLS and Tobit. The CLAD prediction equation based only on SF-12 scores performed better than the fully specified OLS and Tobit models.Conclusion. The current research provides an algorithm for mapping EQ-5D index scores from the SF-12. This algorithm may provide analysts with an avenue to obtain appropriate preference-based health-related quality-of-life scores for use in cost-effectiveness analyses when only SF-12 data are available.

The burden of adult asthma in the United States: Evidence from the Medical Expenditure Panel Survey

BACKGROUND It is important to have an accurate picture of the sources and extent of medical expenditures and productivity loss to understand the nature and scope of the burden of asthma in the United States (US). OBJECTIVE The current study aims to provide recent nationally representative estimates of direct and productivity-related costs attributable to asthma in adults in the US. METHODS The 2003 and 2005 Medical Expenditure Panel Surveys were used to estimate the effect of asthma on medical expenditures, use, productivity, and chronic comorbidity among adults (≥ 18 years). Productivity-related outcome variables included employment, annual wages, missed work days, days spent sick in bed, and activity limitations. Multivariate regression was conducted, controlling for sociodemographics and comorbidity. RESULTS Of 44,795 adults, 1,935 reported an encounter for asthma [corrected]. Compared with those without, subjects with asthma were significantly less likely to be employed (odds ratio, 0.78), spent 1.4 more days sick in bed annually, and were significantly more likely to have activity limitations or to be unable to work. Adults with asthma incurred an additional

The impact of obesity on diabetes, hyperlipidemia and hypertension in the United States

1,907 (2008 US dollars) annually and experienced higher health care use and comorbidity. The total national medical expenditure attributable to adult asthma was

The medical cost of cardiometabolic risk factor clusters in the United States.

18 billion. Adults with asthma were more likely to be covered by Medicaid (30%) than the general adult population (10%). The largest contributors to medical expenditures for adults with asthma were prescription drugs, followed by inpatient hospitalizations and home health care. CONCLUSIONS In recent national data adult asthma is associated with a significant deleterious effect on direct and indirect costs in the US.

The effect of obesity and cardiometabolic risk factors on expenditures and productivity in the United States.

ObjectiveThe prevalence of obesity and associated cardiometabolic risk factors such as diabetes, hyperlipidemia and hypertension is increasing significantly for all demographic groups.Research design and methodsThe 2000 and 2002 Medical Expenditure Panel Survey (MEPS), a nationally representative survey of the U.S. population, was used to estimate the marginal impact of obesity on health function, perception, and preferences for individuals with diabetes, hyperlipidemia, and hypertension using multivariate regression methods controlling for age, sex, race, ethnicity, education, income, insurance, smoking status, comorbidity, and proxy response. Three different instruments were used: SF-12 physical component scale (PCS-12) and mental component scale (MCS-12); EQ-5D index and visual analogue scale (VAS). Censored least absolute deviation was used for the EQ-5D and VAS (due to censoring) and ordinary least squares (OLS) was used for the PCS-12 and MCS-12.ResultsAfter controlling for sociodemographic characteristics, diabetes, hyperlipidemia, and hypertension were associated with significantly lower scores compared to normal weight individuals without the condition for all four instruments. Obesity significantly exacerbated this association. Controlling for comorbidity attenuated the negative association of obesity and cardiometabolic risk factors on instrument scores. In addition, scores decreased for increasing weight and number of risk factors.ConclusionsObesity significantly exacerbates the deleterious association between diabetes, hyperlipidemia, and hypertension, and health function, health perception, and preference-based scores in the United States.

Asthma in USA: its impact on health-related quality of life.

Objective: Diabetes, hypertension, hyperlipidemia, and overweight/obesity often cluster together. The prevalence of these cardiometabolic risk factor clusters (CMRFCs) is increasing significantly for all sociodemographic groups, but little is known about their economic impact.

The relationship between asthma, asthma control and economic outcomes in the United States

Objective: To examine the effect of obesity and cardiometabolic risk factors on medical expenditures and missed work days.