Using EQ-5D to derive general population-based utilities for the quality of life assessment of growth hormone deficiency in adults (QoL-AGHDA)

Health related quality of life among Rheumatic Fever and Rheumatic Heart Disease patients in India

Background

Measurement of health-related quality of life (HRQOL) of people with chronic illnesses has become extremely important as the mortality rates associated with such illnesses have decreased and survival rates have increased. Thereby, such measurements not only provide insights into physical, mental and social dimensions of patient’s health, but also allow monitoring of the results of interventions, complementing the traditional methods based on morbidity and mortality.

Objective

The present study was conducted to describe the HRQOL of patients suffering from Rheumatic Fever (RF) and Rheumatic Heart Disease (RHD), and to identify socio-demographic and clinical factors as predictors of HRQOL.

Methodology

A cross-sectional study was conducted to assess the HRQOL among 702 RF and RHD patients using EuroQol 5-dimensions 5-levels instrument (EQ-5D-5L), EuroQol Visual Analogue Scale and Time Trade off method. Mean EQ-5D-5L quality of life scores were calculated using EQ5D index value calculator across different stages of RF and RHD. Proportions of patients reporting problems in different attributes of EQ-5D-5L were calculated. The impact of socio-economic determinants on HRQOL was assessed.

Results

The mean EQ-5D-5L utility scores among RF, RHD and RHD with Congestive heart failure patients (CHF) were estimated as 0.952 [95% Confidence Interval (CI): 0.929–0.975], 0.820 [95% CI: 0.799–0.842] and 0.800 [95% CI: 0.772–0.829] respectively. The most frequently reported problem among RF/RHD patients was pain/discomfort (33.8%) followed by difficulty in performing usual activities (23.9%) patients, mobility (22.7%) and anxiety/depression (22%). Patients with an annual income of less than 50,000 Indian National Rupees (INR) reported the highest EQ-5D-5L score of 0.872, followed by those in the income group of more than INR 200,000 (0.835), INR 50,000–100,000 (0.832) and INR 100,000–200,000 (0.828). Better HRQOL was reported by RHD patients (including RHD with CHF) who underwent balloon valvotomy (0.806) as compared to valve replacement surgery (0.645).

Conclusion

RF and RHD significantly impact the HRQOL of patients. Interventions aiming to improve HRQOL of RF/RHD patients should focus upon ameliorating pain and implementation of secondary prevention strategies for reducing the progression from ARF to RHD and prevention of RHD-related complications.

Impact of short stature on quality of life: A systematic literature review

OBJECTIVE

We sought to obtain a better understanding of the burden of short stature using a systematic literature review.

METHODS

Studies of the burden of short stature, of any cause in adults and children, were searched using Embase, MEDLINE and Cochrane databases in April 2020, capturing publications from 2008 onwards. Case series and populations with adult-onset growth hormone deficiency (GHD) were excluded.

RESULTS

Of 1684 publications identified, 41 studies (33 in children, 8 in adults) were included. All studies assessed human burden. Most study populations in children included short stature due to GHD, idiopathic short stature (ISS) and short stature after being born small for gestational age (SGA). In these populations, four studies showed that quality of life (QoL) in children with short stature was significantly worse than in children with normal stature. A significant association between QoL and short stature was observed in children with chronic kidney disease (CKD) (3 studies), achondroplasia (1 study) and transfusion-dependent β-thalassaemia (1 study), and in samples with mixed causes of short stature (3 studies). Three studies (one in GHD/ISS/SGA and two in CKD) found no significant association between short stature and QoL, and several studies did not report statistical significance. Approximately half of adult studies showed that QoL was reduced with short stature, and the other half showed no association. Two studies, one in adults with Prader-Willi syndrome and one in children with GHD, suggested a potential association between short stature and poorer cognitive outcomes. Three studies demonstrated an increased caregiver burden in parents of children with short stature.

CONCLUSIONS

Evidence suggests that, compared with those with normal stature, children and adults with short stature of any cause may experience poorer QoL. Further research could extend our understanding of the human burden in this field.

'Mapping' Health State Utility Values from Non-preference-Based Measures: A Systematic Literature Review in Rare Diseases

BACKGROUND

The use of patient-reported outcome measures (PROMs) to monitor the effects of disease and treatment on patient symptomatology and daily life is increasing in rare diseases (RDs) (i.e. those affecting less than one in 2000 people); however, these instruments seldom yield health state utility values (HSUVs) for cost-utility analyses. In such a context, 'mapping' allows HSUVs to be obtained by establishing a statistical relationship between a 'source' (e.g. a disease-specific PROM) and a 'target' preference-based measure [e.g. the EuroQol-5 Dimension (EQ-5D) tool].

OBJECTIVE

This study aimed to systematically review all published studies using 'mapping' to derive HSUVs from non-preference-based measures in RDs, and identify any critical issues related to the main features of RDs, which are characterised by small, heterogeneous, and geographically dispersed patient populations.

METHODS

The following databases were searched during the first half of 2019 without time, study design, or language restrictions: MEDLINE (via PubMed), the School of Health and Related Research Health Utility Database (ScHARRHUD), and the Health Economics Research Centre (HERC) database of mapping studies (version 7.0). The keywords combined terms related to 'mapping' with Orphanet's list of RD indications (e.g. 'acromegaly') in addition to 'rare' and 'orphan'. 'Very rare' diseases (i.e. those with fewer than 1000 cases or families documented in the medical literature) were excluded from the searches. A predefined, pilot-tested extraction template (in Excel^®) was used to collect structured information from the studies.

RESULTS

Two groups of studies were identified in the review. The first group (n = 19) developed novel mapping algorithms in 13 different RDs. As a target measure, the majority used EQ-5D, and the others used the Short-Form Six-Dimension (SF-6D) and 15D; most studies adopted ordinary least squares (OLS) regression. The second group of studies (n = 9) applied previously published algorithms in non-RDs to comparable RDs, mainly in the field of cancer. The critical issues relating to 'mapping' in RDs included the availability of very few studies, the relatively high number of cancer studies, and the absence of research in paediatric RDs. Moreover, the reviewed studies recruited small samples, showed a limited overlap between RD-specific and generic PROMs, and highlighted the presence of cultural and linguistic factors influencing results in multi-country studies. Lastly, the application of existing algorithms developed in non-RDs tended to produce inaccuracies at the bottom of the EQ-5D scale, due to the greater severity of RDs.

CONCLUSIONS

More research is encouraged to develop algorithms for a broader spectrum of RDs (including those affecting young children), improve mapping study quality, test the generalisability of algorithms developed in non-RDs (e.g. HIV) to rare variants or evolutions of the same condition (e.g. AIDS wasting syndrome), and verify the robustness of results when mapped HSUVs are used in cost-utility models.

Targeted literature review of the humanistic and economic burden of adult growth hormone deficiency

BACKGROUND

Quality of life (QoL) and health economic data are becoming increasingly important factors in healthcare decision making. While there is a wealth of information establishing the benefit of growth hormone (GH) replacement therapy in adults with growth hormone deficiency (aGHD), recent reviews on the QoL and health economic impact of aGHD and the effect of treatment on these factors is limited.

OBJECTIVE

The aim of this article is to summarize the impact of early and sustained treatment on the QoL and economic burden of aGHD by conducting a targeted literature review.

METHODS

Standard electronic databases, including PubMed and the Cochrane collaboration website, were searched for publications between January 2006 and July 2016 for evidence of the humanistic and economic burden of aGHD. Search terms included growth hormone deficiency, health-related quality of life, HRQoL, patient-reported outcomes, outcome assessment, well-being and adherence.

RESULTS

The literature search identified 732 initial hits and a final 14 publications were included. The analysis showed that the economic burden of aGHD is largely driven by the productivity losses associated with the disease. This is because most patients with aGHD are of working age and the QoL domains (memory & concentration and energy & vitality) most commonly affected by aGHD severely impair a person's ability to work and may limit their contribution to society.

CONCLUSION

Untreated aGHD can seriously affect patients' functioning. Early and continued treatment with GH replacement therapy could potentially improve the QoL and reduce the economic burden associated with aGHD. This review has limitations: only English language articles published since January 2006 were included and many of the studies were conducted in the Nordic countries; it is unclear how representative these studies are of the population as a whole. This was a literature review and not a systematic review, as it was thought to be unlikely that, in this rare disease, any additional publications would have been identified. Overall, this review reveals a paucity of data in this underserved population and points to research gaps which could be addressed with new studies.

An Updated Systematic Review of Studies Mapping (or Cross-Walking) Measures of Health-Related Quality of Life to Generic Preference-Based Measures to Generate Utility Values

BACKGROUND

Mapping is an increasingly common method used to predict instrument-specific preference-based health-state utility values (HSUVs) from data obtained from another health-related quality of life (HRQoL) measure. There have been several methodological developments in this area since a previous review up to 2007.

OBJECTIVE

To provide an updated review of all mapping studies that map from HRQoL measures to target generic preference-based measures (EQ-5D measures, SF-6D, HUI measures, QWB, AQoL measures, 15D/16D/17D, CHU-9D) published from January 2007 to October 2018.

DATA SOURCES

A systematic review of English language articles using a variety of approaches: searching electronic and utilities databases, citation searching, targeted journal and website searches.

STUDY SELECTION

Full papers of studies that mapped from one health measure to a target preference-based measure using formal statistical regression techniques.

DATA EXTRACTION

Undertaken by four authors using predefined data fields including measures, data used, econometric models and assessment of predictive ability.

RESULTS

There were 180 papers with 233 mapping functions in total. Mapping functions were generated to obtain EQ-5D-3L/EQ-5D-5L-EQ-5D-Y (n = 147), SF-6D (n = 45), AQoL-4D/AQoL-8D (n = 12), HUI2/HUI3 (n = 13), 15D (n = 8) CHU-9D (n = 4) and QWB-SA (n = 4) HSUVs. A large number of different regression methods were used with ordinary least squares (OLS) still being the most common approach (used ≥ 75% times within each preference-based measure). The majority of studies assessed the predictive ability of the mapping functions using mean absolute or root mean squared errors (n = 192, 82%), but this was lower when considering errors across different categories of severity (n = 92, 39%) and plots of predictions (n = 120, 52%).

CONCLUSIONS

The last 10 years has seen a substantial increase in the number of mapping studies and some evidence of advancement in methods with consideration of models beyond OLS and greater reporting of predictive ability of mapping functions.

Design of the Growth hormone deficiency and Efficacy of Treatment (GET) score and non-interventional proof of concept study

BACKGROUND

The adverse effects of growth hormone (GH) deficiency (GHD) in adults (AGHD) on metabolism and health-related quality of life (HRQoL) can be improved with GH substitution. This investigation aimed to design a score summarising the features of GHD and evaluate its ability to measure the effect of GH substitution in AGHD.

METHODS

The Growth hormone deficiency and Efficacy of Treatment (GET) score (0-100 points) assessed (weighting): HRQoL (40%), disease-related days off work (10%), bone mineral density (20%), waist circumference (10%), low-density lipoprotein cholesterol (10%) and body fat mass (10%). A prospective, non-interventional, multicentre proof-of-concept study investigated whether the score could distinguish between untreated and GH-treated patients with AGHD. A 10-point difference in GET score during a 2-year study period was expected based on pre-existing knowledge of the effect of GH substitution in AGHD.

RESULTS

Of 106 patients eligible for analysis, 22 were untreated GHD controls (9 females, mean ± SD age 52 ± 17 years; 13 males, 57 ± 13 years) and 84 were GH-treated (31 females, age 45 ± 13 years, GH dose 0.30 ± 0.16 mg/day; 53 males, age 49 ± 15 years, GH dose 0.25 ± 0.10 mg/day). Follow-up was 706 ± 258 days in females and 653 ± 242 days in males. The GET score differed between the untreated control and treated groups with a least squares mean difference of + 10.01 ± 4.01 (p = 0.0145).

CONCLUSIONS

The GET score appeared to be a suitable integrative instrument to summarise the clinical features of GHD and measure the effects of GH substitution in adults. Exercise capacity and muscle strength/body muscle mass could be included in the GET score.

TRIAL REGISTRATION

NCT number: NCT00934063 . Date of registration: 02 July 2009.

Development of a transformation model to derive general population-based utility: Mapping the pruritus-visual analog scale (VAS) to the EQ-5D utility

RATIONALE, AIMS, AND OBJECTIVES

Although nonpreference-based disease-specific measures are widely used in clinical studies, they cannot generate utilities for economic evaluation. A solution to this problem is to estimate utilities from disease-specific instruments using the mapping function. This study aimed to develop a transformation model for mapping the pruritus-visual analog scale (VAS) to the EuroQol 5-Dimension 3-Level (EQ-5D-3L) utility index in pruritus.

METHODS

A cross-sectional survey was conducted with a sample (n = 268) drawn from the general population of South Korea. Data were randomly divided into 2 groups, one for estimating and the other for validating mapping models. To select the best model, we developed and compared 3 separate models using demographic information and the pruritus-VAS as independent variables. The predictive performance was assessed using the mean absolute deviation and root mean square error in a separate dataset.

RESULTS

Among the 3 models, model 2 using age, age squared, sex, and the pruritus-VAS as independent variables had the best performance based on the goodness of fit and model simplicity, with a log likelihood of 187.13. The 3 models had similar precision errors based on mean absolute deviation and root mean square error in the validation dataset. No statistically significant difference was observed between the mean observed and predicted values in all models.

CONCLUSIONS

In conclusion, model 2 was chosen as the preferred mapping model. Outcomes measured as the pruritus-VAS can be transformed into the EQ-5D-3L utility index using this mapping model, which makes an economic evaluation possible when only pruritus-VAS data are available.

Peer support for patients with type 2 diabetes in rural communities of China: protocol for a cluster randomized controlled trial

BACKGROUND

The prevalence of diabetes has been growing rapidly in developing countries. This causes devastating economic burdens and increases demands on the health care system. Therefore, there is an urgent need to find a cost-effective and multi-faceted approach for diabetes care. Peer support models provide a potentially low-cost, flexible means which complements the current existing health care services. In this way, trained peer leaders can become qualified extensions to a formal healthcare system, capable of assisting education delivery and bolstering the efforts of professional staff. As such, creating a cultural specific peer support program and determining whether it is acceptable and cost-effective in rural communities of China is crucial. This study aims to implement and evaluate biophysical and psychosocial outcomes of peer support program for people with type 2 diabetes in rural communities, and to explore the program's feasibility and sustainability in China.

METHODS/DESIGN

This study is a cluster randomised controlled trial. All consenting patients will be randomised by community staff members to receive either peer support or the control care. The data collection and analysis including social demographics, health status, psychosocial status, economic status and biomedical measures will be collected at baseline, 6 months, and 12 months. The primary indicator measured is the change in HbA1c, whereas secondary indicators include biophysical, psychosocial functioning and other lifestyle factors. Finally, economic evaluations will determine whether the program is cost effective.

DISCUSSION

This protocol is a cluster randomized, controlled trial of group-based peer support for people with type 2 diabetes in the community settings of rural China. Results from this trial may provide evidence to the effectiveness of peer support; furthermore, they will provide valuable information concerning the acceptability and feasibility of a new approach to improve diabetes self-management among resource-constrained settings.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02119572, April 18, 2014.

Mapping the FACT-G cancer-specific quality of life instrument to the EQ-5D and SF-6D

Objective

To help facilitate economic evaluations of oncology treatments, we mapped responses on cancer-specific instrument to generic preference-based measures.

Methods

Cancer patients (n = 367) completed one cancer-specific instrument, the FACT-G, and two preference-based measures, the EQ-5D and SF-6D. Responses were randomly divided to form development (n = 184) and cross-validation (n = 183) samples. Relationships between the instruments were estimated using ordinary least squares (OLS), generalized linear models (GLM), and censored least absolute deviations (CLAD) regression approaches. The performance of each model was assessed in terms of how well the responses to the cancer-specific instrument predicted EQ-5D and SF-6D utilities using mean absolute error (MAE) and root mean squared error (RMSE).

Results

Physical, functional, and emotional well-being domain scores of the FACT-G best explained the EQ-5D and SF-6D. In terms of accuracy of prediction as measured in RMSE, the CLAD model performed best for the EQ-5D (RMSE = 0.095) whereas the GLM model performed best for the SF-6D (RMSE = 0.061). The GLM predicted SF-6D scores matched the observed values more closely than the CLAD and OLS.

Conclusion

Our results demonstrate that the estimation of both EQ-5D and SF-6D utility indices using the FACT-G responses can be achieved. The CLAD model for the EQ-5D and the GLM model for the SF-6D are recommended. Thus, it is possible to estimate quality-adjusted life years for economic evaluation from studies where only cancer-specific instrument have been administered.

The cost-effectiveness of growth hormone replacement therapy (Genotropin®) in hypopituitary adults in Sweden

BACKGROUND

To evaluate the cost-effectiveness of growth hormone (GH) treatment (Genotropin®) compared with no GH treatment in adults with GH deficiency in a Swedish societal setting.

METHODS

A Markov-type cost-utility simulation model was constructed and used to simulate, for men and women, morbidity and mortality for GH-treated and -untreated individuals over a 20-year period. The calculations were performed using current available prices concerning morbidity-related healthcare costs and costs for Genotropin®. All costs and treatment effects were discounted at 3%. Costs were expressed in Euro (1€ = 9.03 SEK). GH-treated Swedish patients (n = 434) were identified from the KIMS database (Pfizer International Metabolic Database) and untreated patients (n = 2135) from the Swedish Cancer Registry and the Hospital Discharge Registry.

RESULTS

The results are reported as incremental cost per quality-adjusted life year (QALY) gained, including both direct and indirect costs for GH-treated versus untreated patients. The weighted sum of all subgroup incremental cost per QALY was €15,975 and €20,241 for men and women, respectively. Including indirect cost resulted in lower cost per QALY gained: €11,173 and €10,753 for men and women, respectively. Key drivers of the results were improvement in quality of life, increased survival, and intervention cost.

CONCLUSIONS

The incremental cost per QALY gained is moderate when compared with informal thresholds applied in Sweden. The simulations suggest that GH-treatment is cost-effective for both men and women at the €55,371 (SEK 500,000 - the informal Swedish cost-effectiveness threshold) per QALY threshold.

Converting condition-specific measures into preference-based outcomes for use in economic evaluation

Quality-adjusted life-years (QALYs) play an important role in reimbursement decisions when one of the criteria is the cost-effectiveness of the health technology. While for many generic QALYs (e.g., based on the EQ-5D) are viewed as the gold standard, there has been a considerable increase in interest in using condition-specific data to generate QALYs. There are two main methods: mapping from the condition-specific data to a generic health-related quality of life measure; and direct valuation of condition-specific health states. Whether one believes condition-specific data are useful even if generic QALY data are available, or simply that condition-specific data are helpful in the absence of generic measures of health-related quality of life, it is timely to review recent research activity directed at making greater use of condition-specific data to inform assessments of cost-effectiveness.

Evaluation of content on EQ-5D as compared to disease-specific utility measures

PURPOSE

The goal of this study was to appraise the extent of unique content on disease-specific preference-based measures (DSPMs) when contrasted with the EQ-5D using published studies and to inform whether EQ-5D could be inadequate as a utility measure in its content coverage for a given disease-specific application.

METHODS

A structured search of published literature was performed using PubMed and EMBASE/Medline database from Jan 1, 1990 to Mar 31, 2011. Articles were eligible for inclusion if algorithms were developed to convert components from disease-specific measures into utility scores.

RESULTS

Of 1,029 articles identified, 50 studies satisfied the inclusion criteria. The most frequent conditions where DSPMs were developed included cancer (12 studies), coronary artery disease (4 studies), osteoarthritis, rheumatoid arthritis (3 studies of each), obesity, and stroke (2 studies of each). Most studies involved mapping items or scores from disease-specific non-preference-based measures onto a preference-based measure of health such as the EQ-5D. A substantial number of DSPMs appeared to include unique content not covered by EQ-5D dimensions.

CONCLUSIONS

Several conditions were identified as potential areas where the richness of the EQ-5D descriptive system could be enhanced. It is yet unclear whether added dimension(s) would contribute unique explained variance to a utility score. Given the resources required to rigorously develop a utility measure, the need for such measures should be carefully vetted.

Utility estimation in chronic obstructive pulmonary disease: a preference for change?

Economic evaluations of chronic obstructive pulmonary disease (COPD) incorporate utilities through multi-attribute utility (MAU) measures, most commonly the EQ-5D, to report health-related quality-of-life (HR-QOL) changes or differences. Questions have been raised about the sensitivity of these measures in COPD. Limitations in detecting adequate patient-level changes in HR-QOL over time in stable and exacerbation states compared with disease-specific instruments could also result in underestimation of known treatment benefits. The purpose of this article was to present and discuss the empirical evidence on the validity of generic MAU measures within the COPD population. We built upon a previously conducted validation review for the period 1997-2007 that used 'respiratory disease' and 'EQ-5D' as keywords. For this discussion, PubMed and EMBASE databases were searched for articles in English from 1988 to August 2009, using similar search words. Based on the performance of MAU measures in COPD and exacerbations, they appear to have limited discriminatory ability, particularly between moderate and severe COPD, despite known differences in HR-QOL. Sensitivity to clinically relevant change in stable COPD over time due to treatment also appears limited. Current research suggests adequate sensitivity regarding detecting the onset and resolution of an exacerbation; however, sensitivity is limited in the short term, such as daily changes in health status. The evidence suggests responsiveness of MAU measures may be restricted to large within-patient change, which leads to difficulties in evaluating the subtle but important impact of exacerbations. Studies presenting alternative methods of deriving COPD-related utilities are also discussed. Overall, the insensitivities of generic MAU measures in COPD can lead to biased cost-effectiveness analyses and ill-informed economic decisions. Alternative measures such as condition-specific preference-based measures may be used in circumstances where more sensitivity is needed. The trade-off allows relevant and sensitive matters most important to patients to be evaluated; however inevitable gaps such as those related to adverse events are not considered.

Perception of own death risk: an assessment of road-traffic mortality risk

This study examines individuals' perception of their own road-mortality risk using a Swedish data set. Individuals' subjective beliefs about their personal risk are compared with the objective risk of his/her own age and gender group, which in this study is defined as the respondents' objective risk. Both descriptive statistics and regression results suggest that low- and high-risk groups over- and underassess their risk levels, respectively. Having access to individual-level data we also find that the probability of underassessment and the size of risk bias is related to individual characteristics, for example, gender. Individuals' formation of risk perception is also analyzed based on the Bayesian learning model. Even though we find a positive relationship between perceived and objective risk, we cannot reject the hypothesis that individuals are not Bayesian in updating their risk beliefs.

Deriving reference values and utilities for the QoL-AGHDA in adult GHD

BACKGROUND

Quality of life (QoL) measures are important in growth hormone (GH) deficiency (GHD) in adults. Ideally, for use in health economics, QoL should be expressed in utilities. The aim of this study was to obtain reference values and utilities for QoL of GHD in adults in Belgium and the Netherlands.

METHODS

The study was conducted in three stages: (1) The Quality of Life-Assessment for Growth Hormone Deficiency in Adults (QoL-AGHDA) and the EQ-5D were administered in a representative sample of 6,875 individuals from the Belgian and 1,400 individuals from the general Dutch population. The EQ-5D(index) can be used to estimate utilities. Using a regression, utilities were predicted from the QoL-AGHDA. (2) QoL-AGHDA scores were obtained from 299 Belgian and 234 Dutch adult patients with GHD and no GH replacement. These scores were converted to utilities and compared the burden of disease with other patient groups. (3) To test the criterion validity, the 'standard' EQ-5D(index) was used in a subsample of 64 Dutch GHD patients and compared with the predicted utilities.

RESULTS

We obtained data from 1,026 Belgian (response rate = 15%) and 1,038 Dutch respondents (response rate = 74%). The Belgian mean QoL-AGHDA value was 6.95 (90% range = 14.00), and the Dutch mean was 5.48 (range = 13.00). The R (2) of the regression model to predict the EQ-5D(index) was 0.360 (Belgium) and 0.482 (the Netherlands). We demonstrated a considerable burden of disease in GHD patients, comparable to patients with hypertension or with type II diabetes. The criterion validity was 0.407 (intraclass correlation, ICC).

CONCLUSIONS

Interventions in GHD can now be evaluated more validly in Belgium and the Netherlands.

Health-related quality of life, and its determinants, among older people in rural Vietnam

Background

The proportion of people in Vietnam aged 60 and above has increased rapidly in recent decades. However, there is a lack of evidence, particularly in rural settings, on their health-related quality of life (HRQoL) within the context of socioeconomic changes and health-sector reform in the country. This study assesses the level and determinants of HRQoL in a rural district in order to provide evidence for designing and implementing appropriate health policies.

Methods

In 2007, 2,873 people aged 60+ living in 2,240 households randomly selected from the FilaBavi demographic surveillance site (DSS) were interviewed using a generic EQ-5D questionnaire to assess their HRQoL. Socioeconomic characteristics of the people and their households were extracted from the DSS's re-census that year, and the EQ-5D index was calculated based on the time trade-off tariff. Multilevel-multivariate linear regression analysis was performed to measure the affect of socioeconomic factors on HRQoL.

Results

The EQ-5D index at old age was found to be 0.876 (95%CI: 0.870-0.882). Age between 60-69 or 70-79 years, position as household head, working until old age, literacy, and belonging to better wealth quintiles are determinants of higher HRQoL. Ageing has a primary influence on the deterioration of HRQoL at older ages, mainly due to reduction in physical rather than mental functions. Educational disparity in HRQoL is low, and exists mostly between basic and higher levels of education. Being a household head and working at old age are advantageous for attaining better quality of life in physical rather than psychological terms. Economic conditions affect HRQoL through sensory rather than physical utilities. Long-term living conditions more likely affect HRQoL than short-term economic conditions.

Conclusions

HRQoL at old age is at a high level, and varies substantially according to socioeconomic factors. Its determinants should be addressed in social and health policies designed to improve health of older people, especially among the most vulnerable groups.

Application of the disease-specific Quality of Life Assessment of Growth Hormone Deficiency in Adults (QoL-AGHDA) questionnaire in a general population: results from a French panel study

OBJECTIVES

To assess the psychometric properties of the disease-specific Quality of Life Assessment of Growth Hormone Deficiency in Adults (QoL-AGHDA) questionnaire in a general population, and collect French normative data.

METHODS

A postal survey was conducted on 2900 adult panelists representative of the French population. The participants were asked to complete a questionnaire including the QoL-AGHDA and an evaluation of their overall health status (OHS). The QoL-AGHDA score ranges from 0 to 25, a lower score indicating better QoL. Psychometric properties of the QoL-AGHDA were assessed. The mean QoL-AGHDA scores were described by sex and age groups.

RESULTS

The return rate was 75%. The quality of completion and internal consistency reliability were good: 95% of the respondents completed all 25 QoL-AGHDA items and Cronbach's alpha was 0.86. The QoL-AGHDA score was able to discriminate between the respondents according to their OHS (from 1.5 for excellent to 12.3 for poor OHS, P < 0.001). The mean QoL-AGHDA score was 4.6 for the overall population, 5.1 for females and 4.2 for males, and ranged from 4.8 for the youngest to 6.1 for the oldest respondents.

CONCLUSIONS

The QoL-AGHDA questionnaire showed good psychometric properties when administered in the French population. French reference values were collected, completing the QoL-AGHDA normative database already available in several European countries.

Assessment of quality of life in adult patients with GH deficiency: KIMS contribution to clinical practice and pharmacoeconomic evaluations

Quality of life (QoL) has emerged as an important construct that has found numerous applications across healthcare-related fields, ranging from research and clinical evaluation of treatment effects to pharmacoeconomic evaluations and global healthcare policy. Impairment of QoL is one of the key clinical characteristics in adult GHD and has been extensively studied in the Pfizer International Metabolic Database (KIMS). We provide summarized evidence on GH treatment effects for both clinical and health economic applications based on the KIMS data. The primary focus is on those aspects of QoL research that cannot be investigated in the traditional clinical trial setting, such as specific patient subgroups, cross-country comparisons and long-term follow-up. First, the impact of age, gender, disease onset, primary aetiology, extent of hypopituitarism, previous radiotherapy and obesity on QoL before and during long-term GH replacement is discussed. Secondly, the studies on QoL in relation to country-specific normative values are reviewed. Finally, health economic data derived from KIMS including both burden of disease and utility assessment are evaluated. We conclude that the wide spectrum of analyses performed on the KIMS data allows for practical application of the results not only to research and clinical practice but also to health policy and global medical decision making.

Mapping utility scores from a disease-specific quality-of-life measure in bariatric surgery patients

OBJECTIVES

To develop algorithms for a conversion of disease-specific quality-of-life into health state values for morbidly obese patients before or after bariatric surgery.

METHODS

A total of 893 patients were enrolled in a prospective cross-sectional multicenter study. In addition to demographic and clinical data, health-related quality-of-life (HRQoL) data were collected using the disease-specific Moorehead-Ardelt II questionnaire (MA-II) and two generic questionnaires, the EuroQoL-5D (EQ-5D) and the Short Form-6D (SF-6D). Multiple regression models were constructed to predict EQ-5D- and SF-6D-based utility values from MA-II scores and additional demographic variables.

RESULTS

The mean body mass index was 39.4, and 591 patients (66%) had already undergone surgery. The average EQ-5D and SF-6D scores were 0.830 and 0.699. The MA-IIwas correlated to both utility measures (Spearman's r = 0.677 and 0.741). Goodness-of-fit was highest (R(2) = 0.55 in the validation sample) for the following item-based transformation algorithm: utility (MA-II-based) = 0.4293 + (0.0336 x MA1) + (0.0071 x MA2) + (0.0053 x MA3) + (0.0107 x MA4) + (0.0001 x MA5). This EQ-5D-based mapping algorithm outperformed a similar SF-6D-based algorithm in terms of mean absolute percentage error (P = 0.045).

CONCLUSIONS

Because the mapping algorithm estimated utilities with only minor errors, it appears to be a valid method for calculating health state values in cost-utility analyses. The algorithm will help to define the role of bariatric surgery in morbid obesity.

[The decline of health-related quality of life associated with some diseases in Korean adults]

OBJECTIVES

This study was conducted to measure the decline in the health-related quality of life (HRQoL) associated with some diseases in South Korean adults.

METHODS

The EQ-5D health states in the 2005 National Health and Nutrition Examination Survey (NHNES) and the Korean EQ-5D valuation set were used to obtain the EQ-5D indexes of the study subjects. Each disease group was defined when the subjects reported to the NHNES that they were diagnosed with the corresponding disease during the previous 1 year by physicians. Since the distributions of the EQ-5D indexes in each subgroup were negatively skewed, median regression analysis was used to estimate the effects of specific diseases on the HRQoL. Median regression analysis produced estimates that approximated the median of the EQ-5D indexes and there are more robust for analyzing data with many outliers.

RESULTS

A total of 16,692 subjects (6,667 patients and 10,025 people without any disease) were included in the analysis. As a result of the median regression analysis, stroke had the strongest impact on the HRQoL for both males and females, followed by osteoporosis, osteoarthritis, rheumatic arthritis, and herniation of an intervertebral disc. While asthma had a significant impact on the HRQoL only in men, cataract, temporo-mandibular dysfunction, and peptic ulcer significantly affected the HRQoL only in women.

CONCLUSIONS

Stroke and musculoskeletal diseases were associated with the largest losses of the HRQoL in Korean adults.

Growth hormone (GH) replacement in hypopituitary adults with GH deficiency evaluated by a utility-weighted quality of life index: a precursor to cost-utility analysis

OBJECTIVES

To examine quality of life (QoL) measured by a utility-weighted index in GH-deficient adults on GH replacement and analyse the impact of demographic and clinical characteristics on changes in utilities during treatment.

DESIGN

Utilities for items in the QoL-Assessment of Growth Hormone Deficiency in Adults (QoL-AGHDA(utility)) were estimated based on data obtained from the general population in England and Wales (E&W). These estimates were used to calculate QoL changes in GH-treated patients and compare these with normative population values.

PATIENTS

A total of 894 KIMS patients (53% women) from E&W were followed for 1 to 6 years.

MEASUREMENTS

QoL-AGHDA(utility) at baseline and at the last reported visit, total QoL-AGHDA(utility) gain and QoL-AGHDA(utility) gain per year of follow-up.

RESULTS

QoL-AGHDA(utility) in patients before GH treatment differed from the expected population values [0.67 (SD 0.174) vs. 0.85 (SD 0.038), P < 0.0001], constituting a mean deficit of -0.19 (SD 0.168). There was a difference in the mean QoL-AGHDA(utility) deficit for men [-0.16 (SD 0.170)] and women [-0.21 (SD 0.162)] (P < 0.001). The main improvement occurred during the first year of treatment [reduction of a deficit to -0.07 (SD 0.163) (P < 0.001) in the total cohort]; however, patients' utilities remained lower than those recorded for the general population during subsequent follow-up (P < 0.001). Despite an observed impact of age, primary aetiology, disease onset and comorbidities on QoL-AGHDA(utility), all patients showed a similar beneficial response to treatment.

CONCLUSIONS

QoL-AGHDA(utility) efficiently monitors treatment effects in patients with GHD. The study confirmed the QoL-AGHDA(utility) deficit before treatment and a similar QoL-AGHDA(utility) gain observed after commencement of GH replacement in all patients.