Usage and impact of patient-reported outcomes in epilepsy.

BACKGROUND: The use of patient-reported outcomes (PRO) in clinical practice is gaining increasing attention. This study aimed to provide a critical assessment of the current state-of-the-art and beliefs about the use of PRO in the management of people with epilepsy across some European countries. METHODS: Structured interviews were conducted with European experts to collect insights about (I) the personal experience with PRO; (II) the value and impact of PRO in the decision-making process at the national level; and (III) the interest for and use of PRO by national health authorities. RESULTS: Nine neurologists (Austria, Belgium, Czechia, Denmark, France, Greece, Italy, Poland, and United Kingdom), three health economists (Portugal, Romania, and Sweden), and one epidemiologist (Slovakia) participated. They all stated that PRO are collected at their own countries in the context of clinical trials and/or specific projects. During everyday clinical practice, PRO are collected routinely/almost routinely in Austria and Sweden and only at the discretion of the treating physicians in Czechia, Denmark, France, Greece, and Portugal. There was complete consensus about the favorable impact that the PRO can have in terms of clinical outcomes, healthcare resources utilization, and general patient satisfaction. Only participants from Portugal and Sweden answered that the PRO are perceived as very important by the National Health Authorities of their respective countries. CONCLUSIONS: Differences exist in attitudes and perspectives about PRO in epilepsy across Europe. An active plan is warranted to harmonize the measurement of PRO and ensure they can be relevant to people with epilepsy and health services.

Health and well-being of the Portuguese citizens: impacts of the COVID-19.

BACKGROUND: COVID-19 pandemic placed unprecedented pressure on societies and healthcare systems around the world. Over the last years, measures imposed in almost all countries dealing with the pandemic sent the entire world into an extensive crisis and thus into a deep global recession. Since the outbreak began, many European countries have faced three/four waves of pandemic. Portugal has mainly dealt with three waves (March/April'2020; October/November'2020; January/February'2021), the third being the deadliest one. The purpose of this article is to provide evidence on the impact of the COVID-19 on health-related quality of life (HRQol) and well-being (W-B) of Portuguese citizens. It aims to (i) characterize these outcomes during the COVID-19 pandemic; (ii) compare them to pre-COVID-19 Portuguese population; and (iii) identify the social determinants that may affect these outcomes during the COVID-19 pandemic. METHODS: This study used data from a survey that collected data on HRQoL, W-B, satisfaction with life, economic and labour impacts, access to healthcare, mental and physical health, amongst others. The survey was implemented by telephone to a representative random sample of 1,255 respondents from the general adult Portuguese population, stratified by sex, age group and region. Data was collected during the end of the second national lockdown. For comparison purposes, we have also used two other representative databases from the general Portuguese population: (i) data from before the pandemic (n = 1,006); and (ii) data from a survey conducted during the first lockdown, (n = 904). RESULTS: Looking at health and access to healthcare, 4% of citizens had their surgeries postponed or cancelled because of COVID-19, more than a quarter had medical appointments or complementary exams postponed or cancelled, with 7% over 65 years old with surgeries cancelled or postponed and 32% medical appointments. COVID-19 pandemic also impacted negatively on the HRQoL of citizens, especially in the first lockdown. Half of the respondents reported feeling nervous, anxious, or on edge, about 45% of citizens felt sad or depressed. Sleeping problems were reported for almost 39% of citizens, and loneliness is reported by 29% of citizens. For about 70-85% of citizens, these feelings were more so than before the pandemic. Citizens with fair/strong economic stability were the most economically affected by the pandemic. CONCLUSIONS: We provided evidence on the impact of COVID-19 on health and W-B of Portuguese citizens. Their health was worse than before the pandemic and the access to healthcare was highly affected.

EQ-5D-5L Portuguese population norms.

OBJECTIVES: The EQ-5D-5L is a generic preference-based quality-of-life measure for which the corresponding Portuguese population value set was only recently developed. This study sought to establish EQ-5D-5L population norms for Portugal and to identify significant relationships with sociodemographic variables. METHODS: The research was based on a representative sample of Portugal's general population (n = 1006) aged 18 or older. The sample was stratified by gender, age group, and geographical region. The respondents were interviewed by telephone and asked to value their own state of health using both the EQ-5D-5L description system and the EuroQol-Visual Analogue Scale (EQ VAS). RESULTS: The estimated mean EQ-5D-5L index for Portugal's general population is 0.887 (standard error [SE] = 0.0051), and the EQ VAS score was estimated as 76.0 (SE = 0.640). One-third of the population reported being in the best health state (11111). Women, individuals 70 years old or more and people with low education or a chronic disease reported a lower EQ-5D-5L index score (p < 0.001). Residents in the Azores and the Algarve reported higher health utility scores. CONCLUSIONS: The EQ-5D-5L Portuguese population norms obtained can be used as reference scores. These norms are consistent with other countries' population norms. The findings facilitate clinical, economic, and policy decision-making processes and provide a fuller understanding of the Portuguese population's health-related quality of life.

Quality of life under the COVID-19 quarantine.

BACKGROUND: COVID-19 has spread rapidly throughout the world, causing thousands of illnesses and deaths. To fight this pandemic, almost all governments and health authorities have focused on prevention. In March or April, most countries' officials imposed home quarantine and lockdown measures nationwide. PURPOSE: This study sought to assess health-related quality of life (HRQoL) and anxiety levels among people in Portugal under mandatory home quarantine due to the COVID-19 pandemic. The results were compared to the general Portuguese population's HRQoL before the COVID-19 outbreak. This research also aimed to understand the factors that can influence the respondents' HRQoL. METHODS: A sample of Portugal's population quarantined at home (n = 904) filled in an online survey comprising the Generalized Anxiety Disorder 7-item and the EQ-5D-5L and other questions about sociodemographic characteristics, feelings, duties and activities during the quarantine. The sample was weighted to mirror the general population's gender, age and education. Descriptive analyses and correlation coefficients were used to evaluation the respondents' anxiety and HRQoL. Generalised linear models were estimated to identify determinants of HRQoL during the COVID-19 quarantine. RESULTS: The results show that individuals quarantined at home reported higher anxiety and lower HRQoL levels and that people with more anxiety tended to have a lower HRQoL. Females and elderly individuals experienced the highest levels of anxiety and poorest HRQoL. In addition, HRQoL during the quarantine can be explained by various occupational and attitudinal variables, as well as sociodemographic variables. CONCLUSION: Individuals' mental health should be taken into consideration during pandemics or other emergency situations. Anxiety and other factors can decrease people's HRQoL, in conjunction with the pandemic's social and economic consequences.

[Erratum to "Does Aortic Valve Replacement Surgery Improve Patients' Quality of Life?", by Pedro COELHO, Lara N. FERREIRA, Clara VITAL, José FRAGATA. Acta Med Port 2018 Jul-Aug;31(7-8):399-408]. / Errata a "A Cirurgia de Substituição Valvular Aórtica Melhora a Qualidade de Vida dos Doentes?" Pedro COELHO, Lara N. FERREIRA, Clara VITAL, José FRAGATA. Acta Med Port 2018 Jul-Aug;31(7-8):399-408.

Article published with errors: https://actamedicaportuguesa.com/revista/index.php/amp/article/view/10241 On page 405, Table 3, where it reads: On bold, the value 34.4 in "limitação do Desempenho" concerning the column "Seguimento a 6 meses" It should read: On bold, the value of 37,9. On page 406, Figure 4, where it reads: The y-axis of index SF-6D values are designed between 0 and 50. It should read: The y-axis of index SF-6D values between are designed between 0 and 1.

Artigo publicado com erros: https://actamedicaportuguesa.com/revista/index.php/amp/article/view/10241 Na página 405, Tabela 3 onde se lê: A negrito o valor 34,4 na dimensão "limitação do Desempenho" referente à coluna "Seguimento a 6 meses"Deverá ler-se: A negrito o valor 37,9. Na página 406, Figura 4, onde se lê:O eixo do índice SF-6D com valores entre 0 a 50.Deverá ler-se:O eixo do índice SF-6D com valores entre 0 a 1.

A hybrid modelling approach for eliciting health state preferences: the Portuguese EQ-5D-5L value set.

BACKGROUND: The EQ-5D is a generic preference-based quality of life measure considered useful for supporting clinical and policy decisions by providing utility values that can easily be converted into quality-adjusted life years to be integrated in cost-utility economic evaluations. Although the three-level classification system of the EuroQol questionnaire (EQ-5D-3L) is still the most popular preference-based instrument used worldwide, several studies reported a ceiling effect on this version, especially in healthy and/or young individuals. In 2009, the EuroQol Group introduced a five-level EQ-5D, which expands the descriptive system from three to five levels within the same five dimensions. For this version to be used in health economic evaluation, societal values need to be assigned to the 3125 health states generated by this instrument. OBJECTIVES: The aims of this study were to elicit the EQ-5D-5L health state preferences from the general Portuguese population and to derive the Portuguese value set for the EQ-5D-5L. METHODS: A representative sample of the Portuguese general population aged above 18 years was stratified by age and gender (n = 1451). Between October 2015 and July 2016, 28 interviewers carried out a series of 1-h-long computer-assisted personal interviews following the EuroQol Valuation Technology protocol. Each interview included the valuation of ten health states using the composite time trade-off (cTTO) and seven pairs of discrete choice experiments (DCEs). A standardized tool for quality control was used to assess the quality of the data as well as direct supervision and cross-examination of 10% of the global sample size. Data from both cTTO and DCE valuation tasks were modelled using a censored heteroskedastic hybrid model. RESULTS: Interviewers complied with the quality control protocol in providing high-quality valuation data. The hybrid econometric model had consistent and significant parameters. The derived societal values for the Portuguese population ranged from - 0.603 to 1. CONCLUSION: This study provided the Portuguese value set for the EQ-5D-5L on the basis of a hybrid econometric model using cTTO and DCE data. These results represent the preferences of the Portuguese population and are recommended to inform health decision-making in Portugal.

[Does Aortic Valve Replacement Surgery Improve Patients' Quality of Life?] / A Cirurgia de Substituição Valvular Aórtica Melhora a Qualidade de Vida dos Doentes?

INTRODUCTION: Aortic valve replacement surgery is done to increase patients' life expectancy and improve their health-related quality of life. Several published studies have found improvement in health-related quality of life after this procedure, but none have involved patients in Portugal. This study sought to evaluate patients' health-related quality of life after the implantation of aortic prostheses and compare these values with preoperative health-related quality of life and the general Portuguese population's health-related quality of life. MATERIAL AND METHODS: A retrospective study was done with elective patients who underwent implantation of an aortic prosthesis between August 2011 and April 2016. Health-related quality of life was evaluated using the Short Form 36 Health Survey and Short Form 6 Health Survey questionnaires in the preoperative period and 3, 6 and 12 months post-surgery. Descriptive and inferential analyses were conducted to process the data and compare preoperative health-related quality of life with postoperative values and the Portuguese population's norms. RESULTS: The sample included 506 patients with an average age of 70.6 years. The majority are male (53.6%). The postoperative results show a statistically significant improvement compared to preoperative health-related quality of life in all eight dimensions of the Short Form 36 Health Survey. When contrasted with the general Portuguese population, patients' health-related quality of life is lower in the preoperative period, improving postoperatively and reaching higher than average health-related quality of life levels in some subgroups of patients and in various dimensions. An analysis of the Short Form 6 Health Survey results revealed that the patients undergoing this surgery have a higher level of preoperative problems compared with the general population, but these patients' values approach those of the general population by the end of one year post-surgery. DISCUSSION: This is the first study in Portugal that compares health-related quality of life using a validated scale, before and after the aortic prosthesis implantation surgery. The results demonstrate a significant improvement in all dimensions, which is not consistently observed in other published studies. CONCLUSION: The results confirm that the implantation of aortic prostheses improves patients' health-related quality of life, over time bringing it close to the general population's levels.

Introdução: O objetivo da cirurgia de substituição valvular aórtica é o aumento da esperança de vida e a melhoria da qualidade de vida relacionada com a saúde. Existem vários estudos que evidenciam melhoria da qualidade de vida relacionada com a saúde nestes doentes, mas não aplicados à população portuguesa. O objetivo deste estudo é avaliar a qualidade de vida relacionada com a saúde pós-implantação de prótese aórtica e comparar com a qualidade de vida relacionada com a saúde pré-operatória e da população em geral. Material e Métodos: Foi feito um estudo retrospetivo de doentes eletivos submetidos a implantação de prótese aórtica entre agosto de 2011 e abril de 2016. A qualidade de vida relacionada com a saúde foi avaliada com o Short Form 36 Health Survey Instrument e com o Short Form 6 Health Survey Instrument no pré-operatório e aos 3, 6 e 12 meses pós-cirurgia. Foram realizadas análises descritivas e inferenciais para analisar globalmente a amostra e para comparar a qualidade de vida relacionada com a saúde pré-operatória com a pós-operatória e com as normas da população portuguesa. Resultados: Foram incluídos 506 doentes, com idade média de 70,6 anos, sendo 53,6% do sexo masculino. Os resultados do pós-operatório evidenciam uma melhoria estatisticamente significativa quando comparados com o pré-operatório nas oito dimensões do Short Form 36 Health Survey Instrument. Comparando com a população Portuguesa em geral, a qualidade de vida relacionada com a saúde dos doentes é inferior no pré-operatório, melhorando no pós-operatório, atingindo níveis de qualidade de vida relacionada com a saúde superiores nalguns subgrupos de doentes e em algumas dimensões. Os resultados do Short Form 6 Health Survey Instrument revelam maior intensidade de problemas no pré-operatório quando comparados com a população em geral, aproximando-se dos valores população em geral ao final de um ano pós-cirurgia. Discussão: Este é o primeiro estudo realizado em Portugal que compara a qualidade de vida relacionada com a saúde, usando uma escala validada, antes e depois da cirurgia de implantação de prótese aórtica. Os resultados demonstram a existência de uma melhoria significativa em todas as dimensões, o que não acontece consistentemente noutros estudos publicados. Conclusão: A implantação de prótese aórtica melhora a qualidade de vida relacionada com a saúde dos doentes, permitindo que esta se aproxime dos resultados da população em geral.

Are condition-specific utilities more valid than generic preference-based ones in asthma? Evidence from a study comparing EQ-5D-3L and SF-6D with AQL-5D.

BACKGROUND: Systematic discrepancies have been shown in utility values derived from different instruments. This study compares utilities from the condition-specific AQL-5D and the generic EQ-5D-3L and SF-6D in an asthmatic population with heterogeneous health-related quality of life (HRQoL), disease severity, and control status. METHODS: A consecutive sample of 104 patients diagnosed with asthma completed a survey containing the Greek versions of SF-36, EQ-5D-3L, and AQLQ(s). Treatment adequacy was assessed with the Asthma Control Questionnaire (ACQ), and asthma severity according to Global Initiative for Asthma 2016 guidelines. Association and agreement between instruments were assessed with Spearman's correlation and Bland-Altman plots. RESULTS: AQL-5D utilities exceeded (p < 0.001) those from EQ-5D-3L and SF-6D. There were weak-to-moderate correlations (<0.5) between most dimensions of AQL-5D, and those of EQ-5D-3L and SF-6D, and strong correlations between similar dimensions of EQ-5D-3L and SF-6D. Significant differences (p < 0.001) were observed throughout the visual analog scale (VAS), asthma severity and asthma control subgroups, with AQL-5D consistently higher than EQ-5D-3L and SF-6D. CONCLUSIONS: All instruments distinguished between differing degrees of asthma control, but only AQL-5D discriminated between asthma severity and HRQoL as well. Although the relatively small sample warrants caution in interpreting the subgroup results, this study contributes to the growing number of comparisons between condition-specific and generic preference-based instruments.

Assessing quality of life of self-reported rheumatic patients.

The aims of this study were to assess the health-related quality of life (HRQoL) in patients with self-reported rheumatic diseases (RD), to classify self-reported rheumatic patients in groups according to their health state and to explore the associations between health status and sociodemographic variables. Data came from the Portuguese Epidemiologic study of the RD. A sample of the Portuguese population aged 18 or more (n = 10,661) stratified by region and locality dimension was interviewed by trained interviewers and answered a standardized questionnaire that included the SF-36v1, the EQ-5D-3L, medical history, identification of potential rheumatic diseases, sociodemographic characteristics, among others. Descriptive statistics and parametric tests were used to compare HRQoL of respondents with and without RD. Comparisons with normative data from the Portuguese population were also carried out. A cluster analysis was used to classify respondents into homogeneous groups. Regression analyses were used to identify factors associated with HRQoL. Respondents with self-reported RD assigned a lower self-perception to their health status. The burden of disease was observed mainly in physical function, role physical and bodily pain. The EQ-5D-3L dimensions show similar results: the intensity of problems is significantly more evident in respondents with self-reported RD. HRQoL of respondents with self-reported RD is related to sociodemographic variables and is significantly lower when compared with the Portuguese population. Four clusters of homogeneous respondents with self-reported RD were formed and characterized according to a number of variables. Factors associated with HRQoL were identified. In conclusion, suffering from a self-reported RD has a significant impact on self-perceived health status and on the quality of life.

Comparing the performance of the EQ-5D-3L and the EQ-5D-5L in young Portuguese adults.

BACKGROUND: Some studies have reported a ceiling effect in EQ-5D-3L, especially in healthy and/or young individuals. Recently, two further levels have been included in its measurement model (EQ-5D-5L). The purposes of this study were (1) to assess the properties of the EQ-5D-5L in comparison with the standard EQ-5D-3L in a sample of young adults, (2) to foreground the importance of collecting qualitative data to confirm, validate or refine the EQ-5D questionnaire items and (3) to raise questions pertaining to the wording in these questionnaire items. METHODS: The data used came from a sample of respondents aged 30 or under (n = 624). They completed both versions of the EQ-5D, which were compared in terms of feasibility, level of inconsistency and ceiling effect. Agreement between the instruments was assessed using correlation coefficients and Bland-Altman plots. Known-groups validity of the EQ-5D-5L was also assessed using non-parametric tests. The discriminative properties were compared using receiver operating characteristic curves. Finally, four interviews were conducted for retrospective reports to elicit respondents' understanding and perceptions of the format, instructions, items, and responses. RESULTS: Quantitative results show a ceiling effect reduction of 25.3 % and a high level agreement between both indices. Known-groups validity was confirmed for the EQ-5D-5L. Explorative interviews indicated ambiguity and low degree of certainty in regards to conceptualizing differences between levels moderate-slight across three dimensions. CONCLUSIONS: The EQ-5D-5L performed better than the EQ-5D-3L. However, the explorative interviews demonstrated several limitations in the EQ-5D questionnaire wording and high context-dependent answers point to lack of illnesses' experience amongst young adults.

SF-6D Portuguese population norms.

BACKGROUND: Population-based norms are important because they provide benchmarks that allow the interpretation of subgroups of population health, comparisons between studies, information on health inequalities and support for health-care interventions. The SF-6D is a preference-based measure of health, the use of which has been increasing throughout the world. OBJECTIVE: Other countries have provided population norms for the SF-6D. To date, SF-6D population norms for Portugal do not exist. This study therefore aimed to derive SF-6D Portuguese population norms. METHODS: A representative sample of the Portuguese general public (n = 1,500) was used in a telephone-based interview. The SF-36v2 was applied and the Portuguese SF-6D value set was used to obtain the SF-6D index. Descriptive and inferential data analyses were applied to sociodemographic variables, the dimensions of the SF-6D and the SF-6D index. Health index scores of the target population and selected subpopulations were estimated using domain estimation techniques when necessary. RESULTS: SF-6D utility scores decline with increasing age. Women, widowed individuals and individuals with low educational attainment report lower levels of SF-6D utility scores than men, those with a high educational attainment and those who are single. CONCLUSIONS: This study reports Portuguese population norms measured using the SF-6D based on a national representative sample. These results can be used as reference data to inform policy.

Comparing the performance of the SF-6D and the EQ-5D in different patient groups.

INTRODUCTION: This research aims to explore the performance of the SF-6D and the EQ-5D in patients suffering from asthma, chronic obstructive pulmonary disease, cataracts, and rheumatoid arthritis. In particular, the aim of this research is twofold: 1) to study the level of agreement between the indexes and the descriptive systems of the dimensions of the SF-6D and the EQ-5D, and 2) to analyze the discriminative ability of the instruments. MATERIAL AND METHODS: A sample of 643 patients completed both the SF-36v2 and the EQ-5D. The discriminative ability of the instruments was analyzed. Furthermore, the level of agreement between the indexes and the descriptive systems of the dimensions of the SF-6D and the EQ-5D were studied. The level of agreement between instruments was investigated using correlation coefficients and the Bland-Altman plots, while the influence of medical condition and other socio-demographic variables was analyzed using nonparametric tests. Paired-samples tests were used to identify differences between the scores. RESULTS AND DISCUSSION: The results show a strong correlation and agreement between both indexes. Overall, questionnaire indexes differ by medical condition and socio-demographic groups and both instruments are able to discriminate between socio-demographic groups. CONCLUSION: This study confirmed the hypothesis that the SF-6D generates higher utility values in less healthy individuals. The SF-6D and the EQ-5D seem to perform differently in each of the diseases studied since the descriptive statistics differ between instruments and the level of correlation is not uniform. Results show that the instruments generate different utility values, but there is a strong agreement between both indexes. Thus, the two instruments are not interchangeable and their results cannot be directly comparable.

Introdução: O objectivo geral deste artigo consiste em comparar o desempenho do EQ-5D e do SF-6D em quatro grupos de doentes que sofrem de asma, doença pulmonar obstrutiva crónica, cataratas e artrite reumatóide. Em particular, este artigo tem dois objectivos específicos: 1) estudar o nível de concordância entre os índices e os sistemas descritivos das dimensões do SF-6D e EQ-5D, e 2) analisar a capacidade de discriminação dos instrumentos.Material e Métodos: Uma amostra de 643 doentes respondeu ao SF-36v2 e ao EQ-5D. Foram analisados a capacidade de discriminação dos instrumentos, bem como o nível de concordância entre os índices e os sistemas descritivos das dimensões do SF-6D e EQ-5D. O nível de concordância entre os instrumentos foi estudado com base em coeficientes de correlação e nos gráficos de Bland-Altman, enquanto a influência da condição médica e de outras variáveis de natureza sociodemográfica nos índices foi analisada com o recurso a testes não paramétricos. Utilizaram-se também testes para amostras emparelhadas para identificar diferenças entre osscores finais dos instrumentos.Resultados e Discussão: Verificou-se a existência de uma correlação forte e de uma concordância elevada entre os dois índices. Em termos globais, os índices diferem por condição médica e por grupo sociodemográfico e ambos os instrumentos demonstraram uma capacidade discriminativa semelhante entre grupos sociodemográficosConclusão: Confirmou-se a hipótese de que o SF-6D gera valores de utilidade superiores em populações com doenças. O SF-6D e o EQ-5D parecem comportar-se de forma diferente em cada uma das doenças analisadas, uma vez que as medidas descritivas diferem entre instrumentos e os coeficientes de correlação não são uniformes. Os resultados demonstraram que o EQ-5D e o SF-6D geram valores de utilidade diferentes, mas que existe uma concordância elevada entre os dois instrumentos. Pode-se concluir que os resultados dos instrumentos não são directamente comparáveis.

The valuation of the EQ-5D in Portugal.

PURPOSE: The EQ-5D is a preference-based measure widely used in cost-utility analysis (CUA). Several countries have conducted surveys to derive value sets, but this was not the case for Portugal. The purpose of this study was to estimate a value set for the EQ-5D for Portugal using the time trade-off (TTO). METHODS: A representative sample of the Portuguese general population (n = 450) stratified by age and gender valued 24 health states. Face-to-face interviews were conducted by trained interviewers. Each respondent ranked and valued seven health states using the TTO. Several models were estimated at both the individual and aggregated levels to predict health state valuations. Alternative functional forms were considered to account for the skewed distribution of these valuations. RESULTS: The models were analyzed in terms of their coefficients, overall fit and the ability for predicting the TTO values. Random effects models were estimated using generalized least squares and were robust across model specification. The results are generally consistent with other value sets. CONCLUSION: This research provides the Portuguese EQ-5D value set based on the preferences of the Portuguese general population as measured by the TTO. This value set is recommended for use in CUA conducted in Portugal.

Exploring the consistency of the SF-6D.

OBJECTIVE: The six-dimensional health state short form (SF-6D) was designed to be derived from the short-form 36 health survey (SF-36). The purpose of this research was to compare the SF-6D index values generated from the SF-36 (SF-6DSF-36) with those obtained from the SF-6D administered as an independent instrument (SF-6DInd). The goal was to assess the consistency of respondents' answers to these two methods of deriving the SF-6D. METHODS: Data were obtained from a sample of the Portuguese population (n = 414). Agreement between the instruments was assessed on the basis of a descriptive system and their indexes. The analysis of the descriptive system was performed by using a global consistency index and an identically classified index. Agreement was also explored by using correlation coefficients. Parametric tests were used to identify differences between the indexes. Regression models were estimated to understand the relationship between them. RESULTS: The SF-6DInd generates higher values than does the SF-6DSF-36. There were significant differences between the indexes across sociodemographic groups. There was a significant ceiling effect in the SF-6DInd but not in the SF-6DSF-36. The correlation between the indexes was high but less than what was anticipated. The global consistency index identified the dimensions with larger differences. Considerable differences were found in two dimensions, possibly as a result of different item contexts. Further research is needed to fully understand the role of the different layouts and the length of the questionnaires in the respondents' answers. CONCLUSIONS: The results show that as the SF-6D was designed to derive utilities from the SF-36 it should be used in this way and not as an independent instrument.

Do Portuguese and UK health state values differ across valuation methods?

PURPOSE: There has been an increasing interest in developing country-specific preference weights for widely used measures of health-related quality of life. The valuation of health states has usually been done using cardinal preference elicitation techniques of standard gamble (SG) or time trade-off (TTO). Yet there is increasing interest in the use of ordinal methods to elicit health state utility values as an alternative to the more conventional cardinal techniques.This raises the issue of firstly whether ordinal and cardinal methods of preference elicitation provide similar results and secondly whether this relationship is robust across different valuation studies and different populations. METHODS: This study examines SG and rank preference weights for the SF-6D derived from samples of the UK and Portuguese general population. The preference weights for the Portuguese sample (n = 140) using rank data are estimated here with 810 health state valuations. The study further examines whether the use of these different preference weights has an impact when comparing the health of different age and severity groups in the Portuguese working population (n = 2,459). RESULTS: The rank model performed well across the majority of measures of goodness of fit used. The preference weights for the Portuguese sample using rank data are systematically lower than the UK weights for physical functioning and pain. Yet our results suggest higher similarity between preference weights derived using rank data than using standard gamble across the UK and Portuguese samples. Our results further suggest that the SF-6D values for a sample of the Portuguese working-age population and differences across groups are affected by the use of different preference weights. CONCLUSION: We suggest that the use of a Portuguese SF-6D weighting system is preferred for studies aiming to reflect the health state preferences of the Portuguese population.

A Portuguese value set for the SF-6D.

OBJECTIVES: The SF-6D is a preference-based measure of health derived from the SF-36 that can be used for cost-effectiveness analysis using cost-per-quality adjusted life-year analysis. This study seeks to estimate a system weight for the SF-6D for Portugal and to compare the results with the UK system weights. METHODS: A sample of 55 health states defined by the SF-6D has been valued by a representative random sample of the Portuguese population, stratified by sex and age (n = 140), using the Standard Gamble (SG). Several models are estimated at both the individual and aggregate levels for predicting health-state valuations. Models with main effects, with interaction effects and with the constant forced to unity are presented. Random effects (RE) models are estimated using generalized least squares (GLS) regressions. Generalized estimation equations (GEE) are used to estimate RE models with the constant forced to unity. Estimations at the individual level were performed using 630 health-state valuations. Alternative functional forms are considered to account for the skewed distribution of health-state valuations. RESULTS: The models are analyzed in terms of their coefficients, overall fit, and the ability for predicting the SG-values. The RE models estimated using GLS and through GEE produce significant coefficients, which are robust across model specification. However, there are concerns regarding some inconsistent estimates, and so parsimonious consistent models were estimated. There is evidence of under prediction in some states assigned to poor health. The results are consistent with the UK results. CONCLUSION: The models estimated provide preference-based quality of life weights for the Portuguese population when health status data have been collected using the SF-36. Although the sample was randomly drowned findings should be treated with caution, given the small sample size, even knowing that they have been estimated at the individual level.

How consistent are health utility values?

The use of preference-based generic instruments to measure the health-related quality of life of a general population or of individuals suffering from a specific disease has been increasing. However, there are several discrepancies between instruments in terms of utility results. This study compares SF-6D and EQ-5D when administered to patients with cataracts and aims at explaining the differences. Agreement between EQ-5D and SF-6D health state classifications was assessed by correlation coefficients. Simple correspondence analysis was used to assess the agreement among the instrument's descriptive systems and to investigate similarities between dimensions' levels. Cluster analysis was used to classify SF-6D and EQ-5D levels into homogeneous groups. There was evidence of floor effects in SF-6D and ceiling effects in EQ-5D. Comparisons of means showed that SF-6D values exceeded EQ-5D values. Agreement between both instruments was high, especially between similar dimensions. However, different valuation methods and scoring algorithms contributed to the main differences found. We suggest that one or both instruments should be revised, in terms of their descriptive systems or their scoring algorithms, in order to overcome the weakness found.