Browsing by Author "Ferreira, Pedro L."
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- A hybrid modelling approach for eliciting health state preferences: the Portuguese EQ-5D-5L value setPublication . Ferreira, Pedro L.; Antunes, Patricia; Ferreira, Lara; Pereira, LN; Ramos-Goni, Juan M.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.
- An application of the SF-6D to create health values in Portuguese working age adultsPublication . Ferreira, Lara Noronha; Ferreira, Pedro L.; Pereira, Luis Nobre; Brazier, JohnObjectives : This study describes the health-related quality of life(HRQOL) of the Portuguese working age population and investigates sociodemographic differences. Methods : Subjects randomly selected from the working age population ( n =2,459) were assessed using the SF-36v2 and converted into the preference-based SF-6D. Results : The mean SF-6D utility value was 0.70 (range 0.63–0.73). The mean utility value was lower for the lower educational level than for the highest. Women, people living in rural areas and older adults reported lower levels of utility values. Non-parametric tests showed that health utility values were signifi cantly related to employment; unskilled manual workers reported utility values lower than non-manual workers. For different diseases, mean utility values ranged from 0.58 (sexual diseases) to 0.66 (hepatic conditions). Cluster analysis was adopted to classify individuals into three groups according to their answers to the SF-6D dimensions. Multinomial logit regression was used to detect sociodemographic characteristics affecting the probability of following each cluster pattern. This study yielded normative data by age and gender for the SF-6D. Conclusions: The authors conclude that SF-6D is an effective tool for measuring HRQOL in the community so that different population groups can be compared. The preference-based measure used seems to discriminate adequately across sociodemographic differences. These results allow a better understanding of the impact of sociodemographic variables on the burden of illness perception.
- Assessing quality of life of self-reported rheumatic patientsPublication . Ferreira, Pedro L.; Gonçalves, Sónia P.; Ferreira, Lara Noronha; Pereira, Luis; Antunes, Patrícia; Gouveia, Nélia; Rodrigues, Ana; Canhão, Helena; Branco, Jaimewere 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. 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 adultsPublication . Ferreira, Lara Noronha; Ferreira, Pedro L.; Perdigão, Filipa; Pereira, LuisBackground 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.
- Comparing the performance of the SF-6D and the EQ-5D in different patient groupsPublication . Ferreira, Lara N.; Ferreira, Pedro L.; Pereira, Luis N.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 non-parametric 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.
- EQ-5D-5L valuation study for PortugalPublication . Ferreira, Pedro L.; Antunes, Patricia; Ferreira, Lara; Pereira, LuisAlthough the EQ-5D-3L still is the most popular preferencebased instrument worldwide, we anticipate that the new version EQ5D-5L with five levels within each dimension will be more used and is likely to leave behind the previous one.
- Erratum to: Reducing the floor effect in the SF-6D: a feasibility study (vol 7, pg 193, 2012)Publication . Ferreira, Lara Noronha; Ferreira, Pedro L.; Pereira, Luis; Rowen, DonnaErratum to: Reducing the Floor Effect in the SF-6D: A Feasibility Study
- Exploring the consistency of the SF-6DPublication . Ferreira, Lara Noronha; Ferreira, Pedro L.; Pereira, Luis; Rowen, Donna; Brazier, John E.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-6D(SF-36)) with those obtained from the SF-6D administered as an independent instrument (SF-6D(Ind)). 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-6D(Ind) generates higher values than does the SF-6D(SF-36), There were significant differences between the indexes across sociodemographic groups. There was a significant ceiling effect in the SF-6D(Ind) a but not in the SF-6D(SF-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.
- Health and well-being of the Portuguese citizens: impacts of the COVID-19Publication . Ferreira, Lara; Pereira, Luis; Ferreira, Pedro L.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.
- How consistent are health utility values?Publication . Ferreira, Pedro L.; Ferreira, Lara Noronha; Pereira, Luis NobreThe 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.