Construct validity of EQ-5D-5L among patients with inflammatory bowel disease-a study based on real-world data from the Swedish Inflammatory Bowel Disease Registry.

OBJECTIVES: The Swedish Inflammatory Bowel Disease Registry (SWIBREG) includes approximately 84% of all patients with inflammatory bowel disease (IBD) treated with immunomodulators, biologics or surgery in Sweden. Data on health-related quality of life (HRQoL) have been collected using EQ-5D-5L in the registry since 2012. Nevertheless, there are few studies assessing the validity of EQ-5D-5L in this patient population. Thus, the aim of this study was to assess the construct validity of EQ-5D-5L amongst patients with IBD (ulcerative colitis and Crohn's disease). METHODS: Individual-level data on EQ-5D-5L and other disease-specific measures were extracted from SWIBREG. Known-groups validity was assessed by analysing whether the EQ-5D-5L captured expected differences between patient groups with different activity levels of the disease. Convergent validity was assessed by analysing whether the reported problems in the dimensions of EQ-5D-5L, EQ VAS, and the EQ-5D-5L index value correlated, as hypothesized, with the four dimensions in the Short Health Scale, a symptom index question, and the Physician Global Assessment (PGA) score. RESULTS: In total, 9769 patients with IBD were included in the study. Patients with active IBD reported more health problems in the EQ-5D-5L descriptive system than patients being in remission. The effect sizes for the differences in reported problems between patients with active and inactive disease were at least small (≥0.1) or medium (≥0.3) in all dimensions except self-care. Differences in the mean EQ-5D-5L index and EQ-VAS score between patients with active and inactive disease were statistically significant (p < 0.001) and larger than pre-defined cut-offs for minimally important differences (>0.08 for the index and >11.0 for EQ-VAS). The analysis of convergent validity showed that EQ-5D-5L results correlated as expected with the disease-specific measures in 16 of the 21 analyses. In total, 22 (79%) of the 28 hypotheses were supported. CONCLUSION: The findings support the construct validity of EQ-5D-5L amongst patients with IBD and contribute to the scarce literature on the validity of the five-level version of EQ-5D in this patient population. These findings have important implications for the choice of HRQoL measure in routine health care registries like SWIBREG as well as for future clinical or health economic studies considering using EQ-5D-5L as a measure of HRQoL.

Association between pulse width and health-related quality of life after electroconvulsive therapy in patients with unipolar or bipolar depression: an observational register-based study.

AIMS: To examine the association between pulse width and HRQoL measured within one week after electroconvulsive therapy (ECT) and at six-month follow-up in patients with unipolar or bipolar depression. METHODS: This was an observational register study using data from the Swedish National Quality Registry for ECT (2011-2019). Inclusion criteria were: age ≥18 years; index treatment for unipolar/bipolar depression; unilateral electrode placement; information on pulse width; EQ-5D measurements before and after ECT. Multiple linear regressions were performed to investigate the association between pulse width (<0.5 ms; 0.5 ms; >0.5 ms) and HRQoL (EQ-5D-3L index; EQ VAS) one week after ECT (primary outcome) and six months after ECT (secondary outcome). RESULTS: The sample included 5,046 patients with unipolar (82%) or bipolar (18%) depression. At first ECT session, 741 patients (14.7%) had pulse width <0.5 ms, 3,639 (72.1%) had 0.5 ms, and 666 (13.2%) had >0.5 ms. There were no statistically significant associations between pulse width and HRQoL one week after ECT. In the subsample of patients with an EQ-5D index recorded six months after ECT (n = 730), patients receiving 0.5 ms had significantly lower HRQoL (-0.089) compared to <0.5 ms, after adjusting for demographic and clinical characteristics (p = .011). The corresponding analysis for EQ VAS did not show any statistically significant associations. CONCLUSION: No robust associations were observed between pulse width and HRQoL after ECT. On average, significant improvements in HRQoL were observed one week and six months after ECT for patients with unipolar or bipolar disease, independent of the pulse width received.

Severe asthma trajectories in adults: findings from the NORDSTAR cohort.

BACKGROUND: There is limited evidence on the pathways leading to severe asthma and we are presently unable to effectively predict the progression of the disease. We aimed to describe the longitudinal trajectories leading to severe asthma and to describe clinical events preceding disease progression in a nationwide population of patients with severe asthma. METHODS: We conducted an observational study based on Swedish data from the NORdic Dataset for aSThmA Research (NORDSTAR) research collaboration platform. We identified adult patients with severe asthma in 2018 according to the European Respiratory Society/American Thoracic Society definition and used latent class analysis to identify trajectories of asthma severity over a 10-year retrospective period from 2018. RESULTS: Among 169 128 asthma patients, we identified 4543 severe asthma patients. We identified four trajectories of severe asthma that were labelled as: trajectory 1 "consistently severe asthma" (n=389 (8.6%)), trajectory 2 "gradual onset severe asthma" (n=942 (20.7%)), trajectory 3 "intermittent severe asthma" (n=1685 (37.1%)) and trajectory 4 "sudden onset severe asthma" (n=1527 (33.6%)). "Consistently severe asthma" had a higher daily inhaled corticosteroid dose and more prevalent osteoporosis compared with the other trajectories. Patients with "gradual onset severe asthma" and "sudden onset severe asthma" developed type 2-related comorbidities concomitantly with development of severe asthma. In the latter group, this primarily occurred within 1-3 years preceding onset of severe asthma. CONCLUSIONS: Four distinct trajectories of severe asthma were identified illustrating different patterns of progression of asthma severity. This may eventually enable the development of better preventive management strategies in severe asthma.

Prevalence and management of severe asthma in the Nordic countries: findings from the NORDSTAR cohort.

Background: Real-life evidence on prevalence and management of severe asthma is limited. Nationwide population registries across the Nordic countries provide unique opportunities to describe prevalence and management patterns of severe asthma at population level. In nationwide register data from Sweden, Norway and Finland, we examined the prevalence of severe asthma and the proportion of severe asthma patients being managed in specialist care. Methods: This is a cross-sectional study based on the Nordic Dataset for Asthma Research (NORDSTAR) research collaboration platform. We identified patients with severe asthma in adults (aged ≥18 years) and in children (aged 6-17 years) in 2018 according to the European Respiratory Society/American Thoracic Society definition. Patients managed in specialist care were those with an asthma-related specialist outpatient contact (only available in Sweden and Finland). Results: Overall, we identified 598 242 patients with current asthma in Sweden, Norway and Finland in 2018. Among those, the prevalence of severe asthma was 3.5%, 5.4% and 5.2% in adults and 0.4%, 1.0%, and 0.3% in children in Sweden, Norway and Finland, respectively. In Sweden and Finland, 37% and 40% of adult patients with severe asthma and two or more exacerbations, respectively, were managed in specialist care; in children the numbers were 56% and 41%, respectively. Conclusion: In three Nordic countries, population-based nationwide data demonstrated similar prevalence of severe asthma. In children, severe asthma was a rare condition. Notably, a large proportion of patients with severe asthma were not managed by a respiratory specialist, suggesting the need for increased recognition of severe asthma in primary care.

Health-related quality of life in patients with lower limb amputation - an assessment of the measurement properties of EQ-5D-3L and EQ-5D-5L using data from the Swedish Amputation and Prosthetics Registry.

PURPOSE: To assess the measurement properties of EQ-5D-3L and EQ-5D-5L in patients with a major lower limb amputation (LLA). METHODS: This was a retrospective register-based study using data from the Swedish Amputation and Prosthetics Registry (SwedeAmp). Patients with a six-months follow-up (including either EQ-5D-3L or EQ-5D-5L) after a major unilateral LLA were included. The measurement properties of EQ-5D-3L and EQ-5D-5L were compared in terms of feasibility, response patterns, informativity, and convergent and known-group validity. RESULTS: The sample included 700 patients with below-knee amputation (76%), above-knee amputation (18%), or knee disarticulation (7%). Responses to EQ-5D-3L and -5L were similar regarding feasibility (98% completion rate) and the proportion reporting no problems (7% and 6%). Compared to EQ-5D-3L, EQ-5D-5L showed higher absolute and relative informativity in all dimensions, with the largest improvement in the mobility dimension. In the analyses of convergent validity, the EQ-5D-5L generally showed stronger correlations with disease-specific measures. Only EQ-5D-5L was able to discriminate between subgroups with different amputation levels. CONCLUSION: The findings support the use of EQ-5D-5L over EQ-5D-3L in patients with an LLA, mainly due to improved informativity and improved convergent and known-group validity.Implications for rehabilitationThe measurement properties of two EQ-5D versions, EQ-5D-3L and EQ-5D-5L, has so far not been evaluated in patients with a lower limb amputation (LLA)The results support the use of EQ-5D-5L over the use of EQ-5D-3L, mainly due to improved informativity and stronger correlations with disease-specific patient-reported outcome measuresThe five-level version of EQ-5D is recommended for future applications of EQ-5D in clinical outcome studies, health economic evaluations, and in the routine follow-up of patients with a major LLAIn the early rehabilitation process six months after an LLA, the majority of patients reported problems with mobility, pain/discomfort, and usual activities.

Reporting and valuing one's own health: a think aloud study using EQ-5D-5L, EQ VAS and a time trade-off question among patients with a chronic condition.

BACKGROUND: The EQ-5D-5L, the EQ VAS, and the time trade-off (TTO) are commonly used to report and value health. Still, there is a need to better understand how these questionnaires and methods are perceived by the respondents, as well as the thoughts and motives behind their responses. The aim of this study was to increase knowledge of how individuals think and reason when reporting and valuing their own current health, using EQ-5D-5L, EQ VAS, and an open-ended TTO question. METHODS: Twenty patients with type 1 diabetes participated in qualitative individual think aloud interviews in Stockholm, Sweden. Participants were asked to describe their thoughts when responding to three assessments. The interviews were transcribed verbatim and analyzed using thematic analysis. RESULTS: The analysis showed that participants conducted the assessments by contextualizing and interpreting instructions, relating the questions to their own health, using different recall periods and time perspectives, and using personal, interpersonal, or normative comparators. It was challenging to reduce the experience of everyday life into a response option, and the thoughts behind the responses differed between the assessments. Before deciding on what to include, participants thought of the purpose and context of the assessments. Current health or past experiences of health were applied in the EQ-5D descriptive system and in EQ VAS, while participants focused on the future in the TTO. Thoughts about the impact on others, personal goals, and expectations on future health were more clearly integrated in the TTO assessment. All participants considered the trade-off between life years and health. However, despite the use of different comparators, the concept of 'full health' was found difficult to imagine or relate to. CONCLUSIONS: This study provides insights as to how responses to the EQ-5D-5L, EQ VAS, and TTO assessments are complementary and where these assessments differ in adults with a chronic condition. The findings may contribute to a better understanding when interpreting the quantitative results and contribute to the literature pertaining to possible explanations for differences in health state values depending on the valuation method.

Collection and use of EQ-5D for follow-up, decision-making, and quality improvement in health care - the case of the Swedish National Quality Registries.

BACKGROUND: The Swedish National Quality Registries (NQRs) contain individual-level health care data for specific patient populations, or patients receiving specific interventions. Approximately 90% of the 105 Swedish NQRs include any patient-reported outcome measure, with EQ-5D being the most common. As there has been no general overview of EQ-5D data within the NQRs, this study fills a knowledge gap by reporting how the data are collected, presented, and used at different levels of the Swedish health care system. METHODS: All 46 NQRs with a license for the use of EQ-5D were included. Information was retrieved from the registries' annual reports or from websites, using a template that was subsequently sent to each registry for completion and confirmation. If considered necessary, the contact was followed-up with an interview, either in-person or over the telephone. The uses of EQ-5D were categorised as denoting usage for follow-up, decision-making, or quality improvement in Swedish health care. RESULTS: In total, 41 of the 46 licensed registries reported collection of EQ-5D data. EQ-5D is most commonly collected within registries related to the musculoskeletal system, but it has a wide application also in other disease areas. Thirty-six registries provide EQ-5D results to patients, clinicians, or other decision-makers. Twenty-two of the registries reported that EQ-5D data are being used for follow-up, decision-making or quality improvement. The registries most commonly reported use of data for assessing interventions, and in quality indicators to follow-up the quality of care at a national level. CONCLUSION: Collection and use of EQ-5D data vary across the Swedish NQRs, which may partly be accounted for by the different purposes of the registries. The provided examples of use illustrate how EQ-5D data can inform decisions at different levels of the health care system. However, there is potential for improving the use of EQ-5D data.

Whom should we ask? A systematic literature review of the arguments regarding the most accurate source of information for valuation of health states.

PURPOSE: To determine and critically evaluate the arguments in the published literature regarding the most accurate source of information for valuation of health states: values based on experienced health states (patient values) or values based on described health states (general public values).

Determinants of quality of life in pediatric- and adult-onset multiple sclerosis.

OBJECTIVE: To evaluate quality of life (QoL), measured by the EQ-5D, in adults with pediatric-onset multiple sclerosis (POMS) or adult-onset multiple sclerosis (AOMS) and explore determinants of QoL in both groups. METHODS: Data were collected from the nationwide Swedish multiple sclerosis (MS) registry. Demographic characteristics, EQ-5D-3 level, Multiple Sclerosis Impact Scale (MSIS-29) score, Expanded Disability Status Scale (EDSS) score, Symbol Digit Modalities Test score, relapses, and disease-modifying therapy (DMT) exposure were collected on an approximately annual basis (2011-2019). Patients with definite MS with ≥2 EQ-5D measurements collected between ages 18 and 50 were included. The principal outcome was the EQ-5D visual analogue scale (EQ-VAS) score. Linear mixed models compared all available EQ-VAS scores between patients with POMS and patients with AOMS and determinants of EQ-VAS among patients with POMS and patients with AOMS (assessed separately). RESULTS: A total of 5,094 persons met inclusion criteria: 354 (6.9%) had POMS. A total of 21,357 unique EQ-5D scores were recorded. Most participants were female (70.0%) with a relapsing-onset disease course (98.1%). There was no difference in EQ-VAS scores between patients with POMS and patients with AOMS following adjustment for confounders (ß-coefficient for patients with POMS vs patients with AOMS [reference]: 0.99; 95% confidence interval -0.89 to 2.87). Experiencing a relapse, severe neurologic disability (EDSS ≥6.0 vs <3.0), and higher MSIS-29 psychological score were consistently associated with lower QoL, while higher information processing efficiency and exposure to first-line DMTs were associated with higher QoL scores in both groups. CONCLUSIONS: There were no differences in QoL between patients with POMS and patients with AOMS in adulthood. Findings provide support for a focus on reducing neurologic disability and improving psychological status as approaches to potentially improve the QoL of persons with MS.

Costs of illness of multiple sclerosis in Sweden: a population-based register study of people of working age.

BACKGROUND: Multiple sclerosis (MS) causes work disability and healthcare resource use, but little is known about the distribution of the associated costs to society. OBJECTIVES: We estimated the cost of illness (COI) of working-aged individuals with MS, from the societal perspective, overall and in different groups. METHODS: A population-based study was conducted, using data linked from several nationwide registers, on 14,077 individuals with MS, aged 20-64 years and living in Sweden. Prevalence-based direct and indirect costs in 2010 were calculated, including costs for prescription drug use, specialized healthcare, sick leave, and disability pension. RESULTS: The estimated COI of all the MS patients were SEK 3950 million, of which 75% were indirect costs. MS was the main diagnosis for resource use, causing 38% of healthcare costs and 67% of indirect costs. The distribution of costs was skewed, in which less than 25% of the patients accounted for half the total COI. CONCLUSIONS: Indirect costs contributed to approximately 75% of the estimated overall COI of MS patients of working age in Sweden. MS was the main diagnosis for more than half of the estimated COI in this patient group. Further studies are needed to gain knowledge on development of costs over time during the MS disease course.

The External Validity of Mapping MSIS-29 on EQ-5D Among Individuals With Multiple Sclerosis in Sweden.

Background: Mapping can be performed to predict utility values from condition-specific measures when preference-based measures are absent. A previously developed algorithm that predicts EQ-5D-3L index values from the Multiple Sclerosis Impact Scale (MSIS-29) has not yet been externally validated. Aim: To examine the external validity of a previously developed mapping algorithm by testing the accuracy of predicting EQ-5D-3L index values from MSIS-29 among multiple sclerosis (MS) patients in Sweden. Methods: Cross-sectional individual-level data were collected from population-based Swedish registers between 2011 and 2014. Health-related quality of life was assessed through MSIS-29 and EQ-5D-3L at one point in time among 767 individuals with known disability level of MS. A previously developed mapping algorithm was applied to predict EQ-5D index values from MSIS-29 items, and the predictive accuracy was assessed through mean absolute error and root mean square error. Results: When applying the algorithm, the predicted mean EQ-5D-3L index value was 0.77 compared to the observed mean index value of 0.75. Prediction error was higher for individuals reporting EQ-5D values <0.5 compared to individuals reporting EQ-5D values ≥0.5. Mean absolute error (0.12) and root mean square error (0.18) were smaller or equal to the prediction errors found in the original mapping study. Conclusion: The mapping algorithm had similar predictive accuracy in the two independent samples although results showed that the highest predictive performance was found in groups with better health. Varied predictive accuracy in subgroups is consistent with previous studies and strategies to deal with this are warranted.

Cost of Illness of Multiple Sclerosis - A Systematic Review.

BACKGROUND: Cost-of-illness (COI) studies of Multiple Sclerosis (MS) are vital components for describing the economic burden of MS, and are frequently used in model studies of interventions of MS. We conducted a systematic review of studies estimating the COI of MS, to compare costs between studies and examine cost drivers, emphasizing generalizability and methodological choices. MATERIAL AND METHOD: A literature search on studies published in English on COI of MS was performed in PubMed for the period January 1969 to January 2014, resulting in 1,326 publications. A mapping of studies using a bottom-up approach or top-down approach, respectively, was conducted for the 48 studies assessed as relevant. In a second analysis, the cost estimates were compared between the 29 studies that used a societal perspective on costs, human capital approach for indirect costs, presenting number of patients included, time-period studied, and year of price level used. RESULTS: The mapping showed that bottom-up studies and prevalence approaches were most common. The cost ratios between different severity levels within studies were relatively stable, to the ratio of 1 to 2 to 3 for disability level categories. Drugs were the main cost drivers for MS-patients with low disease severity, representing 29% to 82% of all costs in this patient group, while the main cost components for groups with more advanced MS symptoms were production losses due to MS and informal care, together representing 17% to 67% of costs in those groups. CONCLUSION: The bottom-up method and prevalence approach dominated in studies of COI of MS. Our findings show that there are difficulties in comparing absolute costs across studies, nevertheless, the relative costs expressed as cost ratios, comparing different severity levels, showed higher resemblance. Costs of drugs were main cost drivers for less severe MS and informal care and production losses for the most severe MS.