How is alcohol consumption and heavy episodic drinking spread across different types of drinking occasion in Great Britain: An event-level latent class analysis.

BACKGROUND: This paper aimed to (i) update a previous typology of British alcohol drinking occasions using a more recent and expanded dataset and revised modelling procedure, and (ii) estimate the average consumption level, prevalence of heavy drinking, and distribution of all alcohol consumption and heavy drinking within and across occasion types. METHODS: The paper uses a cross-sectional latent class analysis of event-level diary data that includes characteristics of 43,089 drinking occasions in 2019 reported by 17,821 adult drinkers in Great Britain. The latent class indicators are characteristics of off-trade only (e.g. home), on-trade only (e.g. bar) and mixed trade (e.g. home and bar) drinking occasions. These describe companions, locations, purpose, motivation, accompanying activities, timings, consumption volume in units (1 UK unit = 8g ethanol) and beverages consumed. RESULTS: The analysis identified four off-trade only, eight on-trade only and three mixed-trade occasion types (i.e. latent classes). Mean consumption per occasion varied between 4.4 units in Family meals to 17.7 units in Big nights out with pre-loading. It exceeded ten units in all mixed-trade occasion types and in Off-trade get togethers, Big nights out and Male friends at the pub. Three off-trade types accounted for 50.8% of all alcohol consumed and 51.8% of heavy drinking occasions: Quiet drink at home alone, Evening at home with partner and Off-trade get togethers. For thirteen out of fifteen occasion types, more than 25% of occasions involved heavy drinking. Conversely, 41.7% of Big nights out and 16.4% of Big nights out with preloading were not heavy drinking occasions. CONCLUSIONS: Alcohol consumption varies substantially across and within fifteen types of drinking occasion in Great Britain. Heavy drinking is common in most occasion types. However, moderate drinking is also common in occasion types often characterised as heavy drinking practices. Mixed-trade drinking occasions are particularly likely to involve heavy drinking.

Change and stability in British drinking practices and culture between 2009 and 2019: A longitudinal latent class analysis of drinking occasions.

Rationale: Theories of practice can support understanding of health-related behaviours, but few studies use quantitative methods to understand time-trends in practices. This paper describes changes in the prevalence and performance of alcohol drinking practices in Great Britain between 2009 and 2019. Methods: Latent class analyses of annual cross-sectional data collected between 2009 and 2019. The dataset come from a one-week retrospective diary survey of adults resident in Great Britain. It contains 604,578 drinking occasions reported by 213,470 adults (18+) who consumed alcohol in the diary-week. The measures describe occasion characteristics including companions, location, motivation, timings, accompanying activities and alcohol consumed. We estimate separate latent class models for each year and for off-trade only (e.g. home), on-trade only (e.g. bar) and mixed-trade occasions. Results: We identified fifteen practices; four off-trade only, eight on-trade only and three mixed-trade. The prevalence of practices was largely stable over time except for shifts away from drinking with a partner and towards drinking alone in the off-trade, and shifts away from Big nights out and towards other forms of heavy drinking in the on-trade. We identified five key trends in the performance of practices: (i) spirits increasingly replaced wine as the main beverage consumed in occasions; (ii) home-drinking moved away from routinised wine-drinking with meals on weekdays and towards spirits-drinking on weekends; (iii) the Male friends at the pub practice changed less than other pub-drinking practices; (iv) Big nights out started later, often in nightclubs, and involved less pub-drinking or heavy drinking and (v) the meal-based and Going out with partner practice formats showed few changes over time. Conclusion: Key recent trends in British drinking practices include a decline in routinised wine-drinking at home, a transformation of big nights out and a mixture of stability and change in pub- and meal-based practices.

The trajectory of a range of commonly captured symptoms with standard care in people with kidney failure receiving haemodialysis: consideration for clinical trial design.

BACKGROUND: Despite the recognized high symptom prevalence in haemodialysis population, how these symptoms change over time and its implications for clinical practice and research is poorly understood. METHODS: Prevalent haemodialysis patients in the SHAREHD trial reported 17 POS-S Renal symptoms (none, mild, moderate, severe and overwhelming) at baseline, 6, 12 and 18 months. To assess the prevalence change at population level in people reporting moderate or worse symptoms at baseline, the absolute change in prevalence was estimated using multi-level mixed effects probit regression adjusting for age, sex, time on haemodialysis and Charlson Comorbidity Score. To assess changes at individual level, the proportion of people changing their symptom score every 6 months was estimated. RESULTS: Five hundred fifty-two participants completed 1725 questionnaires at four timepoints. Across all 17 symptoms with moderate or worse symptom severity at baseline, the majority of the change in symptom prevalence at population level occurred in the 'severe' category. The absolute improvement in prevalence of the 'severe' category was ≤ 20% over 18 months in eleven of the seventeen symptoms despite a large degree of relatively balanced movement of individuals in and out of severe category every six months. Examples include depression, skin changes and drowsiness, which had larger proportion (75-80%) moving in and out of severe category each 6 months period but < 5% difference between movement in and out of severe category resulting in relatively static prevalence over time. Meanwhile, larger changes in prevalence of > 20% were observed in six symptoms, driven by a 9 to 18% difference between movement in and movement out of severe category. All symptoms had > 50% of people in severe group changing severity within 6 months. CONCLUSIONS: Changes in the severity of existing symptoms under standard care were frequent, often occurring within six months. Certain symptoms exhibited clinically meaningful shifts at both the population and individual levels. This highlighted the need to consider improvements in symptom severity when determining sample size and statistical power for trials. By accounting for potential symptom improvements with routine care, researchers can design trials capable of robustly detecting genuine treatment effects, distinguishing them from spontaneous changes associated with standard haemodialysis.

Relationship Between Standardized Measures of Chronic Kidney Disease-associated Pruritus Intensity and Health-related Quality of Life Measured with the EQ-5D Questionnaire: A Mapping Study.

Chronic kidney disease-associated pruritus is linked with decreased health-related quality of life assessed using disease-specific instruments. The extent to which worsening pruritus reduces generic quality of life assessed using the EQ-5D instrument is unknown. Prevalent kidney failure patients receiving in-centre haemodialysis from 5 centres completed the EQ-5D-5L quality of life measure, worst Itching Intensity Numerical Rating Scale and 5-D itch pruritus instruments. Latent class models were used to identify clusters of patients with similarly affected body parts, and mixture models were used to map the pruritus measures to the EQ-5D. Data on 487 respondents were obtained. Latent class analysis identified 3 groups of patients who had progressively worsening severity and an increasing number of body parts affected. Although the worst itching intensity numerical rating scale and 5-D itch instruments correlated with each other, only the latter had a strong relationship with EQ-5D. When controlling for age, sex, diabetes and years receiving dialysis, the meanpredicted EQ-5D utility (1: perfect health, 0: dead) decreased progressively from 0.69 to 0.41. These findings suggest that pruritus instruments that include domains capturing how the individual is physically, mentally and socially affected by their pruritus, in addition to severity, more closely approximate the EQ-5D generic quality of life measure.

Does EQ-5D Tell the Whole Story? Statistical Methods for Comparing the Thematic Coverage of Clinical and Generic Outcome Measures, With Application to Breast Cancer.

OBJECTIVES: This study aimed to develop the following: (1) methods for assessing claims in any specific application that a generic outcome measure, such as EQ-5D is deficient in its coverage of 1 or more specified domains, and (2) a simple method of judging whether any such deficiency is likely to be quantitatively important enough to call into question evaluations based on the generic instrument. Also to demonstrate the applicability of the methods in the important area of breast cancer. METHODS: The methodology requires a data set with observations from a generic instrument (eg, EQ-5D) and also a more comprehensive clinical instrument (eg, FACT-B [Functional Assessment of Cancer Therapy - Breast]). A standardized 3-component statistical analysis is proposed for investigating the claim that the generic measure inadequately captures some specified dimension covered by the latter instrument. A theoretically based upper bound on the bias induced by deficient coverage is derived based on the assumption that the designers of the (k-dimensional) generic instrument did succeed in identifying the k most important domains. RESULTS: Data from the MARIANNE breast cancer trial were analyzed and results suggested that impacts on personal appearance and relationships may be inadequately represented by EQ-5D. Nevertheless, the indications are that the bias in quality-adjusted life-year differences from deficient coverage by EQ-5D is likely to be modest. CONCLUSIONS: The methodology offers a systematic approach to determining whether there is clear evidence consistent with any claim that a generic outcome measure such as EQ-5D misses an important specific domain. The approach is readily implementable using data sets that are available in many randomized controlled trials.

Catalogues of EQ-5D-3L Health-Related Quality of Life Scores for 199 Chronic Conditions and Health Risks for Use in the UK and the USA.

BACKGROUND: Health-related quality of life (HRQoL) measures are essential in economic evaluation, but sometimes primary sources are unavailable, and information from secondary sources is required. Existing HRQoL UK/US catalogues are based on earlier diagnosis classification systems, amongst other issues. A recently published Danish catalogue merged EQ-5D-3L data from national health surveys with national registers containing patient information on ICD-10 diagnoses, healthcare activities and socio-demographics. AIMS: To provide (1) UK/US EQ-5D-3L-based HRQoL utility population catalogues for 199 chronic conditions on the basis of ICD-10 codes and health risks and (2) regression models controlling for age, sex, comorbidities and health risks to enable predictions in other populations. METHODS: UK and US EQ-5D-3L value sets were applied to the EQ-5D-3L responses of the Danish dataset and modelled using adjusted limited dependent variable mixture models (ALDVMMs). RESULTS: Unadjusted mean utilities, percentiles and adjusted disutilities based on two ALDVMMs with different control variables were provided for both countries. Diseases from groups M, G, and F consistently had the smallest utilities and the largest negative disutilities: fibromyalgia (M797), sclerosis (G35), rheumatism (M790), dorsalgia (M54), cerebral palsy (G80-G83), post-traumatic stress disorder (F431), dementia (F00-2), and depression (F32, etc.). Risk factors, including stress, loneliness, and BMI30+, were also associated with lower HRQoL. CONCLUSIONS: This study provides comprehensive catalogues of UK/US EQ-5D-3L HRQoL utilities. Results are relevant in cost-effectiveness analysis, for NICE submissions, and for comparing and identifying facets of disease burden.

Enabling QALY estimation in mental health trials and care settings: mapping from the PHQ-9 and GAD-7 to the ReQoL-UI or EQ-5D-5L using mixture models.

PURPOSE: Patient-reported outcome measures (PROMs) are commonly collected in trials and some care settings, but preference-based PROMs required for economic evaluation are often missing. For these situations, mapping models are needed to predict preference-based (aka utility) scores. Our objective is to develop a series of mapping models to predict preference-based scores from two mental health PROMs: Patient Health Questionnaire-9 (PHQ-9; depression) and Generalised Anxiety Questionnaire-7 (GAD-7; anxiety). We focus on preference-based scores for the more physical-health-focussed EQ-5D (five-level England and US value set, and three-level UK cross-walk) and more mental-health-focussed Recovering Quality-of-Life Utility Index (ReQoL-UI). METHODS: We used trial data from the Improving Access to Psychological Therapies (IAPT) mental health services (now called NHS Talking Therapies), England, with a focus on people with depression and/or anxiety caseness. We estimated adjusted limited dependent variable or beta mixture models (ALDVMMs or Betamix, respectively) using GAD-7, PHQ-9, age, and sex as covariates. We followed ISPOR mapping guidance, including assessing model fit using statistical and graphical techniques. RESULTS: Over six data collection time-points between baseline and 12-months, 1340 observed values (N ≤ 353) were available for analysis. The best fitting ALDVMMs had 4-components with covariates of PHQ-9, GAD-7, sex, and age; age was not a probability variable for the final ReQoL-UI mapping model. Betamix had practical benefits over ALDVMMs only when mapping to the US value set. CONCLUSION: Our mapping functions can predict EQ-5D-5L or ReQoL-UI related utility scores for QALY estimation as a function of variables routinely collected within mental health services or trials, such as the PHQ-9 and/or GAD-7.

Situated drinking: The association between eating and alcohol consumption in Great Britain.

Aims: This paper examines the co-occurrence of drinking alcohol and eating in Great Britain. Applying a practice-theoretical framework, it attends primarily to the nature and characteristics of events - to social situations. It asks whether drinking events involving food are significantly different from those without, whether differences are the same at home as on commercial public premises, and whether differences are the same for men and women. The focus is especially on episodes of drinking with meals at home, an infrequently explored context for a substantial proportion of contemporary alcohol consumption. Data: Employing a secondary analysis of commercial data about the British population in 2016, we examine reports of 47,645 drinking events, on commercial premises and at other locations, to explore how eating food and consumption of alcoholic beverages affect one another. Three types of event are compared - drinking with meals, with snacks, and without any food. Variables describing situations include group size and composition, temporal and spatial parameters, beverages, purposes, and simultaneous activities. Basic sociodemographic characteristics of respondents are also examined, with a special focus on the effects of gender. Results: Behaviours differ between settings. The presence of food at a drinking episode is associated with different patterns of participation, orientations, and quantities and types of beverage consumed. Gender, age, and class differences are apparent. Conclusions: Patterns of alcohol consumption are significantly affected by the accompaniment of food. This is a much-neglected topic that would benefit from further comparative and time series studies to determine the consequences for behaviour and intervention.

Guidance on the use of complex systems models for economic evaluations of public health interventions.

To help health economic modelers respond to demands for greater use of complex systems models in public health. To propose identifiable features of such models and support researchers to plan public health modeling projects using these models. A working group of experts in complex systems modeling and economic evaluation was brought together to develop and jointly write guidance for the use of complex systems models for health economic analysis. The content of workshops was informed by a scoping review. A public health complex systems model for economic evaluation is defined as a quantitative, dynamic, non-linear model that incorporates feedback and interactions among model elements, in order to capture emergent outcomes and estimate health, economic and potentially other consequences to inform public policies. The guidance covers: when complex systems modeling is needed; principles for designing a complex systems model; and how to choose an appropriate modeling technique. This paper provides a definition to identify and characterize complex systems models for economic evaluations and proposes guidance on key aspects of the process for health economics analysis. This document will support the development of complex systems models, with impact on public health systems policy and decision making.

Cost Effectiveness of Difelikefalin Compared to Standard Care for Treating Chronic Kidney Disease Associated Pruritus (CKD-aP) in People with Kidney Failure Receiving Haemodialysis.

BACKGROUND: Chronic kidney disease-associated pruritus (CKD-aP) is associated with an increased risk of depression, poor sleep and reduced health-related quality of life. Two phase III studies (KALM-1 and KALM-2) of difelikefalin showed reduced CKD-aP severity and improved itch-related health-related quality of life in patients with moderate and severe CKD-aP receiving haemodialysis for kidney failure. OBJECTIVE: We aimed to estimate the cost effectiveness of difelikefalin for patients with CKD-aP receiving haemodialysis for kidney failure compared to standard care from a UK National Health Service perspective. METHODS: A cohort model was developed with four health states representing levels of pruritus intensity over time, based on the KALM trials augmented with longer term CKD-aP severity data from another haemodialysis trial (SHAREHD) for standard care. Utilities were estimated from a mapping study of 5-D Itch to EQ-5D-5L in 487 patients receiving haemodialysis, costs were estimated based on resource use alongside the SHAREHD and 2018 unit costs, and inflated to 2021 costs. Costs and quality-adjusted life-years were discounted at 3.5% per annum. A de novo economic model was developed in Microsoft Excel with scenario analyses performed using a range of assumptions. RESULTS: In the base-case analysis over a time horizon of 64 weeks, using a placeholder cost of £75 per 28-days for difelikefalin, the incremental cost-effectiveness ratio of difelikefalin compared with standard care was £19,558/quality-adjusted life-year (QALY). Scenario analyses resulted in incremental cost-effectiveness ratios that ranged from £10,154/QALY (severe only) to £16,957/QALY (5-year horizon) for difelikefalin compared to standard care. Probabilistic sensitivity analyses suggested difelikefalin has a 48.6% probability of being cost effective at a threshold of £20,000/QALY and a 57.2% probability of being cost effective at a threshold of £30,000/QALY. CONCLUSIONS: The cost effectiveness of difelikefalin in a range of scenarios could make it an important pharmacotherapy to address the high burden of disease and unmet need for treatments associated with CKD-aP in the UK.

A model-based economic analysis of the CFHealthHub intervention to support adherence to inhaled medications for people with cystic fibrosis in the UK.

BACKGROUND: Adherence to preventative inhaled therapies in people with cystic fibrosis (CF) is low, resulting in potentially avoidable health losses and the need for costly rescue therapies. OBJECTIVES: To estimate the cost-effectiveness of the CFHealthHub (CFHH) intervention to support adherence to inhaled medications. METHODS: A state transition model was developed to assess the cost-effectiveness of the CFHH intervention versus usual care from the perspective of the UK National Health Service and Personal Social Services over a lifetime horizon. Costs and health outcomes were discounted at a rate of 3.5 percent per annum. Costs were valued at 2021/22 prices. The model structure includes health states defined by survival status, level of lung function, and transplant history. Treatment effects were modeled by changing the probabilities of transitioning between lung function states and reducing exacerbation rates. Model parameters were informed by the CFHH trial, CF Registry data, routine cost databases, literature, and expert opinion. Deterministic and probabilistic sensitivity analyses were undertaken to assess uncertainty. RESULTS: The CFHH intervention is expected to generate additional health gains and cost savings compared with usual care. Assuming that it is delivered for 10 years, the CFHH intervention is expected to generate 0.17 additional quality-adjusted life years and cost savings of GBP 1,600 (EUR 1,662) per patient. CONCLUSIONS: The CFHH intervention is expected to dominate usual care, irrespective of the duration over which the intervention is delivered. The modeled benefits and cost savings are smaller than initially expected and are sensitive to relative treatment effects on lung function.

Estimating the Relationship Between EQ-5D-5L and EQ-5D-3L: Results from a UK Population Study.

OBJECTIVES: The aim of this study was to estimate the relationship between EQ-5D-3L and EQ-5D-5L, in both directions, using a single model. METHODS: An online survey containing both variants of EQ-5D, with randomised ordering, was administered to a large UK sample in 2020. A joint statistical model of the ten EQ-5D responses (five at 5L, five at 3L), using a multi-equation ordinal regression framework was estimated. The joint model ensures mappings in either direction are fully consistent with the information in the sample and satisfy Bayes' rule. Three extensions enhance model flexibility: a copula specification allows differing degrees of correlation between the 3L and 5L responses at the upper and lower extremes of health; a normal mixture residual distribution gives flexibility in the distributional form of responses; and a common factor captures correlations in responses across the five dimensions. RESULTS: Almost 50,000 responses were received. Thirty-five percent of respondents reported an existing medical condition. Ninety percent of possible 3L and 43% of possible 5L health states were observed. The preferred model specification includes age, sex and the responses to the EQ-5D instrument. Close alignment to the observed data was observed both in within-sample and out-of-sample comparisons. CONCLUSION: The results from this study provide a means of translating evidence to or from EQ-5D-3L to or from 5L based on a large-scale UK population survey with randomised ordering. Mapping can be performed either using descriptive system responses, individual utility scores or summary statistics.

Strategies to cut down drinking, alcohol consumption, and usual drinking frequency: Evidence from a British online market research survey.

BACKGROUND: Relatively little is known about how risky drinkers attempt to moderate their drinking in the absence of specialist support. The broader literature has identified multiple potential strategies that people use to cope with temptation when trying to control health-risk behaviours. This study aims to identify types of alcohol moderation strategies used by British adults, and to explore how concurrent alcohol consumption differs across moderation strategies, focusing on the important role of usual drinking frequency. METHODS: We use a continuous repeat cross-sectional survey and one-week drinking diary collected by the market research company Kantar; these provide detailed information on alcohol consumption during a diary week and on how individuals try to moderate alcohol use for 49,204 British adults trying to reduce their drinking from 2013 to 2019. We use Latent Class Analysis (LCA) to identify predominant types of moderation strategies. With a three-step method, we also analyse the associations between adopting different moderation strategies, measures of frequency and intensity of drinking events, and usual drinking frequency. RESULTS: We found evidence of four alcohol moderation strategies: 29% of individuals use a pre-commitment-focused strategy (having fewer drinking occasions), two set of individuals adopt self-control strategies within drinking occasions (specifically 28% select smaller drinks and 5% have fewer drinks), while 38% adopt a mixed strategy that involves all three. Those using commitment tend to have a higher average consumption per drinking occasion but lower overall weekly consumption compared to those using self-control. Weekly alcohol consumption is particularly high among individuals who are usual everyday drinkers and use self-control to cut down drinking. CONCLUSION: This analysis provides a useful platform for further work, using prospective or intervention designs, to test the relative effectiveness of different moderation strategies for alcohol consumers who want to reduce their alcohol consumption.

Mapping between EQ-5D-3L and EQ-5D-5L: A survey experiment on the validity of multi-instrument data.

EQ-5D is a 5-item questionnaire instrument designed to measure health-related quality of life. It is extremely important, since it is used to measure health benefits in many studies providing evidence for reimbursement decisions by the National Institute for Health and Care Excellence in England and similar policy bodies in other countries. EQ-5D has been redesigned in a more detailed form (EQ-5D-5L), but much existing cost-effectiveness evidence is based on the older version (EQ-5D-3L). Statistical mapping from one version to another is widely used, exploiting data from multi-instrument surveys incorporating both variants. However, little is known about the robustness of data from such multi-instrument surveys. We design a randomized experiment to investigate whether inclusion of both versions at different stages in a single interview gives a reliable picture of the relationship between health measures from the two instruments and embed it in individual interviews from the UK Understanding Society household panel. We find that sequencing of the two versions of EQ-5D within an interview has a significant impact not only on the resulting data but also on the estimated mapping models. We illustrate the non-negligible effects in two real-world cost-effectiveness examples and discuss the implications for future multi-instrument survey design.

The relationship between chronic kidney disease-associated pruritus and health-related quality of life: a systematic review.

BACKGROUND: Chronic kidney disease-associated pruritus (CKD-aP) is a common and burdensome condition for end-stage kidney disease (ESKD) patients, especially those receiving haemodialysis. High-quality evidence of the relationship between CKD-aP and health-related quality of life (HRQoL) can therefore inform clinicians and policymakers about treatment choice and reimbursement decisions. METHODS: A systematic literature review and narrative synthesis stratified by study design and HRQoL instrument was conducted to evaluate in adult ESKD patients receiving in-centre haemodialysis the relationship between CKD-aP and HRQoL assessed using multi dimensional generic or condition-specific preference- or non-preference-based measures. MEDLINE, Embase, Web of Science, BIOSIS Citation Index, Cochrane Library and PsycINFO from inception to March 2020 were searched, with two reviewers extracting data independently. RESULTS: Searches identified 2684 unique records, of which 20 papers relating to 18 unique studies [5 randomised controlled trials (RCTs) and 13 observational studies] were included. HRQoL was assessed using four generic and eight disease-specific measures. The impact of CKD-aP was assessed by comparison of means, linear regression and correlation. Observational studies employing comprehensively adjusted multivariable linear regression largely found associations between CKD-aP severities and HRQoL. Analyses suggest this relationship is partially mediated by the sleep disturbance caused by CKD-aP. RCTs showing improvements in CKD-aP severity were associated with clinically meaningful improvements in HRQoL. Compared with generic measures, disease-specific HRQoL instruments reported greater changes with reduced CKD-aP. Heterogeneity in study design and reporting precluded meta-analysis. CONCLUSIONS: CKD-aP severity was found to be associated with a worsening of HRQoL in the majority of observational and RCT studies. Parallel improvements in CKD-aP and HRQoL with interventions may support their use (PROSPERO registration 175035).

Measuring quality of life of patients with axial spondyloarthritis for economic evaluation.

OBJECTIVES: To estimate the relationship between EQ5D (three levels, UK version) and the Ankylosing Spondylitis Disease Activity Score (ASDAS) for use in the economic evaluation of health technologies for people with axial spondyloarthritis (axSpA). To compare against the relationship with the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI). METHODS: An electronic, prospective, Portuguese, nationwide, rheumatic disease register (Reuma.pt) provided data on 1140 patients (5483 observations) with a confirmed diagnosis of axSpA. We estimated models of EQ5D as a function of ASDAS, alone or in combination with measures of functional impairment, using bespoke mixture models which reflect the complex distributional features of EQ5D. The SPondyloArthritis Caught Early cohort provided data from 344 patients (1405 observations) in four European countries and was used for validation. A previously published model of BASDAI/Bath Ankylosing Spondylitis Functional Index (BASFI) was also used to generate predicted EQ5D scores and model performance compared. RESULTS: A non-linear relationship exists between EQ5D from ASDAS. The final model included ASDAS, ASDAS squared, age and age squared and demonstrated close fit in both datasets except where data were sparse for patients with very high levels of disease activity (ASDAS >4). This finding held in the validation dataset. Models that included BASFI improved model fit. The ASDAS based models fit the data marginally less well than models using BASDAI. CONCLUSIONS: Mapping models linking ASDAS to EQ5D allow results from clinical studies to be used in economic evaluation of health technologies with confidence. There is some loss of information compared with BASDAI but this has only a marginal impact.

Understanding long-term trends in smoking in England, 1972-2019: an age-period-cohort approach.

BACKGROUND AND AIMS: Smoking prevalence has been falling in England for more than 50 years, but remains a prevalent and major public health problem. This study used an age-period-cohort (APC) approach to measure lifecycle, historical and generational patterns of individual smoking behaviour. DESIGN: APC analysis of repeated cross-sectional smoking prevalence data obtained from three nationally representative surveys. SETTING: England (1972-2019). PARTICIPANTS: Individuals aged 18-90 years. MEASUREMENTS: We studied relative odds of current smoking in relation to age in single years from 18 to 90, 24 groups of 2-year survey periods (1972-73 to 2018-19) and 20 groups of 5-year birth cohorts (1907-11 to 1997-2001). Age and period rates were studied for two groups of birth cohorts: those aged 18-25 years and those aged over 25 years. FINDINGS: Relative to age 18, the odds of current smoking increased with age until approximately age 25 [odds ratio (OR) = 1.48, 95% confidence interval (CI) = 1.41-1.56] and then decreased progressively to age 90 (OR = 0.06, 95% CI = 0.04-0.08). They also decreased almost linearly with period relative to 1972-73 (for 2018-19: OR = 0.30, 95% CI = 0.26-0.34) and with birth cohort relative to 1902-06, with the largest decreased observed for birth cohort 1992-96 (OR = 0.44, 95% CI = 0.35-0.46) and 1997-2001 (OR = 0.35, 95% CI = 0.74-0.88). Smoking declined in the 18-25 age group by an average of 7% over successive 2-year periods and by an average of 5% in those aged over 25. CONCLUSIONS: Smoking in England appears to have declined over recent decades mainly as a result of reduced smoking uptake before age 25, and to a lesser extent to smoking cessation after age 25.

Mapping the EORTC QLQ-C30 to EQ-5D-3L in patients with breast cancer.

BACKGROUND: The types of outcomes measured collected in clinical studies and those required for cost-effectiveness analysis often differ. Decision makers routinely use quality adjusted life years (QALYs) to compare the benefits and costs of treatments across different diseases and treatments using a common metric. QALYs can be calculated using preference-based measures (PBMs) such as EQ-5D-3L, but clinical studies often focus on objective clinician or laboratory measured outcomes and non-preference-based patient outcomes, such as QLQ-C30. We model the relationship between the generic, preference-based EQ-5D-3L and the cancer specific quality of life questionnaire, QLQ-C30 in patients with breast cancer. This will result in a mapping that allows users to convert QLQ-C30 scores into EQ-5D-3L scores for the purposes of cost-effectiveness analysis or economic evaluation. METHODS: We use data from a randomized trial of 602 patients with HER2-positive advanced breast cancer provided 3766 EQ-5D-3L observations. Direct mapping using adjusted, limited dependent variable mixture models (ALDVMM) is compared to a random effects linear regression and indirect mapping using seemingly unrelated ordered probit models. EQ-5D-3L was estimated as a function of the summary scales of the QLQ-C30 and other patient characteristics. RESULTS: A four component mixture model outperformed other models in terms of summary fit statistics. A close fit to the observed data was observed across the range of disease severity. Simulated data from the model closely aligned to the original data and showed that mapping did not significantly underestimate uncertainty. In the simulated data, 22.15% were equal to 1 compared to 21.93% in the original data. Variance was 0.0628 in the simulated data versus 0.0693 in the original data. The preferred mapping is provided in Excel and Stata files for the ease of users. CONCLUSION: A four component adjusted mixture model provides reliable, non-biased estimates of EQ-5D-3L from the QLQ-C30, to link clinical studies to economic evaluation of health technologies for breast cancer. This work adds to a growing body of literature demonstrating the appropriateness of mixture model based approaches in mapping.

Mapping From Visual Acuity to EQ-5D, EQ-5D With Vision Bolt-On, and VFQ-UI in Patients With Macular Edema in the LEAVO Trial.

OBJECTIVES: Mappings to convert clinical measures to preference-based measures of health such as the EQ-5D-3L are sometimes required in cost-utility analyses. We developed mappings to convert best-corrected visual acuity (BCVA) to the EQ-5D-3L, the EQ-5D-3L with a vision bolt-on (EQ-5D V), and the Visual Functioning Questionnaire-Utility Index (VFQ-UI) in patients with macular edema caused by central retinal vein occlusion. METHODS: We used data from Lucentis, Eylea, Avastin in vein occlusion (LEAVO), which is a phase-3 randomized controlled trial comparing ranibizumab, aflibercept, and bevacizumab in 463 patients with observations at 6 time points. We estimated adjusted limited dependent variable mixture models consisting of 1 to 4 distributions (components) using BCVA in each eye, age, and sex to predict utility within the components and BCVA as a determinant of component membership. We compared model fit using mean error, mean absolute error, root mean square error, Akaike information criteria, Bayesian information criteria, and visual inspection of mean predicted and observed utilities and cumulative distribution functions. RESULTS: Mean utility scores were 0.82 for the EQ-5D-3L, 0.79 for the EQ-5D V, and 0.88 for the VFQ-UI. The best-fitting models for the EQ-5D and EQ-5D V had 2 components (with means of approximately 0.44 and 0.85), and the best-fitting model for VFQ-UI had 3 components (with means of approximately 0.95, 0.74, and 0.90). CONCLUSIONS: Models with multiple components better predict utility than those with single components. This article provides a valuable addition to the literature, in which previous mappings in visual acuity have been limited to linear regressions, resulting in unfounded assumptions about the distribution of the dependent variable.