High-Efficiency Particulate Air Filters for Preventing Wildfire-related Asthma Complications: A Cost-Effectiveness Study.

Rationale: Air pollution caused by wildfire smoke is linked to adverse health outcomes, especially for people living with asthma. Objectives: To evaluate whether government rebates for high-efficiency particulate air (HEPA) filters, which reduce concentrations of smoke particles indoors, are cost effective in managing asthma and preventing exacerbations in British Columbia (BC), Canada. Methods: We used a Markov model to analyze health states for asthma control, exacerbation severity, and death over a retrospective time horizon of 5 years (2018-2022). Concentrations of wildfire smoke-derived particulate matter with an aerodynamic diameter ⩽2.5 µm (PM2.5) from the Canadian Optimized Statistical Smoke Exposure Model and relevant literature informed the model. The base-case analysis assumed continuous use of a HEPA filter. Costs and quality-adjusted life-years (QALYs) resulting from varying rebates were computed for each Health Service Delivery Area (HSDA). Measurements and Main Results: In the base-case analysis, HEPA filter use resulted in increased costs of $83.34 (SE, $1.03) and increased QALYs of 0.0011 (SE, 0.0001) per person. The average incremental cost-effectiveness ratio among BC HSDAs was $74,652/QALY (SE, $3,517), with incremental cost-effectiveness ratios ranging from $40,509 to $89,206 per QALY in HSDAs. Across the province, the intervention was projected to prevent 4,418 exacerbations requiring systemic corticosteroids, 643 emergency department visits, and 425 hospitalizations during the 5-year time horizon. A full rebate was cost effective in 1 of the 16 HSDAs across BC. The probability of cost-effectiveness ranged from 0.1% to 74.8% across HSDAs. A $100 rebate was cost effective in most HSDAs. Conclusions: The cost-effectiveness of HEPA filters in managing wildfire smoke-related asthma issues in BC varies by region. Government rebates up to two-thirds of the filter cost are generally cost effective, with a full rebate being cost effective only in Kootenay Boundary.

Access criteria for anti-TNF agents in spondyloarthritis: influence on comparative 1-year cost-effectiveness estimates.

BACKGROUND: Anti-tumor necrosis factor (anti-TNF) agents are an effective, but costly, treatment for spondyloarthritis (SpA). Worldwide, multiple sets of access criteria aim to restrict anti-TNF therapy to patients with specific clinical characteristics, yet the influence of access criteria on anti-TNF cost-effectiveness is unknown. Our objective was to use data from the DESIR cohort, a prospective study of early SpA patients in France, to determine whether the French anti-TNF access criteria are the most cost-effective in that setting relative to other potential restrictions. METHODS: We used data from the DESIR cohort to create five study populations of patients meeting anti-TNF access criteria from Canada, France, Germany, United Kingdom, and Hong Kong, respectively. For each study population, we calculated the costs and quality-adjusted life years (QALYs) over 1 year of patients treated and not treated with anti-TNF therapy. To control for differences between anti-TNF users and non-users, we used linear regression models to derive adjusted mean costs and QALYs. We calculated incremental cost-effectiveness ratios (ICERs) representing the incremental cost per additional QALY gained by treating with an anti-TNF within each of the five study populations, using bootstrapping to explore the range of uncertainty in costs and QALYs. A series of sensitivity analyses was conducted, including one to simulate the effect of a 24-week stopping rule for anti-TNF non-responders. RESULTS: Anti-TNF access criteria from France were satisfied by the largest proportion of DESIR patients (27.8%), followed by Germany (25.1%), Canada (23.8%), the UK (12.1%) and Hong Kong (8.6%). Confidence intervals around incremental costs and QALYs in the basecase analysis were overlapping, indicating that anti-TNF cost-effectiveness estimates derived from each subset were similar. In the sensitivity analysis that examined the effect of excluding costs accumulated past 24 weeks by anti-TNF non-responders, the incremental cost per QALY was reduced by approximately 25% relative to the basecase analysis (France: €857,992 vs. €1,105,859; Canada: € 626,459 vs. €818,186; Germany: € 422,568 vs. €545,808); UK €578,899 vs. €766,217; Hong Kong €335,418 vs. €456,850). CONCLUSIONS: Anti-TNF cost-effectiveness is strongly affected by treatment continuation among non-responders. Access criteria could improve anti-TNF cost-effectiveness by defining patients likely to respond.

Patient and Public Involvement in Health Economics Modelling Raises the Need for Normative Guidance.

Patient and public involvement in health economics research and health technology assessment has been increasing for some time; however, patient and public involvement in health economics modelling is a more recent development. One reason to advance this type of involvement is to help appropriately manage the social and ethical value judgements that are required throughout model development and interpretation. At the same time, patient and public involvement in health economics modelling raises numerous practical and philosophical issues that invite discussion and debate. Recently, we attended an engagement event which invited patients, members of the public, researchers and decision-makers to discuss some of these issues. One priority that emerged in the discussion was to develop normative guidance for patient and public involvement in health economics modelling. In this article, we reflect on this goal from our own perspective, focusing on why normative guidance is needed and what questions that guidance should answer.

The Epistemic Risk in Representation.

Both the distinction between the 'internal' and 'external' phases of science and the concept of 'inductive risk' are core constructs in the values in science literature. However, both constructs have shortcomings, which, we argue, have concealed the unique significance of values in scientific representation. We defend three closely-related proposals to rectify the problem: i) to draw a conceptual distinction between endorsing a 'fact' and making a decision about representation; ii) to employ a conception of inductive risk that aligns with this distinction, not one between internal/external phases in science; iii) to conceptualize 'representational risk' as a unique epistemic risk, no less significant than inductive risk. We outline the implications of each proposal for current debates in the values in science literature.

Purposes and duties in scientific modelling.

More people than ever are paying attention to philosophical questions about epidemiological models, including their susceptibility to the influence of social and ethical values, sufficiency to inform policy decisions under certain conditions, and even their fundamental nature. One important question pertains to the purposes of epidemiological models, for example, are COVID-19 models for 'prediction' or 'projection'? Are they adequate for making causal inferences? Is one of their goals, or virtues, to change individual responses to the pandemic? In this essay, we offer our perspective on these questions and place them in the context of other recent philosophical arguments about epidemiological models. We argue that clarifying the intended purpose of a model, and assessing its adequacy for that purpose, are moral-epistemic duties, responsibilities which pertain to knowledge but have moral significance nonetheless. This moral significance, we argue, stems from the inherent value-ladenness of models, along with the potential for models to be used in political decision making in ways that conflict with liberal values and which could lead to downstream harms. Increasing conversation about the moral significance of modelling, we argue, could help us to resist further eroding our standards of democratic scrutiny in the COVID-19 era.

Randomized controlled trial evaluating pictogram augmentation of HIV medication information.

BACKGROUND: Antiretroviral therapy for the management of HIV typically requires the chronic use of 3 or more medications. As such, patients with HIV are required to manage complex dosing schedules and are at risk of multiple potential adverse effects. The use of pictograms on medication vials as a means of improving patients' understanding of medication information has been shown to positively influence understanding and adherence compared to those using text alone. OBJECTIVE: To determine whether pictograms (Pharmaglyph) increase patient recall of targeted information associated with HIV medications and whether patients can interpret the intended meaning of pictograms that they had not seen previously. METHODS: A randomized, controlled trial was conducted in HIV-positive patients aged 19 years or older who were receiving a new prescription for an antiretroviral medication from the ambulatory pharmacy at St. Paul's Hospital in Vancouver, British Columbia, Canada. Participants were randomized to receive either pictogram-enhanced medication information or standard counseling. At the first follow-up visit, each patient's recall of the medication information was evaluated, and differences between groups were compared. RESULTS: Eighty-two subjects were randomized, 40 to the intervention group and 42 to the control arm. The mean (SD) number of HIV medications was nearly equal between the intervention and control groups: 3.0 (1.5) and 3.1 (1.4), respectively. After a mean of 34 days, 33 patients in the intervention arm and 39 in the control arm completed the study. The majority (88%) of the targeted pieces of information in the intervention group were correctly identified at follow-up, compared to only 2% in the control group (Fisher exact test; p < 0.0001). CONCLUSIONS: Pictograms improve the recall of targeted medication information among patients receiving antiretroviral therapy for HIV management; however, this appears to be dependent on the fact that these patients received a verbal explanation of each pictogram prior to use.

Agreement between aggregate and individual-level measures of income and education: a comparison across three patient groups.

BACKGROUND: The association between lower socioeconomic status and poorer health outcomes has been observed using both individual-level and aggregate-level measures of income and education. While both are predictive of health outcomes, previous research indicates poor agreement between individual-level and aggregate-level measures. The purpose of this study was to determine the level of agreement between aggregate-level and individual-level measures of income and education among three distinct patient groups, specifically asthma, diabetes, and rheumatoid patients. METHODS: Individual-level measures of annual household income and education were derived from three separate surveys conducted among patients with asthma (n = 359), diabetes (n = 281) and rheumatoid arthritis (n = 275). Aggregate-level measures of income and education were derived from the 2001 Canadian census, including both census tract-and dissemination area-level measures. Cross-tabulations of individual-level income by aggregate-level income were used to determine the percentage of income classifications in agreement. The kappa statistic (simple and weighted), Spearman's rank correlations, and intra-class correlation coefficient (ICC) were also calculated. Individual-level and aggregate-level education was compared using Chi-Square tests within patient groups. Point biserial correlation coefficients between individual-level and aggregate-level education were computed. RESULTS: Individual-level income was poorly correlated with aggregate-level measures, which provided the worst estimations of income among patients in the lowest income category at the individual-level. Both aggregate-level measures were best at approximating individual-level income in patients with diabetes, in whom aggregate-level estimates were only significantly different from individual-level measures for patients in the lowest income category. Among asthma patients, the proportion of patients classified by aggregate-level measures as having a university degree was significantly lower than that classified by individual-level measures. Among diabetes and rheumatoid arthritis patients, differences between aggregate and individual-level measures of education were not significant. CONCLUSIONS: Agreement between individual-level and aggregate-level measures of socioeconomic status may depend on the patient group as well as patient income. Research is needed to characterize differences between patient groups and help guide the choice of measures of socioeconomic status.

Health Economists on Involving Patients in Modeling: Potential Benefits, Harms, and Variables of Interest.

BACKGROUND: Patient involvement in health economics modeling has been advocated on numerous grounds, including as a way to better manage social and ethical value judgments in the modeling process. However, some have pointed to potential risks and variables that could influence the overall benefit of involvement. To inform future research, there is a need to generate knowledge on potential benefits, harms, and variables relevant to patient involvement in health economics modeling. METHODS: This analysis used data from a qualitative study in which 22 health economists were asked their views on the possibility of involving patients in the modeling process. Using qualitative methods, the authors organized participants' responses into theory-driven categories ("potential benefits", "potential harms", "variables of interest") and identified data-driven themes and subthemes within those categories. RESULTS: Findings point to potential benefits and harms to the model, modeler, patient, and modeling process. Variables of interest relevant to future research included patients' specific roles, modeler and patient characteristics, the goals of modeling, dynamics among participators, and features of high-level procedures. The findings raise a number of specific questions that may be fruitful to explore in future research on patient involvement in health economics modeling.

Value judgments in a COVID-19 vaccination model: A case study in the need for public involvement in health-oriented modelling.

Scientific modelling is a value-laden process: the decisions involved can seldom be made using 'scientific' criteria alone, but rather draw on social and ethical values. In this paper, we draw on a body of philosophical literature to analyze a COVID-19 vaccination model, presenting a case study of social and ethical value judgments in health-oriented modelling. This case study urges us to make value judgments in health-oriented models explicit and interpretable by non-experts and to invite public involvement in making them.

Social, ethical, and other value judgments in health economics modelling.

Modelling is a major method of inquiry in health economics. In other modelling-intensive fields, such as climate science, recent scholarship has described how social and ethical values influence model development. However, no similar work has been done in health economics. This study explored the role of social, ethical, and other values in health economics modelling using philosophical theory and qualitative interviews in British Columbia, Canada. Twenty-two professionals working in health economics modelling were interviewed between February and May, 2019. The study findings provide support for four philosophical arguments positing an essential role for social and ethical values throughout scientific inquiry and demonstrate how these arguments apply to health economics modelling. It highlights the role of social values in informing early modelling decisions, shaping model assumptions, making trade-offs between desirable model features, and setting standards of evidence. These results point to several decisions in the modelling process that warrant focus in future health economics research, particularly that which aims to incorporate patient and public values.

HIV/AIDS in Vancouver, British Columbia: a growing epidemic.

The prevalence of HIV in Vancouver, British Columbia was subject to two distinct periods of rapid increase. The first occurred in the 1980s due to high incidence among men who have sex with men (MSM), and the second occurred in the 1990s due to high incidence among injection drug users (IDU). The purpose of this study was to estimate and model the trends in HIV prevalence in Vancouver from 1980 to 2006. HIV prevalence data were entered into the UNAIDS/WHO Estimation and Projection Package (EPP) where prevalence trends were estimated by fitting an epidemiological model to the data. Epidemic curves were fit for IDU, MSM, street-based female sex trade workers (FSW), and the general population. Using EPP, these curves were then aggregated to produce a model of Vancouver's overall HIV prevalence. Of the 505 000 people over the age of 15 that reside in Vancouver, 6108 (ranging from 4979 to 7237) were living with HIV in the year 2006, giving an overall prevalence of 1.21 percent (ranging from 0.99 to 1.43 percent). The subgroups of IDU and MSM account for the greatest proportion of HIV infections. Our model estimates that the prevalence of HIV in Vancouver is greater than one percent, roughly 6 times higher than Canada's national prevalence. These results suggest that HIV infection is having a relatively large impact in Vancouver and that evidence-based prevention and harm reduction strategies should be expanded.

Harm reduction product distribution in British Columbia.

OBJECTIVES: The British Columbia Centre for Disease Control (BCCDC) tracks the distribution of all harm reduction products subsidized by the BC government, including needles and syringes, sterile water vials, alcohol swabs, condoms, and lubricant. This study measures the distribution of harm reduction products in BC, identifies regional variation in distribution, and estimates the supply/demand ratio for needle and syringe units. METHODS: Using three years of administrative data (2004-2006) from the BCCDC, the quantity of harm reduction products distributed was calculated by Health Service Delivery Area (HSDA). Regional hepatitis C virus (HCV) case report rates were calculated to reflect potential variation in IDU populations at the HSDA-level and the number of needle and syringe units distributed per reported case of HCV was calculated and ranked by HSDA. To compare the demand for sterile injecting equipment to the distribution, the number of illicit drug injections per year was approximated using established estimates of IDU populations in BC and Vancouver. RESULTS: Marked regional variation exists in the rates of harm reduction product distribution per 100,000 residents aged 15-64. The average number of needle and syringe units distributed annually in BC from 2004-2006 was 5,382,933. The estimated number of injections per year in BC is 24,951,144, suggesting the province distributed 21.5% of the units required to cover all illicit drug injections in the province. DISCUSSION: Harm reduction product distribution is not equitable between BC HSDAs. The current level of distribution of sterile injecting equipment is inadequate to provide a clean needle for every injection.

More than just needles: an evidence-informed approach to enhancing harm reduction supply distribution in British Columbia.

BACKGROUND: The BC Harm Reduction Strategies and Services (HRSS) policy states that each health authority (HA) and their community partners will provide a full range of harm reduction (HR) services to their jurisdictions and these HR products should be available to all who need them regardless of where they live and choice of drug. Preliminary analysis revealed wide variations between and within HAs. METHODS: The objective of this study is to analyze distribution of HR products by site using Geographic Information Systems (GIS) and to investigate the range, adequacy and methods of HR product distribution using qualitative interviews. The BC Centre for Disease Control pharmacy database tracks HR supplies distributed to health units and community agencies. Additionally, eleven face-to-face interviews were conducted in eight mainland BC communities using an open-ended questionnaire. RESULTS: There is evidence in BC that HR supplies are not equally available throughout the province. There are variations within jurisdictions in how HR supplies are distributed, adequacy of current HR products, collection of used needles, alternative uses of supplies and community attitudes towards HR. GIS illustrates where HR supplies are ordered but with secondary distribution, true reach and availability of supplies cannot be determined. CONCLUSION: Currently, a consultant is employed to develop a 'best practice' document; relevant health files, standard training and protocols within HAs are also being developed. There is a need to enhance the profile and availability of culturally appropriate HR services for Aboriginal populations. Distribution of crackpipe mouthpieces is being investigated.

Adherence to Antitumor Necrosis Factor Use Recommendations in Spondyloarthritis: Measurement and Effect in the DESIR Cohort.

OBJECTIVE: To evaluate a classification system to define adherence to axial spondyloarthritis (axSpA) anti-tumor necrosis factor (anti-TNF) use recommendations and examine the effect of adherence on outcomes in the DESIR cohort (Devenir des Spondylarthropathies Indifférenciées Récentes). METHODS: Using alternate definitions of adherence, patients were classified as adherent "timely" anti-TNF users, nonadherent "late" anti-TNF users, adherent nonusers ("no anti-TNF need"), non-adherent nonusers ("unmet anti-TNF need"). Multivariate models were fitted to examine the effect of adherence on quality-adjusted life-years (QALY), total costs, and nonbiologic costs 1 year following an index date. Generalized linear regression models assuming a γ-distribution with log link were used for costs outcomes and linear regression models for QALY outcomes. RESULTS: Using the main definition of adherence, there were no significant differences between late anti-TNF users and timely anti-TNF users in total costs (RR 0.86, 95% CI 0.54-1.36, p = 0.516) or nonbiologic costs (RR 0.72, 95% CI 0.44-1.18, p = 0.187). However, in the sensitivity analysis, late anti-TNF users had significantly increased nonbiologic costs compared with timely users (RR 1.58, 95% CI 1.06-2.36, p = 0.026). In the main analysis, there were no significant differences in QALY between timely anti-TNF users and late anti-TNF users, or between timely users and patients with unmet anti-TNF need. In the sensitivity analysis, patients with unmet anti-TNF need had significantly lower QALY than timely anti-TNF users (-0.04, 95% CI -0.07 to -0.01, p = 0.016). CONCLUSION: The effect of adherence to anti-TNF recommendations on outcomes was sensitive to the definition of adherence used, highlighting the need to validate methods to measure adherence.

Consumer preferences for food allergen labeling.

BACKGROUND: Food allergen labeling is an important tool to reduce risk of exposure and prevent anaphylaxis for individuals with food allergies. Health Canada released a Canadian food allergen labeling regulation (2008) and subsequent update (2012) suggesting that research is needed to guide further iterations of the regulation to improve food allergen labeling and reduce risk of exposure. OBJECTIVE: The primary objective of this study was to examine consumer preferences in food labeling for allergy avoidance and anaphylaxis prevention. A secondary objective was to identify whether different subgroups within the consumer population emerged. METHODS: A discrete choice experiment using a fractional factorial design divided into ten different versions with 18 choice-sets per version was developed to examine consumer preferences for different attributes of food labeling. RESULTS: Three distinct subgroups of Canadian consumers with different allergen considerations and food allergen labeling needs were identified. Overall, preferences for standardized precautionary and safety symbols at little or no increased cost emerged. CONCLUSION: While three distinct groups with different preferences were identified, in general the results revealed that the current Canadian food allergen labeling regulation can be improved by enforcing the use of standardized precautionary and safety symbols and educating the public on the use of these symbols.

Costs of early spondyloarthritis: estimates from the first 3†years of the DESIR cohort.

OBJECTIVES: To value health resource utilisation and productivity losses in DESIR, a longitudinal French cohort of 708 patients with early spondyloarthritis (SpA) enrolled between 2007 and 2010, and identify factors associated with costs in the first 3 years of follow-up. METHODS: Self-reported clinical data from DESIR and French public data were used to value health resource utilisation and productivity losses in 2013 Euros. Factors associated with costs, including and excluding biological drugs, were identified in generalised linear models using the generalised estimating equations algorithm to account for repeated observations over participants. RESULTS: The mean (±SD) annual cost per patient was €5004±6870 in year 1, decreasing to €4961±7457 in year 3. Patients who never received a biologic had mean 3-year total costs of €4789±6022 compared to €38 206±19 829 among those who received a biologic. Factors associated with increased total costs were peripheral arthritis (rate ratio (RR) 1.19; 95% CI 1.04 to 1.37; p<0.0001), time on biologics (RR 1.23 per month; 1.21, 1.24; p<0.0001), and average BASFI score (RR 1.18/10 point increase; 1.15, 1.25; p<0.0001). Factors associated with increased costs excluding biologics were baseline age (RR 1.10 per 5 year increase; 1.05, 1.16; p<0.0001), peripheral arthritis (RR 1.20; 1.02, 1.40; p<0.0133), time on biologics (RR 1.04 per month; 1.02, 1.05; p<0.0001), and average BASDAI score (RR 1.21 per 10 point increase; 1.16, 1.25; p<0.0001). CONCLUSIONS: In addition to biologics, factors like age, peripheral arthritis and disease activity independently increase SpA-related costs. This study may serve as a benchmark for cost of illness among patients with early SpA in the biologic era.