Association Between T2-related Comorbidities and Effectiveness of Biologics in Severe Asthma.

Rationale: Previous studies investigating the impact of comorbidities on the effectiveness of biologic agents have been relatively small and of short duration and have not compared classes of biologic agents. Objectives: To determine the association between type 2-related comorbidities and biologic agent effectiveness in adults with severe asthma (SA). Methods: This cohort study used International Severe Asthma Registry data from 21 countries (2017-2022) to quantify changes in four outcomes before and after biologic therapy-annual asthma exacerbation rate, FEV1% predicted, asthma control, and long-term oral corticosteroid daily dose-in patients with or without allergic rhinitis, chronic rhinosinusitis (CRS) with or without nasal polyps (NPs), NPs, or eczema/atopic dermatitis. Measurements and Main Results: Of 1,765 patients, 1,257, 421, and 87 initiated anti-IL-5/5 receptor, anti-IgE, and anti-IL-4/13 therapies, respectively. In general, pre- versus post-biologic therapy improvements were noted in all four asthma outcomes assessed, irrespective of comorbidity status. However, patients with comorbid CRS with or without NPs experienced 23% fewer exacerbations per year (95% CI, 10-35%; P < 0.001) and had 59% higher odds of better post-biologic therapy asthma control (95% CI, 26-102%; P < 0.001) than those without CRS with or without NPs. Similar estimates were noted for those with comorbid NPs: 22% fewer exacerbations and 56% higher odds of better post-biologic therapy control. Patients with SA and CRS with or without NPs had an additional FEV1% predicted improvement of 3.2% (95% CI, 1.0-5.3; P = 0.004), a trend that was also noted in those with comorbid NPs. The presence of allergic rhinitis or atopic dermatitis was not associated with post-biologic therapy effect for any outcome assessed. Conclusions: These findings highlight the importance of systematic comorbidity evaluation. The presence of CRS with or without NPs or NPs alone may be considered a predictor of the effectiveness of biologic agents in patients with SA.

Exploring Definitions and Predictors of Severe Asthma Clinical Remission Post-Biologic in Adults.

RATIONALE: There is no consensus on criteria to include in an asthma remission definition in real-life. Factors associated with achieving remission post-biologic-initiation remain poorly understood. OBJECTIVES: To quantify the proportion of adults with severe asthma achieving multi-domain-defined remission post-biologic-initiation and identify pre-biologic characteristics associated with achieving remission which may be used to predict it. METHODS: This was a longitudinal cohort study using data from 23 countries from the International Severe Asthma Registry. Four asthma outcome domains were assessed in the 1-year pre- and post-biologic-initiation. A priori-defined remission cut-offs were: 0 exacerbations/year, no long-term oral corticosteroid (LTOCS), partly/well-controlled asthma, and percent predicted forced expiratory volume in one second ≥80%. Remission was defined using 2 (exacerbations + LTOCS), 3 (+control or +lung function) and 4 of these domains. The association between pre-biologic characteristics and post-biologic remission was assessed by multivariable analysis. MEASUREMENTS AND MAIN RESULTS: 50.2%, 33.5%, 25.8% and 20.3% of patients met criteria for 2, 3 (+control), 3 (+lung function) and 4-domain-remission, respectively. The odds of achieving 4-domain remission decreased by 15% for every additional 10-years asthma duration (odds ratio: 0.85; 95% CI: 0.73, 1.00). The odds of remission increased in those with fewer exacerbations/year, lower LTOCS daily dose, better control and better lung function pre-biologic-initiation. CONCLUSIONS: One in 5 patients achieved 4-domain remission within 1-year of biologic-initiation. Patients with less severe impairment and shorter asthma duration at initiation had a greater chance of achieving remission post-biologic, indicating that biologic treatment should not be delayed if remission is the goal. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Non-parametric inference on calibration of predicted risks.

Moderate calibration, the expected event probability among observations with predicted probability z being equal to z, is a desired property of risk prediction models. Current graphical and numerical techniques for evaluating moderate calibration of risk prediction models are mostly based on smoothing or grouping the data. As well, there is no widely accepted inferential method for the null hypothesis that a model is moderately calibrated. In this work, we discuss recently-developed, and propose novel, methods for the assessment of moderate calibration for binary responses. The methods are based on the limiting distributions of functions of standardized partial sums of prediction errors converging to the corresponding laws of Brownian motion. The novel method relies on well-known properties of the Brownian bridge which enables joint inference on mean and moderate calibration, leading to a unified "bridge" test for detecting miscalibration. Simulation studies indicate that the bridge test is more powerful, often substantially, than the alternative test. As a case study we consider a prediction model for short-term mortality after a heart attack, where we provide suggestions on graphical presentation and the interpretation of results. Moderate calibration can be assessed without requiring arbitrary grouping of data or using methods that require tuning of parameters.

Cost-effectiveness of budesonide-formoterol vs inhaled epinephrine in US adults with mild asthma.

BACKGROUND: The management of mild asthma has lacked an over-the-counter (OTC) option aside from inhaled epinephrine, which is available in the United States. However, inhaled epinephrine use without an inhaled corticosteroid may increase the risk of asthma death. OBJECTIVE: To compare the cost-effectiveness of OTC as-needed budesonide-formoterol as a plausible alternative to inhaled epinephrine. METHODS: We developed a probabilistic Markov model to compare OTC as-needed budesonide-formoterol inhaler use vs inhaled epinephrine use in adults with mild asthma from a US societal perspective over a lifetime horizon, with a 3% annual discount rate (2022 US dollars). Inputs were derived from the SYmbicort Given as-needed in Mild Asthma (SYGMA) trials, published literature, and commercial costs. Outcomes were quality-adjusted life-years (QALY), costs, incremental net monetary benefit (INMB), severe asthma exacerbations, well-controlled asthma days, and asthma-related deaths. Microsimulation was used to evaluate underinsured Americans living with mild asthma (n = 5,250,000). RESULTS: Inhaled epinephrine was dominated (with lower QALYs gains at a higher cost) by both as-needed budesonide-formoterol (INMB, $15,541 at a willingness-to-pay of $100,000 per QALY) and the no-OTC inhaler option (INMB, $1023). Adults using as-needed budesonide-formoterol had 145 more well-controlled asthma days, 2.79 fewer severe exacerbations, and an absolute risk reduction of 0.23% for asthma-related death compared with inhaled epinephrine over a patient lifetime. As-needed budesonide-formoterol remained dominant in all sensitivity and scenario analyses, with a 100% probability of being cost-effective compared with inhaled epinephrine in probabilistic sensitivity analysis. CONCLUSION: If made available, OTC as-needed budesonide-formoterol for treating mild asthma in underinsured adults without HCP management improves asthma outcomes, prevents fatalities, and is cost-saving.

Analysis of comorbidities and multimorbidity in adult patients in the International Severe Asthma Registry.

BACKGROUND: Investigation for the presence of asthma comorbidities is recommended by the Global Initiative for Asthma because their presence can complicate asthma management. OBJECTIVE: To understand the prevalence and pattern of comorbidities and multimorbidity in adults with severe asthma and their association with asthma-related outcomes. METHODS: This was a cross-sectional study using data from the International Severe Asthma Registry from 22 countries. A total of 30 comorbidities were identified and categorized a priori as any of the following: (1) potentially type 2-related comorbidities, (2) potentially oral corticosteroid (OCS)-related comorbidities, or (3) comorbidities mimicking or aggravating asthma. The association between comorbidities and asthma-related outcomes was investigated using multivariable models adjusted for country, age at enrollment, and sex (ie male or female). RESULTS: Of the 11,821 patients, 69%, 67%, and 55% had at least 1 potentially type 2-related, potentially OCS-related, or mimicking or aggravating comorbidities, respectively; 57% had 3 or more comorbidities, and 33% had comorbidities in all 3 categories. Patients with allergic rhinitis, nasal polyposis, and chronic rhinosinusitis experienced 1.12 (P = .003), 1.16 (P < .001), and 1.29 times (P < .001) more exacerbations per year, respectively, than those without. Patients with nasal polyposis and chronic rhinosinusitis were 40% and 46% more likely (P < .001), respectively, to have received long-term (LT) OCS. All assessed potential OCS-related comorbidities (except obesity) were associated with a greater likelihood of LTOCS use (odds ratios [ORs]: 1.23-2.77) and, except for dyslipidemia, with a greater likelihood of uncontrolled asthma (ORs: 1.29-1.68). All mimicking or aggravating comorbidities assessed were associated with more exacerbations (1.24-1.68 times more), all (except bronchiectasis) with increased likelihood of uncontrolled asthma (ORs: 1.57-1.81), and all (except chronic obstructive pulmonary disease) with increased likelihood of LTOCS use (ORs: 1.37-1.57). A greater number of comorbidities was associated with worse outcomes. CONCLUSION: In a global study, comorbidity or multimorbidity is reported in most adults with severe asthma and is associated with poorer asthma-related outcomes. CLINICAL TRIAL REGISTRATION: The International Severe Asthma Registry database has ethical approval from the Anonymous Data Ethics Protocols and Transparency (ADEPT) committee (ADEPT0218) and is registered with the European Union Electronic Register of Post-Authorization Studies (European Network Centres for Pharmacoepidemiology and Pharmacovigilance [ENCEPP]/DSPP/23720). The study was designed, implemented, and reported in compliance with the European Network Centres for Pharmacoepidemiology and Pharmacovigilance (ENCEPP) Code of Conduct (EMA 2014; EUPAS44024) and with all applicable local and international laws and regulations, and registered with ENCEPP (https://www.encepp.eu/encepp/viewResource.htm?id=48848). Governance was provided by ADEPT (registration number: ADEPT1121).

Impact of pre-biologic impairment on meeting domain-specific biologic responder definitions in patients with severe asthma.

BACKGROUND: There is little agreement on clinically useful criteria for identifying real-world responders to biologic treatments for asthma. OBJECTIVE: To investigate the impact of pre-biologic impairment on meeting domain-specific biologic responder definitions in adults with severe asthma. METHODS: This was a longitudinal, cohort study across 22 countries participating in the International Severe Asthma Registry (https://isaregistries.org/) between May 2017 and January 2023. Change in 4 asthma domains (exacerbation rate, asthma control, long-term oral corticosteroid [LTOCS] dose, and lung function) was assessed from biologic initiation to 1 year post-treatment (minimum 24 weeks). Pre- to post-biologic changes for responders and nonresponders were described along a categorical gradient for each domain derived from pre-biologic distributions (exacerbation rate: 0 to 6+/y; asthma control: well controlled to uncontrolled; LTOCS: 0 to >30 mg/d; percent-predicted forced expiratory volume in 1 second [ppFEV1]: <50% to ≥80%). RESULTS: Percentage of biologic responders (ie, those with a category improvement pre- to post-biologic) varied by domain and increased with greater pre-biologic impairment, increasing from 70.2% to 90.0% for exacerbation rate, 46.3% to 52.3% for asthma control, 31.1% to 58.5% for LTOCS daily dose, and 35.8% to 50.6% for ppFEV1. The proportion of patients having improvement post-biologic tended to be greater for anti-IL-5/5R compared with for anti-IgE for exacerbation, asthma control, and ppFEV1 domains, irrespective of pre-biologic impairment. CONCLUSION: Our results provide realistic outcome-specific post-biologic expectations for both physicians and patients, will be foundational to inform future work on a multidimensional approach to define and assess biologic responders and response, and may enhance appropriate patient selection for biologic therapies. TRIAL REGISTRATION: The ISAR database has ethical approval from the Anonymous Data Ethics Protocols and Transparency (ADEPT) committee (ADEPT0218) and is registered with the European Union Electronic Register of Post-Authorization studies (ENCEPP/DSPP/23720). The study was designed, implemented, and reported in compliance with the European Network Centres for Pharmacoepidemiology and Pharmacovigilance (ENCEPP) Code of Conduct (EUPAS38288) and with all applicable local and international laws and regulation, and registered with ENCEPP (https://www.encepp.eu/encepp/viewResource.htm?id=38289). Governance was provided by ADEPT (registration number: ADEPT1220).

Impact of surgical lung biopsy on lung function and survival in patients with idiopathic pulmonary fibrosis in a multi-centre registry cohort.

BACKGROUND AND OBJECTIVE: Establishing an accurate and timely diagnosis of idiopathic pulmonary fibrosis (IPF) is essential for appropriate management and prognostication. In some cases, surgical lung biopsy (SLB) is performed but carries non-negligible risk. The objective of this retrospective study was to determine if SLB is associated with accelerated lung function decline in patients with IPF using the Canadian Registry for Pulmonary Fibrosis. METHODS: Linear mixed models and Cox proportional hazards regression models were used to compare decline in forced vital capacity (FVC)%, diffusion capacity of the lung (DLCO%) and risk of death or lung transplantation between SLB and non-SLB patients. Adjustments were made for baseline age, sex, smoking history, antifibrotic use, and lung function. A similar analysis compared lung function changes 12 months pre- and post-SLB. RESULTS: A total of 81 SLB patients and 468 non-SLB patients were included. In the SLB group, the post-biopsy annual FVC% decline was 2.0% (±0.8) in unadjusted, and 2.1% (±0.8) in adjusted models. There was no difference in FVC% decline, DLCO% decline, or time to death or lung transplantation between the two groups, in adjusted or unadjusted models (all p-values >0.07). In the pre-post SLB group, no differences were identified in FVC% decline in unadjusted or adjusted models (p = 0.07 for both). CONCLUSION: No association between SLB and lung function decline or risk of death or lung transplantation was identified in this multi-centre study of patients with IPF.

QRISK3 underestimates the risk of cardiovascular events in patients with COPD.

BACKGROUND: Patients with chronic obstructive pulmonary disease (COPD) are at increased risk of cardiovascular disease (CVD). The extent to which the excess CVD risk is captured by risk factors in QRISK, a widely used CVD risk scoring tool, is not well studied. METHODS: We created an incidence cohort of diagnosed COPD patients from the United Kingdom (UK) Clinical Practice Research Datalink GOLD database (January 1998-July 2018). The outcome was a composite of fatal or non-fatal CVD events. Sex-specific age-standardised incidence ratios (SIR) were compared with values for the UK primary-care population. The observed 10-year CVD risk was derived using the Kaplan-Meier estimator and was compared with predicted 10-year risk from the QRISK3 tool. RESULTS: 13 208 patients (mean age 64.9 years, 45% women) were included. CVD incidence was 3.53 events per 100 person-years. The SIR of CVD was 1.71 (95% CI 1.61 to 1.75) in women and 1.62 (95%CI 1.54-1.64) in men. SIR was particularly high among patients younger than 65 years (women=2.13 (95% CI 1.94 to 2.19); men=1.86 (95% CI 1.74 to 1.90)). On average, the observed 10-year risk was 52% higher than QRISK predicted score (33.5% vs 22.1%). The difference was higher in patients younger than 65 years (observed risk 82% higher than predicted). CONCLUSION: People living with COPD are at a significantly heightened risk of CVD over and beyond their predicted risk. This is particularly the case for younger people whose 10-year CVD risk can be >80% higher than predicted. Risk scoring tools must be validated and revised to provide accurate CVD predictions in patients with COPD.

Eligibility criteria from pharmaceutical randomised controlled trials of idiopathic pulmonary fibrosis: a registry-based study.

BACKGROUND: Little is known about generalisability of randomised controlled trials (RCTs) for idiopathic pulmonary fibrosis (IPF). We evaluated eligibility criteria for phase III IPF RCTs to determine their representativeness in clinical registries, and calculated forced vital capacity (FVC) changes according to eligibility criteria. METHODS: Common eligibility criteria used in >60% of IPF RCTs were identified from a literature search and applied to patients with IPF from prospective Australian and Canadian registries. Additional pre-specified criteria of 6-min walk distance (6MWD) and different measures of preceding disease progression were also evaluated. Joint longitudinal-survival modelling was used to compare FVC decline according to eligibility for individual and composite criteria. RESULTS: Out of 990 patients with IPF, 527 (53%) met all common RCT eligibility criteria at the first clinic visit, including 343 with definite IPF and 184 with radiological probable usual interstitial pneumonia pattern without histological confirmation (i.e. provisional IPF). The percentages of eligible patients for landmark RCTs of nintedanib and pirfenidone were 19-50%. Adding 6MWD ≥150 m and different measures of preceding disease progression to the composite common criteria reduced the percentages of patients meeting eligibility to 52% (n=516) and 4-18% (n=12-61), respectively. Patients meeting the composite common criteria had less-rapid 1-year FVC decline than those who did not (-90 versus -103 mL, p=0.01). Definite IPF generally had more-rapid 1-year FVC decline compared to provisional IPF. CONCLUSIONS: Eligibility criteria of previous IPF RCTs have limited generalisability to clinical IPF populations, with FVC decline differing between eligible and ineligible populations.

Can we predict who will benefit most from biologics in severe asthma? A post-hoc analysis of two phase 3 trials.

BACKGROUND: Individualized prediction of treatment response may improve the value proposition of advanced treatment options in severe asthma. This study aimed to investigate the combined capacity of patient characteristics in predicting treatment response to mepolizumab in patients with severe asthma. METHODS: Patient-level data were pooled from two multinational phase 3 trials of mepolizumab in severe eosinophilic asthma. We fitted penalized regression models to quantify reductions in the rate of severe exacerbations and the 5-item Asthma Control Questionnaire (ACQ5) score. The capacity of 15 covariates towards predicting treatment response was quantified by the Gini index (measuring disparities in treatment benefit) as well as observed treatment benefit within the quintiles of predicted treatment benefit. RESULTS: There was marked variability in the ability of patient characteristics to predict treatment response; covariates explained greater heterogeneity in predicting treatment response to asthma control than to exacerbation frequency (Gini index 0.35 v. 0.24). Key predictors for treatment benefit for severe exacerbations included exacerbation history, blood eosinophil count, baseline ACQ5 score and age, and those for symptom control included blood eosinophil count and presence of nasal polyps. Overall, the average reduction in exacerbations was 0.90/year (95%CI, 0.87‒0.92) and average reduction in ACQ5 score was 0.18 (95% CI, 0.02‒0.35). Among the top 20% of patients for predicted treatment benefit, exacerbations were reduced by 2.23/year (95% CI, 2.03‒2.43) and ACQ5 score were reduced by 0.59 (95% CI, 0.19‒0.98). Among the bottom 20% of patients for predicted treatment benefit, exacerbations were reduced by 0.25/year (95% CI, 0.16‒0.34) and ACQ5 by -0.20 (95% CI, -0.51 to 0.11). CONCLUSION: A precision medicine approach based on multiple patient characteristics can guide biologic therapy in severe asthma, especially in identifying patients who will not benefit as much from therapy. Patient characteristics had a greater capacity to predict treatment response to asthma control than to exacerbation. TRIAL REGISTRATION: ClinicalTrials.gov number, NCT01691521 (registered September 24, 2012) and NCT01000506 (registered October 23, 2009).

Comparative effectiveness of anti-IL5 and anti-IgE biologic classes in patients with severe asthma eligible for both.

BACKGROUND: Patients with severe asthma may present with characteristics representing overlapping phenotypes, making them eligible for more than one class of biologic. Our aim was to describe the profile of adult patients with severe asthma eligible for both anti-IgE and anti-IL5/5R and to compare the effectiveness of both classes of treatment in real life. METHODS: This was a prospective cohort study that included adult patients with severe asthma from 22 countries enrolled into the International Severe Asthma registry (ISAR) who were eligible for both anti-IgE and anti-IL5/5R. The effectiveness of anti-IgE and anti-IL5/5R was compared in a 1:1 matched cohort. Exacerbation rate was the primary effectiveness endpoint. Secondary endpoints included long-term-oral corticosteroid (LTOCS) use, asthma-related emergency room (ER) attendance, and hospital admissions. RESULTS: In the matched analysis (n = 350/group), the mean annualized exacerbation rate decreased by 47.1% in the anti-IL5/5R group and 38.7% in the anti-IgE group. Patients treated with anti-IL5/5R were less likely to experience a future exacerbation (adjusted IRR 0.76; 95% CI 0.64, 0.89; p < 0.001) and experienced a greater reduction in mean LTOCS dose than those treated with anti-IgE (37.44% vs. 20.55% reduction; p = 0.023). There was some evidence to suggest that patients treated with anti-IL5/5R experienced fewer asthma-related hospitalizations (IRR 0.64; 95% CI 0.38, 1.08), but not ER visits (IRR 0.94, 95% CI 0.61, 1.43). CONCLUSIONS: In real life, both anti-IgE and anti-IL5/5R improve asthma outcomes in patients eligible for both biologic classes; however, anti-IL5/5R was superior in terms of reducing asthma exacerbations and LTOCS use.

Trends in hospital admissions for chronic obstructive pulmonary disease over 16 years in Canada.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is an ambulatory care-sensitive condition, and the rate of hospital admissions for COPD is an indicator of the quality of outpatient care. We sought to determine long-term trends in hospital admissions for COPD in Canada. METHODS: Using a comprehensive national database of hospital admissions in Canada, we identified those with a main discharge diagnosis of COPD for patients aged 40 years and older between 2002 and 2017. We calculated sex-specific, age-standardized trends in annual rates of hospital admissions for COPD separately for younger (40-64 yr) and older adults (≥ 65 yr). We used spline regression to examine changes in the admissions trends for each sex and age group. RESULTS: Over 16 years, 1 134 359 hospital admissions were for COPD. Between 2002 and 2017, the total number of admissions increased by 68.8%, from 52 937 to 89 384. The overall crude admission rate increased by 30.0%, from 368 to 479 per 100 000 population, and the sex-and age-standardized admission rate increased by 9.6%, from 437 to 479 per 100 000 population. Age-standardized rates increased by 12.2% among younger females, by 24.4% among younger males and by 29.8% among older females, but decreased by 9.0% among older males. Over the same period, the all-cause sex-and age-standardized admission rate declined by 23.0%. INTERPRETATION: Hospital admissions for COPD have increased since 2010, even after adjusting for population growth and aging, and despite declining rates of all-cause hospital admissions. The secular increase in COPD admissions indicates that the burden of COPD on Canadian health care systems is increasing.

Role of latent tuberculosis infection on elevated risk of cardiovascular disease: a population-based cohort study of immigrants in British Columbia, Canada, 1985-2019.

We investigated cardiovascular disease (CVD) risk associated with latent tuberculosis infection (LTBI) (Aim-1) and LTBI therapy (Aim-2) in British Columbia, a low-tuberculosis-incidence setting. 49,197 participants had valid LTBI test results. Cox proportional hazards model was fitted, adjusting for potential confounders. Compared with the participants who tested LTBI negative, LTBI positive was associated with an 8% higher CVD risk in complete case data (adjusted hazard ratio (HR): 1.08, 95% CI: 0.99-1.18), a statistically significant 11% higher risk when missing confounder values were imputed using multiple imputation (HR: 1.11, 95% CI: 1.02-1.20), and 10% higher risk when additional proxy variables supplementing known unmeasured confounders were incorporated in the highdimensional disease risk score technique to reduce residual confounding (HR: 1.10, 95% CI: 1.01-1.20). Also, compared with participants who tested negative, CVD risk was 27% higher among people who were LTBI positive but incomplete LTBI therapy (HR: 1.27, 95% CI: 1.04-1.55), whereas the risk was similar in people who completed LTBI therapy (HR: 1.04, 95% CI: 0.87-1.24). Findings were consistent in different sensitivity analyses. We concluded that LTBI is associated with an increased CVD risk in low-tuberculosis-incidence settings, with a higher risk associated with incomplete LTBI therapy and attenuated risk when therapy is completed.

Pandemic Effect on Healthcare Use and Death in Adults with Epilepsy: A Population Study.

OBJECTIVES: We conducted a population-based study using Ontario health administrative data to describe trends in healthcare utilization and mortality in adults with epilepsy during the first pandemic year (March 2020-March 2021) compared to historical data (2016-2019). We also investigated if changes in outpatient visits and diagnostic testing during the first pandemic year were associated with increased risk for hospitalizations, emergency department (ED) visits, or death. METHODS: Projected monthly visit rates (per 100,000 people) for outpatient visits, electroencephalography, magnetic resonance, computed tomography, all-cause ED visits, hospitalizations, and mortality were calculated based on historical data by fitting monthly time series autoregressive integrated moving-average models. Two-way interactions were calculated using Quasi-Poisson models. RESULTS: In adults with epilepsy during the first quarter of the pandemic, we demonstrated a reduction in all-cause outpatient visits, diagnostic testing, ED visits and hospitalizations, and a temporary increase in mortality (observed rates of 355.8 vs projected 308.8, 95% CI: 276.3-345.1). By the end of the year, outpatient visits increased (85,535.4 vs 76,620.6, 95% CI: 71,546.9-82,059.4), and most of the diagnostic test rates returned to the projected. The increase in the rate of all-cause mortality during the pandemic, compared to pre-pandemic, was greater during months with the lower frequency of diagnostic tests than months with higher frequency (interaction p-values <.0001). CONCLUSION: We described the impact of the pandemic on healthcare utilization and mortality in adults with epilepsy during the first year. We demonstrated that access to relevant diagnostic testing is likely important for this population while planning restrictions on non-urgent health services.

A parametric model to jointly characterize rate, duration, and severity of exacerbations in episodic diseases.

BACKGROUND: The natural history of many chronic diseases is characterized by periods of increased disease activity, commonly referred to as flare-ups or exacerbations. Accurate characterization of the burden of these exacerbations is an important research objective. METHODS: The purpose of this work was to develop a statistical framework for nuanced characterization of the three main features of exacerbations: their rate, duration, and severity, with interrelationships among these features being a particular focus. We jointly specified a zero-inflated accelerated failure time regression model for the rate, an accelerated failure time regression model for the duration, and a logistic regression model for the severity of exacerbations. Random effects were incorporated into each component to capture heterogeneity beyond the variability attributable to observed characteristics, and to describe the interrelationships among these components. RESULTS: We used pooled data from two clinical trials in asthma as an exemplary application to illustrate the utility of the joint modeling approach. The model fit clearly indicated the presence of heterogeneity in all three components. A novel finding was that the new therapy reduced not just the rate but also the duration of exacerbations, but did not have a significant impact on their severity. After controlling for covariates, exacerbations among more frequent exacerbators tended to be shorter and less likely to be severe. CONCLUSIONS: We conclude that a joint modeling framework, programmable in available software, can provide novel insights about how the rate, duration, and severity of episodic events interrelate, and enables consistent inference on the effect of treatments on different disease outcomes. Trial registration Ethics approval was obtained from the University of British Columbia Human Ethics Board (H17-00938).

Risk and distribution of chronic obstructive pulmonary disease-related hospitalizations among primary care patients.

OBJECTIVE: To determine the extent of chronic obstructive pulmonary disease (COPD) hospitalization in easily identifiable high-risk subgroups within a typical primary care practice. DESIGN: Prospective cohort analysis of administrative claims data. SETTING: British Columbia. PARTICIPANTS: British Columbia residents who were 50 years or older on December 31, 2014, and received a physician diagnosis of COPD between 1996 and 2014. MAIN OUTCOME MEASURES: Rate of acute exacerbation of COPD (AECOPD) or pneumonia hospitalization in 2015, broken down by risk identifiers including previous AECOPD admission, 2 or more community respirologist consultations, nursing home residence, or none of these. RESULTS: Of the 242,509 identified COPD patients (12.9% of British Columbia residents ≥50 years), 2.8% were hospitalized for AECOPD in 2015 (0.038 AECOPD hospitalizations per patient-year). The 12.0% with prior AECOPD hospitalization accounted for 57.7% of new AECOPD hospitalizations (0.183 hospitalizations per patient-year); the 7.7% with respirologist involvement accounted for 20.4% (0.102 hospitalizations per patient-year); and the 2.2% in nursing homes accounted for 3.6% (0.061 hospitalizations per patient-year). Those with any of the 3 risk identifiers accounted for only 1.5% more COPD hospitalizations (59.2%) than those with prior AECOPD hospitalization, suggesting prior AECOPD hospitalization is the most important indication of risk. A typical primary care practice held a median of 23 (interquartile range=4 to 65) COPD patients, of whom roughly 20 (86.4%) had none of these risk identifiers. This low-risk majority had only 0.018 AECOPD hospitalizations per patient-year. CONCLUSION: Most AECOPD hospitalizations occur in patients with previous such admissions. When time and resources are limited, COPD initiatives targeting primary care practices should focus more on the 2 to 3 patients with prior AECOPD hospitalization or more symptomatic disease, and less on the low-risk majority.

Benefit-harm analysis of azithromycin for the prevention of acute exacerbations of chronic obstructive pulmonary disease.

BACKGROUND: Low-dose oral azithromycin therapy is recommended as a preventive treatment for acute exacerbations of COPD. However, the overall benefit-harm balance of this treatment has not been well studied. METHODS: A probabilistic Markov model of COPD was created to simulate the course of COPD over 20 years. The model was populated with evidence from the literature and dedicated data analysis. The benefit of azithromycin was modelled as a reduction in exacerbation rates. Adverse events, including cardiovascular events, hearing loss, gastrointestinal symptoms and antimicrobial resistance (leading to a gradual decline in the effectiveness of azithromycin), were considered. All outcomes were assigned a health-related utility weight to estimate the overall net change in the quality-adjusted life year (QALY) associated with the use of azithromycin. RESULTS: In patients with a positive exacerbation history, azithromycin resulted in a net QALY gain of 17.9 per 100 patients (99.8% probability of expected QALY gain) over 20 years. The net benefit increased to 21.8 QALYs per 100 patients (99.9% probability of expected QALY gain) among the 'frequent exacerbator' subgroup. Azithromycin was not net beneficial among those without any moderate/severe exacerbations in the previous year. Findings were robust against series of sensitivity, scenario and threshold analyses. CONCLUSIONS: Long-term therapy with azithromycin confers a net benefit to ex-smoker patients with COPD with a recent history of exacerbations and an even larger benefit to those who are frequent exacerbators.

Prevalence and characteristics of progressive fibrosing interstitial lung disease in a prospective registry.

BACKGROUND: Progressive fibrosing interstitial lung disease (PF-ILD) is characterised by progressive physiological, symptomatic and/or radiographic worsening. The real-world prevalence and characteristics of PF-ILD remain uncertain. METHODS: Patients were enrolled from the Canadian Registry for Pulmonary Fibrosis between 2015 and 2020. PF-ILD was defined as a relative forced vital capacity (FVC) decline ≥10%, death, lung transplantation or any two of: relative FVC decline ≥5% and <10%, worsening respiratory symptoms or worsening fibrosis on computed tomography of the chest, all within 24 months of diagnosis. Time-to-event analysis compared progression between key diagnostic subgroups. Characteristics associated with progression were determined by multivariable regression. RESULTS: Of 2746 patients with fibrotic ILD (mean±sd age 65±12 years; 51% female), 1376 (50%) met PF-ILD criteria in the first 24 months of follow-up. PF-ILD occurred in 427 (59%) patients with idiopathic pulmonary fibrosis (IPF), 125 (58%) with fibrotic hypersensitivity pneumonitis (HP), 281 (51%) with unclassifiable ILD (U-ILD) and 402 (45%) with connective tissue disease-associated ILD (CTD-ILD). Compared with IPF, time to progression was similar in patients with HP (hazard ratio (HR) 0.96, 95% CI 0.79-1.17), but was delayed in patients with U-ILD (HR 0.82, 95% CI 0.71-0.96) and CTD-ILD (HR 0.65, 95% CI 0.56-0.74). Background treatment varied across diagnostic subtypes, with 66% of IPF patients receiving antifibrotic therapy, while immunomodulatory therapy was utilised in 49%, 61% and 37% of patients with CHP, CTD-ILD and U-ILD, respectively. Increasing age, male sex, gastro-oesophageal reflux disease and lower baseline pulmonary function were independently associated with progression. CONCLUSIONS: Progression is common in patients with fibrotic ILD, and is similarly prevalent in HP and IPF. Routinely collected variables help identify patients at risk for progression and may guide therapeutic strategies.

Marginal Versus Conditional Odds Ratios When Updating Risk Prediction Models.

Risk prediction models often need to be updated when applied to new settings. A simple updating method involves fixed odds ratio transformation of predicted risks to adjust the model for outcome prevalence in the new setting. When a sample from the target population is available, the gold standard is to use a logistic regression model to estimate this odds ratio. A simpler method has been proposed that calculates this odds ratio from the prevalence estimates in the original and new samples. We show that the marginal odds ratio estimated in this way is generally closer to one than the correct (conditional) odds ratio; thus, the simpler method should be avoided when individual-level data are available. When such data are not available, we suggest an approximate method for recovering the conditional odds ratio from the variance of predicted risks in the development sample. Brief simulations and examples show that this approach reduces undercorrection, often substantially.

Healthcare Costs for Pneumococcal Disease in the Era of Infant Immunization With 13-Valent Pneumococcal Conjugate Vaccine: A Population-Based Study.

OBJECTIVES: Invasive pneumococcal disease (IPD) and a variety of clinical syndromes caused by pneumococci, such as acute otitis media (AOM), acute sinusitis (AS), and community-acquired pneumonia (CAP), cause a substantial burden on healthcare systems. Few studies have explored the short-term financial burden of pneumococcal disease after the 13-valent pneumococcal conjugate vaccine (PCV13) introduction in the infant immunization programs. This population-based study evaluated changes in costs associated with healthcare utilization for pneumococcal disease after the PCV13 introduction in the infant immunization program in British Columbia, Canada. METHODS: Individuals with pneumococcal disease were identified using provincial administrative data for the 2000 to 2018 period. Total direct healthcare costs were determined using case-mix methodology for hospitalization and fee-for-service codes for outpatient visits and medications dispensed. Costs were adjusted to 2018 Canadian dollars. Changes in the annual healthcare costs were evaluated across vaccine eras (pre-PCV13, 2000-2010; PCV13, 2011-2018) using generalized linear models, adjusting for the 7-valent pneumococcal conjugate vaccine program (2004-2010). RESULTS: During the 19-year study period, pneumococcal disease resulted in 6.3 million cases among 85 million total patient-years, resulting in total healthcare costs of $7.9 billion. More than 6.2 million cases were treated in outpatient setting, costing $0.65 billion (8% of total costs associated with pneumococcal disease treatment), whereas 370 000 hospitalized cases were 3% of all cases, which accrued $7.25 billion (92% of total costs) in costs. Healthcare costs for all studied infections nearly doubled over the study period from $248 million in 2000 to $476 million in 2018 (P = .003). In contrast, there were large declines in total annual costs in the PCV13 era for IPD (adjusted relative rate (aRR) 0.73; 95% confidence interval [CI] 0.56-0.95; P = .032), AOM (aRR 0.70; 95% CI 0.59-0.83; P = .001), and AS (aRR 0.68; 95% CI 0.54-0.85; P = .004) compared with the pre-PCV13 era. Total costs increased marginally in the PCV13 era for all-cause CAP (aRR 1.04; 95% CI 0.94-1.15; P = .484). CONCLUSIONS: This study confirms a temporal association in declining economic burden for IPD, AOM, and AS after the PCV13 introduction. Nevertheless, the total economic burden continues to be high in the PCV13 era, mainly driven by increasing CAP costs.