Run-in bias in randomised trials: the case of COPD medications

Comparative Effectiveness and Safety of Generic Versus Brand-Name Fluticasone-Salmeterol to Treat Chronic Obstructive Pulmonary Disease

BACKGROUND

In 2019, the U.S. Food and Drug Administration (FDA) approved the first generic maintenance inhaler for asthma and chronic obstructive pulmonary disease (COPD). The inhaler, Wixela Inhub (fluticasone-salmeterol; Viatris), is a substitutable version of the dry powder inhaler Advair Diskus (fluticasone-salmeterol; GlaxoSmithKline). When approving complex generic products like inhalers, the FDA applies a special "weight-of-evidence" approach. In this case, manufacturers were required to perform a randomized controlled trial in patients with asthma but not COPD, although the product received approval for both indications.

OBJECTIVE

To compare the effectiveness and safety of generic (Wixela Inhub) and brand-name (Advair Diskus) fluticasone-salmeterol among patients with COPD treated in routine care.

DESIGN

A 1:1 propensity score-matched cohort study.

SETTING

A large, longitudinal health care database.

PATIENTS

Adults older than 40 years with a diagnosis of COPD.

MEASUREMENTS

Incidence of first moderate or severe COPD exacerbation (effectiveness outcome) and incidence of first pneumonia hospitalization (safety outcome) in the 365 days after cohort entry.

RESULTS

Among 45 369 patients (27 305 Advair Diskus users and 18 064 Wixela Inhub users), 10 012 matched pairs were identified for the primary analysis. Compared with Advair Diskus use, Wixela Inhub use was associated with a nearly identical incidence of first moderate or severe COPD exacerbation (hazard ratio [HR], 0.97 [95% CI, 0.90 to 1.04]) and first pneumonia hospitalization (HR, 0.99 [CI, 0.86 to 1.15]).

LIMITATIONS

Follow-up times were short, reflecting real-world clinical practice. The possibility of residual confounding cannot be completely excluded.

CONCLUSION

Use of generic and brand-name fluticasone-salmeterol was associated with similar outcomes among patients with COPD treated in routine practice.

PRIMARY FUNDING SOURCE

National Heart, Lung, and Blood Institute.

Rational use of inhaled corticosteroids for the treatment of COPD

Inhaled corticosteroids (ICS) are the mainstay of treatment for asthma, but their role in chronic obstructive pulmonary disease (COPD) is debated. Recent randomised controlled trials (RCTs) conducted in patients with COPD and frequent or severe exacerbations demonstrated a significant reduction (~25%) in exacerbations with ICS in combination with dual bronchodilator therapy (triple therapy). However, the suggestion of a mortality benefit associated with ICS in these trials has since been rejected by the European Medicines Agency and US Food and Drug Administration. Observational evidence from routine clinical practice demonstrates that dual bronchodilation is associated with better clinical outcomes than triple therapy in a broad population of patients with COPD and infrequent exacerbations. This reinforces guideline recommendations that ICS-containing maintenance therapy should be reserved for patients with frequent or severe exacerbations and high blood eosinophils (~10% of the COPD population), or those with concomitant asthma. However, data from routine clinical practice indicate ICS overuse, with up to 50-80% of patients prescribed ICS. Prescription of ICS in patients not fulfilling guideline criteria puts patients at unnecessary risk of pneumonia and other long-term adverse events and also has cost implications, without any clear benefit in disease control. In this article, we review the benefits and risks of ICS use in COPD, drawing on evidence from RCTs and observational studies conducted in primary care. We also provide a practical guide to prescribing ICS, based on the latest global treatment guidelines, to help primary care providers identify patients for whom the benefits of ICS outweigh the risks.

Chronic Obstructive Pulmonary Disease Exacerbations and Pneumonia Hospitalizations Among New Users of Combination Maintenance Inhalers

Importance

Clinical guidelines on chronic obstructive pulmonary disease (COPD) recommend inhalers containing long-acting muscarinic antagonists (LAMAs) and long-acting β-agonists (LABAs) over inhalers containing inhaled corticosteroids (ICSs) and LABAs. However, data from randomized clinical trials comparing these combination inhalers (LAMA-LABAs vs ICS-LABAs) have been conflicting and raised concerns of generalizability.

Objective

To assess whether LAMA-LABA therapy is associated with reduced COPD exacerbations and pneumonia hospitalizations compared with ICS-LABA therapy in routine clinical practice.

Design, Setting, and Participants

This was a 1:1 propensity score-matched cohort study using Optum's Clinformatics Data Mart, a large commercial insurance-claims database. Patients must have had a diagnosis of COPD and filled a new prescription for a combination LAMA-LABA or ICS-LABA inhaler between January 1, 2014, and December 31, 2019. Patients younger than 40 years were excluded, as were those with a prior diagnosis of asthma. The current analysis was performed from February 2021 to March 2023.

Exposures

Combination LAMA-LABA inhalers (aclidinium-formoterol, glycopyrronium-formoterol, glycopyrronium-indacaterol, tiotropium-olodaterol, or umeclidinium-vilanterol) and combination ICS-LABA inhalers (budesonide-formoterol, fluticasone-salmeterol, fluticasone-vilanterol, or mometasone-formoterol).

Main Outcome

The primary effectiveness outcome was first moderate or severe COPD exacerbation, and the primary safety outcome was first pneumonia hospitalization. Propensity score matching was used to control for confounding between the 2 groups. Logistic regression analysis was used to estimate propensity scores. Hazard ratios (HRs) and 95% CIs were estimated using Cox proportional hazards models stratified on matched pairs.

Results

Among 137 833 patients (mean [SD] age, 70.2 [9.9] years; 69 530 [50.4%] female) (107 004 new ICS-LABA users and 30 829 new LAMA-LABA users), 30 216 matched pairs were identified for the primary analysis. Compared with ICS-LABA use, LAMA-LABA use was associated with an 8% reduction in the rate of first moderate or severe COPD exacerbation (HR, 0.92; 95% CI, 0.89-0.96) and a 20% reduction in the rate of first pneumonia hospitalization (HR, 0.80; 95% CI, 0.75-0.86). These findings were robust across a range of prespecified subgroup and sensitivity analyses.

Conclusion

In this cohort study, LAMA-LABA therapy was associated with improved clinical outcomes compared with ICS-LABA therapy, suggesting that LAMA-LABA therapy should be preferred for patients with COPD.

Emulation of Randomized Clinical Trials With Nonrandomized Database Analyses: Results of 32 Clinical Trials

Importance

Nonrandomized studies using insurance claims databases can be analyzed to produce real-world evidence on the effectiveness of medical products. Given the lack of baseline randomization and measurement issues, concerns exist about whether such studies produce unbiased treatment effect estimates.

Objective

To emulate the design of 30 completed and 2 ongoing randomized clinical trials (RCTs) of medications with database studies using observational analogues of the RCT design parameters (population, intervention, comparator, outcome, time [PICOT]) and to quantify agreement in RCT-database study pairs.

Design, Setting, and Participants

New-user cohort studies with propensity score matching using 3 US claims databases (Optum Clinformatics, MarketScan, and Medicare). Inclusion-exclusion criteria for each database study were prespecified to emulate the corresponding RCT. RCTs were explicitly selected based on feasibility, including power, key confounders, and end points more likely to be emulated with real-world data. All 32 protocols were registered on ClinicalTrials.gov before conducting analyses. Emulations were conducted from 2017 through 2022.

Exposures

Therapies for multiple clinical conditions were included.

Main Outcomes and Measures

Database study emulations focused on the primary outcome of the corresponding RCT. Findings of database studies were compared with RCTs using predefined metrics, including Pearson correlation coefficients and binary metrics based on statistical significance agreement, estimate agreement, and standardized difference.

Results

In these highly selected RCTs, the overall observed agreement between the RCT and the database emulation results was a Pearson correlation of 0.82 (95% CI, 0.64-0.91), with 75% meeting statistical significance, 66% estimate agreement, and 75% standardized difference agreement. In a post hoc analysis limited to 16 RCTs with closer emulation of trial design and measurements, concordance was higher (Pearson r, 0.93; 95% CI, 0.79-0.97; 94% meeting statistical significance, 88% estimate agreement, 88% standardized difference agreement). Weaker concordance occurred among 16 RCTs for which close emulation of certain design elements that define the research question (PICOT) with data from insurance claims was not possible (Pearson r, 0.53; 95% CI, 0.00-0.83; 56% meeting statistical significance, 50% estimate agreement, 69% standardized difference agreement).

Conclusions and Relevance

Real-world evidence studies can reach similar conclusions as RCTs when design and measurements can be closely emulated, but this may be difficult to achieve. Concordance in results varied depending on the agreement metric. Emulation differences, chance, and residual confounding can contribute to divergence in results and are difficult to disentangle.

Triple therapy in COPD: understanding the data

Effectiveness of single-inhaler triple therapy on exacerbation risk and mortality in COPD is exaggerated in IMPACT and ETHOS trials from confounding by prior ICS discontinuation: effectiveness fades in analyses and studies with no prior ICS discontinuation https://bit.ly/3tOgNdW.

Single-Inhaler Triple versus Dual Bronchodilator Therapy in COPD: Real-World Comparative Effectiveness and Safety

Purpose

Randomized trials report that single-inhaler triple therapy is more effective than dual bronchodilators at reducing exacerbations in patients with chronic obstructive pulmonary disease (COPD). However, this effect may have been influenced by the forced withdrawal of inhaled corticosteroids (ICS) at randomization. We used an adaptive selection new-user design to compare single-inhaler triple therapy with dual bronchodilators in real-world clinical practice.

Patients and Methods

We identified a cohort of COPD patients, 40 years or older, treated during 2017–2020, from the United Kingdom’s Clinical Practice Research Datalink, a real-world practice setting. ICS-naïve patients initiating single-inhaler triple therapy or dual bronchodilators were compared on the incidence of COPD exacerbation and pneumonia over one year, after adjustment by propensity score weighting.

Results

The cohort included 4106 new users of single-inhaler triple therapy and 29,702 of dual bronchodilators. Single-inhaler triple therapy was the first maintenance treatment in 44% of the users and 43% had no COPD exacerbations in the prior year. The adjusted hazard ratio (HR) of a first moderate or severe exacerbation with triple therapy relative to dual bronchodilators was 1.08 (95% confidence interval (CI): 1.00–1.16). Among patients with two or more prior exacerbations the HR was 0.83 (95% CI: 0.74–0.92), while for those with prior asthma diagnosis it was 0.86 (95% CI: 0.70–1.06) and with blood eosinophil count >300 cells/µL it was 0.89 (95% CI: 0.76–1.05). The incidence of severe pneumonia was increased with triple therapy (HR 1.50; 95% CI: 1.29–1.75).

Conclusion

In a real-world setting of COPD treatment among ICS-naïve patients, thus unaffected by ICS withdrawal, single-inhaler triple therapy was not more effective than dual bronchodilators at reducing the incidence of exacerbation, except among patients with multiple exacerbations. Single-inhaler triple therapy should be initiated mainly in patients with multiple exacerbations while, for most others, dual bronchodilators are just as effective whilst avoiding the excess risk of severe pneumonias.

Triple Inhaler versus Dual Bronchodilator Therapy in COPD: Real-World Effectiveness on Mortality

Randomized trials of triple therapy including an inhaled corticosteroid (ICS) for chronic obstructive pulmonary disease (COPD) reported remarkable benefits on mortality compared with dual bronchodilators, likely resulting from ICS withdrawal at randomization. We compared triple therapy with dual bronchodilator combinations on major COPD outcomes in a real-world clinical practice setting. We identified a cohort of COPD patients, age 50 or older, treated during 2002-2018, from the United Kingdom's Clinical Practice Research Datalink. Patients initiating treatment with a long-acting muscarinic antagonist (LAMA), a long-acting beta₂-agonist (LABA) and an ICS on the same day, were compared with patients initiating a LAMA and LABA, weighted by fine stratification of propensity scores. Subjects were followed-up one year for all-cause mortality, severe exacerbation and pneumonia. The cohort included 117,729 new-users of LAMA-LABA-ICS and 26,666 of LAMA-LABA. The adjusted hazard ratio (HR) of all-cause mortality with LAMA-LABA-ICS compared with LAMA-LABA was 1.17 (95% CI: 1.04-1.31) while for severe exacerbation and pneumonia it was 1.19 (1.08-1.32) and 1.29 (1.16-1.45) respectively. However, mortality was not elevated with triple therapy among patients with asthma diagnosis (HR 0.99; 95% CI: 0.74-1.34), with two or more prior exacerbations (HR 0.88; 95% CI: 0.70-1.11), and with FEV₁ percent predicted >30%. In a real-world setting of COPD treatment, triple therapy initiation was not more effective than dual bronchodilators at preventing all-cause mortality and severe COPD exacerbations. Triple therapy may be unsafe among patients without prior exacerbations, in whom ICS are not recommended, with no asthma diagnosis and with very severe airflow obstruction.

Ten Commandments for Randomized Trials of Pharmacological Therapy for COPD and Other Lung Diseases

The randomized controlled trial is the quintessential scientific tool to evaluate the effectiveness and safety of medications. While early trials of drugs used for the treatment of chronic obstructive pulmonary disease (COPD) and other respiratory diseases were generally unambiguous, more recent studies have been controversial. It has become evident that the conduct, design and analysis of these trials were highly variable and may have been responsible for incoherencies in results and interpretation. With the advent of new studies, the need for guiding principles for the conduct of future randomized trials has become manifest. We describe the concept of the counterfactual principle as it applies to the treatment of patients and to the randomized trial. We then present ten methodological tenets for the design and statistical aspects of randomized controlled trials evaluating the effectiveness of drugs used in the treatment of several respiratory diseases. They include eight study design and two statistical analysis principles: 1) Study question; 2) Intervention; 3) Study population; 4) Blinding; 5) Run-in period; 6) Follow-up; 7) Outcome; 8) Safety; 9) Intent-to-treat; 10) Covariate adjustment. These tenets are described using mainly examples from trials of pharmacological treatments for COPD, as well as some from asthma and idiopathic pulmonary fibrosis, conducted over the last 30 years. The careful application of these principles in the conduct of randomized trials will provide rigorous studies and improve the validity of results. The ensuing clearer interpretation of findings will permit their well-founded contribution to treatment guidelines and optimal clinical management.

Microenterprise Intervention to Reduce Sexual Risk Behaviors and Increase Employment and HIV Preventive Practices Among Economically-Vulnerable African-American Young Adults (EMERGE): A Feasibility Randomized Clinical Trial

Economic vulnerability, such as homelessness and unemployment, contributes to HIV risk among U.S. racial minorities. Yet, few economic-strengthening interventions have been adapted for HIV prevention in this population. This study assessed the feasibility of conducting a randomized clinical trial of a 20-week microenterprise intervention for economically-vulnerable African-American young adults. Engaging MicroenterprisE for Resource Generation and Health Empowerment (EMERGE) aimed to reduce sexual risk behaviors and increase employment and uptake of HIV preventive behaviors. The experimental group received text messages on job openings plus educational sessions, mentoring, a start-up grant, and business and HIV prevention text messages. The comparison group received text messages on job openings only. Primary feasibility objectives assessed recruitment, randomization, participation, and retention. Secondary objectives examined employment, sexual risk behaviors, and HIV preventive behaviors. Outcome assessments used an in-person pre- and post-intervention interview and a weekly text message survey. Several progression criteria for a definitive trial were met. Thirty-eight participants were randomized to experimental (n = 19) or comparison group (n = 19) of which 95% were retained. The comparison intervention enhanced willingness to be randomized and reduced non-participation. Mean age of participants was 21.0 years; 35% were male; 81% were unemployed. Fifty-eight percent (58%) of experimental participants completed ≥ 70% of intervention activities, and 74% completed ≥ 50% of intervention activities. Participation in intervention activities and outcome assessments was highest in the first half (~ 10 weeks) of the study. Seventy-one percent (71%) of weekly text message surveys received a response through week 14, but responsiveness declined to 37% of participants responding to ≥ 70% of weekly text message surveys at the end of the study. The experimental group reported higher employment (from 32% at baseline to 83% at week 26) and lower unprotected sex (79% to 58%) over time compared to reported changes in employment (37% to 47%) and unprotected sex (63% to 53%) over time in the comparison group. Conducting this feasibility trial was a critical step in the process of designing and testing a behavioral intervention. Development of a fully-powered effectiveness trial should take into account lessons learned regarding intervention duration, screening, and measurement.Trial Registration ClinicalTrials.gov. NCT03766165. Registered 04 December 2018. https://clinicaltrials.gov/ct2/show/NCT03766165.

Efficacy and safety of two doses of budesonide/formoterol fumarate metered dose inhaler in COPD

Inhaled corticosteroid/long-acting β₂-agonist combination therapy is a recommended treatment option for patients with chronic obstructive pulmonary disease (COPD) and increased exacerbation risk, particularly those with elevated blood eosinophil levels. SOPHOS (NCT02727660) evaluated the efficacy and safety of two doses of budesonide/formoterol fumarate dihydrate metered dose inhaler (BFF MDI) versus formoterol fumarate dihydrate (FF) MDI, each delivered using co-suspension delivery technology, in patients with moderate-to-very severe COPD and a history of exacerbations.

In this phase 3, randomised, double-blind, parallel-group, 12–52-week, variable length study, patients received twice-daily BFF MDI 320/10 µg or 160/10 µg, or FF MDI 10 µg. The primary endpoint was change from baseline in morning pre-dose trough forced expiratory volume in 1 s (FEV₁) at week 12. Secondary and other endpoints included assessments of moderate/severe COPD exacerbations and safety.

The primary analysis (modified intent-to-treat) population included 1843 patients (BFF MDI 320/10 µg, n=619; BFF MDI 160/10 µg, n=617; and FF MDI, n=607). BFF MDI 320/10 µg and 160/10 µg improved morning pre-dose trough FEV₁ at week 12 versus FF MDI (least squares mean differences 34 mL [p=0.0081] and 32 mL [p=0.0134], respectively), increased time to first exacerbation (hazard ratios 0.827 [p=0.0441] and 0.803 [p=0.0198], respectively) and reduced exacerbation rate (rate ratios 0.67 [p=0.0001] and 0.71 [p=0.0010], respectively). Lung function and exacerbation benefits were driven by patients with blood eosinophil counts ≥150 cells·mm⁻³. The incidence of adverse events was similar, and pneumonia rates were low (≤2.4%) across treatments.

SOPHOS demonstrated the efficacy and tolerability of BFF MDI 320/10 µg and 160/10 µg in patients with moderate-to-very severe COPD at increased risk of exacerbations.

Co-suspension delivery technology budesonide/formoterol fumarate metered dose inhaler improve lung function and reduce exacerbation risk versus LABA monotherapy in patients with moderate to very severe COPD and an exacerbation history in the prior yearhttp://bit.ly/3aDOvru

Comparative Effects of LAMA-LABA-ICS vs LAMA-LABA for COPD: Cohort Study in Real-World Clinical Practice

BACKGROUND

Triple therapy combinations of a long-acting muscarinic antagonist (LAMA), a long-acting beta₂-agonist (LABA), and an inhaled corticosteroid (ICS) for COPD were studied in randomized trials and observational studies, with variable results. We compared the effectiveness and safety of triple therapy with a LAMA-LABA combination in a real-world clinical practice setting.

METHODS

We identified a cohort of patients with COPD during 2002 through 2015, ≥ 55 years of age, from the UK's Clinical Practice Research Datalink. Patients initiating LAMA-LABA-ICS were matched 4:1 on time-conditional propensity scores with patients initiating LAMA-LABA, and followed for 1 year for the occurrence of a moderate or severe COPD exacerbation and severe pneumonia.

RESULTS

The cohort included 6,921 initiators of LAMA-LABA-ICS matched to 1,932 initiators of LAMA-LABA. The adjusted hazard ratio (HR) of a COPD exacerbation associated with LAMA-LABA-ICS initiation compared with LAMA-LABA initiation was 0.97 (95% CI, 0.87-1.08). For patients with blood eosinophil counts > 6%, the HR was 0.66 (95% CI, 0.46-0.94). For patients with two or more prior exacerbations, it was 0.83 (95% CI, 0.70-0.98). The incidence of severe pneumonia requiring hospitalization was increased with LAMA-LABA-ICS initiation (HR, 1.46; 95% CI, 1.03-2.06).

CONCLUSIONS

In a real-world setting of COPD treatment, the triple combination of LAMA, LABA, and ICS inhalers is generally as effective as combining LAMA and LABA inhalers in preventing COPD exacerbations. However, with the possible exception of patients with significant eosinophilia or frequent exacerbators, a LAMA-LABA combination without ICS may be preferable because it is associated with fewer severe cases of pneumonia.

Microenterprise intervention to reduce sexual risk behaviors and increase employment and HIV preventive practices in economically-vulnerable African-American young adults (EMERGE): protocol for a feasibility randomized clinical trial

Background

Economic vulnerability, such as homelessness and unemployment, contributes to the HIV risk among racial minorities in the U.S., who are disproportionately infected. Yet, few economic-strengthening interventions have been adapted for HIV prevention in economically-vulnerable African-American young adults. Engaging Microenterprise for Resource Generation and Health Empowerment (EMERGE) is a feasibility randomized clinical trial of an HIV prevention microenterprise intervention with integrated text messages (“nudges”) that are informed by behavioral economic principles. The trial aims to reduce sexual risk behaviors and increase employment and uptake of HIV preventive behaviors.

Methods/design

In total, 40 young adults who are African-American, aged 18–24, live in Baltimore City, have experienced at least one episode of homelessness in the last 12 months, are unemployed or underemployed (fewer than 10 h per week), are not enrolled in school, own a cell phone with text messaging, and report at least one episode of unprotected or unsafe sex in the prior 12 months will be recruited from two community-based organizations providing residential supportive services to urban youth. Participants will undergo a 3-week run-in period and thereafter be randomly assigned to one of two groups with active interventions for 20 weeks. The first group (“comparison”) will receive text messages with information on job openings. The second group (“experimental”) will receive text messages with information on job openings plus information on HIV prevention and business educational sessions, a mentored apprenticeship, and a start-up grant, and business and HIV prevention text messages based on principles from behavioral economics. The two primary outcomes relate to the feasibility of conducting a larger trial. Secondary outcomes relate to employment, sexual risk behaviors, and HIV preventive practices. All participants will be assessed using an in-person questionnaire at pre-intervention (prior to randomization) and at 3 weeks post-intervention. To obtain repeated, longitudinal measures, participants will be assessed weekly using text message surveys from pre-intervention up to 3 weeks post-intervention.

Discussion

This study will be one of the first U.S.-based feasibility randomized clinical trials of an HIV prevention microenterprise intervention for economically-vulnerable African-American young adults. The findings will inform whether and how to conduct a larger efficacy trial for HIV risk reduction in this population.

Trial registration

ClinicalTrials.gov, NCT03766165. Registered on 4 December 2018.

Electronic supplementary material

The online version of this article (10.1186/s13063-019-3529-7) contains supplementary material, which is available to authorized users.

Comparative Effectiveness and Safety of LABA-LAMA vs LABA-ICS Treatment of COPD in Real-World Clinical Practice

BACKGROUND

Long-acting β₂-agonists (LABAs) and long-acting muscarinic antagonists (LAMAs) are recommended as initial maintenance treatments for COPD, with their combination (LABA-LAMA) advocated as the disease progresses. Randomized trials comparing the effectiveness of this combination with the alternative combination of LABA with inhaled corticosteroid (LABA-ICS) have reported conflicting data, while there are no real-world comparative effectiveness and safety studies of these regimens in clinical practice settings.

METHODS

We identified a cohort of patients with COPD during 2002-2015, age 55 years or older, from the United Kingdom's Clinical Practice Research Datalink. Patients initiating LABA-LAMA on the same day (no ICS) were matched on time-conditional high-dimensional propensity scores with patients initiating LABA-ICS on the same day (no LAMA), and monitored for 1 year for the occurrence of a moderate or severe COPD exacerbation and severe pneumonia.

RESULTS

The cohort included 1,977 initiators of LABA-LAMA matched with 1,977 initiators of LABA-ICS. The hazard ratio (HR) of moderate or severe COPD exacerbation associated with LABA-LAMA initiation, relative to LABA-ICS initiation, was 1.04 (95% CI, 0.90-1.20), while for a severe exacerbation it was 0.94 (95% CI, 0.65-1.36). The incidence of severe pneumonia requiring hospitalization was lower with LABA-LAMA initiation (HR, 0.66; 95% CI, 0.41-1.05), particularly in the on-treatment analysis (HR, 0.66; 95% CI, 0.50-0.87).

CONCLUSIONS

In a real-world clinical practice setting of COPD treatment, combined LABA-LAMA inhalers appear to be as effective as combined LABA-ICS inhalers in preventing COPD exacerbations. However, a LABA-LAMA combination may be preferred because it is associated with fewer severe pneumonias.

Comparative effectiveness of LABA-ICS versus LAMA as initial treatment in COPD targeted by blood eosinophils: a population-based cohort study

BACKGROUND

Long-acting β₂ agonists (LABAs) and long-acting muscarinic antagonists (LAMAs) are the recommended initial maintenance treatment for chronic obstructive pulmonary disease (COPD), with almost all LABAs dispensed in fixed combination with inhaled corticosteroids (LABA-ICS). We compared the effectiveness and safety of LABA-ICS versus LAMA treatment initiation as a function of blood eosinophilia, a potential biomarker of ICS effectiveness, in a real-world setting.

METHODS

In this population-based cohort study, we identified a cohort of patients with COPD initiating treatment with a LAMA or LABA-ICS during 2002-15, age 55 years or older, from the UK's Clinical Practice Research Datalink. We excluded patients who initiated treatment with both bronchodilators on the same date. All patients required at least 1 year of medical history and a measure of blood eosinophil concentration before cohort entry, defined by the date of the first cohort-defining bronchodilator prescription. Patients initiating a LAMA were matched on high-dimensional propensity scores with patients initiating a LABA-ICS. They were followed up for 1 year for the occurrence of a moderate or severe COPD exacerbation and for severe pneumonia. Sensitivity analyses included, among others, repeating the analysis among patients with two blood eosinophil concentration measures and stratification by concurrent asthma and previous exacerbations.

FINDINGS

The base cohort included 539 643 patients with a prescription for LABAs or LAMAs from Jan 1, 2002, to Dec 31, 2015, of whom 18 500 were initiated on LABA-ICS and 13 870 on LAMAs. Propensity score analysis resulted in 12 366 initiators of LAMAs (mainly tiotropium) matched to 12 366 initiators of LABA-ICS. The hazard ratio (HR) of COPD exacerbation associated with LABA-ICS initiation, relative to LAMA initiation, was 0·95 (95% CI 0·90-1·01). In patients with blood eosinophil concentrations of less than 2% of white blood cell count, the HR was 1·03 (95% CI 0·93-1·13) and for those with eosinophil concentrations of 2-4%, the HR was 1·00 (0·91-1·10). For patients with eosinophil concentrations of more than 4%, the HR was 0·79 (0·70-0·88). The incidence of pneumonia increased with LABA-ICS initiation (HR 1·37 [95% CI 1·17-1·60]) and was similar across all eosinophil concentrations. Sensitivity analyses were consistent with these findings, but the incidence of exacerbation with LABA-ICS among the 2766 (11%) of all 24 732 patients with two or more COPD exacerbations during the baseline year was marginally lower (HR 0·87 [95% CI 0·79-0·97]).

INTERPRETATION

In this real-world, clinical practice, observational study, initial COPD treatment with LABA-ICS inhalers was only more effective than with LAMAs in patients with high blood eosinophil concentrations (>4%) or counts (>300 cells per μL) and possibly in frequent exacerbators. Because of the increased risk of pneumonia associated with the ICS component, initiation with a LAMA should be preferred in patients with blood eosinophil concentrations of less than 4%.

FUNDING

Canadian Institutes of Health Research, Canadian Foundation for Innovation.

Cardiovascular disease and COPD: dangerous liaisons?

Chronic obstructive pulmonary disease (COPD) and cardiovascular disease (CVD) frequently occur together and their coexistence is associated with worse outcomes than either condition alone. Pathophysiological links between COPD and CVD include lung hyperinflation, systemic inflammation and COPD exacerbations. COPD treatments may produce beneficial cardiovascular (CV) effects, such as long-acting bronchodilators, which are associated with improvements in arterial stiffness, pulmonary vasoconstriction, and cardiac function. However, data are limited regarding whether these translate into benefits in CV outcomes. Some studies have suggested that treatment with long-acting β₂-agonists and long-acting muscarinic antagonists leads to an increase in the risk of CV events, particularly at treatment initiation, although the safety profile of these agents with prolonged use appears reassuring. Some CV medications may have a beneficial impact on COPD outcomes, but there have been concerns about β-blocker use leading to bronchospasm in COPD, which may result in patients not receiving guideline-recommended treatment. However, there are few data suggesting harm with these agents and patients should not be denied β-blockers if required. Clearer recommendations are necessary regarding the identification and management of comorbid CVD in patients with COPD in order to facilitate early intervention and appropriate treatment.