Samy Suissa

Samy Suissa
McGill University | McGill · Centre for Clinical Epidemiology and Community Studies

PhD

About

634
Publications
57,673
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
41,504
Citations
Additional affiliations
January 2009 - December 2013
January 1997 - December 2012
McGill University

Publications

Publications (634)
Article
Triple therapy for chronic obstructive pulmonary disease (COPD) is recommended for some patients, but the inhaled corticosteroids (ICS) may differ in effectiveness and safety. We compared budesonide-based and fluticasone-based triple therapy given in two inhalers on the incidence of exacerbation, mortality and severe pneumonia, using an observation...
Article
Recent reports provide evidence-based guidelines for the withdrawal of inhaled corticosteroids (ICS) in COPD, but data on patients treated with ICS-based triple therapy are sparse and contradictory. We assessed the effect of ICS discontinuation on the incidence of severe exacerbation and pneumonia in a real-world population of patients with COPD wh...
Article
Objective: To evaluate whether the increased risk of breast cancer is dependent on the formulation of menopausal hormone therapy (HT) used. Methods: We performed a population-based case-control study of women aged 50 years or older using data from the U.K. Clinical Practice Research Datalink. Women with incident cases of breast cancer were age-m...
Article
Objective: Assess the effect of statin use on the risk of cardiovascular disease (CVD), all-cause mortality, and type 2 diabetes mellitus (T2DM) in patients with rheumatoid arthritis (RA). Methods: We identified a cohort of patients with RA between 1989 and 2018, within the UK Clinical Practice Research Datalink (CPRD). We employed a prevalent n...
Article
Background Guidelines for the treatment of chronic obstructive pulmonary disease (COPD) patients with multiple exacerbations and eosinophilia recommend a long-acting beta2-agonist (LABA) and inhaled corticosteroid (ICS) combined inhaler, with no distinction between different agents. We compared the effectiveness and safety of budesonide-formoterol...
Article
Recent trials reported significant reductions in all-cause mortality with single-inhaler triple therapy for chronic obstructive pulmonary disease (COPD). However, reviews of these trials identified inconsistencies in the findings and methodological issues with the design and analysis, including the “adverse impact of inhaled corticosteroid (ICS) wi...
Article
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...
Article
Several observational studies report decreased incidence of mortality and of exacerbations with aspirin use in patients with chronic obstructive pulmonary disease (COPD), with calls for a large randomized trial. Aspirin does have local and systemic pulmonary mechanisms of action that could make this drug beneficial in the treatment of COPD. However...
Article
Full-text available
Objective To determine whether new users of proton pump inhibitors (PPIs) are at an increased risk of gastric cancer compared with new users of histamine-2 receptor antagonists (H2RAs). Design Using the UK Clinical Practice Research Datalink, we conducted a population-based cohort study using a new-user active comparator design. From 1 January 199...
Article
Objective To determine whether proton pump inhibitors (PPIs) are associated with an increased risk of colorectal cancer, compared with histamine-2 receptor antagonists (H2RAs). Design The United Kingdom Clinical Practice Research Datalink was used to identify initiators of PPIs and H2RA from 1990 to 2018, with follow-up until 2019. Cox proportiona...
Article
We thank Weisman et al for their letter regarding our review of the observational studies reporting on the effectiveness of allopurinol on reducing mortality, particularly the studies affected by immeasurable time bias.1,2 Indeed, our review explained that immeasurable time bias can be an important complexity in observational studies where the outc...
Article
Objective Several observational studies reported that allopurinol, an effective treatment for gout, was associated with important reductions in cardiovascular events, with calls for large randomized trials, though some results were conflicting. We assessed the extent of time-related biases in these observational studies. Methods We searched the li...
Article
Full-text available
Importance: Ondansetron is frequently used to treat nausea and vomiting during pregnancy. Although some studies reported important safety signals, few studies have been sufficiently large to assess rare pregnancy outcomes. Objective: To study the association between ondansetron exposure during pregnancy and the risks of spontaneous abortion, sti...
Article
Background: Previous studies suggested a link between various infectious pathogens and the development of Alzheimer's disease (AD), posing the question whether infectious disease could present a novel modifiable risk factor. Objective: To assess whether infectious disease burden due to clinically apparent infections is associated with an increas...
Article
Objective: The treatment of gout with allopurinol is effective at reducing urate levels and the frequency of flares. Several observational studies reported important reductions in mortality with allopurinol use, with wide variations in results. The extent of bias in these studies, particularly time-related biases such as immortal time bias, is unc...
Article
The Global Initiative for Chronic Obstructive Lung Disease (GOLD) recommendations for the initial bronchodilator to use in newly diagnosed chronic obstructive pulmonary disease (COPD) are based on trials of patients with longstanding disease and treatment. We compared the real world effectiveness of initial treatment with long-acting muscarinic age...
Article
The coronavirus disease 2019 (COVID-19) pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has led to an unprecedented effort to generate real-world evidence on the safety and effectiveness of various treatments. A growing number of observational studies evaluating the effects of certain drugs have been conducted, i...
Article
Objective Randomized controlled trials of the effectiveness of statins on rheumatic disease outcomes have shown limited or no benefit. On the other hand, observational studies have reported remarkable effectiveness of statins at reducing mortality in patients with rheumatic diseases. We evaluated these observational studies for the presence of immo...
Article
The prevalent new-user cohort design is useful to assess the effectiveness of a drug in the absence of an active comparator. Alternative approaches, particularly in the presence of informative censoring, include a variant of this design based on never-users of the study drug and the marginal structural Cox model approach. These were compared in ass...
Article
Full-text available
Objective: To compare the risk of cardiovascular events between sodium glucose cotransporter 2 (SGLT2) inhibitors and dipeptidyl peptidase-4 (DPP-4) inhibitors among people with type 2 diabetes in a real world context of clinical practice. Design: Multi-database retrospective cohort study using a prevalent new user design with subsequent meta-an...
Article
Background Gastroesophageal reflux disease is a common co-morbidity in idiopathic pulmonary fibrosis (IPF) and may contribute to its progression. Anti-acid therapy, such as proton pump inhibitors (PPIs), has been considered as a potential treatment option for IPF. The evidence for this treatment comes from several observational studies affected by...
Article
Purpose Observational studies using computerized healthcare databases have become popular to investigate the potential effectiveness of old drugs for new indications. Many of these studies reporting remarkable effectiveness were shown to be affected by different time‐related biases. We describe these biases and illustrate their effects using a coho...
Article
Aims: To determine the risk of fracture associated with direct oral anticoagulants (DOACs) compared with vitamin K antagonists (VKAs) in patients with nonvalvular atrial fibrillation (NVAF), accounting for cumulative duration of use. Methods and results: Using Quebec administrative healthcare databases, we formed a cohort of all patients aged 40...
Article
The association between aromatase inhibitors and cardiovascular outcomes is controversial. While some observational studies have assessed their cardiovascular safety as up-front treatments, their cardiotoxic effects as sequential treatments with tamoxifen remains unknown. Thus, we conducted a population-based cohort study using the United Kingdom C...
Article
Background The association between aromatase inhibitors and cardiovascular outcomes among women with breast cancer is controversial. Given the discrepant findings from randomized controlled trials and observational studies, additional studies are needed to address this safety concern. Methods We conducted a population-based cohort study using the...
Article
A recent study found a decreased risk of Parkinson's disease (PD) associated with the β2 agonist salbutamol. However, other mechanisms may explain this apparent association. Using the United Kingdom Clinical Practice Research Datalink, we formed a cohort of 2,430,884 patients aged 50 or over between 1995 and 2016. During follow-up, 8,604 cases of P...
Article
Full-text available
Background: Several registries of idiopathic pulmonary fibrosis (IPF) have been established to better understand its natural history, though their size and duration of follow-up are limited. Here, we describe the large European MultiPartner IPF Registry (EMPIRE) and validate predictors of long-term survival in IPF. Methods: The multinational pro...
Article
In their Letter to the Editor1, the authors asserted that biased and inconsistent studies were included in a meta‐analysis by Ripamonti et al.2 Let us clarify that in the cited paper2 we showed heterogeneity measures, but no pooled estimate has been calculated for any effect measure, exactly for the reason that included studies were, for different...
Article
A traditional principle of the randomized controlled trial is that the p-value comparing treatment groups should be computed from the simple crude data. This assumes that the size of the study is sufficiently large for an accurate and precise estimation of the difference between groups. There are situations where the accuracy and precision of the s...
Article
Background Inhaled corticosteroids (ICS) are suggested as potential chemoprevention of lung cancer. Several observational studies in patients with COPD reported inconsistent results, either significant reductions in lung cancer incidence with ICS use or no effect. We assessed this association, using an approach that avoided biases affecting some of...
Article
Full-text available
Background: Patients with rheumatoid arthritis (RA) are at an increased risk of developing certain cancers and infections compared with the general population. Biologic and targeted synthetic disease-modifying antirheumatic drugs (b/tsDMARDs) are effective treatment options for RA, but limited evidence is available on the comparative risks among b...
Article
Background: Triple therapy combinations of a long-acting muscarinic antagonist, a long-acting beta2-agonist and an inhaled corticosteroid (LAMA-LABA-ICS) for chronic obstructive pulmonary disease (COPD) were studied in randomized trials and observational studies, with variable results. We compared the effectiveness and safety of triple therapy to...
Article
Aim: To assess the incidence of cardiovascular and hypoglycaemic adverse events associated with glimepiride compared with other second-generation sulphonylureas among patients with type 2 diabetes in a real-world clinical setting. Materials and methods: We identified all sulphonylurea initiators between 1998 and 2017 in the UK Clinical Practice...
Article
Objectives: Abatacept, a biologic DMARD, was associated with respiratory adverse events in a small subgroup of RA patients with chronic obstructive pulmonary disease (COPD) in a trial. Whether this potential risk is specific to abatacept or extends to all biologics and targeted synthetic DMARDs (tsDMARDs) is unclear. We assessed the risk of advers...
Article
Aims: Sulfonylureas are recommended as second-line treatment in the management of type 2 diabetes. However, they are still commonly used also as first-line treatment instead of metformin. Given the controversial cardiovascular safety of sulfonylureas, we aimed to determine if their use as first-line treatment is associated with adverse cardiovascu...
Article
Full-text available
Introduction The new user cohort design is widely used to assess the effects of a new drug, such as dabigatran, but inherently excludes some users due to prior use of the comparator drug, for example warfarin. The prevalent new-user design offers a solution that includes all eligible users of the new drug. Objective To evaluate the safety and effe...
Article
Objective: To assess whether abatacept as initial biologic disease-modifying antirheumatic drug (DMARD) in the treatment of rheumatoid arthritis is associated with an increased risk of serious infections, including bone and joint, gastrointestinal, respiratory tract, skin and soft tissue, and urinary tract, when compared with other biologic DMARDs...
Conference Paper
Background The abatacept global post-marketing epidemiology programme consists of observational studies based on biologic disease registries and healthcare claims databases to assess infection and malignancy risks associated with abatacept treatment, as used in routine clinical practice. Objectives To evaluate the risk of infection in patients wit...
Conference Paper
Background The abatacept global post-marketing epidemiology programme includes observational studies based on biologic disease registries and healthcare claims database studies to evaluate infection and malignancy risks associated with abatacept treatment, as used in routine clinical practice. Objectives To assess the risk of solid tumour malignan...
Conference Paper
Background The biologic DMARD abatacept has been associated with respiratory adverse events in patients with RA who have chronic obstructive pulmonary disease (COPD) in the ASSURE trial (NCT00048932), based on only 54 patients with RA and COPD.¹ A large observational study of patients with RA and COPD, involving over 1,800 patients using abatacept...
Article
Objectives To explore the trends and the predictors of incident malignant cancer among patients with inflammatory bowel disease (IBD). Methods We identified a cohort of all patients with incident IBD in Quebec, Canada, from 1998 to 2015, using provincial administrative healthcare databases (RAMQ and Med-Echo). Annual incidence rates (IRs) of cance...
Article
Objective: The ASSURE randomized trial of abatacept safety in rheumatoid arthritis (RA) reported more frequent respiratory adverse events with abatacept among the subgroup of 54 patients with chronic obstructive pulmonary disease (COPD), leading to a label warning. We assessed the risk of adverse respiratory events associated with abatacept, compa...
Article
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 cortic...
Article
Importance Some reports have raised concerns regarding a potential psychiatric worsening associated with first-time use of aripiprazole in patients already treated with other antipsychotic medications. Whether aripiprazole use, particularly in the long term, increases the risk for serious psychiatric events is unclear. Objective To assess whether...
Article
Aims To conduct a systematic review of all observational studies of the effect of pioglitazone on the risk of bladder cancer. Methods The MEDLINE and EMBASE databases were queried for papers published between January 1, 2000 and October 30, 2017. We took into consideration observational studies (both retrospective and prospective) including partic...
Article
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 t...
Article
Purpose: Patients with nonvalvular atrial fibrillation commonly have comorbidities requiring concurrent use of oral anticoagulants and antiplatelets. There are no real-world data on the comparative safety of concomitant antithrombotic treatments in the era of direct oral anticoagulant (DOACs). Thus, we compared the incidence of intracranial hemorr...
Article
The use of beta-blockers in patients with chronic obstructive pulmonary disease (COPD) has received much attention. Several observational studies reported important reductions in mortality and exacerbations with these drugs, but the extent of bias in these studies is unclear. Nevertheless, the large ongoing randomized trial (βLOCK-COPD) was initiat...
Article
Full-text available
Objective To assess whether adding or switching to sulfonylureas is associated with an increased risk of myocardial infarction, ischaemic stroke, cardiovascular death, all cause mortality, and severe hypoglycaemia, compared with remaining on metformin monotherapy in patients with type 2 diabetes. Design Population based cohort study. Setting Gene...
Article
International treatment guidelines for idiopathic pulmonary fibrosis (IPF) give a conditional recommendation for anti-acid therapy. As some observational studies reported discrepant findings on the effectiveness of anti-acid therapy on mortality in IPF, we reviewed all studies to evaluate whether immortal time bias explains these discrepancies. We...
Article
Background: Randomized controlled trials at times investigate findings suggested by observational studies. For example, the TORCH trial, which did not show a mortality reduction with inhaled corticosteroids (ICS) in chronic obstructive pulmonary disease (COPD), was motivated by some observational studies that suggested considerable reductions in m...
Article
Full-text available
Objective Unlike several other national health agencies, French health authorities recommended that the newer direct oral anticoagulant (DOAC) agents only be prescribed as second choice for the treatment of newly diagnosed non-valvular atrial fibrillation (NVAF), with vitamin K antagonists (VKA) remaining the first choice. We investigated the patte...
Article
Full-text available
Objectives To evaluate the effectiveness and safety of novel oral anticoagulants (NOACs) compared with vitamin K antagonists (VKAs) among patients with non-valvular atrial fibrillation (NVAF), particularly those with chronic kidney disease (CKD). Design Population-based matched cohort study. Setting Over 670 primary care practices in the UK, cont...
Article
Objective: To evaluate the association of cesarean deliveries on the incidence of small bowel obstruction. Methods: We formed a population-based cohort of all women with a first live birth between 1998 and 2007 using the U.K. Clinical Practice Research Datalink. Women were followed until 2015, the occurrence of a small bowel obstruction, or loss...
Article
Objective: To investigate whether fungus-derived statins are associated with a lower risk of incident Alzheimer disease (AD) compared with synthetic statins using real-world clinical practice data. Methods: We identified a population-based retrospective cohort of patients aged ≥60 years newly prescribed a statin between January 1, 1994, and Dece...
Article
IntroductionMany autoimmune diseases, including rheumatoid arthritis (RA), share common mechanisms; however, population-based studies of the magnitude of multiple autoimmune diseases in patients with RA have not been performed. Methods We conducted a cross-sectional study using a US administrative healthcare thcare claims database to screen for pre...
Article
Purpose: Studies on long-term utilization of non-vitamin K antagonist oral anticoagulants (NOACs) in non-valvular atrial fibrillation (NVAF) are scarce. We evaluated predictors of use and long-term persistence of NOACs in a real-world setting. Methods: This population-based cohort study used the computerized databases of the Canadian Province of...
Article
Purpose: The magnitude of the risk of severe hypoglycemia associated with sulfonylureas as the initial treatment for type 2 diabetes in the real-world setting is unknown. We assessed the risk of severe hypoglycemia associated with initiating monotherapy with sulfonylurea compared to metformin for the treatment of type 2 diabetes. Methods: Using...
Article
Purpose The association between long-acting insulin analogs and increased breast cancer risk is uncertain, particularly with the short follow-up in previous studies. We assessed this risk long term in women with type 2 diabetes. Methods A population-based cohort of women 40 years or older, all of whom were treated with long-acting (glargine, detem...