Inhaled glucocorticoids in COPD: immortal time bias

The Neutrophil-to-Lymphocyte Ratio Determines Clinical Efficacy of Corticosteroid Therapy in Patients with COVID-19

Corticosteroid therapy is now recommended as a treatment in patients with severe COVID-19. But one key question is how to objectively identify severely ill patients who may benefit from such therapy. Here, we assigned 12,862 COVID-19 cases from 21 hospitals in Hubei Province equally to a training and a validation cohort. We found that a neutrophil-to-lymphocyte ratio (NLR) > 6.11 at admission discriminated a higher risk for mortality. Importantly, however, corticosteroid treatment in such individuals was associated with a lower risk of 60-day all-cause mortality. Conversely, in individuals with an NLR ≤ 6.11 or with type 2 diabetes, corticosteroid treatment was not associated with reduced mortality, but rather increased risks of hyperglycemia and infections. These results show that in the studied cohort corticosteroid treatment is associated with beneficial outcomes in a subset of COVID-19 patients who are non-diabetic and with severe symptoms as defined by NLR.

Bias in pharmacoepidemiologic studies using secondary health care databases: a scoping review

BACKGROUND

The availability of clinical and therapeutic data drawn from medical records and administrative databases has entailed new opportunities for clinical and epidemiologic research. However, these databases present inherent limitations which may render them prone to new biases. We aimed to conduct a structured review of biases specific to observational clinical studies based on secondary databases, and to propose strategies for the mitigation of those biases.

METHODS

Scoping review of the scientific literature published during the period 2000-2018 through an automated search of MEDLINE, EMBASE and Web of Science, supplemented with manually cross-checking of reference lists. We included opinion essays, methodological reviews, analyses or simulation studies, as well as letters to the editor or retractions, the principal objective of which was to highlight the existence of some type of bias in pharmacoepidemiologic studies using secondary databases.

RESULTS

A total of 117 articles were included. An increasing trend in the number of publications concerning the potential limitations of secondary databases was observed over time and across medical research disciplines. Confounding was the most reported category of bias (63.2% of articles), followed by selection and measurement biases (47.0% and 46.2% respectively). Confounding by indication (32.5%), unmeasured/residual confounding (28.2%), outcome misclassification (28.2%) and "immortal time" bias (25.6%) were the subcategories most frequently mentioned.

CONCLUSIONS

Suboptimal use of secondary databases in pharmacoepidemiologic studies has introduced biases in the studies, which may have led to erroneous conclusions. Methods to mitigate biases are available and must be considered in the design, analysis and interpretation phases of studies using these data sources.

Differentiating COPD from asthma in clinical practice

Asthma and chronic obstructive pulmonary disease (COPD) are interrelated diseases of airflow limitation. They share several common origins, symptoms, and treatments, but there are important differences that affect both diagnosis and recommended treatments. In fact, the most important reason for distinguishing COPD from asthma is the difference in treatment strategies. Although both asthma and COPD use the same types of treatments, the timing of their use in the disease course can have dramatic and important effects. Spirometry should be used to detect COPD in patients with symptoms. Many patients do not recognize their COPD symptoms so the primary care physician should be proactive in asking about symptoms. This article summarizes the key pathophysiologic, epidemiologic, and clinical differences and similarities between asthma and COPD, as well as recommended treatment strategies for both diseases and criteria for referring patients to a pulmonologist.

Survival among COPD patients using fluticasone/salmeterol in combination versus other inhaled steroids and bronchodilators alone

Recent retrospective studies have suggested that use of inhaled corticosteroids (ICS) may improve survival in chronic obstructive pulmonary disease (COPD), particularly when combined with a long-acting beta-agonist (LABA). However, the study methodologies have been questioned, and no study has examined the survival effect of the newer combination ICS/LABA inhalers. The goal of this project was to further examine the relationship between ICS treatment, with or without LABA, and survival in COPD. COPD patients were identified from the administrative databases of four different integrated health care delivery systems. All patients who were diagnosed with COPD between September 1, 2000 and August 31, 2001 and who had at least 3 months treatment with either a combined fluticasone/salmeterol inhaler (FSI, N=866), any ICS used with a LABA (ICS/LABA, N=525), ICS alone (N=742), LABA alone (N=531), or a short-acting bronchodilator alone (SABD, N=1832), were included. Analyses were conducted using three different analysis approaches that adjust for various biases that may affect the results. In the basic Cox proportional hazards models, use of FSI, ICS/LABA, ICS alone, and LABA alone had significant survival benefits as compared to SABD, after adjustment for differences in age, gender, comorbidities, asthma status, and disease severity (HRs 0.61 [0.45-0.83], 0.59 [0.46-0.77], 0.76 [0.61-0.95], 0.75 [0.57-0.98], respectively). Propensity score matching to reduce the clinical differences between the treatment groups versus the SABD reference group found very similar results. Nested case-control analyses, which are based on survival status instead of treatment, continued to show a significant survival benefit for FSI, ICS/LABA, and ICS alone. Treatment with FSI or another ICS with or without LABA is associated with improved survival in COPD. The treatment benefit is reproducible and is robust to application of a number of different analysis techniques designed to adjust for differences in confounding variables and for bias by indication.

Inhaled corticosteroids and mortality in COPD

STUDY OBJECTIVES

To assess the influence of inhaled corticosteroids (ICSs) on mortality in COPD patients, which is currently a controversial topic.

SETTING

Manitoba Health maintains a population-wide research database that includes pharmaceutical information.

DESIGN AND PATIENTS

We examined mortality in people 90 to 365 days after hospital discharge for COPD, comparing those persons who received inhaled steroids within 90 days of hospital discharge with those who did not. Cox proportional hazards models were used with adjustments for other respiratory drugs, comorbidities, and physician visits before and after hospital discharge. We also compared mortality in patients who received inhaled steroids with those who received other respiratory drugs, but not inhaled steroids, and those who received neither. Using nested case control analysis, we examined the time of receipt of inhaled steroids in relation to fatal events.

RESULTS

In people > 65 years of age, inhaled steroids were associated with a 25% reduction in mortality between 90 and 365 days after hospital discharge, while mortality increased with bronchodilator use, physician visits, age, and comorbidities. The exclusion of people who had also received a diagnosis of asthma or had received inhaled steroids before hospitalization did not change the result. Inhaled steroids were associated with an even larger mortality reduction in people aged 35 to 64 years. People who received bronchodilators but no steroids had higher mortality than people who received no bronchodilators or received both bronchodilators and inhaled steroids. The reduction in all-cause mortality was largely due to the decreased number of cardiovascular deaths. The receipt of inhaled steroids within 30 days of death was protective, but this was not the case for greater time intervals.

CONCLUSIONS

Therapy with ICSs reduced mortality in COPD patients; the effect was particularly notable for cardiovascular death and was short term in that it was dependent on recent exposure.

Economic evaluation of treating chronic obstructive pulmonary disease with inhaled corticosteroids and long-acting beta2-agonists in a health maintenance organization

OBJECTIVES

In light of recent results from observational studies showing prolonged survival in subjects taking long-acting beta2-agonists (LABA) and/or inhaled corticosteroids (ICS) for chronic obstructive pulmonary disease (COPD), we investigated their cost-effectiveness (CE).

METHODS

Costs and survival data were collected for a sample of members enrolled in a large Health Maintenance Organization in the United States. An observational study design was used to evaluate cumulative costs and health benefits of LABA, ICS, ICS+LABA, or comparison drugs. Survival was estimated using a parametric regression model. Costs were adjusted for censoring and prognostic factors. CE was evaluated over a time horizon of 36 months and the remaining lifetime of subjects.

RESULTS

Over 36 months, life expectancy and costs were: 2.4 years (95% confidence interval (CI): 2.3; 2.5) and $28,030 (CI: $23,400; $33,570) for not receiving ICS or LABA; 2.6 years (CI: 2.6; 2.7) and $35,170 (CI: $29,970; $40,620) for ICS alone; 2.6 years (CI: 2.5; 2.7) and $27,380 (CI: $21,780; $32,510) for LABA alone; and, 2.7 years (CI: 2.6; 2.8) and $33,780 (CI: $28,700; $39,440) for subjects treated with ICS+LABA. The lifetime analysis showed similar trends.

CONCLUSIONS

There is an acute need to find effective, life-extending treatments for persons with COPD. ICS, LABA or their combination represent promising treatment options and are currently being tested in randomized trials. If the impact on survival seen in these trials compares to that seen in observational studies, LABA and the combination treatment are likely to be cost-effective in the United States.

Survival of COPD patients using inhaled corticosteroids and long-acting beta agonists

We conducted a historical cohort study to examine the relationship between survival and use of inhaled corticosteroids (ICS) and/or long-acting beta agonists (LABA) in patients with chronic obstructive pulmonary disease (COPD). All COPD patients aged 40 years who were enrolled in one of two regional managed care organizations during 1995-2000, and who had 90 days use of an ICS and/or LABA (N=1288) or of a short-acting bronchodilator (N=397), were identified. Of patients treated with ICS and/or LABA, 14.4% died during the follow-up period, as compared to 28.2% of comparison patients (P<0.01). In a Cox proportional hazards model that controlled for age, sex, comorbidities, COPD severity, and asthma status, a reduced risk of death was found for ICS treatment (HR 0.59 [95% CI 0.46-0.78]), LABA (HR 0.55 [0.34-0.89]), and ICS plus LABA treatment (HR 0.34 [0.21-0.56]). A second model that excluded any patient who also had an ICD-9 code for asthma (N=840) still found improved survival among those using the combination of ICS plus LABA (HR 0.35 [CI 0.17-0.71]). Additional analyses that varied the exposure criteria also found a consistent treatment benefit. Inclusion of ICS or bronchodilator treatment during the follow-up period as a time-dependent function appears to negate the survival benefit; however, the underlying assumptions for valid time-dependent modeling are clearly violated in this situation. In conclusion, we found that COPD patients who used ICS alone or in combination with LABA had substantially improved survival even after adjustment for asthma and other confounding factors.

In a retrospective study of chronic obstructive pulmonary disease inpatients, respiratory comorbidities were significantly associated with prognosis

BACKGROUND AND OBJECTIVE

Comorbidities may be related to the prognosis for chronic obstructive pulmonary disease (COPD). We examined respiratory comorbidities associated with length of stay and in-hospital mortality among COPD patients.

METHODS

We used the Hospital Person Oriented Information (HPOI) database of Statistics Canada for a 5-year period. Over 4 years (fiscal years 1994-1995 to 1998-1999), 143,135 records listed COPD as the most responsible diagnosis for men and 122,065 records for women aged 40 years or more, and 75,780 men and 69,539 women were admitted to hospital at least once. Logistic regression modeling was used to examine the relationships between respiratory comorbidities and hospital outcomes adjusting for covariates.

RESULTS

Of the COPD patients, 10% had pneumonia-influenza and 3% had asthma as comorbid conditions. Women had a higher prevalence of asthma than men. The median length of stay at hospital was approximately 7 days, and 95% of patients were discharged alive. The odds ratio (95% confidence interval) for pneumonia-influenza in relation to in-hospital death was 3.56 (3.31, 3.83) for men and 3.29 (3.00, 3.61) for women. For comorbid asthma the corresponding odds ratios were 0.56 (0.36, 0.61) and 0.54 (0.35, 0.57), respectively.

CONCLUSIONS

COPD inpatients with pneumonia-influenza had a worse prognosis and those with asthma had a better prognosis.

Treatment implications on morbidity and mortality in COPD

Inhaled corticosteroids (ICSs) remain controversial in COPD, although recent clinical trials have consistently found that they reduce chronic respiratory symptoms and, in some population-based studies, improve survival. Their impact on the general COPD population depends on the variability in clinical response among individuals, the magnitude of treatment benefits, and the prevalence of adverse events in the population. The clinical benefits of ICSs in COPD are less obvious than in asthma; however, even patients with COPD without airway hyperresponsiveness experience significant improvement in baseline lung function and other outcomes after treatment with ICS. Population-based surveys suggest that a majority of patients with COPD have asthma or chronic bronchitis features and, therefore, are predisposed to a stronger treatment benefit from ICS. Clinical data support the use of ICS in patients with moderate-to-severe COPD, and suggest that they have impacts on morbidity and mortality that are as great or greater than those seen among commonly accepted treatments for other chronic diseases.

The place of inhaled corticosteroids in chronic obstructive pulmonary disease

The role of systemic corticosteroids in the treatment of exacerbations of chronic obstructive pulmonary disease (COPD) is well established. However, despite being frequently prescribed for the treatment of COPD, the clinical utility of inhaled corticosteroids (ICS) is less clearly defined. This review article seeks to clarify the role of ICS in the clinical management of COPD through a review of key pivotal short-, medium- and long-term studies in this field. Studies for inclusion in this review were identified by means of a computerised search of several databases (including MEDLINE, BIOSIS and EMBASE) from 1980 to 2003. While individual clinical and epidemiological studies have yielded conflicting results, meta-analysis of available data suggests that ICS may reduce the frequency and severity of exacerbations, the number of hospitalisations and the mortality rate, as well as yielding improvements in lung function and health-related quality of life (HRQL) in some subgroups of COPD patients. More recently, clinical trials evaluating the effect of combination therapy with ICS and long-acting beta2-agonists (LABA) have shown significant effects on the prevention of exacerbations and HRQL. Emerging data are expected to clarify the role of ICS in the management of patients with COPD of different severities as well as the place of treatment with ICS/LABA combinations in the management of this chronic and disabling disorder.