Landscape review of global real-world data sources for studying medication use in pregnancy and lactation that support regulatory decision making.

PURPOSE: Most pregnant people take at least one medication during gestation or while breastfeeding, however data are lacking on the safety of medication use in these populations. We conducted a landscape review of real-world data sources specific to medication use in pregnancy and breastfeeding populations that have met, or have potential to meet, health authorities' requirements for post-authorization safety studies. METHODS: A 2-phase approach identified data sources from literature, publicly available registers of non-interventional post-authorization studies of pregnant women, existing database inventories, and emerging data sources known to the authors. RESULTS: Required key attributes were assessed according to current regulatory guidance, resulting in selection of 49 suitable data sources. All global regions were represented, with North America (37%) and Europe (33%) most common; 12% of the data sources included pregnancy information from low-to middle-income countries. Administrative healthcare claims (25%) and electronic healthcare records (21%) comprised the largest types of data sources. Across data sources, 53% were managed by national or regional governments, 27% by industry, and 20% by academic institutions. Maternal age, diagnoses, prenatal care, and reproductive history were available in most, whereas fewer included demographic data (e.g., race/ethnicity). Breastfeeding data were collected in 37% of the final data sources. CONCLUSION: We conducted a systematic approach to data source evaluation of pregnancy and breastfeeding to be used as a resource for investigators to consider when designing pregnancy-related research studies to satisfy regulatory requirements.

Real-World Monitoring of COVID-19 Vaccines: An Industry Expert View on the Successes, Challenges, and Future Opportunities.

Pharmacovigilance leaders from major vaccine developers describe the learnings from the coronavirus disease 2019 (COVID-19) pandemic in the area of pharmacovigilance and pharmacoepidemiology. The authors aim to raise awareness of the co-operation among vaccine developers, highlight common challenges, advocate for solutions, and propose recommendations for the future in the areas of real-world safety and effectiveness, safety reporting and evaluation, and regulatory submissions. To enable timely evaluation of real-world safety and effectiveness, multi-sponsor study platforms were implemented, resulting in quicker recruitment over wide geographical areas. Future gains could be derived by developing geographically flexible, common protocols and/or joint company-sponsored studies for multiple vaccines and a collective strategy to build low/middle-income country (LMIC) sentinel sites. Safety reporting, signal detection and evaluation was particularly challenging given the unprecedented number of adverse events reported. New methods were required to manage increased report volume while maintaining the ability to quickly identify and respond to new data that could impact the benefit-risk profile of each vaccine. Worldwide health authority submissions, requests for information and differing regulatory requirements imposed significant burden on regulators and industry. Industry consensus on the safety reporting requirements and joint meetings with regulatory authorities markedly reduced this burden for all stakeholders. The most impactful innovations should be undertaken rapidly and expanded to other vaccines and therapeutics, with a multi-stakeholder approach. The authors of this paper make future recommendations and have launched an initiative named BeCOME (Beyond COVID Monitoring Excellence) with a focus on actions in each of the highlighted areas.

A prospective patient registry to monitor safety, effectiveness, and utilisation of bedaquiline in patients with multidrug-resistant tuberculosis in South Korea.

BACKGROUND: Multidrug-resistant tuberculosis (MDR-TB) represents a major public health concern, with an ongoing need for new effective treatments. Bedaquiline is an oral diarylquinoline that has shown encouraging treatment success and culture conversion rates in MDR-TB. METHODS: A South Korean patient registry was set up across 19 centres between 2016 and 2018 for the prospective collection of data from patients with MDR-TB who received either a bedaquiline-containing or a non-bedaquiline-containing regimen. Treatment was at the physician's discretion (bedaquiline use requiring approval by special committee) and was based on patient characteristics, disease status, and local treatment guidelines. RESULTS: The safety population included 172 patients (88 bedaquiline and 84 non-bedaquiline). The mean (standard deviation, SD) duration of follow-up was 24.3 (9.5) months. Mean (SD) durations of treatment were 5.4 (1.8) months in bedaquiline-treated patients and 15.7 (6.7) months in the non-bedaquiline group. Treatment success (cured and treatment completed according to WHO 2013 treatment outcome definitions) was achieved by 56.3% of bedaquiline-treated and 45.2% of non-bedaquiline-treated patients. Sputum culture conversion rates were 90.4% and 83.7% with and without bedaquiline, respectively. Diarrhoea and nausea were the most frequently reported treatment-emergent adverse events (TEAEs) in the bedaquiline group (27.3% [24/88] and 22.7% [20/88], respectively). The most frequent bedaquiline-related TEAEs were prolonged QT interval (10.2%; 9/88), and diarrhoea and nausea (9.1% each; 8/88). QT interval prolongation was reported in 19.3% (17/88) of bedaquiline-treated and 2.4% (2/84) of non-bedaquiline-treated patients, but bedaquiline was not discontinued for any patient for this reason. There were 13 (14.7%) and three (3.6%) deaths in the bedaquiline-treated and non-bedaquiline groups, respectively. Review of fatal cases revealed no unexpected safety findings, and no deaths were bedaquiline-related. The most common cause of death was worsening cancer (three patients). Patients in the bedaquiline group tended to have poorer baseline risk profiles than non-bedaquiline patients and were more likely to have relapsed or already failed second-line treatment. Interpretation of mortality data was complicated by high rates of loss to follow-up in both groups. CONCLUSIONS: The South Korean registry findings support previous risk/benefit observations and the continued use of bedaquiline as part of combination therapy in patients with MDR-TB.

Bedaquiline safety, efficacy, utilization and emergence of resistance following treatment of multidrug-resistant tuberculosis patients in South Africa: a retrospective cohort analysis.

BACKGROUND: This retrospective cohort study assessed benefits and risks of bedaquiline treatment in multidrug-resistant-tuberculosis (MDR-TB) combination therapy by evaluating safety, effectiveness, drug utilization and emergence of resistance to bedaquiline. METHODS: Data were extracted from a register of South African drug-resistant-tuberculosis (DR-TB) patients (Electronic DR-TB Register [EDRWeb]) for newly diagnosed patients with MDR-TB (including pre-extensively drug-resistant [XDR]-TB and XDR-TB and excluding rifampicin-mono-resistant [RR]-TB, as these patients are by definition not multidrug-resistant), receiving either a bedaquiline-containing or non-bedaquiline-containing regimen, at 14 sites in South Africa. Total duration of treatment and follow-up was up to 30 months, including 6 months' bedaquiline treatment. WHO treatment outcomes within 6 months after end-of-treatment were assessed in both patient groups. Longer term mortality (up to 30 months from treatment start) was evaluated through matching to the South African National Vital Statistics Register. Multivariable Cox proportional hazards analyses were used to predict association between receiving a bedaquiline-containing regimen and treatment outcome. RESULTS: Data were extracted from EDRWeb for 5981 MDR-TB patients (N = 3747 bedaquiline-treated; N = 2234 non-bedaquiline-treated) who initiated treatment between 2015 and 2017, of whom 40.7% versus 80.6% had MDR-TB. More bedaquiline-treated than non-bedaquiline-treated patients had pre-XDR-TB (27.7% versus 9.5%) and XDR-TB (31.5% versus 9.9%) per pre-2021 WHO definitions. Most patients with treatment duration data (94.3%) received bedaquiline for 6 months. Treatment success (per pre-2021 WHO definitions) was achieved in 66.9% of bedaquiline-treated and 49.4% of non-bedaquiline-treated patients. Death was reported in fewer bedaquiline-treated (15.4%) than non-bedaquiline-treated (25.6%) patients. Bedaquiline-treated patients had increased likelihood of treatment success and decreased risk of mortality versus non-bedaquiline-treated patients. In patients with evaluable drug susceptibility testing data, 3.5% of bedaquiline-susceptible isolates at baseline acquired phenotypic resistance. Few patients reported bedaquiline-related treatment-emergent adverse events (TEAEs) (1.8%), TEAE-related bedaquiline discontinuations (1.4%) and QTcF values > 500 ms (2.5%) during treatment. CONCLUSION: Data from this large cohort of South African patients with MDR-TB showed treatment with bedaquiline-containing regimens was associated with survival and effectiveness benefit compared with non-bedaquiline-containing regimens. No new safety signals were detected. These data are consistent with the positive risk-benefit profile of bedaquiline and warrant continued implementation in combination therapy for MDR-TB treatment.

Update on prevalence of diagnosed systemic lupus erythematosus (SLE) by major health insurance types in the US in 2016.

OBJECTIVE: To provide current estimates of the number of patients with prevalent systemic lupus erythematosus (SLE) by major health insurance types in the US and to describe patient characteristics. Four large US health insurance claims databases were analyzed to represent different types of insurance coverage, including private insurance, Medicaid, and Medicare Supplemental. RESULTS: Overall unadjusted SLE prevalence per 100,000 persons in the US ranged from 150.1 (private insurance) to 252.9 (Medicare Supplemental insurance). Extrapolating to the US civilian population in 2016, we estimated roughly 345,000 to 404,000 prevalent SLE patients with private/Medicare insurance and 99,000 prevalent SLE patients with Medicaid insurance. Comorbidities, including renal failure/dialysis were commonly observed across multiple organ systems in SLE patients (8.4-21.1%). We estimated a larger number of prevalent SLE cases in the US civilian population than previous reports and observed extensive disease burden based on a 1-year cross-sectional analysis.

Uncontrolled Extensions of Clinical Trials and the Use of External Controls-Scoping Opportunities and Methods.

Increased interest in real-world evidence (RWE) for clinical and regulatory decision making and the need to evaluate long-term benefits and risks of pharmaceutical products raise the importance of understanding the use of external controls (ECs) for uncontrolled extensions of randomized controlled trials (RCTs). We searched clinicaltrials.gov from 2009 to 2019 for uncontrolled extensions and assessed the use of ECs in the trial protocol registry and PubMed. We present characteristics of identified uncontrolled extensions, their adoption of ECs, and a qualitative appraisal of published uncontrolled extensions with ECs according to good pharmacoepidemiologic practice. The number of uncontrolled extensions increased slightly across the study period, resulting in a total of 1,115 studies. Most originated from phase III RCTs (62.2%) and specified safety outcomes (61.9% among those with specified outcomes). Most uncontrolled extensions incorporated no control group with only 7 out of 1,115 (0.6%) employing ECs. For those studies with ECs, all involved treatments for rare conditions and assessment of effectiveness. Attempts to balance comparison groups varied from none mentioned to propensity score matching. We noted consistent deficiencies in outcome ascertainment methods and approaches to address attrition bias. The contrast of the large and growing number of uncontrolled extensions with the small number of studies that utilized ECs showed clear opportunities for enhancement in design, measurement, and analysis of uncontrolled extensions to allow causal inferences on long-term treatment effects. As extensions continue to expand within RWE regulatory frameworks, development of guidelines for use of EC with uncontrolled extensions is needed.

Challenges of evaluating and modelling vaccination in emerging infectious diseases.

Outbreaks of emerging pathogens pose unique methodological and practical challenges for the design, implementation, and evaluation of vaccine efficacy trials. Lessons learned from COVID-19 highlight the need for innovative and flexible study design and application to quickly identify promising candidate vaccines. Trial design strategies should be tailored to the dynamics of the specific pathogen, location of the outbreak, and vaccine prototypes, within the regional socioeconomic constraints. Mathematical and statistical models can assist investigators in designing infectious disease clinical trials. We introduce key challenges for planning, evaluating, and modelling vaccine efficacy trials for emerging pathogens.

Understanding patient journey in ulcerative colitis prior to biologic initiation: a 5-year exploration.

BACKGROUND: There has been a more pronounced shift toward earlier, more aggressive therapies in Crohn's disease than in ulcerative colitis (UC). The aim of this study was to describe the pre-biologic treatment and health care experience, including co-morbidities and overall health care utilization, for UC patients who initiated biologic therapies, in the 5 years prior to the initiation of the first biologic agent. METHODS: UC patients who initiated a biologic agent approved for UC between 9/15/2005 and 1/30/2018 were identified from the IBM® MarketScan® Commercial Database, a large US database. The date of the first recorded UC biologic exposure was defined as the index date, and ≥ 5 years of pre-index records were required to evaluate patients' treatment, disease progression and overall health care utilization prior to initiating biologic agents. RESULTS: Among the 1891 eligible patients, treatment with oral corticosteroids, 5-aminosalicylates, and other non-biologic immunomodulators, all increased progressively across the 5 years prior to the index. From within year-five to within year-one prior to the index, the median duration of oral corticosteroid treatment increased from 34 to 88 days per year and the proportion of patients who experienced more extensive/pancolitis disease increased from 16 to 59%. Overall, the frequency of all-cause health care visits also increased. CONCLUSIONS: Patients with UC experienced increasing morbidity and treatment burden in the 5 years prior to initiating biologic therapy. To achieve reduced corticosteroids in UC management, better risk stratification is needed to help identify patients for more timely biologic treatment.

Methods for external control groups for single arm trials or long-term uncontrolled extensions to randomized clinical trials.

PURPOSE: Clinical trials compare outcomes among patients receiving study treatment with comparators drawn from the same source. These internal controls are missing in single arm trials and from long-term extensions (LTE) of trials including only the treatment arm. An external control group derived from a different setting is then required to assess safety or effectiveness. METHODS: We present examples of external control groups that demonstrate some of the issues that arise and make recommendations to address them through careful assessment of the data source fitness for use, design, and analysis steps. RESULTS: Inclusion and exclusion criteria and context that produce a trial population may result in trial patients with different clinical characteristics than are present in an external comparison group. If these differences affect the risk of outcomes, then a comparison of outcome occurrence will be confounded. Further, patients who continue into LTE may differ from those initially entering the trial due to treatment effects. Application of appropriate methods is needed to make valid inferences when such treatment or selection effects are present. Outcome measures in a trial may be ascertained and defined differently from what can be obtained in an external comparison group. Differences in sensitivity and specificity for identification or measurement of study outcomes leads to information bias that can also invalidate inferences. CONCLUSION: This review concentrates on threats to the valid use of external control groups both in the scenarios of single arm trials and LTE of randomized controlled trials, along with methodological approaches to mitigate them.

Masking in Pragmatic Trials: Who, What, and When to Blind.

Masking (or blinding) of treatment assignment is routinely implemented in classical randomized clinical trials (RCTs) to isolate the effect of the intervention itself and to minimize the potential for bias that could occur with traditional trials. Such biases could be introduced with the conduct, assessment of endpoints, management of conditions, analysis, and reporting when the treatment assignments are known. However, masking of treatments is not only complex but it hinders how generalizable the findings are to the "real world" clinical setting. Pragmatic RCTs (pRCTs) are intended to evaluate the effects of interventions within routine medical care, and as such, do not typically mask treatment groups; moreover, pRCTs assess comparators that are available in routine medical practice, not masked placebos. Whether pRCTs should be masked if intended for regulatory or other purposes has recently been questioned. The literature on pRCTs, while extensive, does not address how much actual benefit is gained from masking outcomes and how masking may affect the "real world" nature of a study. Here, we propose an approach to evaluate sources of bias, describe stakeholders in the conduct of pRCTs who are most likely affected, and offer a framework for considering how masking may be implemented effectively while maintaining generalizability.

Data linkage in pharmacoepidemiology: A call for rigorous evaluation and reporting.

PURPOSE: The purpose of this paper is to provide guidance on the evaluation of data linkage quality through the development of a checklist for reporting key elements of the linkage process. METHODS: Responding to a call for manuscripts from the International Society for Pharmacoepidemiology (ISPE), a working group including international representation from the academic, industry, and contract research, and regulatory sectors was formed to develop a checklist for evaluation of data linkage performance and reporting data linkage specifically for pharmacoepidemiologic research. This checklist expands on the reporting of studies conducted using observational routinely collected health data specific to pharmacoepidemiology (RECORD-PE) guidelines. RESULTS: A key aspect of data linkage evaluation for pharmacoepidemiology is to articulate how a linkage process was performed and its accuracy in terms of validation and verification of the resulting linked data. This study generates a checklist, which covers domains including data sources, linkage variables, linkage methods, linkage results, and linkage evaluation. For each domain, specific recommendations provide a clear and transparent assessment of the linkage process. CONCLUSIONS: Linking data sources can help to enrich analytic databases to more accurately define study populations, enable adjustment for confounding, and improve the capture of health outcomes. Clear and transparent reporting of data linkage processes will help to increase confidence in the evidence generated from these data by allowing researchers and end users to critically assess the potential for bias owing to the data linkage process.

Chronic obstructive pulmonary disease exacerbation episodes derived from electronic health record data validated using clinical trial data.

PURPOSE: To validate an algorithm for acute exacerbations of chronic obstructive pulmonary disease (AECOPD) episodes derived in an electronic health record (EHR) database, against AECOPD episodes collected in a randomized clinical trial using an electronic case report form (eCRF). METHODS: We analyzed two data sources from the Salford Lung Study in COPD: trial eCRF and the Salford Integrated Record, a linked primary-secondary routine care EHR database of all patients in Salford. For trial participants, AECOPD episodes reported in eCRF were compared with algorithmically derived moderate/severe AECOPD episodes identified in EHR. Episode characteristics (frequency, duration), sensitivity, and positive predictive value (PPV) were calculated. A match between eCRF and EHR episodes was defined as at least 1-day overlap. RESULTS: In the primary effectiveness analysis population (n = 2269), 3791 EHR episodes (mean [SD] length: 15.1 [3.59] days; range: 14-54) and 4403 moderate/severe AECOPD eCRF episodes (mean length: 13.8 [16.20] days; range: 1-372) were identified. eCRF episodes exceeding 28 days were usually broken up into shorter episodes in the EHR. Sensitivity was 63.6% and PPV 71.1%, where concordance was defined as at least 1-day overlap. CONCLUSIONS: The EHR algorithm performance was acceptable, indicating that EHR-derived AECOPD episodes may provide an efficient, valid method of data collection. Comparing EHR-derived AECOPD episodes with those collected by eCRF resulted in slightly fewer episodes, and eCRF episodes of extreme lengths were poorly captured in EHR. Analysis of routinely collected EHR data may be reasonable when relative, rather than absolute, rates of AECOPD are relevant for stakeholders' decision making.

Study investigating the generalisability of a COPD trial based in primary care (Salford Lung Study) and the presence of a Hawthorne effect.

INTRODUCTION: Traditional phase IIIb randomised trials may not reflect routine clinical practice. The Salford Lung Study in chronic obstructive pulmonary disease (SLS COPD) allowed broad inclusion criteria and followed patients in routine practice. We assessed whether SLS COPD approximated the England COPD population and evidence for a Hawthorne effect. METHODS: This observational cohort study compared patients with COPD in the usual care arm of SLS COPD (2012-2014) with matched non-trial patients with COPD in England from the Clinical Practice Research Datalink database. Generalisability was explored with baseline demographics, clinical and treatment variables; outcomes included COPD exacerbations in adjusted models and pretrial versus peritrial comparisons. RESULTS: Trial participants were younger (mean, 66.7 vs 71.1 years), more deprived (most deprived quintile, 51.5% vs 21.4%), more current smokers (47.5% vs 32.1%), with more severe Global initiative for chronic Obstructive Lung Disease stages but less comorbidity than non-trial patients. There were no material differences in other characteristics. Acute COPD exacerbation rates were high in the trial population (98.37th percentile). CONCLUSION: The trial population was similar to the non-trial COPD population. We observed some evidence of a Hawthorne effect, with more exacerbations recorded in trial patients; however, the largest effect was observed through behavioural changes in patients and general practitioner coding practices.

Patterns and management of chronic obstructive pulmonary disease in urban and rural China: a community-based survey of 25 000 adults across 10 regions.

INTRODUCTION: Chronic obstructive pulmonary disease (COPD) is the third leading cause of death worldwide, with COPD deaths in China accounting for one-third of all such deaths. However, there is limited available evidence on the management of COPD in China. METHODS: A random sample of 25 011 participants in the China Kadoorie Biobank, aged 38-87 years, from 10 regions in China was surveyed in 2013-2014. Data were collected using interviewer-administered questionnaires on the diagnosis ('doctor-diagnosed' or 'symptoms-based') and management of COPD (including use of medication and other healthcare resources), awareness of diagnosis and severity of symptoms in COPD cases. RESULTS: Overall, 6.3% of the study population were identified as COPD cases (doctor-diagnosed cases: 4.8% and symptom-based cases: 2.4%). The proportion having COPD was higher in men than in women (7.9% vs 5.3%) and varied by about threefold (3.7%-10.0%) across the 10 regions. Among those with COPD, 54% sought medical advice during the last 12 months, but <10% reported having received treatment for COPD. The rates of hospitalisation for COPD, use of oxygen therapy at home and influenza or pneumococcal vaccinations in the previous year were 15%, 3% and 4%, respectively. Of those with COPD, half had moderate or severe respiratory symptoms, and over 80% had limited understanding of their disease and need for treatment. CONCLUSION: Despite a high prevalence of COPD in China and its substantial impact on activities of daily living, knowledge about COPD and its management were limited.

Excess risk of major vascular diseases associated with airflow obstruction: a 9-year prospective study of 0.5 million Chinese adults.

Background: China has high COPD rates, even among never-regular smokers. Little is known about nonrespiratory disease risks, especially vascular morbidity and mortality after developing airflow obstruction (AFO) in Chinese adults. Objective: We aimed to investigate the prospective association of prevalent AFO with major vascular morbidity and mortality. Materials and methods: In 2004-2008, a nationwide prospective cohort study recruited 512,891 men and women aged 30-79 years from 10 diverse localities across China, tracking cause-specific mortality and coded episodes of hospitalization for 9 years. Cox regression yielded adjusted HRs for vascular diseases comparing individuals with spirometry-defined prevalent AFO at baseline to those without. Results: Of 489,382 participants with no vascular disease at baseline, 6.8% had AFO, with prevalence rising steeply with age. Individuals with prevalent AFO had significantly increased vascular mortality (n=1,429, adjusted HR 1.29, 95% CI 1.21-1.36). There were also increased risks of hemorrhagic stroke (n=823, HR 1.18, 95% CI 1.09-1.27), major coronary events (n=635, HR 1.33, 95% CI 1.22-1.45), and heart failure (n=543, HR 2.19, 95% CI 1.98-2.41). For each outcome, the risk increased progressively with increasing COPD severity and persisted among never-regular smokers. Conclusion: Among adult Chinese, AFO was associated with significantly increased risks of major vascular morbidity and mortality. COPD management should be integrated with vascular disease prevention and treatment programs to improve long-term prognosis.

Physician perspectives on the burden and management of asthma in six countries: The Global Asthma Physician Survey (GAPS).

BACKGROUND: Despite recognition of asthma as a growing global issue and development of global guidelines, asthma treatment practices vary between countries. Several studies have reported patients' perspectives on asthma control. This study presents physicians' perspectives and strategies for asthma management. METHODS: Physicians seeing ≥4 adult patients with asthma per month in Australia, Canada, China, France, Germany, and Japan were surveyed (N=1809; ≈300 per country). A standardised questionnaire was developed for this study and administered by telephone, online or face-to-face. Statistics were weighted to account for the sampling scheme. RESULTS: Physicians estimated that 71% of their adult patients received maintenance medication, with adherence monitored by 76-97% of physicians. Perceived major barriers to patient adherence included: patients taking treatment as needed; acceptance of symptoms; and patients not perceiving treatment benefits. Written action plans (37%) and technology (15%) were seldom employed by physicians to aid patients' asthma management. Physicians rarely (10%) used validated patient-reported questionnaires to monitor asthma control, instead monitoring selected symptoms, exacerbations, and/or lung function measurements. Awareness of single maintenance and reliever therapy (SMART/MART) varied among countries (56-100%); although most physicians (72%) had prescribed SMART/MART, the majority (91%) co-prescribed a short-acting bronchodilator at least some of the time. CONCLUSIONS: These results show that physicians generally do not employ standardised tools to monitor asthma control or to manage its treatment and that despite high awareness of SMART/MART, the strategy appears to be commonly misapplied. Better education for patients and physicians is required to improve asthma management and resulting patient outcomes.

Asthma and Chronic Obstructive Pulmonary Disease Overlap: The Effect of Definitions on Measures of Burden.

Background: Although the overlap between asthma and COPD has been recognized for years this overlap has only recently been given a name, asthma-COPD overlap syndrome (ACOS), and better defined. Different definitions of the component diseases can affect prevalence and outcome measures of ACOS. Methods: We used data from the National Health and Nutrition Examination Survey (NHANES) from 2007-2012 to determine the population estimates of ACOS in U.S. adults using 2 different definitions of ACOS (ACOS1= self-reported COPD and current asthma; ACOS2 = spirometric-confirmed COPD [pre-bronchodilator FEV1/FVC < 70%] and current asthma) and to describe variation in other factors, such as lung function impairment and health care utilization, by ACOS definitions. Results: Among U.S. adults aged 20 and older, 1.6% had ACOS1, and 1.9% had ACOS2. Both case definitions were similar with regard to symptoms and impairment of lung function. ACOS1 individuals were more likely to have one or more overnight hospital stays relative to those with neither asthma nor COPD, (odds ratio [OR] 3.4, 95% confidence interval [CI] 2.5, 4.6) than ACOS2 (OR 1.6, 95% CI 0.9, 2.9). Conclusions: Different definitions of ACOS in population-based studies affect both estimates of disease prevalence and outcomes related to the disease. These definitions need to be carefully considered in the design of epidemiologic studies and clinical trials.

Disease Burden of Patients with Asthma/COPD Overlap in a US Claims Database: Impact of ICD-9 Coding-based Definitions.

The inclusion of an asthma/chronic obstructive pulmonary disease (COPD) overlap syndrome (ACOS) population in the 2015 Global Initiative for Chronic Obstructive Lung Disease strategic documents has raised questions about the profile of these patients in clinical practice, as they are mostly excluded from asthma and COPD clinical trials. We estimated the disease burden, co-morbidities, and respiratory treatments of patients with asthma/COPD overlap, utilizing the Truven MarketScan commercial and Medicare databases. Patients with ≥1 COPD or chronic obstructive asthma diagnostic code were identified between January 1, 2008, and December 31, 2011. The asthma/COPD overlap group was defined and stratified based upon type and frequency of asthma diagnostic code (chronic obstructive asthma only, COPD and chronic obstructive asthma, and COPD and ≥1 asthma code). 1,488,613 patients were identified; of these, 1,171,626 were diagnosed with COPD alone and 316,987 with asthma/COPD overlap. Patients with asthma and COPD had higher disease burden indicators and inhaled corticosteroid/long-acting beta-agonist use compared with COPD alone. This trend was consistent for all definitions of asthma/COPD overlap. Patients with obstructive asthma and COPD tended to be older, with greater disease burden compared with other definitions; this population may represent a more severe form of asthma/COPD overlap. Disease burden and treatment also varied based on the codes defining asthma/COPD overlap, indicating possible phenotypic differences. More clinical insight and detailed phenotyping is needed to determine the reasons for coding variation in asthma/COPD overlap, with implications for further research to address unmet needs.