Reduction in asthma exacerbation rate after mepolizumab treatment initiation in patients with severe asthma: A real-world database study in Japan.

OBJECTIVE: To investigate the changes in asthma exacerbation, as well as in oral corticosteroid (OCS) use, exacerbation-related healthcare resource utilization (HRU), and healthcare costs before and after mepolizumab treatment initiation in patients with severe asthma who started treatment with mepolizumab in a real-world clinical setting in Japan. METHODS: A retrospective, observational, self-controlled study was conducted in Japan using a hospital-based administrative claims database. Patients who were diagnosed with asthma and who were new users of mepolizumab were included in the study. The primary outcome was the incidence rate of any asthma exacerbation/patient-year during the 12-month period before (baseline period) and after (follow-up period) the first mepolizumab prescription. Secondary outcome measures included the proportion of patients with ≥1 any asthma exacerbation, patients with exacerbation requiring hospitalization, the incidence rate of exacerbations requiring hospitalization/patient-year, the median daily OCS dose (OCS sparing effect), exacerbation-related HRU (hospitalization length, the proportion of patients with emergency visits, and the number of emergency/outpatient visits), and associated costs. RESULTS: Of the 377 patients included, 56.2% were ≥65 years of age. Following the first mepolizumab prescription, incidence rates for any asthma exacerbation were reduced by 40.6% (4.00/patient-year to 2.38/patient-year; the incidence rate ratio [95% confidence interval]: 0.60 [0.53-0.67]; p < 0.0001) from the baseline to follow-up periods. The incidence rate of exacerbations requiring hospitalization was reduced by 55.8% (0.37/patient-year to 0.16/patient-year) from the baseline to follow-up periods. The proportion of patients experiencing any exacerbation decreased from 84.4% to 57.8% and those requiring hospitalization decreased from 23.9% to 10.3% both from the baseline to follow-up periods. The median daily OCS dose decreased by 44.6% (median [interquartile range]: 6.7 [4.7-9.9] mg/day to 3.3 [0.9-5.6] mg/day) from the last baseline quarter to the 4th quarter of the follow-up period. All exacerbation-related HRUs decreased from the baseline to follow-up periods. Inpatient cost reduced by >50% (123,279 Japanese Yen [JPY]/patient-year vs. 57,283 JPY/patient-year), reducing the total cost by 80,716 JPY from the baseline to follow-up periods. CONCLUSION: Mepolizumab was effective in treating patients with severe asthma by reducing the incidence rates of exacerbations and exacerbation requiring hospitalization, OCS dose, exacerbation-related HRU, and cost in routine clinical practice in Japan.

Prevalence and Characteristics of Individuals with Preserved Ratio Impaired Spirometry (PRISm) and/or Impaired Lung Function in Japan: The OCEAN Study.

PURPOSE: Many individuals with obstructive airway disease (OAD), including chronic obstructive pulmonary disease (COPD) and asthma, remain undiagnosed, despite the potential for reducing disease burden through early detection and treatment. OCEAN aimed to determine the prevalence of, and characteristics associated with, impaired lung function in a Japanese population, with the goal of improving strategies for early OAD detection. METHODS: OCEAN was an observational, cross-sectional study in sequentially recruited Japanese individuals ≥40 years of age undergoing routine health examinations. Participants completed screening questionnaires and spirometry testing. Airflow limitation was defined as forced expiratory volume in 1 second/forced vital capacity (FEV1/FVC) <0.7 by pre-bronchodilator spirometry. Preserved ratio impaired spirometry (PRISm) was defined as FEV1/FVC ≥0.7 and FEV1 <80% predicted. The primary endpoint was prevalence of spirometry-based airflow limitation and PRISm. The characteristics of study participants were reported as secondary endpoints. RESULTS: Overall, 2518 individuals were included; 79% were <60 years of age (mean 52.0 years). Airflow limitation and PRISm were observed in 52 (2.1%) and 420 (16.7%) participants, respectively. FEV1 in the PRISm group was between that in the no airflow limitation/PRISm and airflow limitation groups, FVC was similar in the PRISm and airflow limitation groups. The PRISm group had higher mean body mass index and a higher proportion of comorbid metabolic disease compared with the airflow limitation group. The prevalence of airflow limitation and PRISm was highest among current smokers (3.9% and 21.3%, respectively) versus former or never smokers. CONCLUSION: A significant proportion of Japanese individuals <60 years of age attending their annual health examination had impaired lung function (airflow limitation and PRISm); prevalence was highest among current smokers. These findings support screening of current or former smokers ≥40 years of age using patient-reported questionnaires to inform the need for spirometry to confirm an OAD diagnosis.

Utility of Self-Administered Questionnaires for Identifying Individuals at Risk of COPD in Japan: The OCEAN (Okinawa COPD casE finding AssessmeNt) Study.

Purpose: A considerable proportion of patients with chronic obstructive pulmonary disease (COPD) remain undiagnosed and untreated even though they may have a burden of respiratory symptoms that impact quality of life. The OCEAN study assessed the ability of screening questionnaires to identify individuals with, or at risk of, COPD by comparing questionnaire outcomes with spirometric measures of lung function. Methods: This observational study included participants ≥40 years of age presenting for their annual health examination at a single medical center in Okinawa, Japan. Participants completed COPD screening questionnaires (CAPTURE and COPD-Q), the Chronic Airways Assessment Test (CAAT), and general demographic and health-related questionnaires. The performance characteristics of CAPTURE and COPD-Q were compared with spirometry-based airflow limitation by calculating the area under the receiver operating characteristic (ROC-AUC) curve. Results: A total of 2518 participants were included in the study; 79% of whom were <60 years of age (mean 52.0 years). A total of 52 (2.1%) participants had airflow limitation defined as forced expiratory volume in 1 second (FEV1)/forced vital capacity (FVC) <0.7, and 420 (16.7%) participants were classified as Preserved Ratio Impaired Spirometry (PRISm). Among participants with PRISm, 75 (17.9%) had a CAAT total score ≥10. Airflow limitation and PRISm were more prevalent in current smokers versus past smokers. For the CAPTURE questionnaire, ROC-AUC for screening airflow limitation, PRISm, and PRISm with a CAAT total score ≥10 were 0.59, 0.55, and 0.69, respectively; for COPD-Q, these three clinical features were 0.67, 0.58 and 0.68, respectively. Conclusion: This study demonstrated that CAPTURE and COPD-Q appear to be effective screening tools for identifying symptomatic individuals with undiagnosed, or at risk of developing COPD in adults ≥40 years of age in Okinawa. Furthermore, early diagnosis and management of PRISm is important to improve future outcomes and the societal burden of disease.