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

Toshihiko Kaise,1 Eishin Sakihara,2 Kentaro Tamaki,3 Hiroaki Miyata,4 Norimichi Hirahara,4 Oksana Kirichek,5 Ryosuke Tawara,1 Shoko Akiyama,1 Masayuki Katsumata,1 Mei Haruya,6 Takeo Ishii,7 Edgar P Simard,8 Bruce E Miller,8 Ruth Tal-Singer8 1Japan Development, GSK, Tokyo, Japan; 2Lifestyle Related Disease Medical Center, Naha Medical Association, Okinawa, Japan; 3Department of Breast Surgery, Nahanishi Clinic, Okinawa, Japan; 4Health Policy and Management, School of Medicine, Keio University, Tokyo, Japan; 5Value Evidence and Outcomes, GSK, Stockley Park, UK; 6Government Affairs and Market Access, GSK, Tokyo, Japan; 7Medical Japan, GSK, Tokyo, Japan; 8Value Evidence and Outcomes, GSK, Collegeville, PA, USACorrespondence: Toshihiko KaiseJapan Development, GSK, Tokyo, JapanTel +81 80 5927 9500Fax +81 3 4231 5993Email toshihiko.kaise@gsk.comPurpose: 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.Keywords: CAPTURE, CAAT, PRISm, COPD-Q, Japan, airflow limitation