title: Small, moderate, and large changes, and the minimum clinically important difference in the University of California, San Diego Shortness of Breath Questionnaire.
abstract: Minimum clinically important change of 5 points in the University of California, San Diego Shortness of Breath Questionnaire (SOBQ) is established, but cutoff values between a small, a moderate, and a large change are still unknown. We used the data set of National Emphysema Treatment Trial consisting of severe and very severe chronic obstructive pulmonary disease patients, whose mean age was 64 years. Changes from baseline to post-surgical 6-month follow-up were evaluated. The St. George's Respiratory Questionnaire was used as anchor: |∆SGRQ| < 4, meaningless change; 4 ≤ |∆SGRQ| < 8, small change; 8 ≤ |∆SGRQ| < 13, moderate change; 13 ≤ |∆SGRQ|, large change. We decided the final cutoff values for the SOBQ as medians of the three anchor methods. We also decided the range of cutoff values as the range of three values. In a cohort of surgically treated patients (N = 484), we propose value of 5 (range 5-6), 11 (range 9-15), and 16 (range 14-20) for the cutoff values between a meaningless and a small change (minimum clinically important difference), a small and a moderate change, and a moderate and a large change, respectively. In a cohort of medically treated patients, numbers of patients categorized according to ∆SOBQ scores were similar to those of the patients categorizes according to the ∆SGRQ (N = 480) or ∆Forced expiratory volume in 1 second (N = 425). We propose group-level cutoff values and range between a small, a moderate, and a large changes.
authors.affiliation: 1Department of Internal Medicine and Clinical Immunology, Yokohama City University Graduate School of Medicine , Yokohama , Japan.
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Horita
authors.forename: Naoki
authors.initials: N
authors.lastname: Miyazawa
authors.forename: Satoshi
authors.initials: S
authors.lastname: Morita
authors.forename: Ryota
authors.initials: R
authors.lastname: Kojima
authors.forename: Naoko
authors.initials: N
authors.lastname: Kimura
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kaneko
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Ishigatsubo
mesh_terms: D000368:Aged; D001993:Bronchodilator Agents / Q000627:therapeutic use*; D015331:Cohort Studies; D004417:Dyspnea / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D010102:Oxygen Inhalation Therapy / Q000379:methods*; D011013:Pneumonectomy / Q000379:methods*; D011656:Pulmonary Emphysema / Q000150:complications / Q000503:physiopathology / Q000628:therapy*; D011788:Quality of Life; D012138:Respiratory Therapy / Q000379:methods*; D012720:Severity of Illness Index; D016540:Smoking Cessation; D011795:Surveys and Questionnaires; D016896:Treatment Outcome
chemical_list: D001993:Bronchodilator Agents