Predicting future risk of exacerbations in Japanese patients with adult asthma: A prospective 1-year follow up study.
BACKGROUND
To avoid future risk is a definitive goal of long-term asthma management. Exacerbations are considered to be the most relevant future risk in real life asthma management. Few comparative studies have evaluated the risk factors associated with exacerbations in Japanese patients with asthma.


METHODS
We performed the prospective 1-year follow up study in Japanese patients with adult asthma. A total of 189 patients with asthma were enrolled and followed up for 1 year. Finally, 181 patients completed the study protocol.


RESULTS
Of 181 patients, 43 patients (23.8%) had exacerbations during the follow-up period. Among the 45 patients who had exacerbations during the preceding year, 32 patients (71.1%) had exacerbations. Prevalence of patients with previous exacerbations and those with previous admissions were significantly higher in patients with exacerbations than those with no exacerbation. Logistic regression analysis also identified a significant association between exacerbations during the follow-up period and exacerbations during the preceding year, admissions during the preceding 3 years, ACT score below 20, low %FVC (<80%), or low FEV1(<70%), respectively. Of the 55 patients with severe asthma, 29 patients (52.7%) had exacerbations. Among the 36 patients with severe asthma with previous exacerbations, 26 patients (72.2%) had exacerbations. The history of exacerbations during the preceding year was associated with a significantly increased risk of exacerbations both among the patients with severe asthma and those with non-severe asthma.


CONCLUSIONS
This study implicated that exacerbations during the preceding year reliably predict future risk of exacerbations in Japanese patients with asthma.
Department of Medicine, Division of Respiratory Medicine and Allergology, Showa University, School of Medicine, Tokyo, Japan. Electronic address: tanakaa@med.showa-u.ac.jp.
Akihiko
A
Tanaka
Department of Medicine, Division of Respiratory Medicine and Allergology, Showa University, School of Medicine, Tokyo, Japan.
Tomoki
T
Uno
Department of Medicine, Division of Respiratory Medicine and Allergology, Showa University, School of Medicine, Tokyo, Japan.
Haruna
H
Sato
Department of Medicine, Division of Respiratory Medicine and Allergology, Showa University, School of Medicine, Tokyo, Japan.
Megumi
M
Jinno
Department of Medicine, Division of Respiratory Medicine and Allergology, Showa University, School of Medicine, Tokyo, Japan.
Kuniaki
K
Hirai
Department of Medicine, Division of Respiratory Medicine and Allergology, Showa University, School of Medicine, Tokyo, Japan.
Yoshito
Y
Miyata
Department of Medicine, Division of Respiratory Medicine and Allergology, Showa University, School of Medicine, Tokyo, Japan.
Munehiro
M
Yamaguchi
Department of Medicine, Division of Respiratory Medicine and Allergology, Showa University, School of Medicine, Tokyo, Japan.
Shin
S
Ohta
Department of Medicine, Division of Respiratory Medicine and Allergology, Showa University, School of Medicine, Tokyo, Japan.
Tetsuya
T
Homma
Department of Medicine, Division of Respiratory Medicine and Allergology, Showa University, School of Medicine, Tokyo, Japan.
Mayumi
M
Yamamoto
Department of Medicine, Division of Respiratory Medicine and Allergology, Showa University, School of Medicine, Tokyo, Japan.
Shintaro
S
Suzuki
Department of Medicine, Division of Respiratory Medicine and Allergology, Showa University, School of Medicine, Tokyo, Japan.
Takuya
T
Yokoe
Department of Medicine, Division of Respiratory Medicine and Allergology, Showa University, School of Medicine, Tokyo, Japan.
Hironori
H
Sagara
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001249:Asthma / Q000175:diagnosis / Q000453:epidemiology*; D015415:Biomarkers; D015897:Comorbidity; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide / Q000032:analysis; D011379:Prognosis; D011446:Prospective Studies; D012129:Respiratory Function Tests; D018570:Risk Assessment; D012307:Risk Factors; D012720:Severity of Illness Index
D015415:Biomarkers; D009569:Nitric Oxide
Asthma control; Exacerbation; FeNO; Future risk; Pulmonary function test