Patients with asthma and asthma control test scores 20-22: A grey zone between Japanese and global remission criteria

The definition of clinical remission has not been fully standardized. The Japanese guideline adopts a criterion of Asthma Control Test (ACT) score ≥23, compared with the global threshold of ≥20. In this study, we focused on patients with ACT scores of 20-22 to clarify their clinical characteristics.

We analyzed asthma survey data from Niigata and Kumamoto for 2021 and 2023, respectively. A total of 611 patients with complete clinical data were included. Japanese clinical remission (jCR) was defined as ACT ≥23, no OCS use, no exacerbations, and %FEV₁ ≥80%. Patients who met any of the criteria ACT <20, OCS use, exacerbations in the previous year, or %FEV₁ <80% were classified as non-clinical remission (nCR). Patients with an ACT of 20-22 who otherwise met the remission criteria were defined as global-clinical remission (gCR).

In 2021, 248, 276, and 87 patients achieved jCR, nCR, and gCR. Compared with the jCR group, the gCR group showed no significant differences in severity, but had significantly higher Patient Health Questionnaire (PHQ-9) and Nijmegen Questionnaire (NQ) scores, similar to the nCR group. The frequency of exacerbations in the following year was lower in the gCR group than in the nCR group.

Although patients with gCR had a lower disease severity than those with nCR, their PHQ-9 and NQ scores were higher than those with jCR, suggesting that psychological factors may hinder remission. Specific management of strategies for patients with gCR may be required in addition to pharmacological care.