Using clinically important deterioration (CID) as a composite endpoint for disease progression may be beneficial in predicting long-term clinical outcomes in Japanese patients with chronic obstructive pulmonary disease (COPD), according to study results published in BMC Pulmonary Medicine.

Western studies have proposed CID as a composite endpoint of disease progression in COPD; however, its usefulness in more diverse populations is unclear. Compared with patients in Western studies, Japanese patients with COPD generally tend to be older, thinner, have a lower St George’s Respiratory Questionnaire (SGRQ) score, and fewer exacerbations.

A team of investigators conducted a study in which 2 definitions of CID were used to determine “whether the presence of any component of the composite CID over a 1-year period was associated with subsequent clinical outcomes (exacerbations and mortality) in Japanese patients with COPD.”

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The first definition (D1) of CID included a decrease of ≥100 mL from the postbronchodilator forced expiratory volume in 1 second (FEV1) at baseline, an increase of ≥4 units in the SGRQ score from baseline, and the incidence of moderate or severe exacerbation. The second definition (D2) of CID doubled the thresholds for FEV1 (≥200 mL) and increased SGRQ score (≥8 units).

In the 259 patients included in the analysis, the mean age was 69.6 years, 5.8% were women, and 28.2% were current smokers. In accordance with D1, 152 (58.7%) of patients had CID. Among these patients, the most common cause of CID in the first year was deterioration of FEV1 (35.5%), while the least common cause was exacerbation (14.7%). Using D2, 97 (37.5%) of patients had CID; however, positive rates for deterioration of FEV1, deterioration of SGRQ, and exacerbation were similar.

Of the single components of CID, exacerbation was significantly linked to early onset of moderate exacerbation and the SGRQ (≥8 units) was linked to early onset of severe exacerbation and death from respiratory diseases; however, none of the single components of CID were linked to all-cause mortality.

There was a significant association between CID using D2 and early onset of moderate exacerbation (P =.01) and a suggested association with severe exacerbation (P =.06); however, these relations were not observed with CID using D1.

Using D1, CID was significantly linked to all-cause mortality (P =.047) and death from respiratory disease (P =.04), while CID using D2 tended to relate to these outcomes (P =.052 and P =.0501, respectively). After adjustments for postbronchodilator FEV1, both D1 and D2 CID tended to be linked to all-cause mortality.

“This concept of evaluating short-term changes across multiple endpoints may help identify patients at high risk for worsening of COPD earlier,” the investigators noted. “Further research may be needed on the relationship between CID thresholds and long-term outcomes for future clinical trials,” the authors concluded.

Disclosure: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.


Abe Y, Suzuki M, Makita H, et al. One-year clinically important deterioration and long-term clinical course in Japanese patients with COPD: a multicenter observational cohort study. BMC Pulm Med. 2021;21(1):159. doi:10.1186/s12890-021-01510-w