Table 2 Characteristics of included observational studies
Study | Inclusion criteria | Exclusion criteria | Disease severity | Exacerbation history | LAMA use at/prior to enrolment | ICS use at/prior to enrolment | Eosinophils measured |
|---|---|---|---|---|---|---|---|
Song 2017 [35] 168 patients | > 40 years. Smoked > 10 years. FEV1/FVC < 0.7 | Asthma. FEV1 reversibility > 12%. Hx atopy, allergic rhinitis. Blood eos > 5% IgE > 100 | FEV1% predicted 55.5 ± 18 | Mean 31.9% patients AECOPD in 12 months prior to study enrolment. Recorded 6-monthly patient reviews | 59% | 43% | Not stated |
Suissa 2018 [36] 24,732 patients | ≥55 years. COPD new users of LAMA or LABA+ICS from 1.1.02. Blood eosinophil count before cohort entry | Initiated on LAMA & LABA+ICS at same time. Asthma NOT excluded | Not known | Record drawn from READ code. Mean 33.6% patients had ≥1 AECOPD in 12 months prior to study enrolment | 0% | 0% | Prior to study entry. |
Oshagbemi 2018 [37] 32,693 patients | ≥40 year. New diagnosis COPD from 1.1.05 | Asthma. Any previous AECOPD. ICS use in past year | Not known | Record drawn from READ code | 14% | 0% | Single eosinophil measure at point closest to index date (start of follow-up) |
Oshagbemi 2019 [38] 48,157 patients | ≥40 year. New diagnosis COPD from 1.1.05 | Asthma. AECOPD in 6 months prior to index date | Not known | Record drawn from READ code | 18% | 28% | Single eosinophil measure at point closest to index date (start of follow-up) |
Suissa 2019 [39] 3954 patients | ≥55 years. new use LAMA or LABA+ICS from 1.1.02. Blood eosinophil count before cohort entry | Asthma | FEV1% predicted 53.9% (LABA + LAMA) 52.7% (LABA + ICS) | Record drawn from READ code. Mean 41% of patients had ≥1 AECOPD in 12 months prior to study enrolment | 77% (LABA+LAMA) 49.1% (LABA + ICS) | 37% (LABA+LAMA) 52.8% (LABA+ICS) | Baseline |