Baseline characteristics of patients with COPD with and without inhaled corticosteroid (ICS) withdrawal, before and after 1–2 propensity score (PS) matching and after stabilised inverse probability weighting (IPTW)
| Characteristic | All patients | 1–2 PS matching | Stabilised IPTW | ||||||
| ICS withdrawal (n=971) | Control (n=2764) | smd | ICS withdrawal (n=904) | Control (n=1808) | smd | ICS withdrawal (n=872) | Control (n=2591) | smd | |
| Males | 84.0% | 79.0% | −12.9% | 84.0% | 82.0% | −5.6% | 80.0% | 81.0% | 0.7% |
| Fiscal year | |||||||||
| 2010 | 4.1% | 10.1% | −23.6% | 4.1% | 3.9% | 1.1% | 7.3% | 8.3% | −3.4% |
| 2011 | 9.4% | 17.0% | −22.6% | 9.4% | 8.7% | 2.5% | 16.8% | 14.6% | 6.0% |
| 2012 | 13.8% | 20.2% | −16.9% | 13.8% | 12.9% | 2.8% | 18.7% | 17.8% | 2.4% |
| 2013 | 18.3% | 18.4% | −0.4% | 18.3% | 20.7% | −6.3% | 16.3% | 18.6% | −5.9% |
| 2014 | 25.0% | 19.9% | 12.4% | 25.0% | 25.2% | −0.5% | 21.4% | 22.2% | −1.9% |
| 2015 | 29.4% | 14.5% | 36.8% | 29.4% | 28.6% | 1.8% | 19.4% | 18.6% | 2.1% |
| Season at admission | |||||||||
| Spring | 23.7% | 24.9% | −2.8% | 23.7% | 24.3% | −1.4% | 23.6% | 24.0% | −1.0% |
| Summer | 24.4% | 22.2% | 5.4% | 24.4% | 25.1% | −1.5% | 23.3% | 23.3% | 0.1% |
| Autumn | 24.4% | 23.1% | 3.1% | 24.4% | 24.8% | −0.8% | 24.2% | 24.2% | 0.1% |
| Winter | 27.4% | 29.8% | −5.3% | 27.4% | 25.8% | 3.6% | 28.9% | 28.5% | 0.8% |
| Residential region | |||||||||
| Hokkaido and Tohoku | 10.1% | 10.6% | −1.8% | 10.1% | 10.2% | −0.5% | 8.8% | 10.8% | −6.6% |
| Kanto | 30.6% | 35.6% | −10.6% | 30.6% | 29.9% | 1.7% | 36.2% | 34.1% | 4.5% |
| Chubu | 15.7% | 15.7% | 0.0% | 15.7% | 14.8% | 2.5% | 13.9% | 15.2% | −3.7% |
| Kansai | 16.0% | 16.0% | 0.2% | 16.0% | 16.1% | −0.2% | 14.6% | 15.4% | 2.1% |
| Chugoku, Shikoku, Kyushu and Okinawa | 27.5% | 22.0% | 12.8% | 27.5% | 29.0% | −3.2% | 26.4% | 24.5% | 4.3% |
| Hugh–Jones dyspnoea score at admission | |||||||||
| 1 | 10.8% | 9.5% | 4.3% | 10.8% | 11.2% | −1.2% | 9.6% | 9.5% | 0.2% |
| 2–3 | 33.7% | 32.2% | 3.2% | 33.7% | 30.9% | 6.0% | 32.7% | 32.7% | 0.0% |
| 4–5 | 45.7% | 51.8% | −12.3% | 45.7% | 48.2% | −5.1% | 50.9% | 50.3% | 1.2% |
| Missing | 9.7% | 6.4% | 12.2% | 9.7% | 9.6% | 0.4% | 6.8% | 7.5% | −2.6% |
| ADL at admission (Barthel Index score) | |||||||||
| 100 | 37.1% | 37.9% | −1.7% | 37.1% | 35.0% | 4.3% | 35.4% | 37.4% | −4.1% |
| 0–90 | 49.0% | 46.4% | 5.2% | 49.0% | 50.8% | −3.7% | 48.4% | 47.6% | 1.5% |
| Missing | 13.9% | 15.7% | −5.0% | 13.9% | 14.2% | −0.6% | 16.2% | 15.0% | 3.4% |
| ADL at discharge (Barthel Index score) | |||||||||
| 100 | 55.4% | 62.4% | −14.3% | 55.4% | 53.4% | 4.1% | 57.8% | 59.8% | −4.0% |
| 0–90 | 36.0% | 29.8% | 13.2% | 36.0% | 36.7% | −1.6% | 34.7% | 31.9% | 6.1% |
| Missing | 8.6% | 7.8% | 3.1% | 8.6% | 9.9% | −4.4% | 7.4% | 8.3% | −3.2% |
| Smoking index | |||||||||
| 200–599 | 9.0% | 9.8% | −2.8% | 9.0% | 7.5% | 5.2% | 8.9% | 9.3% | −1.2% |
| ≥600 | 49.4% | 48.3% | 2.3% | 49.4% | 49.8% | −0.7% | 48.3% | 49.3% | −2.1% |
| Missing | 41.6% | 41.9% | −0.7% | 41.6% | 42.7% | −2.2% | 42.8% | 41.4% | 2.9% |
| Age years | 77.8±7.0 | 76.9±6.6 | 13.9 | 77.8±7.0 | 78.1±6.9 | −4.2 | 77.5±7.1 | 77.2±6.7 | 0.4 |
| Body mass index kg·m−2 | 20.5±3.9 | 21.3±4.0 | −19.9 | 20.5±3.9 | 20.3±3.7 | 3.4 | 20.8±4.1 | 21.0±4.0 | −4.1 |
| Frequency of hospitalisation before hospitalisation for COPD exacerbation | 0.84±1.3 | 0.59±1.2 | 18.5 | 0.84±1.3 | 0.98±2.1 | −8.1 | 0.83±1.2 | 0.77±1.6 | 4.4 |
| Observation period before hospitalisation for COPD exacerbation days | 1055.4±574.0 | 847.0±571.3 | 35.9 | 1058.2±576.7 | 1055.4±610.1 | 0.5 | 912.7±567.4 | 913.9±587.4 | −0.2 |
Data are presented as mean±sd unless otherwise stated. smd: standardised mean difference; ADL: activities of daily living.