5. Table of study characteristics outcomes: exacerbation outcomes.
| Author | Outcome domain | Outcome measure | Time points, months (time frame) | Data reported | Pooled |
| Aboumatar 2019 | hospitalisations; ED visit | respiratory‐related hospital admissions; hospital admissions (all causes); ED visits | 6 (ST) | Incidence rate, 95% CI, N/group | Yes |
| Bernocchi 2017 | hospitalisations | respiratory‐related hospital admissions; hospital admissions (all causes) | 6 (ST) | n, N/group | Yes |
| Bourbeau 2003 | hospitalisations; ED visit; exacerbation | respiratory‐related hospital admissions; hospital days per patient; ED visits; number of patients experiencing ≥ 1 exacerbation | 6 (ST); 9 (MT) | n, N/group, mean, SD/group | Yes |
| Boxall 2005 | hospitalisations | respiratory‐related hospital admissions; hospital days per patient | 3 (ST); 12 (MT) | n, N/group, mean, SD/group | Yes |
| Engstrom 1999 | hospitalisations | hospital days per patient | 12 (MT) | mean, SD/group | Yes |
| Fan 2012 | hospitalisations; ED visit; exacerbation | respiratory‐related hospital admissions; hospital days per patient; ED visits; patients using ≥ 1 course of oral steroids; patients using ≥ 1 course of antibiotics | 12 (MT) | n, N/group, rate per person‐year, mean, SD, N/group | Yes |
| Farrero 2001 | hospitalisations | hospital days per patient | 12 (MT) | mean, SD/group | Yes |
| Freund 2016 | hospitalisations | hospital days per patient | 12 (MT) | mean difference, 95% CI, N, P value | No |
| Güell 2000 | exacerbation | mean exacerbation rate | 24 (LT) | n as count data, mean, SD/group | Yes |
| Kalter‐Leibovici 2018 | hospitalisations | respiratory‐related hospital admissions; hospital admissions (all causes) | 36 (LT) | n, N/group | Yes |
| Kessler 2018 | hospitalisations, exacerbation | total hospital admissions (all causes); percentage of hospital days | 12 (MT) | n, N/group | Yes |
| total respiratory‐related hospital admissions | 12 (MT) | n, N/group | No | ||
| hospital days per patient; number of patients experiencing ≥ 1 exacerbation | 12 (MT) | n, N/group; mean, SD/group | Yes | ||
| Ko 2016 | hospitalisations | hospital days per patient | 12 (MT) | mean, SD/group | Yes |
| Koff 2009 | hospitalisations | respiratory‐related hospital admissions | 3 (ST) | n, N/group | Yes |
| Kruis 2014 | hospitalisations | hospital days per patient; mean exacerbation rate | 12 (MT) | mean, 95% CI/group, incidence rate ratio, 95% CI, N (for mild and severe exacerbations) | Yes |
| Lenferink 2019 | hospitalisations; exacerbation | respiratory‐related hospital admissions; hospital admissions (all causes); hospital days per patient; number of patients experiencing ≥ 1 exacerbation | 12 (MT) | n, N/group, mean, 95% CI, N/group | Yes |
| Littlejohns 1991 | hospitalisations; exacerbation | hospital admissions (all causes); patients using ≥ 1 course of oral steroids; patients using ≥ 1 course of antibiotics | 12 (MT) | n, N/group | Yes |
| Lou 2015 | hospitalisations; ED visit | hospital admissions (all causes); ED visits | 48 (LT) | %, N/group | Yes |
| Rea 2004 | hospitalisations; ED visit; exacerbation | respiratory‐related hospital admissions; hospital admissions (all causes); hospital days per patient; ED visits; patients using ≥ 1 course of oral steroids; patients using ≥ 1 course of antibiotics | 12 (MT) | n, N/group, mean/group | Yes |
| Rice 2010 | hospitalisations; ED visit | respiratory‐related hospital admissions; ED visits | 12 (MT) | n, N/group | Yes |
| Rose 2017 | hospitalisations; ED visit | hospital days per patient; ED visits | 12 (MT) | n, N/group, median, IQR/group | Yes |
| Sanchez‐Nieto 2016 | hospitalisations; ED visit; exacerbation | respiratory‐related hospital admissions; ED visits; patients using ≥ 1 course of oral steroids; patients using ≥ 1 course of antibiotics | 12 (MT) | n, N/group | Yes |
| Silver 2017 | hospitalisations; ED visit | hospital days per patient; ED visits | 12 (MT) | n, N/group, median, IQR/group | Yes |
| Smith 1999 | hospitalisations; ED visit | respiratory‐related hospital admissions; ED visits | 12 (MT) | n, N/group | Yes |
| Sridhar 2008 | hospitalisations; exacerbation | hospital admissions (all causes); number of patients experiencing ≥ 1 exacerbation | 24 (LT) | n, N/group | Yes |
| Tabak 2014 | ED visit | ED visits | 3 (MT) | median, IQR/group | No |
| Titova 2017 | hospitalisations | Total number of hospitalisations; categories of patients "HA category 1 (≤ 1 HA per year) and HA category 2 (≥ 2 HA per year)" | 12 (MT); 24 (LT) | n, N (count data) | No |
| Trappenburg 2011 | hospitalisations; exacerbation | respiratory‐related hospital admissions; hospital days per patient; number of patients experiencing ≥ 1 exacerbation | 6 (ST) | n, N; mean, SD, N/group/time point mean difference, 95% CI, P value | Yes |
| van Wetering 2010 | hospitalisations; exacerbation | hospital days per patient; number of patients experiencing ≥ 1 exacerbation | 24 (LT) | mean, SD/group, n, N/group | Yes |
| Vasilopoulou 2017 | hospitalisations; exacerbation | respiratory‐related hospital admissions; hospital admissions (all causes); hospital days per patient; number of patients experiencing ≥ 1 exacerbation; mean exacerbation rate | 14 (MT); 24 (LT) | n, N/ group/time point, mean, SD/group | Yes |
| Vianello 2016 | hospitalisations; ED visit | hospital days per patient (all causes); hospital days per patient (respiratory related); ED visits | 12 (MT) | mean, SD, N/group, rate per person‐year | Yes |
| Wakabayashi 2011 | ED visit | ED visits | 12 (MT) | mean, SD, N/group/time point | Yes |
| Zhang 2020 | hospitalisations; ED visit | admission rates; length of stay; ED visits (all outcomes for entire study population) | 3 (ST);6 (ST); 12 (MT); 24 (LT) | n, N (count data), median, IQR/group | No |
Abbreviations. CI: confidence interval; ED: emergency department; IQR: interquartile range; T: long‐term follow‐up; MD: mean difference; MT: medium‐term follow‐up; SD: standard deviation; SE: standard error; ST: short‐term follow‐up.