Table 1 Summary of studies included in the quantitative synthesis
Publication | Country | Source | Age of participants | Primary outcome/Definition | Follow up duration | Sample size (Development/Validation) | Events per variable | Predictors in model |
|---|---|---|---|---|---|---|---|---|
Bateman 2014 [22] | Multiple | 3 double blind trials Retrospective | 12–89 | Time to first exacerbation/ GINA | 6–12 months | 4962/2482 | NR/24 | Body mass index (BMI), Asthma control questionnaire 5 (ACQ-5) score, Post bronchodilator forced expiratory volume in 1 sec (FEV1), Reliever use, GINA step. |
Blakey 2017 [23] | UK | UK electronic medical database Retrospective | 12–80 | ≥2 exacerbations ≥4 exacerbations Asthma related admission or OCS | 2 years | 118,981 | 59,514/55 =1082.07 | Age, Sex, BMI, Smoking status, Rhinitis, Eczema, Gastroesophageal reflux disease (GERD), Nasal polyps, Anaphylaxis, Non-steroidal anti-inflammatory drug (NSAID) use, Peak expiratory flow (PEF), Blood eosinophil, Mean short-acting beta agonist (SABA) use, Leukotriene receptor antagonist (LTRA) use, Long-acting beta agonist (LABA) use, Inhaled corticosteroid (ICS) use, Acute oral corticosteroid (OCS) use, Asthma related hospital admissions, Primary care consultations. |
Finkelstein 2013 [24] | Multiple | Self-reported study Retrospective | Adult | High/low risk of exacerbation/ Patient defined | Not reported | 1862/3306 | NR/147 | Wheeze, Sputum production, Chest tightness, Shortness of breath, Limitation of physical activity, Over-all use of quick-relief inhaler, Exposure to triggers, Over-all asthma estimate, Presence of cold, Number of quick-relief puffs, number of preventative puffs, Sleep problems, Number of times awoken, Last night quick-relief use, Last 24 h prednisone use, Last 24 h nebulizer use, Last 24 h second controller use, Last use of quick-relief inhaler |
Finkelstein 2017 [25] | Multiple | Self-reported study Retrospective | Adult | High/low risk of exacerbation/ Patient defined | Not reported | 1862/3306 | NR/147 | Wheeze, Sputum production, Chest tightness, Shortness of breath, Limitation of physical activity, Over-all use of quick-relief inhaler, Exposure to triggers, Over-all asthma estimate, Presence of cold, Number of quick-relief puffs, number of preventative puffs, Sleep problems, Number of times awoken, Last night quick-relief use, Last 24 h prednisone use, Last 24 h nebulizer use, Last 24 h second controller use, Last use of quick-relief inhaler |
Honkoop 2013 [26] | New Zealand | Two studies Retrospective | 12–75 | Severe exacerbation/ Asthma score | 1 year | 164/94 | 88/25 =3.52 | Asthma symptoms, PEF |
Loymans 2016 [27] | Netherlands | ACCURATE study group Retrospective | 17–55 | Exacerbation ATS/ERS | 1 year | 611/504 | 80/15 =5.33 | ACQ-5 score, Current smoking status, Chronic sinusitis, Admissions, Oral steroid use, FEV1, Fractional exhaled nitrous oxide (FeNO) |
McCarren 1998 [28] | US | Hospital cohort Retrospective | 18–55 | Severe exacerbation/ Unscheduled ED visit | 6 weeks | 284 | 130/18 =7.22 | 3 or more emergency department (ED) visits in the last 6 months, Difficulty performing activities in the last 4 weeks, Left ED before 24 h without achieving 50% of predicted peak expiratory flow rate (PEFR) |
Sato 2009 [29] | Japan | Hospital cohort Prospective | 62.5 ± 13.5 | Severe exacerbation/ 2 days < 70% PEF | Until event | 78 | 16/4 =4.00 | Asthma control test (ACT) score, FEV1, FeNO |
Yii 2012 [30] | Singapore | Hospital cohort Prospective | 56 ± 18 and 50 ± 19 | Severe exacerbation ATS/ERS | 3 years | 177/84 | NR/12 | 2 or more ED or hospital visits in the past year, BMI, History of near-fatal asthma, Depression, Obstructive sleep apnoea, GERD |