Table 2.
Characteristics of the included studies
| Authors | Country | Year | Sample size | Age (mean or median) | Gender | Frailty tool | Type of AE |
|---|---|---|---|---|---|---|---|
| Deiner et al. [42] | USA | 2023 | 505 | 76.7 (SD ± 5.22) | Female n = 297 (58.8%) | Frailty index and frailty phenotype | Postoperative delirium POD |
| Esmaeeli et al. [27] | USA | 2022 | 556 | 85 (SD ± 7) | Female 388 (69.78%) | FRAIL Score | Postoperative delirium POD |
| Sieber et al. [29] | USA | 2022 | 324 | 4AT < 4 = mean age 73.1 (SD 6.2)/4AT ≥ 4 = mean age 77.5 (SD 6.3) | Female 128 (39.5%) | Edmonton frailty scale EFS | Postoperative delirium POD |
| Joseph et al. [43] | USA | 2017 | 350 |
Non-frail: 76.5/SD = 5.1 Pre-frail: 76.9/SD = 7.9 Frail: 77.5/SD = 8.4 |
Non-frail (n = 126): 63 males (50%), 63 females (50%) Pre-frail (n = 91): 62 males (68%), 29 females (32%) Frail (n = 133): 71 males (53%), 62 females (47%) |
Trauma-Specific Frailty Index (TSFI) | Urinary tract infection UTI, pneumonia, sepsis, disseminated intravascular coagulation DIC, deep venous thrombosis DVT and pulmonary embolism PE |
| Leung et al. [44] | USA | 2010 | 63 |
Delirium 74.2 SD 6.0 No delirium 71.9 SD 6.3 |
Female: Delirium (n = 16) 8 (50%) No delirium (n = 47) 26 (55%) |
Fried phenotype | Postoperative delirium POD |
| Hanlon et al. [33] | USA | 2004 | 397 | Aged 65–74/213 (53.6%), Aged ≥ 75/184 (46.4%) | Female 11 (2.8%) | 10-item frailty score based on Veterans Affairs (VA) Cooperative Study health service trial | Inappropriate drug prescribing |
| Mcevoy et al. [30] | Australia | 2023 | 44,721 | 80 (SD 7) | Female 25,306 (57%) | Clegg’s clinical ICD-10-AM coded cumulative deficit items | Falls, pressure injury, delirium, pneumonia, thromboembolism |
| Thillainadesan et al. [26] | Australia | 2021 | 150 | 79.5 (SD ± 7.7) | Males 102 (68.0%) | The clinical frailty scale CFS and a 37-item FI based on the Rockwood FI | Functional decline, constipation, pressure injury, fall, delirium |
| Hubbard et al. [31] | Australia | 2017 | 1418 | 81.0 (SD 6.8) | Female 780 (55.0%) | A frailty index (FI-AC) | Inpatient fall, delirium, pressure ulcer functional decline |
| Chan et al. [37] | Canada | 2019 | 423 | CFS 1–3 n = 71 mean SD: 77.1 (6.9)/CFS 4 n = 72 mean SD: 79.3 (8.1)/CFS 5 n = 92 mean SD: 83.4 (7.2)/CFS 6–9 n = 187 mean SD: 85.2 (8.2) | Female: CFS 1–3 n = 45 (63.4%)/CFS 4 n = 47 (65.3%)/CFS 5 n = 50 (54.4%)/CFS 6–9 n = 125 (66.8%) | Clinical Frailty Scale CFS | Delirium, venous thromboembolism, pneumonia, urinary tract infection, myocardial injury, need for transfusion, pressure ulcer and falls |
| Dasgupta et al. [41] | Canada | 2009 | 125 | Entire cohort (mean): 77.4/Patients without complications (n = 94): 76.3 ± 5.0/Patients with complications (n = 31): 80.8 ± 5.8 | Female: n = 72 (58%) | Edmonton frailty scale EFS |
Cardiac complications: one of either ischaemia, congestive heart failure, new arrhythmia or sudden death Pulmonary complications: one of either pneumonia, significant bronchospasm, deep venous thrombosis or pulmonary embolisms (DVT or PE), the excessive need for respiratory support. Delirium |
| Jung et al. [34] | South Korea | 2022 | 1016 | CFS < 5 (n = 637) 71.8 ± 5.1, CFS ≥ 5 (n = 379) 75.0 ± 7.2 |
Female CFS < 5 (n = 637) 215 (33.8%), CFS ≥ 5 (n = 379) 200 (52.8%) |
Clinical frailty scale CFS | Fall, pressure ulcer, delirium |
| Kim et al. [36] | South Korea | 2021 | 85 | 74.05(SD ± 6.47) | Female 50 (58.8%) | Korean version of the fatigue, resistance, ambulation, illnesses, and loss of weight (K-FRAIL) scale | Poor oral intake, Voiding difficulty, urinary tract infection, delirium, pneumonia, postoperative hematoma, acute kidney injury, electrolyte imbalance, sepsis, cardiac arrest, superficial wound infection |
| Nowak et al. [35] | Poland | 2023 | 174 | Robust 70.8 ± 4.2, Pre-frail 72.8 ± 5.8, Frail 79.2 ± 8.0 | Female: Robust (n = 54) 15 (27.8%) Pre-Frail (n = 52) 24 (46.1%), Frail (n = 68) 39 (57.4%) | FRAIL Score | Bleeding, infection, arrhythmia, acute kidney injury (AKI), delirium, stroke/transient ischaemic attack (TIA), liver injury, hypoglycaemia |
| Chen et al. [39] | China | 2022 | 227 | 71.2 [SD ± 4.8] | Male 140 (61.7%) | FRAIL Score | Postoperative pulmonary complications PPCs (pneumonia, pulmonary congestion, bronchospasm, atelectasis, pneumothorax, respiratory failure, pleural effusion or requirement for mechanical ventilation) |
| Aceto et al. [40] | Italy | 2021 | 97 | With PPC 73.3 ± 7.1/Without PPC 69.7 ± 4.7 | Female n = 47 (44.7%) | Modified Frailty Index (mFI) | PPCs (respiratory failure, pulmonary infection, aspiration pneumonia, pleural effusion, pneumothorax, atelectasis on chest X-ray, bronchospasm, or un-planned urgent re-intubation) |
| Welch et al. [28] | UK | 2019 | 1507 | 80.0 (SD ± 8.3) | Female 798 (54.2%) | Clinical frailty scale CFS | Delirium |
| Birkelbach et al. [38] | Germany | 2019 | 1186 | 74.0 [SD ± 4] | Male 623 (52.5%) | Fried phenotype | Pneumonia, pulmonary embolism, acute kidney injury, cerebrovascular accident, coma, superficial and deep wound infections, urinary tract infection, sepsis, deep vein thrombosis, myocardial infarction, cardiac arrest |
| Joosten et al. [32] | Belgium | 2014 | 220 | Pre-frail and non-frail 83.7 ± 4.8, Frail 83.3 SD ± 5.4) | Female 126 (57%) | Cardiovascular Health Study (CHS) and the Study of Osteoporotic Fracture (SOF) frailty index | In-hospital delirium and falls |