Table 1.
Baseline characteristics of the eligible studies
| Study | Region | Centre(s) | Design | Obesity n% | Total | Male | Age | Outcomes | NOS score |
|---|---|---|---|---|---|---|---|---|---|
| Alkhatib [19] | USA | Single | Retrospective | 60.76 | 158 | 61 | 57 | ICU admission | 7 |
| Argenziano [20] | USA | Single | Retrospective | 41.85 | 1000 | 596 | 63 50–75 |
ICU admission | 7 |
| Bello-Chavolla [21] | Mexico | Multiple | Retrospective | 16.42 | 177 133 | 90 582 | 42.58 | Risk of COVID 19 infection Mortality ICU admission Need of IMV |
7 |
| Buckner [22] | USA | Multiple | Retrospective | 47.31 | 105 | 53 | 69 23–97 |
Severe cases | 7 |
| Busetto [11] | Italy | Single | Retrospective | 31.52 | 92 | 57 | 70.5 ± 13.3 | Mortality ICU admission Need of IMV |
8 |
| Cai1 [23] | China | Single | Retrospective | NA | 298 | 145 | 47 33–61 |
Severe cases | 7 |
| Cai2 [24] | China | Single | Retrospective | 10.70 | 383 | 183 | 48.4 | Severe cases | 7 |
| Caussy [25] | France | Single | Retrospective | 25 | 340 | NA | NA | Severe cases | 7 |
| Chand [26] | USA | Multiple | Retrospective | 54.33 | 300 | 182 | 57.8 ± 12.2 | Mortality | 8 |
| Chao [27] | USA | Single | Retrospective | 26.09 | 46 | 31 | 13.1 0.4–19.3 |
ICU admission | 7 |
| Cummings [29] | USA | Double | Prospective | 46.30 | 257 | 171 | 62 51–72 |
Mortality | 8 |
| Czernichow [28] | France | Multiple | Prospective | 21.81 | 5795 | 3791 | NA | Mortality | 8 |
| Docherty [30] | UK | Multiple | Prospective | 10.48 | 20 133 | 12 068 | 73 58–82 |
Mortality | 8 |
| Duanmu [31] | USA | Single | Retrospective | 22 | 100 | 56 | 45 32-65 |
Hospitalisation | 7 |
| Escalera-Antezana [32] | Bolivia | Single | Retrospective | 5.61 | 107 | 55 | 43.9 ± 17.6 | Mortality | 8 |
| Gao [33] | China | Multiple | Retrospective | 50 | 150 | 94 | 48 | Severe cases | 7 |
| Gerwen [34] | USA | Multiple | Retrospective | 28.95 | 3703 | 2049 | 56.8 ± 18.2 | Mortality Need of IMV Hospitalisation |
8 |
| Giannouchos [35] | Mexico | Multiple | Retrospective | 16.7 | 236 439 | 120 347 | 42.5 ± 16.9 | Risk of COVID-19 infection Hospitalisation |
7 |
| Goyal1 [36] | USA | Single | Retrospective | 34.60 | 393 | 238 | 62.2 48.6–73.7 |
Need of IMV | 7 |
| Goyal2 [37] | USA | Double | Retrospective | 31.12 | 1687 | 1004 | 66.5 53.7–77.2 |
Mortality | 8 |
| Giracomelli [38] | Italy | single | Prospective | 16.31 | 233 | 161 | 61 50–72 |
Mortality | 8 |
| Hajifathalian [39] | USA | Double | Retrospective | 35.97 | 770 | 468 | 63.5 ± 17 | Mortality ICU admission Need of IMV |
8 |
| Halasz [40] | Italy | Single | Retrospective | 19.83 | 242 | 194 | 64 56–71 |
Mortality | 8 |
| Hamer [41] | UK | Multiple | Prospective | 23.84 | 334 329 | 152 162 | NA | Risk of COVID-19 infection | 7 |
| Hu [42] | China | Single | Retrospective | 4.02 | 323 | 166 | 61 23–91 |
Severe cases | 7 |
| Hur [43] | USA | Multiple | Retrospective | 53.29 | 486 | 271 | 59 47–69 |
Need of IMV | 7 |
| Jung [44] | South Korea | Multiple | Retrospective | NA | 18 940 | 7185 | 53.7 ± 13.8 | Risk of COVID-19 infection | 7 |
| Kalligeros [45] | USA | Single | Retrospective | 47.57 | 103 | 63 | 60 50–72 |
ICU admission Need of IMV |
7 |
| Killerby [46] | Atlanta | Multiple | Retrospective | 42.75 | 531 | 228 | 51.63 | Hospitalisation | 7 |
| Kim [47] | USA | Multiple | Retrospective | 46.33 | 2491 | 1326 | 62 50–75 |
ICU admission | 7 |
| Klang [48] | USA | Single | Retrospective | 36.14 | 3406 | 1961 | 65.9 | Mortality | 8 |
| Lighter [49] | USA | Single | Retrospective | 37.90 | 3615 | NA | NA | Hospitalisation ICU admission |
7 |
| Lodigiani [67] | Italy | Single | Retrospective | 23.97 | 388 | 264 | 66 | ICU admission | 7 |
| Lusignan [50] | UK | Multiple | Retrospective | 21.70 | 3802 | 1612 | NA | Risk of COVID-19 infection | 7 |
| Monterio [51] | USA | Single | Retrospective | 35.71 | 112 | 74 | 61 45–74 |
Need of IMV | 7 |
| Nakeshbandi [52] | USA | Single | Retrospective | 42.66 | 504 | 263 | 68 ± 15 | Mortality Need of IMV |
8 |
| Ong [53] | Singapore | Single | Retrospective | NA | 91 | 51 | 54.92 | Mortality ICU admission Need of IMV |
7 |
| Oriz-Brizuela [54] | Mexico | Single | Prospective | 21.68 | 309 | 183 | 43 33–54 |
Hospitalisation ICU admission |
7 |
| Palaiodimos [55] | USA | Single | Retrospective | NA | 200 | 98 | 64 50–73.5 |
Mortality Need of IMV |
8 |
| Parra-Bracamonte [56] | Mexico | Multiple | Retrospective | 19.92 | 142 690 | 79 280 | 45 34–57 |
Mortality | 8 |
| Petrilli [57] | USA | Multiple | Retrospective | 26.81 | 4103 | 2072 | 52 36–65 |
Hospitalisation Severe cases |
7 |
| Price-Haywood [58] | USA | Single | Retrospective | 49.61 | 3481 | 1394 | 54 | Hospitalisation | 7 |
| Shah [59] | USA | Multiple | Retrospective | 66.48 | 522 | 347 | 63 50–72 |
Mortality | 8 |
| Simonnet [60] | France | Single | Retrospective | NA | 124 | 90 | 60 51–70 |
Need of IMV | 7 |
| Soares [61] | Brazil | Multiple | Retrospective | 5.57 | 10 713 | 4804 | NA | Hospitalisation | 7 |
| Suleyman [62] | USA | Multiple | Retrospective | 56.59 | 463 | 204 | 57.5 ± 16.8 | Hospitalisation ICU admission Need of IMV |
7 |
| Williamson [63] | UK | Multiple | Retrospective | 21.82 | 17 278 392 | 8 630 403 | NA | Mortality | 8 |
| Wu [64] | China | Multiple | Retrospective | NA | 280 | 151 | 43.12 ± 19.02 | Severe cases | 7 |
| Zachariah [65] | USA | Single | Retrospective | 22 | 50 | 27 | 9.9 | Severe cases | 7 |
| Zheng [66] | China | Multiple | Retrospective | 68.18 | 66 | 49 | 47 | Severe cases | 7 |
IMV, invasive mechanical ventilation; ICU, intensive care unit; NA, not available; NOS, Newcastle−Ottawa quality assessment scale.