Items | Summary statistics (n (%)) |
---|---|
Study designs (32 studies) | |
 Prospective design | 29 (90.62%) |
 Retrospective design | 3 (9.38%) |
Repeated-measures design (32 studies) | |
 Yes (that is, more than one SpO2-SaO2 data pair collected per person) | 21 (65.62%) |
 No | 11 (34.38%) |
Care settings (32 studies) | |
 Hospital care settings | 27 (84.38%) |
 Laboratory setting (only recruiting healthy volunteers) | 5 (15.62%) |
Types of participants (32 studies) | |
 Children | 7 studies (21.88%), with 1608 participants involving: • A current critical illness [23, 26, 51] • Hypoxemic conditions and/or cyanotic congenital heart disease [30, 32, 33, 45] |
 Adults | 25 (78.12%), with 4897 participants involving a variety of health conditions: • Healthy volunteers [24, 29, 47, 49, 53] • Critical illnesses or conditions needing intensive care unit admission and/or mechanical ventilation [25, 27, 34,35,36,37,38, 46] • Pulmonary/respiratory conditions including COVID-19 [28, 39, 43, 44, 50, 52] • Cirrhosis [21], • Chronic rheumatic heart disease [48] • Postoperative hypothermia [31] • Hospitalised patients in general [22, 41] • Adults under the need of a long-term home oxygen therapy [40] |
Sample sizes (32 studies) | Median 50 (range: 6 to 1562) |
Age (32 studies) | |
 Mean or median specified (23 studies) | Median 56.40 years (range: 4 days to 69 years) |
Range of arterial blood oxygen saturation SaO2 (%) | |
 SaO2 range specified (16 studies) | • The minimum values of the reported ranges, ranging from 50 to 94% (median 76%) • The maximum values of the reported ranges, ranging from 92 to 100% (median 100%) |
Factors related to skin pigmentation (32 studies) | |
 Levels of skin pigmentation | 15 studies (46.88%), with 1800 participants |
 Descriptors of ethnicity | 22 studies (68.88%), with 4910 participants |