7. Comparison 2 (HFNC vs NIV or NIPPV): summary effects of additional outcomes.
| Additional outcomes | Study IDs |
Effect estimate (short‐term) |
Effect estimate (long‐term) |
Comment |
| Duration of respiratory support | Cong 2019; Jing 2019 | MD ‐6.12 hours, 95% CI ‐54.61 to 42.37; 2 studies, 210 participants; I2 = 60%; Analysis 2.7 | ‐ | We noted a wide variation in results between these studies; this variation may be caused by differences in illness severity in the included participants in each study. |
| Long‐term PaO2/FiO2 | Jing 2019; Stephan 2015 | ‐ | MD ‐31.67 mmHg, 95% CI ‐49.37 to ‐13.97; 2 studies, 344 participants; I2 = 0%; Analysis 2.8 | |
| PaO2 | Cong 2019; Frat 2015 | MD ‐9.57 mmHg, 95% CI ‐30.25 to 11.11; 2 studies, 384 participants; I2 = 89%; Analysis 2.9 | MD ‐0.35 mmHg, 95% CI ‐5.02 to 4.32; 1 study, 168 participants; Table 8 | |
| SpO2 | Cong 2019 | MD ‐0.82%, 95% CI ‐3.14 to 1.50; 1 study, 168 participants; Table 8 | MD ‐0.82%, 95% CI ‐2.09 to 0.45; 1 study, 168 participants; Table 8 | |
| PaCO2 | Cong 2019; Frat 2015; Jing 2019; Stephan 2015 | MD ‐0.46 mmHg, 95% CI ‐2.08 to 1.16; 4 studies, 1254 participants; I2 = 49%; Analysis 2.10 | MD ‐1.80 mmHg, 95% CI ‐5.57 to 1.98; 2 studies, 208 participants; I2 = 0%; Analysis 2.10 | |
| Respiratory rate | Chanques 2013; Frat 2015; Jing 2019; Stephan 2015 | MD ‐1.06 breaths/min, 95% CI ‐1.80 to ‐0.32; 4 studies, 1090 participants; I2 = 0%; Analysis 2.11 | MD 1.40 breaths/min, 95% CI ‐1.36 to 4.16; 1 study, 40 participants; Table 8 | |
| Other adverse events Ventilator‐acquired tracheobronchitis | Hernandez 2016a | RR 0.66, 95% CI 0.32 to 1.38; 1 study, 604 participants; Table 7 | ‐ | |
| Length of hospital stay | Cong 2019 | MD ‐0.27 days, 95% CI ‐2.26 to 1.72; 1 study, 168 participants; Table 8 | ‐ | Additional data available from 2 studies (Hernandez 2016a; Stephan 2015)ab; see Table 8 |
|
Other participant‐reported outcomes Dyspnoea |
Frat 2015; Stephan 2015 | RR 1.05, 95% CI 0.74 to 1.48; 2 studies, 1023 participants; I2 = 85 %; Analysis 2.12 | ‐ | |
|
aWe did not combine data from these studies in analyses because data were reported as median values bFrom visual inspection, we noted that these data were likely to be right skewed due to the comparable magnitudes of the mean and standard deviation. This is expected for outcomes such as length of hospital stay due to most participants being discharged in a short time period with some outliers staying significantly longer. However, right skew introduces artefact into calculation of the effect estimate, limiting the interpretation of the result. | ||||
CI: confidence interval MD: mean difference PaCO2: partial pressure of carbon dioxide in arterial blood PaO2/FiO2: ratio of partial pressure of arterial oxygen to fraction of inspired oxygen RR: risk ratio SpO2: oxygen saturation