TABLE 3.
Win Ratio of Composite Major Adverse Pulmonary Events for Patients Receiving High-Flow Nasal Cannula Versus Noninvasive Positive Pressure Ventilation
| Tier | Outcome | Overall Cohort | Matched Cohort | ||||
|---|---|---|---|---|---|---|---|
| NIV Wins | HFNC Wins | Ties | NIV Wins | HFNC Wins | Ties | ||
| 1 | Time to death (28-d mortality) | 77,511 (24.9%) | 41,718 (13.4%) | 191,499 (61.6%) | 23,811 (21.3%) | 16,321 (14.6%) | 71,424 (64.0%) |
| 2 | Ventilator-free days | 39,220 (12.6%) | 35,714 (11.5%) | 116,565 (37.5%) | 11,833 (10.6%) | 14,006 (12.6%) | 45,585 (40.9%) |
| 3 | Noninvasive respiratory support hours | 73,207 (23.6%) | 38,171 (12.3%) | 5,187 (1.7%) | 27,909 (25.0%) | 15,712 (14.1%) | 1,964 (1.8%) |
| Totals, by category | 189,938 (61.1%) | 115,603 (37.2%) | 5,187 (1.7%) | 63,553 (57.0%) | 46,039 (41.3%) | 1,964 (1.8%) | |
| Total possible pairs | 310,728 | 111,556 | |||||
| Win ratio (95% CI), p | 1.64 (1.42–1.90), p < 0.001 | 1.38 (1.15–1.65), p < 0.001 | |||||
HFNC = high-flow nasal cannula, NIV= noninvasive positive pressure ventilation.
Details of the win ratio used to calculate the composite major adverse pulmonary events in the overall cohort (n = 1154) and in the matched study cohort (n = 668). The win ratio in the matched cohort is the primary outcome, which is also displayed visually in Figure 2. Ventilator-free days were calculated from admission through day 28. Noninvasive respiratory support hours were hours spent on HFNC or NIV calculated from initiation through hour 72. The win ratio is the ratio of overall “wins for NIV” over “wins for HFNC.” A positive win ratio suggests NIV results in a better composite outcome compared with HFNC. Percentages represent the percent of pairs out of the total possible pairs. On tier 1 (time to death) and overall, the percentages sum to 100% because all patient pairs are compared at these levels. However, tiers 2 and 3 only compare patients who tied on the previous tier. For example, in tier 2 (ventilator-free days), the percentages add to the number of patients who tied on the previous tier.