Table 1

Baseline characteristics of the patients in the case and control groups

Early group (controls) n=103Late group (cases) n=103
CPAP (count)3 (1 survived and two died)15 (8 survived and seven died)
Mean A-a gradient at the start of CPAP40.8940.83
Mean A-a gradient at the end of CPAP33.9031.94
Mean A-a difference start/end19.537.03
Median O2 for CPAP patients (kPa)NA9.4
Median CO2 for CPAP patients (kPa)NA4.8
Median FiO2 for CPAP patientsNA56.5
Intubated (count)157
Average stay in hospital (until discharged) (days)*812
Mean time in hospital until death (days)9.27
Average age (years)70.570.3
Average age at death (years)74.976.1
Sex (count)66 M / 37F66 M / 37F
Deaths (count)41 (34M/7F)46 (35M/11F)
From care homes (count)2139
Diabetic (count)2335
Pulmonary (count)3522
With asthma1410
With emphysema209
With bronchiectasis35
Cardiac (count)3627
Renal (count)107
Hypertension (count)3636
Average no of comorbidities per patient1.371.23
  • A-A stands for alveolar–arterial gradient a measure of gas/exchange diffusion. Values of O2, CO2 and FiO2 for early group not reported since they were available for only one patient.

  • *Since confirmation of COVID-19.

  • CPAP, continuous positive air pressure; Fio2, fractional inspired oxygen; ICU, Intensive Care Unit; NA, not available.