Monitors to Improve Indoor Carbon Dioxide (CO2) Concentrations in the Hospital

In this pilot, randomized, sham-controlled open-label RCT, hospital rooms will be fitted with Aranet4 Home CO2 sensors.

Each device will continuously measure indoor CO2 concentrations at 1-minute intervals during 4 time periods:

• Baseline: staff blinded to CO2 levels displayed on sensor

2-3. Sham/Intervention period: sensors on the same ward will be randomized to placebo (sensor not showing CO2 levels to staff) or Intervention (sensor displaying CO2 levels to staff) in a cross-over design

• Post-intervention phase (3 weeks post-intervention): staff blinded to CO2 levels

Each measurement period will consist of 7 days with no washout period.

Our primary hypothesis is that CO2 sensors will record less time (minutes) with elevated CO2 levels during the intervention period, compared to the Sham periods. However, carry-over effects will be investigated by comparing the Intervention periods to the Baseline and Post-intervention phases.

Note [February 27, 2021]: due to technical problems with the Aranet4 device Bluetooth connection, outcome data will be analyzed according to measurement data at 2-5 minute intervals (measurements can be made every minute, but data cannot be downloaded with the current version of the app due to technical problems).

Inclusion criteria

• Double-bed hospital rooms

Exclusion criteria

• Unoccupied rooms