Fig. 4.

Costs of intervention scenarios. NI=no intervention, L=lockdown, Q=household quarantine with community support teams, M=compulsory mask wearing. The black bars for the lockdown (L) intervention describe the range of each cost outcome over the scenarios where lockdown is as implemented in Bangladesh and where this lockdown is extended by up to three months. For interventions involving mask-wearing (M), the three coloured bars describe scenarios with different values of ${\epsilon }^m$, the proportional reduction in outward emissions by mask wearers. These bars range over the scenarios where masks provide no protection to the wearer to where they provide proportional protection to the wearer from others’ emissions that is equal to ${\epsilon }^m$. (A) Implementation costs of each intervention scenario (i.e. total cost minus the hospital care cost). Note that the costs of the mask-wearing scenarios are assumed to be the same regardless of mask effectiveness. (B) Total cost of each intervention scenario based on costings in Table 1. (C) Cost of each death averted relative to the baseline (NI) scenario. (D) Percentage return on investment in interventions in terms of healthcare savings.