A nationwide programme of frequent, home-based SARS-CoV-2 antigen testing and self-isolation to decrease transmission could greatly reduce total infections and mortality at a reasonable cost, according to a study from the US.

The study used a simple compartmental epidemic model to predict the clinical, epidemiological and economic outcomes of US population-wide, home-based SARS-CoV-2 antigen testing combined with self-enforced isolation for those who have a positive result. Input data for the model were obtained from published sources. The analysis was conducted from a societal perspective; costs included those associated with testing (assuming $US5 for the initial testing kit and $US20 for the confirmatory polymerase chain reaction [PCR]-based test), inpatient care and lost workdays.

Without a testing intervention, the model predicted 11.6 million infections, 119 000 deaths and $US10.1 billion in total costs ($US6.5 billion in inpatient care and $US3.5 billion in lost productivity) over a 60-day horizon. Weekly home testing would reduce infections to 8.8 million and deaths to 103 000, increasing costs by $US22.3 billion. Lower inpatient costs ($US5.9 billion) would partially offset additional outlays for testing ($US12.5 billion) and greater lost workdays ($US14.0 billion). The incremental cost-effectiveness ratios for the testing intervention, compared with no testing, were $US7890 per infection averted and $US1.43 million per death averted. When applying the lowest estimate for the recommended range for the benchmark value of a statistical life ($US5.3 million), this suggests that the intervention would be "exceptionally good value", note the researchers. They conclude that "this strategy can prevent transmission and save lives at a reasonable cost."