Cost-effectiveness of whole area testing of asymptomatic SARS-CoV-2 infections in Merthyr Tydfil, 2020: A Modelling and economic analysis

ObjectivesTo evaluate the cost effectiveness of an asymptomatic SARS-CoV-2 whole area testing pilot. DesignEpidemiological modelling and cost effectiveness analysis. SettingThe community of Merthyr Tydfil County Borough between20 Nov and 21 Dec 2020. ParticipantsA total of 33,822 people tested as part of the pilot in Merthyr Tydfil County Borough, 712 of whom tested positive by lateral flow test and reported being asymptomatic. Main outcome measuresEstimated number of cases, hospitalisations, ICU admissions and deaths prevented, and associated costs per quality-adjusted life years (QALYs) gained and monitory cost to the healthcare system. ResultsAn initial conservative estimate of 360 (95% CI: 311 - 418) cases were prevented by the mass testing, representing a would-be reduction of 11% of all cases diagnosed in Merthyr Tydfil residents during the same period. Modelling healthcare burden estimates that 24 (16 - 36) hospitalizations, 5 (3 - 6) ICU admissions and 15 (11 - 20) deaths were prevented, representing 6.37%, 11.1% and 8.19%, respectively of the actual counts during the same period. A less conservative, best-case scenario predicts a much higher number of cases prevented of 2328 (1761 - 3107), representing 80% reduction in would-be cases. Cost effectiveness analysis indicates 108 (80 - 143) QALYs gained, an incremental cost ratio of {pound}2,143 ({pound}860-{pound}4,175) per QALY gained and net monetary benefit of {pound}6.2m ({pound}4.5m-{pound}8.4m). In the less conservative scenario, the net monetary benefit increases to {pound}15.9m ({pound}12.3m-{pound}20.5m). ConclusionsA significant number of cases, hospitalisations and deaths were prevented by the mass testing pilot. Considering QALYs lost and healthcare costs avoided, the pilot was cost-effective. These findings suggest mass testing with LFDs in areas of high prevalence (>2%) is likely to provide significant public health benefit. It is not yet clear whether similar benefits will be obtained in low prevalence settings. SummaryO_ST_ABSWhat is already known on this topicC_ST_ABSO_LIAs part of the UK nations strategies for controlling COVID-19, mass testing by lateral flow devices (LFD) has been widely used to identify asymptomatic SARS-CoV-2 infections in the community and thus reduce prevalence C_LIO_LIThis approach has proved controversial with concerns expressed about sensitivity and predictive positive value of the LFD, and about whether their use in mass testing programmes is a cost effective way of controlling COVID-19 C_LIO_LIMerthyr Tydfil Borough has had some of the highest rates of SARS-CoV-2 infection in the United Kingdom, and a mass asymptomatic testing pilot was introduced in an attempt to reduce community transmission. C_LIO_LIThe cost of mass testing with LFD has been predicted to be high, but there are little data indicating effectiveness or cost-effectiveness in terms of healthcare costs averted and quality life years (QALYs) gained. C_LI What this study addsO_LIWe estimate that during the mass testing pilot in Merthyr Tydfil a significant number of cases, hospitalisations and deaths, that would otherwise have occurred, were prevented. C_LIO_LIThis may have contributed to a subsequent decline in disease burden in the area in early 2021 C_LIO_LIIn high prevalence settings, mass testing by LFD appears to be highly cost effective when considering healthcare costs averted and QALYs gained. C_LI