Table 1

The PICOST model for the review question

PICOST element	Description
Population/setting	Adults (18 years and above) in LMIC settings as defined by the World Bank.
Intervention/exposure	New index laboratory test; peripheral laboratory testing strategy or mass testing (pooling).
Comparator	Reference tests for COVID-19 (gold standard) and the current standard of testing strategy (centralised and individualised).
Outcome	Types of tests available; diagnostic test accuracy (sensitivity, specificity, predictive values); costs and cost–effectiveness of the tests; relative risk of testing strategy.
Study design	Diagnostic accuracy studies of observational design (cross-sectional, case–control and cohort studies), and diagnostic strategy studies of experimental design or randomised trials on COVID-19 laboratory testing.
Timing of outcome assessment	72 hours.