Table 2.

A priori inclusion and exclusion criteria applied.

PICOSTa component	Inclusion criteria	Exclusion criteria
Population	The study examines infectious viral disease in humans during pandemic or epidemic settings.	The study examines bacterial, fungal, parasitic, protozoan, and prion diseases. The study does not explicitly state viral disease has reached epidemic or pandemic status.
Intervention	The study focuses on the contact tracing aspect of NPIsb. Contact tracing is measured in terms of the detection of asymptomatic cases and following testing or diagnosis of a confirmed case they may have had close contacts with or random testing. The study may examine single or multiple NPIs, and combinations of contact tracing interventions. Combination contact tracing interventions can also include other interventions such as diagnostic testing, pharmaceutical interventions, and other NPIs.	The study describes NPIs without contact tracing included in the combination intervention.
Comparison	N/Ac	N/A
Outcomes	The study reports on the following outcomes: Disease incidence: Incidence proportion or attack rate/risk: The percentage of the population that contracts the disease in an at-risk population during a specified time interval. Other included variations will allow cumulative and peak attack rates. Infection rate (or incident rate): An incidence rate is typically used to measure the frequency of occurrence of new cases of infection within a defined population during a specified time frame. Disease transmission: Reproduction number (R0): The basic reproduction number that is used to measure the transmission potential of a disease. Reduction and risk of transmission (primary or secondary) will be abstracted. Mortality: Case fatality proportion: The proportion of deaths within a defined population of interest. Peak excess death rates: A temporary increase in the mortality rate in a given population. Mortality rate: The total number of deaths from a particular cause in one year divided by the number of people alive within the population at mid-year. An example is cumulative death rate. Total deaths: The number of deaths considered all-cause mortality. Hospitalization: This includes both regular and intensive care unit admissions. The study may also report qualitative findings of outcomes from modeling studies.	The study does not report quantitative or qualitative data on the effectiveness of contact tracing.
Settings	No study limits on geography, global findings.	N/A
Study limits	Study type: primary literature (original studies, case studies) or secondary literature (including systematic reviews with the same inclusion criteria) with or without meta-analyses and modeling. The publications are either already printed in peer-reviewed journals, conference proceedings, or in the prepublication print phase.	Study types other than a primary study or a secondary study (ie, commentaries, policy reviews, letters, editorials, and reports).

^aPICOST: Population, Intervention, Control, Outcomes, Study design and Timeframe.

^bNPI: nonpharmaceutical intervention.

^cN/A: not applicable.