Table 3.

Potential Outcomes of Screening Tests with Varying Levels of Sensitivity and Specificity [Reprinted with permission from © 2020 BioMed Central Ltd. Part of Springer nature. 2012, BMC Research Notes; Vol 5, Iss 1; TGK Bentley et al. Implications of the impact of prevalence on test thresholds and outcomes: lessons from tuberculosis, p563]

Test characteristic	High sensitivity	High specificity
Impact on results	↑ True positives	↑ True negatives
Testing goal	Identify people with disease	Identify people without disease
Treatment goal	Treat disease Prevent future illness and, in the case of infection, possible disease spread	Avoid unnecessary treatment
Potential harms of opposite test characteristic	Low sensitivity:	Low specificity:
	↑ False negatives ↑ Potential future illness and suffering ↑ Potential future spread of disease (in the case of infection)	↑ False positives ↑ Bodily harms, toxicity, and financial costs of unnecessary treatment ↑ Social stigmatization ↓ confidence in screening program