What characteristics define a good screening test?

From the Guidelines

A good screening test should be able to detect the majority of prevalent or incident cancers at the time of testing, with high sensitivity and specificity, and be cost-effective, acceptable to patients, and have minimal risks or discomfort. When evaluating a screening test, several key characteristics are important to consider, including:

• Sensitivity, which refers to the test's ability to correctly identify those with the disease
• Specificity, which measures how well it identifies those without the disease
• Cost-effectiveness, to allow widespread implementation
• Acceptability to patients, to encourage participation
• Minimal risks or discomfort, to minimize harm Ideally, a screening test should detect disease at an early, asymptomatic stage when intervention can improve outcomes, as noted in 1. It should have a high positive predictive value in the population being screened, meaning a positive result is likely to represent true disease. The condition being screened for should have significant health impact and effective treatment options available, as discussed in 1. Additionally, the test should be reliable and reproducible, with clear cut-off values for normal versus abnormal results. Practical considerations include ease of administration, quick results, and minimal specialized training requirements, as highlighted in 1. The overall benefit of early detection through screening must outweigh potential harms such as false positives, overdiagnosis, anxiety, and unnecessary follow-up procedures, as cautioned in 1.

Some key points to consider when selecting a screening test include:

• The test's ability to detect prevalent or incident cancers, as emphasized in 1
• The test's sensitivity and specificity, as discussed in 1
• The test's cost-effectiveness and acceptability to patients, as noted in 1
• The potential harms of the test, such as false positives and overdiagnosis, as warned in 1
• The test's reliability and reproducibility, as highlighted in 1 By carefully considering these factors, healthcare providers can select a screening test that is effective, safe, and beneficial for patients, as recommended in 1.

From the Research

Characteristics of a Good Screening Test

A good screening test should have several key characteristics, including:

• High sensitivity and specificity for the disease being screened 2
• The ability to reduce mortality or morbidity from the disease 2
• A significant negative impact on health, an identifiable asymptomatic period, and improved outcomes with early intervention 2
• Cost effectiveness and acceptability to patients 2
• The ability to detect disease at an early stage, when it is more treatable 3, 4

Technical Characteristics

Technical characteristics of a good screening test include:

• High sensitivity, which is the ability of the test to correctly identify those with the disease 4, 2
• High specificity, which is the ability of the test to correctly identify those without the disease 4, 2
• A high positive predictive value, which is the likelihood that a positive test result indicates that the disease is present 2
• A low false-positive rate, which can lead to unnecessary tests and invasive procedures 5
• A low false-negative rate, which can lead to delayed diagnosis and treatment 2

Population Characteristics

Population characteristics that are important for a good screening test include:

• A high prevalence of the disease in the population being screened 2
• A population that is at high risk for the disease, such as smokers for lung cancer 3, 5
• A population that is likely to benefit from early detection and treatment of the disease 5

Implementation Characteristics

Implementation characteristics of a good screening test include:

• The ability to implement the test in a large-scale, multicenter setting 3
• The ability to select the right population for screening, using risk-prediction models and a personalized approach 3
• The ability to reduce costs and associated harms, such as by extending the screening interval for low-risk individuals 3
• The ability to reduce false-positive results, such as by using volumetric-based measurement and follow-up 3