Validity and Reliability in Diagnosis

Explain the importance of validity and reliability in diagnostic testing or research. Describe how validity relates to sensitivity and specificity in diagnostic testing. Identify a health screen specific to a diagnostic test that is currently being debated regarding its use, recommended ages, or frequency, and discuss how validity and reliability play into this debate. What other factors should you consider when you assess the recommendations for a diagnostic test or screen?

Validity and Reliability in Diagnosis and Research


The importance of reliability and validity in diagnostic testing is the ability to differentiate between different related infection and hence, the accuracy of the test. Moreover, reliability ensures that a test can be conducted with the expectation of similar subset of results with little or no variance hence can be applied in the test of a disease or condition (Sullivan, 2011). Ultimately, they are both required in diagnostic testing and research. Reliability of test clusters the results together with minimal variance or standard deviation.

Relationship Between Validity, Sensitivity, and Specificity

Validity is described in terms of sensitivity, which describes the ability of a test to accurately provide positive results with the lowest number of false positives from a diagnostic test. Additionally, it is required to be highly sensitive, thus more effective (Sullivan, 2011). On the other, specificity is a validity measure which describes the ability of a test to pick out a certain condition or disease amid related conditions or infections. As such, validity requires a highly sensitive and specific test to be the most efficient and effective. 

Health Screening and Recommendations

The screening of Zika Virus has been important in the recent past due to the spread off the epidemic in the united states. Pregnant women are recommended for testing, and people traveling from the endemic areas are also required to be tested for the infection. An RNA NAT test is conducted early at the onset of the infection while a more sensitive Zika Virus IgM test is used for the long term and is more sensitive and specific (Waggoner & Pinsky, 2016). All ages can be subjected to the two tests, but active infections require both methods for up to 12 weeks. Consequently, the tests employed to test for any disease should provide a high level of specificity and sensitivity. The reliability of the test choice should have a low degree of dispersal of the different measures form the tests which can be characterized by a variance or standard deviation.


Sullivan, G. M. (2011). A primer on the validity of assessment instruments. Journal of Graduate Medical Education, 3(2), 119-120.

Waggoner, J. J., & Pinsky, B. A. (2016). Zika virus: Diagnostics for an emerging pandemic threat. Journal of Clinical Microbiology, 54(4), 860-867.