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Investigation Momentum: Less is More When it Comes to Unreliable Screening Tests

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While the debate continues surrounding the reliability and effectiveness of prostate-specific antigen (PSA) screening tests, a recent study, conducted by Sunita Sah, assistant professor of business ethics at Georgetown University’s McDonough School of Business, investigates another downside of unreliable screening tests – the effect of receiving inconclusive results.

After undergoing a PSA screening test, a man who receives an inconclusive result has the same information as if he never took a test – the diagnosis is still unknown. However, due to the psychological uncertainty experienced after receiving an ambiguous test result, individuals may opt to pursue additional, costly and potentially more invasive tests than if they had never taken the initial screening test.

“Unreliable screening tests often give ambiguous results. Such information is essentially meaningless for predicting the condition in question and should have no influence on future decision-making compared with not conducting the test at all,“ said Sah. “However, receiving an inconclusive result can lead to investigation momentum – a situation in which patients seek additional and potentially excessive diagnostic testing.”

Sah and her co-authors investigated whether receiving an inconclusive result from an unreliable PSA test – compared with not undergoing a test –motivated more individuals to take an additional, more invasive, test such as a prostate biopsy.

The study examined 727 men, between the ages of 40 and 75, who participated in an online survey which gave them information on the risk factors for prostate cancer. The men were blindly randomized into four conditions – in the first condition, men received information on the risks and benefits of undergoing a prostate biopsy and were asked whether or not they would undergo such a biopsy. In the other three conditions, the men were asked to imagine a scenario in which they had received the results of a PSA test (which were one of 3 levels: normal, elevated, or inconclusive) and then asked whether they would undergo a prostate biopsy. The inconclusive test result stated “this result provides no information about whether or not you have prostate cancer.”

“The results of our study showed that significantly more men, 40%, stated that they would undergo a prostate biopsy if they received an inconclusive PSA test result whereas only 25% of men opted for a biopsy when they had no PSA test result,” said Sah. “These results suggest that the ubiquitous use of unreliable screening tests may lead to consequences beyond the initial cost and patient anxiety of inconclusive results; they could also lead to investigation momentum.”

The full study, “Investigation Momentum: The Relentless Pursuit to Resolve Uncertainty,” was published by JAMA: Internal Medicine.

Sunita Sah, M.D., M.B.A., Ph.D., is an Assistant Professor of Business Ethics at Georgetown University and a Research Fellow at the Ethics Center at Harvard University. Her research focuses on behavioral business ethics, decision-making and advice—in particular, how professionals who give advice alter their behavior as a result of conflicts of interest and disclosure policies.

About Georgetown University’s McDonough School of Business
Georgetown University’s McDonough School of Business provides a transformational education through classroom and experiential learning, preparing students to graduate as principled leaders in service to business and society. Through numerous centers, initiatives, and partnerships, Georgetown McDonough seeks to create a meaningful impact on business practice through both research and teaching. All academic programs provide a global perspective, woven through the undergraduate and graduate curriculum in a way that is unique to Washington, D.C. – the nexus of world business and policy – and to Georgetown University’s connections to global partner organizations and a world-wide alumni network. Founded in 1957, Georgetown McDonough is home to some 1,400 undergraduates, 1,000 MBA students, and 1,200 participants in executive degree and open enrollment programs. Learn more at http://msb.georgetown.edu. Follow us on Twitter @msbgu.