Unreliable Testing May Lead To More Invasive Medical Procedures Than Necessary

Unreliable testing may be a major cause in unnecessary, medically-invasive procedures, according to a study published in the Journal of the American Medical Association.

Scientists submitted a randomized survey to 727 men between the ages of 40 and 75 in which they were asked how likely they would be to undergo a prostate biopsy given a certain result of the famously erratic specific antigen test (PSA) or, in the case of some, no test at all.

The different hypothetical diagnoses included normal, which would indicate no cancer, elevated, indicating a likely presence of cancer, or inconclusive, which was defined as providing "no information about whether or not" the patient had cancer. Finally, no testing or results were posed to those of the fourth group.

Furthermore, participants were asked to rate their certainty, 1 to 100, of their decision to either undergo a biopsy or not.

The results, according to the researchers, were telling.

Forty percent of those who received inconclusive results said they would likely undergo a biopsy, versus only 25 percent of those who didn't receive any PSA result said they would. 

Despite the unreliable nature of the PSA, those who were given an "elevated" result were much more likely to opt for biopsy, though 38 percent still said they would choose not to.

Lead author Sanita Sah of Georgetown University is calling the phenomenon she and her group witnessed "investigation momentum," that she blames on the psychological uncertainty that can result after an inconclusive test. 

"These results suggest that the ubiquitous use of simple but unreliable screening tests may lead to consequences beyond the initial cost and patient anxiety of inconclusive results," Sah said. This is despite the fact that, as far as she is concerned, unreliable and ambiguous results are "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."