Incorrect recall of residual risk three years after carrier screening for cystic fibrosis: a comparison of two-step and couple screening.

Abstract

This study was undertaken to compare long-term recall of the meaning of test results after a negative result of 2-step or couple antenatal screening. In a randomized controlled trial a subject-completed questionnaire was sent to 275 women who had undergone couple testing 3 years earlier and 83 women who had undergone 2-step testing 3 years earlier (n = 263/358 for a response rate of 73%). The main outcome measure was understanding of test results. Three years after testing women who had undergone couple testing were 4.5 times (95% confidence interval 2.4-8.4 times) more likely than those who had undergone 2-step testing to accurately recall that the test result meant that they were unlikely to be carriers for cystic fibrosis (80%, 95% confidence interval 74%-86%, versus 49%, 95% confidence interval 36%-61%). Anxiety level, plans to have more children, and age were unrelated to recall. The results of this study, together with those from other evaluations, suggest that not only does couple testing avoid the high levels of anxiety associated with 2-step testing but it also results in greater awareness of the residual risk inherent in a negative screening test result.