Characteristics and Reporting of Number Needed to Treat, Number Needed to Harm, and Absolute Risk Reduction in Controlled Clinical Trials, 2001-2019
Review of 875 controlled trial reported in 6 major journals in 4 set years between 2001 and 2019 found 8.7% reported at least 1 Number Needed to Treat (NNT), 0.9% reported at least 1 Number Needed to Harm (NNH), and 28.5% reported at least 1 Absolute Risk Reduction (ARR).
Source:
JAMA Internal Medicine
SPS commentary:
Authors highlight that use of absolute measures, such as NNT, NNH and ARR can be easier to interpret, more clinically meaningful, and less likely to exaggerate differences when outcome risk is low, and thus advocate their reporting. They state that these low rates of reporting of absolute measures raise concerns about persistent incomplete and selective reporting in controlled trials published in widely cited general medical journals.