What does a null effect indicate?

A null effect indicates that neither drug affects the specific indicator being measured. In experimental or clinical settings, a null effect suggests that any observed changes in the outcome are not statistically significant, meaning that neither drug contributes positively or negatively to an effect. This is critical in understanding drug interactions and outcomes in treatment; it informs researchers and clinicians that the combination of drugs does not produce a measurable impact on the intended effect. Recognizing a null effect is vital for accurately interpreting study results, guiding future research, and informing treatment decisions.