Final answer:
Overlapping confidence intervals between a treatment and placebo suggest that the difference in effects might not be statistically significant, indicating that the drug's efficacy is not demonstrably different from the placebo.
Step-by-step explanation:
When considering confidence intervals for the effect of treatment versus placebo, if these intervals overlap, it may suggest that the difference in the effects of the treatment and the placebo is not statistically significant. This means that the true effect of the drug may not differ from the placebo effect.
Confidence intervals are a range of values, defined by the point estimate ± the margin of error, within which we can be a certain percentage confident that the true parameter lies. In a pharmaceutical context, researchers might use confidence intervals to assess whether a new drug is effective compared to a placebo. If both the treatment and placebo confidence intervals overlap, it could indicate that any observed effect might be due to chance rather than the efficacy of the drug. Therefore, overlapping confidence intervals warrant caution when making conclusions about the treatment's effectiveness.