Table 3. Mean heart rate (HR) for subjective placebo responders (n = 3) and percentage difference from mean heart for placebo non-responders (n = 9) in informed caffeine/received caffeine and informed caffeine/received placebo conditions. Condition HR beats·min-1 Difference (%) from placebo non-responders Chances effect is clinically beneficial (trivial/harmful)+ Mean (SD) Mean (SD) 95% CI* Informed caffeine/received caffeine 161 (3) -2.3 (1.8) -4.1 to -0.6 0 (16/84) Informed caffeine/received placebo 159 (1) -.3 (2.4) -3.1 to 2.5 8 (74/18) smallest worthwhile effect of 1.5%. 95% CI = 95% confidence interval.