Thus graphically, if we are only interested in a 3% survival benefit (ie a hazard ratio < 0.97), the upper hazard ratio must be set to 0.97. With the original point estimate of 0.72, and a standard error of 0.192, the 88% CI is 0.53-0.97. Thus 12% confidence lies on either side (6% above the 88% CI, and 6% below the 88% CI). Thus the confidence below 0.97 is 88% + 6% = 94%.