This paper, the second in a series of two, discusses how readers of clinical trials can extract simple estimates of treatment effect size from trial reports when trial outcomes are measured on a dichtomous scale. A method is given to quantify the degree of uncertainty of these estimates. Estimates of treatment effect size can be adjusted on the basis of baseline risk to determine the probability that treatment will help a particular patient. The probability that the treatment will be helpful should be weighed against the costs and risks of the treatment.