Mortality of the 57 patients following recovery from TTP. The probability of patient death (solid circles) is compared with the expected probability based on age, race, and gender-specific rates from the reference United States (US; +) and Oklahoma (OK; open circles) populations obtained from the CDC. Broken lines indicate the 95% confidence intervals (CIs) around the patient mortality. The probability of patient death and 95% CIs as well as the population probability of death for the US and Oklahoma were calculated by using the Kaplan-Meier methods with point-wise limits. The data for the probability of patient death at 1, 5, 10, and 15 years after their initial episode of TTP, with 95% CIs and expected probability of death based on the US and Oklahoma reference populations are presented in the box.