[The use of Bayes' theorem in controlling the coming epidemic peak of epidemic meningitis in the 1980s].

To control the coming epidemic peak of epidemic cerebrospinal meningitis (ECM) in the 1980s in the regions with 100 million population in China, the mathematical models based upon Bayes' theorem (BT) were established and used respectively in provincial, regional and county's level. Reports of ECM from each ten-day's period or each month during the meningitis season were analysed to create forecast models. Records of ECM vaccinating rate in previous years were fully taken into account to modify the theoretical values. Calibration, split-sample, random-sample selection, as well as actual forecast tests, were used to check the efficiency of the models. The distribution of meningitis vaccine was planned according to the final predictive results. The incidence rates of ECM of above regions decreased obviously faster than other areas in China. Attributing the application of BT forecast research, it was estimated only in Henan province 79795 ECM cases; 4388 deaths and 21 million Yuan economic damage were avoided during the 4 years period, from 1985 to 1988.