OBJECTIVE: The Japan Kawasaki Disease Research Committee has conducted a surveillance of Kawasaki disease in order to monitor changes in incidence continually, and to provide timely incidence data to the hospitals and related organizations. This study aims at clarifying the 11-year time trend between 1984 and 1995 of the incidence of Kawasaki disease in Japan and evaluating the validity of the surveillance system. METHODS: Incidence data were obtained from 143 monitor hospitals throughout Japan with a postcard notification form, which included the number of patients with Kawasaki disease by sex for each of three 10-day periods every month. RESULTS: 1. The total number of patients thus reported in the 11-year period by the 143 facilities was 21,406. 2. After experiencing the two major outbreaks observed in 1984 and 1985, no abnormal increase has been seen for a least 8 1/2 years. 3. The changes in the time trend of the incidence from the surveillance data was almost identical to those of the nationwide surveys, indicating the high validity of the surveillance system for timely estimation of an abnormal increase in incidence. 4. Because about one-third of the total number of the patients reported by the nationwide surveys come from only about 9% of the total number of hospitals included in the nationwide survey, efficiency in data collection without serious distortion was confirmed for the surveillance system. 5. The estimated number of patients in 1993 and 1994 calculated from the ratio of the numbers of patients between the surveillance and nationwide surveys was 5700 in 1993 and 6000 in 1994. The average yearly incidence rates per 100,000 children aged 0-4 years was 90. CONCLUSION: From the above results it is recommended that the surveillance system be continued in order to provide timely data on changes in the incidence of Kawasaki disease in Japan. It appears that the methods of data collection adopted in this system is applicable to the surveillance of other diseases.
OBJECTIVE: The Japan Kawasaki Disease Research Committee has conducted a surveillance of Kawasaki disease in order to monitor changes in incidence continually, and to provide timely incidence data to the hospitals and related organizations. This study aims at clarifying the 11-year time trend between 1984 and 1995 of the incidence of Kawasaki disease in Japan and evaluating the validity of the surveillance system. METHODS: Incidence data were obtained from 143 monitor hospitals throughout Japan with a postcard notification form, which included the number of patients with Kawasaki disease by sex for each of three 10-day periods every month. RESULTS: 1. The total number of patients thus reported in the 11-year period by the 143 facilities was 21,406. 2. After experiencing the two major outbreaks observed in 1984 and 1985, no abnormal increase has been seen for a least 8 1/2 years. 3. The changes in the time trend of the incidence from the surveillance data was almost identical to those of the nationwide surveys, indicating the high validity of the surveillance system for timely estimation of an abnormal increase in incidence. 4. Because about one-third of the total number of the patients reported by the nationwide surveys come from only about 9% of the total number of hospitals included in the nationwide survey, efficiency in data collection without serious distortion was confirmed for the surveillance system. 5. The estimated number of patients in 1993 and 1994 calculated from the ratio of the numbers of patients between the surveillance and nationwide surveys was 5700 in 1993 and 6000 in 1994. The average yearly incidence rates per 100,000 children aged 0-4 years was 90. CONCLUSION: From the above results it is recommended that the surveillance system be continued in order to provide timely data on changes in the incidence of Kawasaki disease in Japan. It appears that the methods of data collection adopted in this system is applicable to the surveillance of other diseases.