Most studies on the frequency of autism have had methodological problems. Most notable of these have been differences in diagnostic criteria between studies, degree of cases overlooked by the initial screening, and type of measurement. This study aimed to replicate the first report on childhood autism to address cumulative incidence as well as prevalence, as defined in the International Statistical Classification of Diseases and Related Health Problems, 10th revision (ICD-10) Diagnostic Criteria for Research. Here, the same methodological accuracy (exactness of a measurement to the true value) as the first study was used, but population size was four times larger to achieve greater precision (reduction of random error). A community-oriented system of early detection and early intervention for developmental disorders was established in the northern part of Yokohama, Japan. The city's routine health checkup for 18-month-old children served as the initial mass screening, and all facilities that provided child care services aimed to detect all cases of childhood autism and refer them to the Yokohama Rehabilitation Center. Cumulative incidence up to age 5 years was calculated for childhood autism among a birth cohort from four successive years (1988 to 1991). Cumulative incidence of childhood autism was 27.2 per 10000. Cumulative incidences by sex were 38.4 per 10000 in males, and 15.5 per 10000 in females. The male:female ratio was 2.5:1. The proportions of children with high-functioning autism who had Binet IQs of 70 and over and those with Binet IQs of 85 and over were 25.3% and 13.7% respectively. Data on cumulative incidence of childhood autism derived from this study are the first to be drawn from an accurate, as well as precise, screening methodology.

Most studies on the frequency of autism have had methodological problems. Most notable of these have been differences in diagnostic criteria between studies, degree of cases overlooked by the initial screening, and type of measurement. This study aimed to replicate the first report on childhood autism to address cumulative incidence as well as prevalence, as defined in the International Statistical Classification of Diseases and Related Health Problems, 10th revision (ICD‐10) Diagnostic Criteria for Research. Here, the same methodological accuracy (exactness of a measurement to the true value) as the first study was used, but population size was four times larger to achieve greater precision (reduction of random error). A community‐oriented system of early detection and early intervention for developmental disorders was established in the northern part of Yokohama, Japan. The city's routine health checkup for 18‐month‐old children served as the initial mass screening, and all facilities that provided child care services aimed to detect all cases of childhood autism and refer them to the Yokohama Rehabilitation Center. Cumulative incidence up to age 5 years was calculated for childhood autism among a birth cohort from four successive years (1988 to 1991). Cumulative incidence of childhood autism was 27.2 per 10 000. Cumulative incidences by sex were 38.4 per 10 000 in males, and 15.5 per 10 000 in females. The male: female ratio was 2.5:1. The proportions of children with high‐functioning autism who had Binet IQs of 70 and over and those with Binet IQs of 85 and over were 25.3% and 13.7% respectively. Data on cumulative incidence of childhood autism derived from this study are the first to be drawn from an accurate, as well as precise, screening methodology.

An extraction and refinement methodology utilizing child health surveillance programs achieve high efficacy for early detection of autism.

In this study, the water vapor sorption of four types of alginate, namely, alginic acid (Alg), Na‐Alg, Ca‐Alg, and NH4‐Alg, were measured, and the effect of differences in counter cations on water vapor solubility and crystallization mechanism associated with the arrangement of hydrogen bonds generated during humidification was investigated. The sorption amounts in the high‐humidity region can be arranged as follows: Na‐Alg > NH4‐Alg > Ca‐Alg > Alg. All samples formed a (C)‐type double helix structure before and after the sorption based on the results of Fourier transform infrared spectroscopy and wide‐angle X‐ray diffraction. The counter cation affects the arrangement of the hydrogen bonds in this structure. Only Ca‐Alg possessed a pseudocrosslinking among the (C)‐type double helix structures due to the divalent Ca2+ ions, which induced variations in the crystal arrangement behavior of the other three samples before and after sorption. Cases I–III show a case of how the orientation is aligned with a new hydrogen bond and classified for each sample.

Background: Previous longitudinal studies have demonstrated that psychosocial outcomes for autistic adults are very limited. However, most studies are clinic-based and liable to selection bias and major methodological problems. Methods: We conducted a long-term follow-up study with 278 autistic individuals from our previous birth cohort study comprising 31,426 individuals. All participants were born in northern Yokohama between 1988 and 1996, diagnosed with autism spectrum disorder (ASD) by age seven, and followed up over 20 years. A total of 170 consented to participate in the study. Outcome measures included overall social functioning based on work, independent living, and friendships. Moreover, the time-use data concerning social participation and activities of daily living were compared with the general population. Results: Psychosocial outcomes in adulthood (average age 25) were very good in 13.7%, good in 25.0%, fair in 31.0%, poor in 25.6%, and very poor in 4.8% of the participants. The majority participated in major life areas of and work and education (96.4%), sports (82.1%), and recreational activities and/or hobbies (98.8%). The proportion of participants who engaged in housework and self-care was comparable to that of the general population. Participants with IQ < 50 at age five had significantly worse outcomes than those with higher IQ; however, for those with IQ ≥ 50, outcomes were not significantly associated with IQ levels. Conclusions: Although complete independence was difficult to accomplish, many autistic adults engaged in organized community activities and housework and self-care. Time-use survey could offer a variety of data in investigating psychosocial outcomes of ASD cross-culturally.