bb‐Uno 2012.

Study characteristics
Methods	Case‐control study, Japan
Participants	Data from patients of the Yokohama Psycho‐Developmental Clinic (YPDC), Kanto area, Japan, which accepts only patients with suspected developmental disorders. Of the patients who initially consulted the YPDC from April 1997 (opening of the clinic) until March 2011. Children aged 6 to 36 months Cases: patients (1) were diagnosed with ASD, and (2) had been born between 1 April 1984 and 30 April 1992, the possible time period for MMR vaccination (n = 189). Controls: 1 to 2 controls were selected for each case, matched for sex and year of birth and recruited as volunteers from general schools in the Kanto area, the same area where YPDC patients reside (N = 224).
Interventions	MMR vaccination was introduced in April 1989, and only 1 vaccination using MMR was included in the immunisation schedule. The monovalent mumps and rubella vaccines remained the choice. After several cases of aseptic meningitis (caused by mumps Urabe strain), the Japanese government ceased extensive inoculation with MMR in April 1993. Consequently, children born from April 1984 to April 1992 could have received the MMR vaccination, and those children were included in the present study.
Outcomes	Diagnosis of ASD. Patients were diagnosed based on the classifications of pervasive developmental disorders in the Diagnostic and Statistical Manual of Mental Disorders, 4th edition, and standardised criteria using the Diagnostic Interview for Social and Communication Disorder (DISCO). The DISCO is recognised as one of the best ways to obtain a reliable and valid diagnosis of ASD.
Funding Source	Government
Notes	Same study and data were reported in Uno 2015; this last study reports data by age groups and analyses the possible association between thimerosal and ASD.
Risk of bias
Bias	Authors' judgement	Support for judgement
CCS ‐ case selection	Low risk	Adequate ‐ secure record
CCS ‐ control selection	Unclear risk	Volunteer from general schools in the same area
CCS ‐ comparability	Unclear risk	Matched sex and age (probable residual confounding)
CCS ‐ exposures	Low risk	Adequate ‐ data form Maternal and Child Health Handbook
Summary Risk of Bias assessment	Unclear risk	We had concerns regarding at least 1 domain such that some doubt is raised about the results.