db‐Miller 2005.

Study characteristics
Methods	Self‐controlled case series. To determine whether any association between gait disturbance and MMR vaccination exceeds the age‐related background rate of gait disturbance
Participants	Children hospitalised with gait disturbance between April 1995 and June 2001 (N = 127, aged 12 to 24 months). Computerised hospital admission and immunisation records for children in the former North and South Thames regions were obtained for the period April 1995 to June 2001 and linked on National Health Service (NHS) number, or sex, date of birth, and full post code, a highly specific linking algorithm. Admissions in children aged 12 to 24 months with an ICD‐10 diagnosis code indicating a possible acute gait disorder or other condition suggestive of cerebellar dysfunction or disturbed motor control were identified, irrespective of whether a linked MMR record was found. The ICD codes used were G111, G112, G25, R26, R27, R29, H55, and F984. Children with gait disturbance resulting from general practice visit general practice research database (GPRD archive), born between 1988 and 1997 (N = 1398, aged 12 to 24 months). For the analysis of gait disorders presenting in general practice, information on all children born from 1988 to 1997 with at least 2 years of continuous follow‐up from birth in a GPRD practice deemed as supplying data of research standard was obtained from the Office for National Statistics. Read and OXMIS codes that indicated a consultation for possible gait disturbance in children aged 12 to 24 months were identified by mapping to ICD‐9 codes and by searching on the following keywords: ataxia, gait, co‐ordination, mobility, movement.
Interventions	MMR immunisation
Outcomes	Relative incidence of gait disturbance after MMR immunisation (considered risk periods 0 to 30 and 31 to 60 days
Funding Source	Government
Notes	Conclusion: no evidence of an increased rate of hospital admission or general practice consultations for gait disturbance was found in the putative postvaccination risk periods. This study provides no evidence for a causal association between MMR and gait disturbance.
Risk of bias
Bias	Authors' judgement	Support for judgement
SCCS/PTC ‐ case selection	Low risk	Adequate ‐ independent validation
SCCS/PTC ‐ exposure	Low risk	Adequate ‐ secure record
SCCS/PTC ‐ observation and exposure risk period	Low risk	Adequate ‐ observation periods are well‐defined, exposure period appears to be well‐documented
SCCS/PTC ‐ comparability	Low risk	Adequate ‐ adjusted for age
Summary Risk of Bias assessment	Low risk	Plausible bias is unlikely to have seriously altered the results.