bb Payne 2006.

Methods	Case‐control study assessing the association between influenza and other vaccines (data not extracted for this review) and optic neuritis. "A matched case‐control study design was used with each optic neuritis case matched to 3 controls based on sex, deployment during the 18 weeks preceding the diagnosis date, and the military component in which the individual served (eg, active or reserve/National Guard). The protocol for this vaccine postmarketing surveillance investigation was approved by the Centers for Disease Control and Prevention (CDC) Institutional Review Board and reviewed by the Food and Drug Administration and Department of Defense"
Participants	US military personnel aged at least 18 years
Interventions	Cases (n = 1131): participants with a diagnosis of optic neuritis between 1 January 1998 and 31 December 2003. The following ICD‐9 codes were considered: 377.30‐32, 377.39. Controls (n = 4524): participants were matched to the cases on the basis of sex, deployment during the 18 weeks before diagnosis, military component. The study was carried out using data from the Defense Medical Surveillance System (DMSS), a longitudinal surveillance database.
Outcomes	Date of case diagnosis was ascertained, and immunisation status (anthrax, smallpox, hepatitis B, influenza) verified by means of electronic records with respect to 3 time intervals: 6, 12, and 18 weeks before onset. For controls, vaccination status was determined for the 3 intervals before the index date. Results were focused on the 18‐week time interval.
Notes	Rare events (safety) Government funded
Risk of bias
Bias	Authors' judgement	Support for judgement
CC ‐ case selection All outcomes	Low risk	"We defined optic neuritis cases as those having a first‐time diagnosis of the following ICD‐9‐CM codes: optic neuritis, unspecified (377.30); optic papillitis (377.31); retrobulbar neuritis, acute (377.32); and optic neuritis, other (377.39) during the period between 1 January 1998 and 31 December 2003."
CC ‐ control selection All outcomes	Low risk	Controls were selected if their DMSS diagnostic records indicated no history of an optic neuropathy, if they served in the military on the same date of diagnosis as their matched case, and if they had at least 18 weeks of military service preceding this index date.
CC ‐ comparability All outcomes	Low risk	Matching
CC ‐ exposure All outcomes	Low risk	"We ascertained the date of each case’s first diagnosis of optic neuritis and determined all vaccinations received during each of the following 3 prior study intervals from the electronic record; 6 weeks (42 days), 12 weeks (84 days) and 18 weeks (126 days). For each of the 3 matched controls, we determined all vaccinations during the 3 intervals predating their index date."
Summary assessment	Low risk	Low