|
O’Leary et al. 2009 [30]
|
Minimal (sample selected from a general population rather than a select group)
|
Low (indirect assessment (postal survey, mailed question))
|
Minimal (direct question to mother)
|
Minimal (assessed for common confounders)
|
Minimal (analyses appropriate for type of sample (if matched))
|
Moderate (11 to 20% attrition but reasons for loss to follow-up not explained)
|
Minimal
|
|
Faden and Graubard 2000 [29]
|
Minimal (sample selected from general population, Eligibility Criteria explained)
|
Low (indirect assessment (postal survey, mailed question))
|
Minimal (direct question to mother)
|
High (not assessed for confounders)
|
Low (analyses not accounting for common statistical adjustment and sample size calculation not performed but all eligible patients studied)
|
Moderate (11 to 20% but reasons for loss to follow-up not explained)
|
High
|
|
Greene et al. 1990 [31]
|
Moderate (sample selection ambiguous but may be representative)
|
Minimal (direct questioning (interview) or completion of survey by mother at the time of exposure or close to time of exposure)
|
Minimal (direct question to mother)
|
Minimal (assessed for common confounders)
|
Low (analyses not accounting for common statistical adjustment, power calculation performed)
|
High (>20% attrition but reasons for loss to follow-up not explained)
|
Moderate
|
