the authors SIDS rates could do not be achieved if comment on parents avoided their quality. bed sharing. Missing data was Comment: The addressed studies selected using multiple for inclusion in imputation. this Matching were characteristics not selected varied across using a the included systematic studies. literature search. Response rate among Potential controls selection bias appeared to (studies and be low in controls within some studies some studies) (33%, 58.7% and lack of were information on provided). quality Some aspects – so included evidence has cases may been have not had downgraded to C matched from a potential controls. B. Another paper (Mitchell above) Synthesis: uses data from Meta-analysis the German dataset and Findings: In there were the combined questions about dataset, study quality. 22.2% of cases and 9.6% of controls were bed sharing, adjusted OR (AOR) for all ages 2.7; 95% CI (1.4 to 5.3). Bed
the authors do not comment on their quality. Missing data was addressed using multiple imputation. Matching characteristics varied across the included studies. Response rate among controls appeared to be low in some studies (33%, 58.7% were provided). Some included cases may have not had matched controls. Synthesis: Meta-analysis Findings: In the combined dataset, 22.2% of cases and 9.6% of controls were bed sharing, adjusted OR (AOR) for all ages 2.7; 95% CI (1.4 to 5.3). Bed SIDS rates could be achieved if parents avoided bed sharing. Comment: The studies selected for inclusion in this were not selected using a systematic literature search. Potential selection bias (studies and controls within some studies) and lack of information on quality aspects – so evidence has been downgraded to C from a potential B. Another paper (Mitchell above) uses data from the German dataset and there were questions about study quality.