Two unmatched case-control studies nested within the cohort provide information on potential risk factors.

Methods: A hospital based unmatched case control study was conducted between April and September 2017.

We conducted a single-center unmatched case-control study.

Methods: We conducted an unmatched case-control study among women who were in the third trimester of pregnancy at New Mulago hospital, Uganda.

By fitting an unconditional logistic regression model to unmatched case-control data, an estimate of the joint population attributable risk for the factor included is obtained.

IF-03: Make sure that a CASE statement is inclusive, or construct a handler to catch any unmatched cases