Controls will be accrued as soon as cases are identified to match with. The index date for controls is the date of the event in the matched cases, i.e. information after this index date is dismissed in the analyses. Matching will be based on year of birth, sex and region of residence. In addition, all controls have to be either current COC users or recent past users (non-use for 3 months or less). The recruitment of matched controls will be stopped as soon as 4 matched controls have been identified that are current new or incident users of a CMA or LNG COC in the pre-defined dosage (as defined as primary exposure).