Post-market pharmacovigilance primarily aims to identify suspected adverse drug reaction (ADR) signals as early as possible, with less focus on identifying potential risk factors for ADRs. Attelind et al. considered this is due to a perceived lack of control groups, aside from the suspected drugs based on spontaneous reports, and argued that patients with other ADRs to the same drug should be able to be used as controls as an improvement. 1 They propose a method in which reports of ADRs of interest from the pharmacovigilance database maintained by the Swedish Medical Products Agency (SMPA) are used as cases, and all other reports of