Unintended impact of pharmacovigilance regulatory interventions: a systematic review.

Studies assessing the impact of pharmacovigilance regulatory interventions often focus on the expected (or intended) outcomes, while any possible unintended impact may be overlooked. The update of the Good Pharmacovigilance Practice (GVP) guideline in 2017 elaborated on impact assessment, emphasising the need also to assess possible unintended impact. This systematic literature review investigated how often the unintended impact of regulatory interventions was considered in publications of studies investigating pharmacovigilance regulatory interventions in Europe. We conducted a systematic review of the literature on MEDLINE and EMBASE from 1 January 2012 to 28 February 2022 to identify publications that investigated the impact of regulatory interventions in Europe. The primary outcome of the study was the number of publications reporting assessments of unintended impact. In addition, we studied the characteristics of these publications, including the type of outcomes assessed, the analytical methods applied, and the type of data used. In total, 96 publications were included in the analysis. The unintended impact of pharmacovigilance regulatory interventions was investigated in 23 of 96 publications (24%). The drug classes most frequently studied in the publications assessing unintended impact of regulatory interventions were oral glucose-lowering drugs (n=6, 26%), opioids (n=4, 17%), antidepressants (n=4, 17%) and antipsychotics (n=3, 13%). The reported methods to assess the unintended impact were interrupted time series (n=10, 43%) and descriptive statistics with or without significance testing (n=2 (9%), and n=9 (39%), respectively). The outcomes selected for unintended impact assessments included the use of other drugs (n=16, 52%), health outcomes (n=8, 35%), and behavioural changes (n=4, 17%). Most of the publications reported on the use of electronic health record databases (n=15, 65%), followed by claims databases (n=11, 47%), while registries were used in four publications (17%). The unintended impact of pharmacovigilance regulatory interventions was reported in only a quarter of identified publications. There was no apparent increase in attention to unintended impact assessments after the update of the GVP guidelines.