Causality Assessment of Adverse Events by Healthcare Professionals in an Academic Hospital Setting: A Descriptive Retrospective Study

Assessing the causality of a drug product-related adverse event (AE) is a very important aspect of pharmacovigilance. However, it is unclear whether AEs are investigated for causality in a hospital setting. The aims of this study were to: 1) evaluate the proportion of AEs for which causality is sought and, 2) list the causality assessment (CA) tools used by healthcare professionals. This retrospective study includes 500 randomized patients (125 patients/year) admitted to a tertiary care academic hospital between 2018-2021. Electronic medical records were reviewed and relevant variables were extracted: 1) demographic, 2) hospitalization, 3) drug product, 4) AE and, 5) CA. A descriptive analysis was carried out (median, minimum-maximum, proportion) to characterize our sample. The characteristic of our sample was as follows: median age 69 years old (range: 21-96 yrs), 43.6% female, median comorbidities/patient 4 (0-12), and median hospital stay of 3 days (1-19). We identified a total of 9,568 drug products and 2,541 AEs, among these, 302 (8.4%) were SAEs. No CA (n=0) or CA tools (n=0) were found in our sample. In this study, we report that no AEs, whether serious or non-serious, were subject to documented CA.