Comparison of Prospective and Retrospective Methods of a Tigecycline Post-Marketing Surveillance Study in the Safety Outcomes of Patients with Complicated Skin Structure Infection, Complicated Intraabdominal Infection and Community-Acquired Pneumonia.

introductionSafety data can be collected through prospective and retrospective methods during post-marketing surveillance (PMS). This study aimed to compare prospective and retrospective methods in terms of examining safety data from PMS of tigecycline.

methodsThis PMS study was an open-label, noncomparative, observational, noninterventional and multicenter study of patients who received tigecycline for infections. From July 2007 to April 2015, 3172 patients were included in this study, of which 738 were enrolled prospectively and 2434 retrospectively. To reduce selection bias, demographic and baseline characteristics were adjusted using 1:2 propensity score matching.

resultsAfter propensity score matching, data from 1446 patients were analyzed. The incidences of adverse events (AEs) and serious AEs (SAEs) were determined to be significantly higher in the prospective method compared with those of the retrospective method (P < 0.001 and P = 0.004, respectively). However, no significant differences in the incidences of adverse drug reactions (ADRs) and serious ADRs (SADRs) were detected between the two groups (P = 0.09 and P = 0.33, respectively). In a subgroup analysis of 360 patients from 14 hospitals involved in both prospective and retrospective methods, the incidence of AEs was found to be significantly higher using the prospective method compared with when the retrospective method was used (P < 0.001), but there were no significant differences in ADRs (P = 0.14), SAEs (P = 0.24) and SADRs.

conclusionIn general, the prospective method can detect safety data effectively in a PMS study, whereas retrospective data collection may be an alternative option in collecting ADR data when a prospective PMS study is not deemed feasible.