Outcome observability in evidence on proton pump inhibitor-associated clostridioides difficile outcomes: a result-specific methodological audit

The study examined heterogeneity in published evidence on the relationship between proton pump inhibitor (PPI) use and Clostridioides difficile infection (CDI). The research team conducted a methodological audit of 11 evidence sources containing relevant data on PPI exposure and CDI-related outcomes. Eight studies focused on incident CDI, one on detection without clinical CDI confirmation, one on severity in patients with established CDI, and one on mortality. Researchers found that nine estimates were expressed as odds ratios, one as a risk ratio, and one as a hazard ratio. The study concluded that the included estimates did not represent one common measurement target and that the resulting observability profile can identify methodological non-comparability between studies.