OBJECTIVE: Proton pump inhibitor (PPI) use has risen substantially, primarily driven by ongoing use over months to years. However, there is no consensus on how to define long-term PPI use. Our objectives were to review and compare definitions of long-term PPI use in existing literature and describe the rationale for each definition. Moreover, we aimed to suggest generally applicable definitions for research and clinical use.
DESIGN: The databases PubMed and Cochrane Library were searched for publications concerning long-term use of PPIs and ClinicalTrials.gov was searched for registered studies. Two reviewers independently screened the titles, abstracts, and full texts in two series and subsequently extracted data.
RESULTS: A total of 742 studies were identified, and 59 met the eligibility criteria. In addition, two ongoing studies were identified. The definition of long-term PPI use varied from >2 weeks to >7 years. The most common definition was ≥1 year or ≥6 months. A total of 12/61 (20%) of the studies rationalised their definition.
CONCLUSION: The definitions of long-term PPI treatment varied substantially between studies and were seldom rationalised.In a clinical context, use of PPI for more than 8 weeks could be a reasonable definition of long-term use in patients with reflux symptoms and more than 4 weeks in patients with dyspepsia or peptic ulcer. For research purposes, 6 months could be a possible definition in pharmacoepidemiological studies, whereas studies of adverse effects may require a tailored definition depending on the necessary exposure time. We recommend to always rationalise the choice of definition.