Presentation (CTI)

OBJECTIVES: Self-controlled pre-post observational designs assess outcomes within the same individuals across defined pre- and post-treatment periods and are increasingly used in real-world effectiveness research. By design, these approaches account for time-invariant patient characteristics, including baseline disease severity, comorbidities, and demographics. This systematic literature review (SLR) aimed to identify real-world studies applying these designs and to describe their methodological characteristics, including study structure, observation windows, therapeutic areas, and evaluated outcomes.
METHODS: A systematic literature review was conducted using a predefined search strategy incorporating terms related to self-controlled, within-patient, pre-post, observational, and real-world evidence designs. Searches were restricted to human studies published within the past five years. Titles and abstracts were screened, followed by full-text assessment. Studies were included if they applied a within-patient pre-post design or explicitly described a self-controlled observational approach to evaluate treatment effectiveness. Data were extracted descriptively on study design, index date definition, observation periods, therapeutic area, and endpoints.
RESULTS: Of 738 records screened, 8 studies met inclusion criteria. All were observational, non-interventional, single-arm cohort studies using a self-controlled or pre-post framework. Seven studies evaluated biologic therapies in severe or bronchial asthma, and one evaluated cystic fibrosis. Treatment initiation was consistently defined as the index date, with outcomes compared across pre-treatment periods (commonly 6 or 12 months) and post-treatment follow-up ranging from 12 to 48 months. Frequently assessed outcomes included exacerbation rates, oral corticosteroid use, healthcare resource utilization, symptom control measures, and lung function. Despite methodological alignment, explicit use of “self-controlled” terminology was uncommon, with most studies described as “pre-post” or “before-after.”
CONCLUSIONS: Self-controlled pre-post designs are consistently applied in real-world effectiveness studies, particularly in severe asthma, with aligned observation windows and clinically relevant endpoints. However, inconsistent terminology may limit methodological visibility in the literature.