The outcomes measured and reported in observational studies of incidental and untreated intracranial meningioma: a systematic review

The clinical management of patients with incidental intracranial meningioma varies markedly and is often based on clinician choice and observational data. Heterogeneous outcome measurement has likely hampered knowledge progress by preventing comparative analysis of similar cohorts of patients. This systematic review aimed to summarise the outcomes measured and reported in observational studies. A systematic literature search was performed to identify published full-texts describing active monitoring of adult cohorts with incidental and untreated intracranial meningioma (PubMed, EMBASE, MEDLINE, and CINAHL via EBSCO, completed 24th Jan 22). Reported outcomes were extracted verbatim, along with an associated definition and method of measurement if provided. Verbatim outcomes were deduplicated and the resulting unique outcomes grouped under standardised outcome terms. These were classified using the taxonomy proposed by the ‘Core Outcome Measures in Effectiveness Trials’ (COMET) initiative. Thirty-three published articles and one ongoing study were included describing 32 unique studies: study designs were retrospective n=27 and prospective n=5. In total, 268 verbatim outcomes were reported, of which 77 were defined. Following de-duplication, 178 unique verbatim outcomes remained and were grouped into 53 standardised outcome terms. These were classified using the COMET taxonomy into 9 outcome domains and 3 core areas. Outcome measurement across observational studies of incidental and untreated intracranial meningioma is heterogeneous. The standardised outcome terms identified will be prioritised through an eDelphi survey and consensus meeting of key stakeholders (including patients), in order to develop a Core Outcome Set (COS) for use in future observational studies.