Phenotypes of atrial fibrillation diagnosed before-versus-after ischaemic stroke and TIA: study protocol for a systematic review and meta-analysis
Bibliographic record
Abstract
Introduction The underlying pathophysiology of atrial fibrillation (AF) detected after stroke (AFDAS) is relatively unknown. Preliminary evidence suggests AFDAS has a lower prevalence of cardiovascular comorbidities and higher incidence of insular cortex involvement than AF known to exist before stroke occurrence (KAF). This favours a neurogenic AF substrate (autonomic dysregulation) in which the presence of underlying heart disease is not necessary for AF to occur. The main objective of this systematic review and meta-analysis is to compare the prevalence of cardiovascular comorbidities and echocardiographic abnormalities in patients with AFDAS, KAF and no AF (NAF). Secondary objectives are to compare the proportion with insular cortex involvement, stroke recurrence and death in the three rhythm groups. Methods and analysis We will perform a systematic review including cross-sectional, case–control, cohort studies and clinical trials involving ≥18 years patients, with ischaemic stroke or transient ischaemic attack published between inception and 31 December 2020 in any language, and reporting the proportion of patients with AFDAS, KAF and NAF. We will search PubMed, EMBASE and Scopus by applying predefined search terms. Two reviewers will independently screen titles and abstracts and retrieve full texts, extract data in a predesigned form, and assess the risk of bias. We will perform a meta-analysis of all included studies and we will report the results of the main outcome as proportions. We will report results of secondary outcomes as risk ORs. We will estimate heterogeneity across studies by using t 2 , Q and I 2 measures. We will use funnel plots, Rosenthal’s Fail-Safe N and Egger’s regression intercept to assess publication bias. Ethics and dissemination This study will be based on published data and does therefore not require ethical clearance. The results will be published in peer-reviewed journals. PROSPERO registration number CRD42020202622.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.034 | 0.059 |
| Meta-epidemiology (narrow) | 0.005 | 0.003 |
| Meta-epidemiology (broad) | 0.024 | 0.030 |
| Bibliometrics | 0.007 | 0.007 |
| Science and technology studies | 0.002 | 0.002 |
| Scholarly communication | 0.005 | 0.005 |
| Open science | 0.004 | 0.003 |
| Research integrity | 0.005 | 0.004 |
| Insufficient payload (model declined to judge) | 0.044 | 0.003 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".