DESIGN: Retrospective observational analysis.

SETTING: 56 acute stroke hospitals in eight countries.

PARTICIPANTS: 1074 trial physiotherapists, nurses, and other clinicians.

OUTCOME MEASURES: Number of babies born during trial recruitment per trial participant recruited.

RESULTS: With 198 site recruitment years and 2104 patients recruited during AVERT, 120 babies were born to trial staff. Births led to an estimated 10% loss in time to achieve recruitment. Parental leave was linked to six trial site closures. The number of participants needed to recruit per baby born was 17.5 (95% confidence interval 14.7 to 21.0); additional trial costs associated with each birth were estimated at 5736 Australian dollars on average.

CONCLUSION: The staff absences registered in AVERT owing to parental leave led to delayed trial recruitment and increased costs, and should be considered by trial investigators when planning research and estimating budgets. However, the celebration of new life became a highlight of the annual AVERT collaborators' meetings and helped maintain a cohesive collaborative group.

TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry no 12606000185561.

DESIGN: AVERT is a prospective, parallel group, assessor-blinded randomised clinical trial. This paper presents data assessing the generalisability of AVERT.

SETTING: Acute stroke units at 44 hospitals in 8 countries.

PARTICIPANTS: The first 20,000 patients screened for AVERT, of whom 1158 were recruited and randomised.

MODEL: We use the Proximal Similarity Model, which considers the person, place, and setting and practice, as a framework for considering generalisability. As well as comparing the recruited patients with the target population, we also performed an exploratory analysis of the demographic, clinical, site and process factors associated with recruitment.

RESULTS: The demographics and stroke characteristics of the included patients in the trial were broadly similar to population-based norms, with the exception that AVERT had a greater proportion of men. The most common reason for non-recruitment was late arrival to hospital (ie, >24 h). Overall, being older and female reduced the odds of recruitment to the trial. More women than men were excluded for most of the reasons, including refusal. The odds of exclusion due to early deterioration were particularly high for those with severe stroke (OR=10.4, p<0.001, 95% CI 9.27 to 11.65).

CONCLUSIONS: A model which explores person, place, and setting and practice factors can provide important information about the external validity of a trial, and could be applied to other clinical trials.

METHODS: We conducted a systematic review and individual patient meta-analysis, which we report according to the Preferred Reporting Items for Systematic Review and Meta-analyses of Individual Participant Data guidelines. PubMed and Embase were searched from inception to May 29, 2023, using the terms ((stroke) AND (randomised OR randomized) AND (tranexamic acid) AND (haemorrhage OR hemorrhage)). We included randomized trials comparing tranexamic acid with placebo in participants with primary intracerebral hemorrhage who had a spot sign and who had follow-up imaging within the required timeframe. Individual patient data were provided by each study and were integrated by the coordinating center. Data were pooled using a random-effects model. The primary endpoint was hematoma growth within 24 hours, defined as ≥33% relative or ≥6 mL absolute hematoma expansion compared with baseline, analyzed using mixed-effects-modified Poisson regression with robust standard errors, adjusted for baseline hematoma volume. Safety outcomes were mortality and major thromboembolic events within 90 days.

RESULTS: Of 197 studies identified, 3 were eligible, contributing 162 participants for the primary analysis (60 female and 102 male). Hematoma growth occurred in 36 of 74 (49%) participants treated with tranexamic acid, compared with 48 of 88 (55%) participants treated with placebo (adjusted risk ratio 0.86, 95% CI 0.84-0.89, p < 0.001). Adjusted median absolute hematoma growth was 1.60 mL (95% CI 0.77-2.43) lower with tranexamic acid vs placebo. No differences in functional outcome or safety were observed.