Introduction: Strict patient selection in medical or surgical trials on intracerebral hemorrhage (ICH) is needed to optimize therapeutic benefit but limits trial enrolment as well as overall applicability of results. We studied the applicability of previous, current, and planned large interventional ICH trials by applying each trial’s defined inclusion criteria to an unselected cohort of ICH patients.
Methods: Large interventional ICH trials were identified via trial registration databases. To estimate eligibility rates, each trial’s inclusion criteria were applied on an unselected consecutive group of first-ever ICH patients from the prospective hospital-based Lund Stroke Register. Subsequently, 30 day survival status was obtained from the National Census Office and 90 day poor functional outcome (modified Rankin Scale ≥4 or death) from the Swedish Stroke Register or medical files.
Results: Among 253 included ICH patients, estimated eligibility rates ranged from 2-38% for the identified 11 large interventional ICH trials (Figure 1). Patients not eligible for any of the trials (N=91, 36%) had: more extensive intraventricular hemorrhage (p<0.001); lower baseline level of consciousness (p<0.001); higher rate of cerebellar ICH and lower rates of lobar ICH (p<0.001). No significant age, sex, or ICH volume differences were observed. The 30 day mortality rates among eligible patients were 0-33% depending on selected trial. The mortality rate for patients not eligible for any trial was 55% vs 19% for patients eligible in ≥1 trial (95% CI: 45-65% vs 13-25%; p<0.001). Non-eligible ICH patients more frequently had poor functional outcome (75% vs 49%; 95% CI: 65-85% vs 41-57%; p<0.001).
Conclusions: There is great variation in proportions of unselected ICH patients eligible for inclusion in treatment trials. Even in trials with broad entry criteria only a minority is eligible, which need to be considered when translating ICH-trial results into clinical practice.