Assessing the external validity of the VALIDATE-SWEDEHEART trial
Research article published in Clin Trials (2021)
Abstract
AIMS: The VALIDATE-SWEDEHEART trial was a registry-based randomized trial comparing bivalirudin and heparin in patients with acute myocardial infarction undergoing percutaneous coronary intervention. It showed no differences in mortality at 30 or 180 days. This study examines how well the trial population results may generalize to the population of all screened patients with fulfilled inclusion criteria in regard to mortality at 30 and 180 days. METHODS: The standardized difference in the mean propensity score for trial inclusion between trial population and the screened not-enrolled with fulfilled inclusion criteria was calculated as a metric of similarity. Propensity scores were then used in an inverse-probability weighted Cox regression analysis using the trial population only to estimate the difference in mortality as it would have been had the trial included all screened patients with fulfilled inclusion criteria. Patients who were very likely to be included were weighted down and those who had a very low probability of being in the trial were weighted up. RESULTS: The propensity score difference was 0.61. There were no significant differences in mortality between bivalirudin and heparin in the inverse-probability weighted analysis (hazard ratio 1.11, 95% confidence interval (0.73, 1.68)) at 30 days or 180 days (hazard ratio 0.98, 95% confidence interval (0.70, 1.36)). CONCLUSION: The propensity score difference demonstrated that the screened not-enrolled with fulfilled inclusion criteria and trial population were not similar. The inverse-probability weighted analysis showed no significant differences in mortality. From this, we conclude that the VALIDATE results may be generalized to the screened not-enrolled with fulfilled inclusion criteria.
Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.
Summary
Using propensity-score weighting for trial inclusion, this analysis found that not-enrolled patients meeting VALIDATE-SWEDEHEART's eligibility criteria differed from the trial population but showed no significant differences in 30- or 180-day mortality between bivalirudin and heparin, supporting generalizability of the trial results.
Why This Matters for Hirudotherapy
This study assessed the external validity of the VALIDATE-SWEDEHEART trial — which compared bivalirudin versus heparin in acute myocardial infarction patients undergoing percutaneous coronary intervention — by using propensity score weighting to compare trial participants with screened but not-enrolled patients who fulfilled inclusion criteria. The propensity score difference of 0.61 indicated the two populations were not similar, but the inverse-probability weighted analysis showed no significant mortality differences between bivalirudin and heparin at 30 or 180 days. This is a methodological generalizability analysis of a cardiology trial. Bivalirudin (formerly Hirulog) is a synthetic peptide anticoagulant designed partly on the C-terminal sequence of hirudin, the anticoagulant of the medicinal leech (Maraganore et al., 1990); this paper studies the drug, not leech therapy.
Citation
Reference (Vancouver style)
Rylance RT, Wagner P, Omerovic E, Held C, James S, Koul S, et al. Assessing the external validity of the VALIDATE-SWEDEHEART trial. Clin Trials. 2021;18(4):427-435. doi:10.1177/17407745211012438. PMID: 34011198
Bibliographic details (authors, volume, pages, DOI) are taken from the PubMed record.
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