Trial Design
VTE, THA
The CRISTAL trial was a cluster randomized, crossover, noninferiority trial performed across 31 hospitals in Australia between April 15, 2019, and December 18, 2020. It was nested within the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR). The primary aim was to determine whether aspirin was noninferior to enoxaparin in preventing symptomatic VTE after THA or TKA. The protocol and statistical analysis plan (which included this planned a priori study) are available in 