RESUMEN
INTRODUCTION: Registration of study protocols brings about transparency and traceability and the amount of publication bias can be estimated. In this study, we have collected and presented data regarding clinical study registries, preclinical, in vitro and in silico study registries across the globe. MATERIALS AND METHODS: We searched via Google Search Engine with appropriate keywords e.g. name of country (n = 198), name of continent (n = 7), registry, study registry, animal, in silico, virtual, simulation, preclinical, animal, clinical trial. The overall pooled prevalence of clinical study registries and WHO primary registries in per continent was calculated using Medcalc software. RESULTS: The overall pooled prevalence of clinical study registries were 13% in each continent. The prevalence of WHO primary study registries were 8.9% of the countries per continent. Overall, there are 17 primary registries associated with WHO ICTRP as primary registries, 2 partner registries and 6 registries are affiliated to ICMJE. However, the amount of preclinical animal study registry was quite less (n = 4). Regarding in vitro studies, only country specific in vitro fertilization registries were available, however, in other research domains, registries were absent. Only one simulation study registry was available. CONCLUSION: At priori study registration is essential to deal with selective reporting. Comparison between study protocol and final report allows us to know the protocol deviations and allows us to evaluate risk of bias and internal validity of the research findings. Although trialists are responsible for the completeness of records, yet the registries must have some measures for their periodic update and quality control of the data.