Disparities in COVID-19 clinical studies from high-income and low-and middle-income countries

To examine the disparities between COVID-19 studies conducted in high-income countries (HICs) and low-and middle-income countries (LMICs).

We used the International Clinical Trials Registry Platform to identify COVID-19-related studies registered from December 31, 2019 to December 31, 2021. The World Bank definition was used to classify countries as high-, upper-middle-, lower-middle-, and low-income. The last three were considered to be LMICs. We examined the disparities in response speed, classification of medicines and vaccines, and registration and results reporting compliance between COVID-19 studies conducted in HICs and LMICs.

We included 12,396 COVID-19 studies, with 6631 (53.5%) from HICs. HIC-registered studies reached a peak of 1039 in April 2020, whereas LMICs had only 440 studies. Of the 6969 interventional trials, those from HICs showed higher registration compliance (2199, 62.3% vs 1979, 57.6%, P <0.001) and results reporting compliance (hazard ratio 0.39, 95% confidence interval 0.28-0.55, P < 0.001) than LMICs. HICs also conducted significantly more small-molecule drug (956, 57.5% vs 868, 41.2%, P <0.001) and messenger RNA vaccine trials (135, 32.9% vs 19, 4.8%, P <0.001) than LMICs.

HICs conducted COVID-19 trials with faster response speed and higher registration and publication compliance and produced more innovative pharmaceutical and vaccine products to combat COVID-19 than LMICs.