Health inequality and genetic disparity are a significant issue in the United Kingdom (UK). This study focuses on diseases that are associated with significant morbidity and mortality in the UK, and specifically examines the extent and basis of treatment failure in different patient populations. The vast majority of drug registration clinical trials have under-representation of ethnic minority populations. In addition, the wider Caucasian populations have reasonably different clinical characteristics to the population that participated in the drug licencing clinical trials. A consequence of this is that drugs are licensed for use in real-world general patient populations where the clinical trial results are simply not statistically significant to specifically demonstrate efficacy or safety in populations that were either absent or under-represented in the drug registration clinical trials. When these facts are considered alongside data that supports significant under-reporting of adverse events in the real-world setting within the UK (and globally, e.g the USA and Europe), it highlights that pharmacovigilance systems are unable to capture drug effectiveness and safety data in a manner that can reasonably assure appropriate prescribing in the wider patient populations. This large real-world research study aims to identify whether commonly prescribed drugs are effective in treating illnesses that cause significant poor health and death in the different patient populations that represent the UK. The goal of this study is to generate large quantitative data-sets that may inform clinical practice to reduce the existing health inequality and genetic disparity in the UK.