Rahul is a physician, researcher and founder of ACALM (Algorithm for Comorbidities, Associations, Length of Stay & Mortality). His clinical epidemiology research unit was one of the first to use big data in medical research. Prominent studies have shown a novel link between high cholesterol and cancer, and have evaluated the 'weekend effect' regarding differences in death rates in UK hospitals, the interplay between mental and physical health and ethnic disparities.