Is ‘institutional racism’ in Britain no more than a conspiracy theory or urban myth?

Since the inquiry into the death of Stephan Lawrence in 1999, the phrase ‘institutional racism’ has been used in Britain with increasing frequency. What, if anything, does this expression actually mean? British Medical Journal (2019) Keeping it in the family: consanguineous marriage and genetic disorders, from Islamabad to Bradford, BMJ 2019;365:l1851, 29/4/2019. British Medical Journal (2021) Doing the work to end health inequalities caused by systemic racism, BMJ 2021;373:n821, 16/4/2021.