The leading underlying causes of death are based on a list developed by the World Health Organization (WHO). This categorises causes using the International Classification of Diseases version 10 (ICD-10), specially designed for determining the leading causes of death. The original list is available. This was modified in 2016 for use on 2015 mortality data. Minor changes were made in 2017 to ensure mutual exclusivity between groupings. This involved the removal of meningitis and meningococcal diseases (A39), sepsis due to haemophilus influenzae (A41.3), rabies (A82), certain mosquito-borne diseases (A83) and yellow fever (A95) from the vaccine preventable diseases grouping. Our explorable datasets available within NOMIS use the revised list.