Survival curves of study population patients aged 80–90 years and of an age- and sex-matched general English population (log-rank test P = 0.96). At 10-year follow-up, observed survival was 33% (SE: 1.6%) and expected survival was 33% (SE: 1.1%). Time from surgery was considered for the observed survival (https://www.ons.gov.uk/peoplepopulationandcommunity/birthsdeathsandmarriages/lifeexpectancies/datasets/singleyearlifetablesuk1980to2018).