Multimorbidity is common in older age groups and is associated with disability, frailty, and poor quality of life. Research using clinical databases and surveys has shown associations between multimorbidity, older age, and indicators of disadvantage. Use of multiple coded death registration data has been proposed as an additional source of information on multimorbidity which may also provide insights into quality of cause of death certification. In this project MiSoC Co-I Emily Grundy and collaborator Rachel Stuchbury (Centre for Longitudinal Study Information and User Support, UCL) use nationally representative data for England and Wales over the period 2001-2017 to investigate trends in reporting multiple causes of death among decedents aged 65. They investigate how the number of mentions of causes of death recorded varies by age, sex, marital status and place of death, and by indicators of health status and socio-economic disadvantage at the census prior to death. Preliminary findings show that the number of mentions of different causes recorded at death registration increased over the period 2001-17, increased with age, peaking among decedents aged 85-9, and was positively associated with indicators of prior disadvantage and poor health, although effects were small. Ongoing work is directed at understanding place of death effects.