Objectives To estimate the proportion of children who die with chronic conditions and examine time trends in childhood deaths involving chronic conditions.

Design Retrospective population-based death cohort study using linked death certificates and hospital discharge records.

Setting England, Scotland and Wales.

Participants All resident children who died aged 1–18 years between 2001 and 2010.

Primary and secondary outcome measures The primary outcome was the proportion of children who died with chronic conditions according to age group and type of chronic condition. The secondary outcome was trends over time in mortality rates involving chronic conditions per 100 000 children and trends in the proportion of children who died with chronic conditions.

Results 65.4% of 23 438 children (95% CI 64.8%, 66.0%) died with chronic conditions, using information from death certificates. This increased to 70.7% (95% CI 70.1% to 71.3%) if hospital records up to 1 year before death were also included and was highest (74.8–79.9% depending on age group) among children aged less than 15 years. Using data from death certificates only led to underascertainment of all types of chronic conditions apart from cancer/blood conditions. Neurological/sensory conditions were most common (present in 38.5%). The rate of children dying with a chronic condition has declined since 2001, whereas the proportion of deaths affected by chronic conditions remained stable.

Conclusions The majority of children who died had a chronic condition. Neurological/sensory conditions were the most prevalent. Linkage between death certificate and hospital discharge data avoids some of the under-recording of non-cancer conditions on death certificates, and provides a low-cost, population-based method for monitoring chronic conditions in children who die.