Evaluating coroner data for carbon monoxide mortality surveillance, England and Wales, 2020-2024

Background

Carbon monoxide (CO) can reach lethal levels undetected, yet there is no specific public health surveillance system for CO mortality in the United Kingdom. We evaluated the use of coroner narratives for surveillance of unintentional non-fire related (UNFR) CO deaths.

Methods

We enhanced death registrations mentioning CO for England and Wales between 2020-2024 using coroner narratives. We summarised date of registration, case demographics, and reasons for exposure, and compared these to findings from a similar analysis of death registrations from 1998-2019 and to estimates for Western Europe from the Global Burden of Disease Study (GBD).

Results

We identified an average of 19 UNFR CO deaths in England and Wales per year between 2020-2024, a decrease from 34 per year between 1998-2019. The median age was 64 (range: 14 to 95) and 71% of deaths occurred in males. Place of exposure, source of CO, and exposure reason were missing in 32% of records. Where known, 61% of exposures occurred inside the home. Common exposures were using a faulty or unmaintained appliance (30%), an outside appliance in enclosed space (21%), a blocked chimney (21%), and running an engine inside (14%). The median delay between death occurrence and registration was 180 days (range: 6 to 915). The total number of UNFR CO deaths was smaller than the estimate for Western Europe by the GBD (51 per year in 2000-2021).

Discussion

Enhanced death registration data suggests the number of UNFR CO deaths is decreasing in England and Wales. However, the GBD indicates death registration data may underestimate CO mortality and many 2020-2024 death registrations were delayed and/or missing exposure information in the coroner narratives. Despite this, enhanced death registration data can provide insights into common CO exposures. Strengthening of CO mortality surveillance using additional data sources is needed to accurately quantify and characterise UNFR CO deaths and inform public health action.

Key messages

• Enhancing death registration data with coroner narratives provides valuable information on groups most affected by fatal carbon monoxide (CO) poisoning and common CO sources and exposures.

• Using death registration data may underestimate CO mortality. A dedicated surveillance system for CO poisoning and deaths is needed to inform the development of timely and targeted interventions.