Effect of COVID-19 pandemic on mortality in people with intellectual disabilities extended beyond deaths from COVID itself

• Mortality from COVID-19 in people with intellectual disabilities five times higher than general population
• Study showed death rates for cancers, mental health disorders, circulatory disorders, external causes, and other natural causes in people with intellectual disabilities were higher during the COVID pandemic than pre-pandemic
• Observed effects likely to be due a range of factors including disruptions to care during pandemic

Recently, a groundbreaking study was unveiled at the 2023 European Congress of Clinical Microbiology & Infectious Diseases in Copenhagen, held from April 15-18. The research, published in The Lancet Public Health, revealed that the impact of COVID-19 on mortality among individuals with intellectual disabilities was not limited to deaths caused by the virus alone. The study, led by Dr. Maarten Cuypers from Radboud University Medical Center in Nijmegen, the Netherlands, unveiled a concerning correlation between COVID-19 and increased mortality in individuals with intellectual disabilities suffering from various other health conditions.

Although high rates of COVID-19-related deaths have been reported for people with intellectual disabilities during the first 2 years of the pandemic, it is unknown to what extent the pandemic has impacted existing mortality disparities for people with intellectual disabilities.

In this population-based cohort study, the research team utilized a pre-existing cohort that encompassed the entire adult population of the Netherlands aged 18 years and above as of January 1, 2015. Individuals with presumed intellectual disabilities were identified through data linkage. The study then collected mortality data from the Dutch mortality register for all individuals within the cohort who passed away up to and including December 31, 2021. This comprehensive approach allowed for a robust analysis of the impact of COVID-19 on mortality in people with intellectual disabilities over an extended period of time.

The researchers had access to a wealth of information for each individual in the cohort, including demographics such as sex and date of birth, indicators of intellectual disability based on chronic care and social services utilization, and, in the case of death, the date and underlying cause of death. To assess the impact of COVID-19 on mortality in people with intellectual disabilities, the authors compared data from the first two years of the pandemic (2020 and 2021) with the pre-pandemic period (2015-2019). The primary outcomes of interest were all-cause mortality and cause-specific mortality. To analyze the data, rates of death were calculated, and hazard ratios (HRs) were generated using statistical modeling techniques. This robust methodology allowed for a comprehensive evaluation of the association between COVID-19 and mortality in individuals with intellectual disabilities.

The study commenced with a total of 187,149 Dutch adults who had indicators of intellectual disability at the start of follow-up in 2015. Additionally, 12.6 million adults from the general population were included in the cohort. The findings revealed a staggering discrepancy in mortality rates from COVID-19 between the population with intellectual disabilities and the general population. Specifically, individuals with intellectual disabilities had a five-fold higher mortality rate from COVID-19 compared to the general population. Notably, this discrepancy was particularly pronounced among younger age groups, with mortality rates 22 times higher for those below 30 years of age and nine times higher for those below 60 years of age. However, the disparity in mortality rates gradually declined with increasing age. These findings highlight the disproportionate impact of COVID-19 on individuals with intellectual disabilities, particularly among younger age groups.

The study findings revealed that the overall mortality disparity from all causes during the COVID-19 pandemic was 3.38 times higher in individuals with intellectual disabilities, which was a 5% increase compared to the pre-pandemic period (3.23 times higher). Importantly, this increased overall mortality disparity could not be fully explained by the excess risk of COVID-19-related deaths alone. The study observed widening mortality disparities in causes of death related to cancer, mental, behavioural, and nervous system disorders, as well as external causes. This indicates that individuals with intellectual disabilities faced increased mortality risks not only from COVID-19, but also from other health conditions during the pandemic. These findings highlight that the pre-existing mortality disparity faced by individuals with intellectual disabilities was exacerbated during the COVID-19 pandemic, with a greater magnitude of risk difference compared to the general population.

The authors say: “Our study showed that the full impact of the COVID-19 pandemic has been much greater than indicated by reported deaths due to COVID-19 alone. Existing mortality disparities between people with and without intellectual disabilities have been further widened compared with the period 2015–19.”

The authors of the study concluded that the health risks faced by individuals with intellectual disabilities call for targeted policy measures to protect this vulnerable population during the current COVID-19 pandemic and future pandemic preparedness efforts. They emphasized that protective measures should not solely focus on the causative agent of a pandemic, but also consider the unique needs and challenges faced by individuals with intellectual disabilities. The study underscores the importance of improved monitoring and attention to vulnerable populations, including people with disabilities, who may be at risk of being overlooked, leading to significant consequences. These findings highlight the urgent need for inclusive and comprehensive approaches to pandemic preparedness and response that prioritize the health and well-being of all individuals, including those with intellectual disabilities.

*Note: this is a joint press release from the European Congress of Clinical Microbiology & Infectious Diseases (ECCMID) and The Lancet Public Health.  Please credit both the congress and the journal in your stories*

The Lancet Public Health: All-cause and cause-specific mortality among people with and without intellectual disabilities during the COVID-19 pandemic in the Netherlands: a population-based cohort study

To be presented at a special Lancet journals COVID-19 session in Hall I of the European Congress on Clinical Microbiology & Infectious Diseases (ECCMID 2023) in Copenhagen on Monday April 217 at 16.15-18.15 Copenhagen time (CEST).