Rates, causes, place and predictors of mortality in adults with intellectual disabilities with and without Down syndrome: cohort study with record linkage

Abstract

ObjectivesTo investigate mortality in adults with intellectual disabilities: rates, causes, place, demographic and clinical predictors.DesignCohort study with record linkage to death data.SettingGeneral community.Participants961/1023 (94%) adults (16–83 years; mean=44.1 years; 54.6% male) with intellectual disabilities, clinically examined in 2001–2004; subsequently record-linked to their National Health Service number, allowing linkage to death certificate data, 2018.Outcome measuresStandardised mortality ratios (SMRs), underlying and all contributing causes of death, avoidable deaths, place, and demographic and clinical predictors of death.Results294/961 (30.6%) had died; 64/179 (35.8%) with Down syndrome, 230/783 (29.4%) without Down syndrome. SMR overall=2.24 (1.98, 2.49); Down syndrome adults=5.28 (3.98, 6.57), adults without Down syndrome=1.93 (1.68, 2.18); male=1.69 (1.42, 1.95), female=3.48 (2.90, 4.06). SMRs decreased as age increased. More severe intellectual disabilities increased SMR, but ability was not retained in the multivariable model. SMRs were higher for most International Statistical Classification of Diseases and Related Health Problems, 10th Revision chapters. For adults without Down syndrome, aspiration/reflux/choking and respiratory infection were the the most common underlying causes of mortality; for Down syndrome adults ‘Down syndrome’, and dementia were most common. Amenable deaths (29.8%) were double that in the general population (14%); 60.3% died in hospital. Mortality risk related to percutaneous endoscopic gastrostomy/tube fed, Down syndrome, diabetes, lower respiratory tract infection at cohort-entry, smoking, epilepsy, hearing impairment, increasing number of prescribed drugs, increasing age. Bowel incontinence reduced mortality risk.ConclusionsAdults with intellectual disabilities with and without Down syndrome have different SMRs and causes of death which should be separately reported. Both die younger, from different causes than other people. Some mortality risks are similar to other people, with earlier mortality reflecting more multimorbidity; amenable deaths are also common. This should inform actions to reduce early mortality, for example, training to avoid aspiration/choking, pain identification to address problems before they are advanced, and reasonable adjustments to improve healthcare quality.

Premature Mortality, Risk Factors, and Causes of Death Following Childhood-Onset Neurological Impairments: A Systematic Review

“…Three studies, however, did not report mortality by the severity of ID ( 44 , 46 , 50 ). Mortality in ID was significantly increased by genetic disorders (Down syndrome and Fragile X), maternal alcohol use, low-birth weight and postnatal injury, and the presence and number of comorbid neurological conditions such as epilepsy and cerebral palsy ( 43 , 45 , 48 , 51 ) ( Table 5 ).…”

“…Respiratory infections (34%), accidents (18%), and epilepsy (10.7%) were the most common causes of death in ID in one study from Western Australia ( 43 ); while, the leading causes of death in a Swedish study were congenital malformations (SMR 46.3 [32.9–65.0]), neurological diseases (SMR 9.7 [5.5–17.0]), mental disorders (SMR 4.0 [1.9–8.4]), and respiratory diseases (SMR 3.3 [2.0–5.5]) ( 45 ). Diseases of the respiratory system (21.8%), the circulatory system (19.1%) and the nervous system (13.0%) were the most common causes of death in the Scottish study ( 51 ). Another Scottish study ( 50 ) identified diseases of the nervous system (33%), congenital malformations, deformations and chromosomal anomalies (22%), and nutritional, metabolic and endocrinal diseases (8%) as the most frequent causes of death.…”

Understanding inequalities in COVID-19 outcomes following hospital admission for people with intellectual disability compared to the general population: a matched cohort study in the UK

“…2 Poorer health outcomes compared with the general population have been consistently reported for people with ID, 3 with an increased incidence of comorbidities including dysphagia and respiratory diseases, with respiratory disease identified as a leading cause of death. 4 These health comorbidities are associated with poor outcomes following infections and other acute conditions, 5 6 which may be exacerbated by barriers in accessing health and social care, associated with concerns about ongoing discrimination and bias. 7 To date there have been over 64 million cases of COVID-19 reported worldwide and 1.4 million deaths.…”

COVID-19 infection and outcomes in a population-based cohort of 17,173 adults with intellectual disabilities compared with the general population

“…(1) The WHO defines intellectual disabilities as impairments in adaptive, social, and intellectual functioning (IQ<70), requiring daily support, with the onset in the developmental phase (<18 years). (2) People with intellectual disabilities account for <1% of the global population,(3, 4) and about 0.5% of adults, (4) and they experience substantial health inequalities, including multimorbidity,(5) and premature and avoidable mortality,(6, 7) often from respiratory conditions. (8, 9) They are also more likely to live in congregate settings or be in receipt of social care (10); recent studies have reported high rates of COVID-19 mortality within multi-occupancy residences.…”