A recent study conducted by Scottish researchers has found that students with ID are more likely to die in comparison to their peer group. The findings of the study have been published today in The British Medical Journal (BMJ).
The researchers have conducted a retrospective cohort study to find out the death rate and their causes among children with ID, which can be defined as a significant limitation in intellectual functioning and adaptive behavior in which the person experiences delay and deficiency in every developmental period including development of motor skills, cognitive functioning, social interaction, and poor language functions.
The rate of ID in children from 2014 to 2016 have increased from 5.76% to 6.99%, according to an estimation published by the Center for Disease Control and Prevention (CDC).
The Scottish researchers collected the data extracted from Scotland’s annual pupil census between 2008 and 2013. The data was comprised of 947,922 children and young students with and without ID from different schools in Scotland. The study sample was leid in an age group of four to nineteen. During the long term study, the ages exceeded up to 25 as well.
People with ID have high chances to develop Autism Spectrum Disorder (ASD) which is also a developmental disorder characterized by difficulty with social skills, behaviors with repetition, speech, and non- verbal communication. The focus of the attention of the researchers was only on ID. Therefore, they excluded those participants who have ID with an underlying condition of ASD.
The investigators divided the data into two groups. The first group included those students with an ID that have at least one record of support at school due to ID. The second control group included all pupils with at least one census record, and without support records for ID or ASD.
Areas of Assessment Among Kids with ID
The team aimed to assess the age of death, age-standardized mortality ratios (age-SMRs); causes of death including cause-specific age-SMRs; avoidable deaths as defined by the UK Office of National Statistics.
For the purpose to find all of the study variables the team used demographics of the study participants from individual record linkage based on probabilistic record matching from on date of birth, sex and postcode, to the Community Health Index. Information about the death rate of every participant gained from the National Records of Scotland (NRS) deaths register, to ascertain all deaths up to February 2015 in Scotland.
The team conducted a sensitive analysis of both of the groups. After the compilation of all the measurements, the team determined that out of the total 947,922 students, 27,140 students were found to be registered in having an additional support needs due to ID whereas, 1.9% of the total had at least two records of support. They also found that 909,688 students did not have any diagnosis of ID or ASD.
Rate and Causes of Death Among Study Sample
The record from the NRS register of deaths was conducted till February 2015. The NRS register included 3,739,568 person-years of follow-up. Person-year or person-month can be defined as the number of participants included in the study and the amount of time which is spent by the study participants during the cohort. For example, date of death, date of the event (if death is not the event of interest), date of loss to follow-up, and date of the end of the study.
Mortality Rate Analysis
However, In just one year, the team determined 564 deaths have occurred during 3,739,568 person-years of which 0.6% deaths were due to ID over 67,342 person-years and crude mortality rate included 157 cases of deaths over 100,000 person-years.
In a comparison group, the researchers found 458 deaths over 3,739,568 person-years of which crude mortality rate included 12 fatality cases over 100,000 person-years.
The team also found out high mortality cases in males over females. It has been measured that 62% and 61% of deaths have occurred males of both of the ID group and without ID group, respectively. On another hand, the SMR rate was significantly higher in female students than males.
Causes of Death
The investigators have determined that the overall 95% of deaths have occurred in the ID group whereas, 91% of cases of deaths were found in the controlled group. There were 33% deaths were due to the diseases of the nervous system, 8% deaths were caused by nutritional, metabolic, and endocrine diseases and 22% deaths have resulted in congenital malformations, deformations, and chromosomal abnormalities.
Overall, a total of 71% and 100% deaths were occurred in male participants due to the external cause in the controlled group and ID group, respectively.
By taking all into account, the current study suggested that the rate of death among student with ID were significantly higher as compared to other students. Therefore, there is a need to develop a combination of medication and therapeutic interventions to decrease the mortality rate of ID.
The data for the current study was provided by the Scottish Exchange of Educational Data (ScotXed) Pupil Census, the National Records of Scotland and Information Services Division (ISD) of National Health Service Scotland. The data linkage and assisted by the eData Research and Innovation Service team at ISD Scotland.