Prevalence, risk factors and comorbidities of neurodevelopmental disorders in Kenyan children: A population-based study
Abstract
Background: Neurodevelopmental disorders (NDD) such as autism spectrum disorder (ASD), attention-deficit hyperactivity disorder (ADHD) and intellectual disability contribute to a tenth of the global burden of mental and neurological disorders. The burden of NDD is not well documented in Africa, where the incidence of perinatal and early risk factors is high.
Methods: We conducted a population-based epidemiological study to assess the epidemiology of NDD in 11,223 children (6-9 years) and comorbidities in the Kilifi Health and Demographic Surveillance System (KHDSS). In the stage I of the study, we used the neurodevelopmental screening questionnaire to detect NDD. Those screening positive and a proportion of those negative invited to undergo clinical evaluation to confirm the diagnosis (stage II)· Prevalence of NDD was estimated. We determined risk factors and medical comorbidities associated with NDD, using generalised linear models, with appropriate distribution and link functions.
Findings: Of the 11,223 screened in stage I, 524 children had a NDD confirmed in stage II, with an overall adjusted prevalence of 90·8/1,000 children (95%CI:83·4-98·6), which differed by sex and spatial distribution. The NDD with the highest prevalence was ADHD (50·8/1,000 (95%CI:45·2-57·1)) and intellectual disability (27·1/1,000 (95%CI:22·9-31·9). Co-occurrence of NDD in a child was reported in 22·6% (95%CI: 19·1-26·4%). Key risk factors for NDD were adverse perinatal events (RR=1·64 (1·29-2·09)), febrile infections (RR=1·28 (1·05-1·56)), eating soil (RR=1⋅45 (95%CI: 1·13-1·85)), snoring (RR=1·50 (95%CI:1⋅27-1⋅76)) and being a landless squatter (RR=1·32 (1·12-1·56)). Head injuries were unique to developmental conditions and febrile infections to neurological conditions, with many risk factors shared. Common medical comorbidities for NDD included motor neuron dysfunction, and malnutrition.
Interpretation: NDD are common in school-going children in this Kenyan rural area and are associated with preventable risk factors. These disorders and associated comorbidities should be identified and addressed in children in Africa.