Design
This was an analytical cross-sectional study of children attending the Mulago National Referral Hospital.
Setting
The study was done at the pediatric neurology and psychiatry clinics of Mulago National Referral Hospital, the largest hospital in Uganda. It is a teaching hospital of Makerere University College of Health Sciences. The pediatric neurology clinic is an outpatient’s specialized clinic and operates every Thursday from 9:00 a.m. to 3:00 p.m. except on public holidays. The pediatric neurology clinic receives referred patients from all over the country with neurologic complications. About 20 children are seen on each clinic day. The team of health workers during clinic days includes a pediatric neurologist, two senior house officers/residents, a medical officer, two nursing officers and a records clerk. Medications prescribed from the clinic are dispensed at the clinic pharmacy when available. Patients diagnosed with ADHD are sent to the psychiatry clinic to get further assessment from a child psychiatrist and then get the necessary treatment and specific medications.
The child psychiatry clinic at Mulago Hospital is under the Department of Psychiatry and Mental Health. It is also a specialized centre for all mental disorders in the country. It operates as an outpatient’s specialized mental clinic on Tuesdays and Thursdays between 9:00 a.m. and 3:00 p.m. except on public holidays.
On every clinic day, about 10 children are attended to by a team of health workers including a child psychiatrist, a child psychologist, two psychiatric senior house officers/residents, two clinical officers, two nursing officers and two records clerks. Prescribed drugs are dispensed from the psychiatry clinic pharmacy when available.
Sample size estimation
The sample size was calculated using the formula: \(\left\{ {n = \frac{{Z_{\alpha }^{2} (pq)}}{{d^{2} }}} \right\}\) where p = prevalence of ADHD, q = complement of the prevalence, margin of error is error = d, alpha = significance level. Setting the significance at 0.05 and error margin at 5%, we adjusted the sample size requirement for an assumed 30% level of non-response. Based on a previous study in the USA [4] where ADHD prevalence was 12% and N* = 332, we recruited 332 participants.
Study questionnaire
The disruptive behavior disorders rating scale (DBRS) was completed for each study participant to identify the children who were likely to have ADHD symptoms. The scale consists of 45 items representing symptoms of disruptive behavior disorders including; conduct disorder, oppositional defiant disorder and ADHD. All 45 screening items were scored in the present study. Each symptom is rated on a four-point scale indicating the occurrence and severity or symptoms; 0 (not at all), 1 (just a little) 2 (pretty much) and 3 (very much). The scales were scored using the scoring method described by Pelham [12]. According to the DSM-IV, ADHD is divided into three subtypes that are predominantly inattentive (ADHD-I), predominantly hyperactivity/impulsivity (ADHD-HI) and combined (ADHD-C) [13].
The diagnosis of ADHD was confirmed by the child psychiatrist using the Mini International Neuropsychiatric Interview for Children and Adolescents (MINI Kid) version 6.0, a tool based on DSM IV criteria for diagnosis of psychiatric conditions [14]. The co-morbid conditions coexisting with and factors associated with ADHD were diagnosed using the same tool. The study participants’ care giver/guardians’ were asked if there were any delayed milestones for the children and a history of maternal abnormal vaginal discharge during pregnancy.
Study subjects
Study subjects were children aged between 4 and 18 years attending the Mulago National Referral Hospital, neurology and psychiatry clinics between 7th August 2014 and 4th June 2015. The inclusion criteria included; children aged between 4 and 18 years attending the neurology and psychiatry outpatient clinics. All children enrolled into the study had to be a companied by adult caregivers who consented for their participation in the study. Children whose caregivers during the clinic visit did not know much about the children’ illness and symptoms were excluded from the study.
Study procedures
Study participants were approached, screened and consecutively enrolled from the outpatient clinic days until the required sample size was obtained. Identification and screening of the participants were systematically done by the study team in the reception areas. The guardians/parents were approached by the study team for consent to participate in the study. Among study participants age eight or older without severe intellectual disability, assent was sought to participate in the study. The PI or research assistant interviewed the caretakers of study participants or the study participants (those who gave assent) using pretested questionnaire written in English, but administered in the language best understood by the parent/guardian. A structured self-administered questionnaire was used to collect information from the parents of children, as well as older children, who presented to paediatric outpatient clinics during the study period. In a few cases in which the parents were illiterate, the questionnaire was administered by study investigators. Parents were asked to recall symptoms, from a list of criteria for the diagnosis of ADHD, exhibited by their children either at home or at school. We used the DSM-IV-TR diagnostic criteria for ADHD. The responses were recorded in English. The physical examination of the study participant was done by the PI or the research assistant. A medical screening of each study participant, including height, weight, temperature and a review of systems, was conducted by the study pediatricians to identify any existent health problems that required immediate medical treatment. Neurological and mental status examinations were done in detail by study pediatricians. Abnormalities of movement and coordination such as tremors, chorea, athetosis, dystonia, gait and ataxia were also assessed. Children who were identified (using the disruptive rating scale) with symptoms consistent with ADHD were referred to a psychiatrist for further diagnostic assessment and appropriate treatment including long term management. All children with ADHD were confirmed by a child psychiatrist.
Statistical analysis
All questionnaires were cross-checked for completeness, sorted, coded and entered into the computer using Epidata version 2.1 packages. The raw data was securely stored to maintain confidentiality. Data was analyzed with the help of a statistician using Stata version 12.0 software (StataCorp. 2011. Stata Statistical Software: Release 12. College Station, TX: StataCorp LP).