OBJECTIVES: This study aimed to systematically summarise all global evidence on the economic burden of ADHD.
METHODS: A systematic search for published studies on costs of ADHD was conducted in EconLit, EMBASE, PubMed, ERIC, and PsycINFO. Additional literature was identified by searching the reference lists of eligible studies. The quality of the studies was assessed using the Larg and Moss checklist.
RESULTS: This review included 44 studies. All studies were conducted in high-income countries and were limited to North America and Europe except for four studies: two in Asia and two in Australia. Most studies were retrospective and undertook a prevalence-based study design. Analysis revealed a substantial economic impact associated with ADHD. Estimates based on total costs ranged from $US831.38 to 20,538 for per person estimates and from $US356 million to 20.27 billion for national estimates. Estimates based on marginal costs ranged from $US244.15 to 18,751.00 for per person estimates and from $US12.18 million to 141.33 billion for national estimates. Studies that calculated economic burden across multiple domains of direct, indirect, and education and justice system costs for both children and adults with ADHD reported higher costs and translated gross domestic product than did studies that captured only a single domain or age group.
CONCLUSIONS: Despite the wide variation in methodologies in studies reviewed, the literature suggests that ADHD imposes a substantial economic burden on society. There is a dire need for cost-of-illness research in low- and middle-income countries to better inform the treatment and management of ADHD in these countries. In addition, guidelines on the conduct and reporting of economic burden studies are needed as they may improve standardisation of cost-of-illness studies.
SETTING: A single centre study, Malaysia.
PARTICIPANTS: Adults aged between 18 and 60 years with mTBI as a result of road traffic accident, with no previous history of head trauma, minimum of 9 years education and abnormal cognition at 3 months will be included. The exclusion criteria include pre-existing chronic illness or neurological/psychiatric condition, long-term medication that affects cognitive/psychological status, clinical evidence of substance intoxication at the time of injury and major polytrauma. Based on multiple estimated calculations, the minimum intended sample size is 50 participants (Cohen's d effect size=0.35; alpha level of 0.05; 85% power to detect statistical significance; 40% attrition rate).
INTERVENTIONS: Intervention group will receive individualised structured cognitive rehabilitation. Control group will receive the best patient-centred care for attention disorders. Therapy frequency for both groups will be 1 hour per week for 12 weeks.
OUTCOME MEASURES: Primary: Neuropsychological Assessment Battery-Screening Module (S-NAB) scores. Secondary: Diffusion Tensor Imaging (DTI) parameters and Goal Attainment Scaling score (GAS).
RESULTS: Results will include descriptive statistics of population demographics, CogniPlus cognitive program and metacognitive strategies. The effect of intervention will be the effect size of S-NAB scores and mean GAS T scores. DTI parameters will be compared between groups via repeated measure analysis. Correlation analysis of outcome measures will be calculated using Pearson's correlation coefficient.
CONCLUSION: This is a complex clinical intervention with multiple outcome measures to provide a comprehensive evidence-based treatment model.
ETHICS AND DISSEMINATION: The study protocol was approved by the Medical Research Ethics Committee UMMC (MREC ID NO: 2016928-4293). The findings of the trial will be disseminated through peer-reviewed journals and scientific conferences.
TRIAL REGISTRATION NUMBER: NCT03237676.
METHOD: 783 Australian and 928 Malaysian parents provided ratings for an ADHD rating scale. Invariance was tested across these groups (Comparison 1), and North European Australian (n = 623) and Malay Malaysian (n = 571, Comparison 2) groups.
RESULTS: Results indicate support for form and item factor loading invariance; more than half the total number of symptoms showed item intercept invariance, and 14 symptoms showed invariance for error variances. There was invariance for both the factor variances and the covariance, and the latent mean scores for hyperactivity/impulsivity. For inattention latent scores, the Malaysian (Comparison 1) and Malay Malaysian (Comparison 2) groups had higher scores.
CONCLUSION: These results indicate fairly good support for invariance for parent ratings of the ADHD symptoms across the groups compared.