Key PointsQuestion
What are the prevalence and risk factors associated with attention-deficit/hyperactivity disorder (ADHD) among US Black individuals?
Findings
This systematic review and meta-analysis assessing the results of 21 studies found that the pooled prevalence of ADHD among 154 818 US Black individuals was approximately 15% and suggested that the associated risk factors included sociodemographic characteristics (age, sex, race, socioeconomic status), risk behaviors, and familial and environmental factors.
Meaning
The higher prevalence of ADHD observed in this study among US Black individuals highlights the need to increase assessment, accurate diagnoses, and culturally appropriate care.
Importance
As stated in the DSM-5, it is generally reported that the prevalence of attention-deficit/hyperactivity disorder (ADHD) is lower among Black individuals compared with the general population. However, Black individuals living in countries where they are considered a minority population group (eg, in Northern America and Europe) are underrepresented in studies evaluating ADHD.
Objective
To estimate the pooled prevalence of ADHD and identify associated risk factors among US Black individuals.
Data Sources
This systematic review and meta-analysis identified peer-reviewed studies published until October 18, 2019, using the APA PsycInfo, MEDLINE, Embase, Cochrane CENTRAL, CINAHL, ERIC, and Education Source databases.
Study Selection
Eligible trials were published in French or English, had empirical data on the prevalence of ADHD in samples or subsamples of Black people, and were conducted in countries with Black minority populations. All studies were assessed and passed quality evaluation.
Data Extraction and Synthesis
The PRISMA guideline was used for extracting and reporting data. Random-effects meta-analyses were generated to estimate the prevalence of ADHD among Black individuals using the metafor package in R.
Main Outcomes and Measures
Prevalence and risk factors associated with ADHD among Black individuals were identified.
Results
A total of 24 independent samples and subsamples from 21 studies published between 1979 and 2020 (154 818 Black participants) were included in this systematic review and meta-analysis. All included studies were conducted in the US. Two studies were conducted assessing adults (aged 18 years or older), 8 assessing children (0-12 years), 1 assessing adolescents (aged 13-17 years), and 13 assessing both children and adolescents. The pooled prevalence of ADHD was 14.54% (95% CI, 10.64%-19.56%). In a narrative review of the studies in this analysis, some studies found risk factors associated with ADHD, such as sociodemographic characteristics (age, sex, race, and socioeconomic status), familial factors, environmental factors, and risk behaviors, but the data did not permit a moderation analysis to assess these findings in this study.
Conclusions and Relevance
Contrary to what is stated in the DSM-5, the results of this systematic review and meta-analysis suggest that Black individuals are at higher risk for ADHD diagnoses than the general US population. These results highlight a need to increase ADHD assessment and monitoring among Black individuals from different social backgrounds. They also higlight the importance of establishing accurate diagnoses and culturally appropriate care.
According to the DSM-5, attention-deficit/hyperactivity disorder (ADHD) is characterized by the persistence of inattentive or hyperactive-impulsive behaviors that impact the functioning or development of individuals.1 Previous meta-analyses conducted on the prevalence of ADHD have found varying results.2,3 The results of a systematic review revealed a prevalence of 5.6% worldwide,2 whereas another indicated a prevalence ranging from 8.5% to 13.3%, depending on whether the assessment informant was a parent, youth, or a teacher.4 Another systematic review found a prevalence of 7.2% by pooling 175 studies.3 Certain ethnocultural groups, such as Black individuals, are underrepresented in studies.5-8 The few studies that have included ethnocultural groups are often criticized for including samples from disadvantaged neighborhoods and using assessment tools that do not integrate cultural specificities.6,8
Despite the paucity of primary studies and the availability of only 1 systematic review that used data from African American persons and found a higher prevalence of ADHD among Black children than among White youth,6 the DSM-5 states that the frequency of ADHD tends to be lower among Black youth than among White youth in the United States.1 Moreover, studies conducted on the prevalence of ADHD among Black individuals have shown a wide range of results.9-18 Whereas some studies assessing Black individuals have found a prevalence of ADHD of less than 5%,19,20 others have found a prevalence of more than 20%.21-23
Several factors might explain the variability observed in the prevalence of ADHD among Black individuals. First, studies have highlighted trends for the overdiagnosis or underdiagnosis of ADHD in the general population.2-4 Second, studies have shown that low socioeconomic status (SES) is a risk factor associated with the diagnosis of ADHD and for its overdiagnosis.3,5,8 Many studies reporting high prevalence rates of ADHD have included samples of Black individuals from disadvantaged families.21,24 Contrarily, other studies have shown that a lower SES may be the basis for the underdiagnosis of ADHD among US Black individuals.19,25 Limited access to insurance and mental health services for disadvantaged families is a factor that prevents children from receiving appropriate ADHD diagnoses.19,26 Other factors, such as cultural differences of parents’ perspectives on their child's behavior, cultural biases in testing and diagnosis, communication barriers in the language of assessment, and biases based on racial discrimination, were also identified.5,6,8,22,24 In societies where Black individuals are a minority, specifically in the United States, a disproportionate number of families are in the low SES group, which is associated with structural and systemic racism. These individuals face racial discrimination and profiling, racist microaggression, and racism that may affect the behavior of both youths and adults. Furthermore, these elements may likely serve as major risk factors associated with ADHD among Black individuals and may also limit access to health care services.6-8
Given the wide variability in the prevalence of ADHD, the lack of knowledge of risk factors associated with ADHD among Black individuals, including racial issues, and the need for reliable data to develop evidence-based and culturally adapted programs, the objectives of the present study were to conduct a systematic review and meta-analysis to (1) calculate a pooled prevalence estimate of ADHD and (2) determine individual, familial, and social factors associated with ADHD among Black individuals.
Protocol and Registration
We registered this meta-analysis with PROSPERO (CRD42020155634) to avoid unnecessary replication of this project. The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline was used.27
Identification and Selection of Studies
The focus of this meta-analysis was on studies pertaining to the prevalence and risk factors associated with ADHD among Black individuals. A social sciences research librarian (P.R.L.) with experience in conducting knowledge synthesis assisted in drafting, developing, and implementing a search strategy to retrieve results in APA PsycInfo (Ovid), MEDLINE (Ovid), Embase (Ovid), Cochrane CENTRAL (Ovid), CINAHL (EBSCO), ERIC (Education Resources Information Center; Ovid), and Education Source (EBSCO) to October 18, 2019. The strategy was designed by considering previous systematic review search strategies focused on Black individuals28,29 and ADHD30-33 and through consultation among members of the research team (J.M.C. and C.B.-R.). The final strategy used relevant keywords as well as database-specific controlled vocabulary (the complete search strategy is available in the eAppendix in the Supplement). Some authors were contacted by email to obtain precise or additional information on their articles.
Inclusion and Exclusion Criteria
All peer-reviewed journal articles published were included if they met the following criteria: (1) were published in either French or English, (2) had empirical data on the prevalence of ADHD in samples of Black people, and (3) were conducted in countries where Black people are considered a minority population group (eg, United States and Canada). There were no restrictions on age.
We found 7053 references using 7 different databases. Once 3220 duplicates were removed, we used Covidence tool to screen the remaining 3833 articles by title and abstract and retained 99 articles. For each selection step (eg, data extraction and assessment of quality), 2 authors (C.M. and M.-P.V.) screened and coded all the studies. Disagreements in screening and coding were resolved by 1 of 2 additional authors (C.B.-R. or P.-G.N.). Some disagreements were resolved by discussions between the 2 screening authors (C.M. and M.-P.V.). There were 12 articles for which the full texts were not available. Thus, we downloaded all 87 articles and proceeded to screen by full text, keeping 20 articles. We found 1 additional article by manually searching the reference lists of retained articles, for a total of 21 included articles. From these articles, we identified 24 independent samples or subsamples that we used for our meta-analysis. The screening process is recorded in the PRISMA flowchart (Figure 1).
Data Extraction and Management
The Table presents the characteristics of the 24 independent samples. All included studies were conducted in the United States. Sample characteristics of the studies included in the meta-analysis are summarized in the Table5,9,11-21,24-26,34-38 and included the following: author names, year of publication, group, range or mean age, age group, type of sample, sample size, and number of Black people with ADHD. Primary findings (including associated risk and protective factors), type of survey and ADHD assessment, and quality evaluation for each article are presented in the eTable in the Supplement.
The quality of the 21 retained articles was assessed by using The Joanna Briggs Institute Checklist for Prevalence Studies.39 The evaluation criteria were as follows: (1) appropriateness of the sample frame; (2) recruitment procedure; (3) adequacy of the sample size; (4) description of participants and setting; (5) coverage of the identified sample; (6) validity of the method used to identify ADHD; (7) reliability of the method used to identify ADHD; (8) adequacy of statistical analyses; and (9) response rate. Articles were assigned 1 point per criterion met, for a maximum of 9 points. Articles were to be excluded if their total score was less than 5 points; however, no identified article received a rating lower than 5. Thus, all 21 articles passed quality assessment.
Random-effects meta-analyses were generated on the proportions of Black individuals with ADHD among a sample of Black people using the metafor package in R, version 4 (The R Foundation).40 We used random effects because it accounts for heterogeneity among studies. We used the logit-transformed proportions and transformed them back for ease of interpretation in a forest plot. The binomial-normal model was indicated because it provides unbiased estimates and a good coverage of confidence intervals for meta-analyses with proportions.41,42
The final sample consisted of 24 samples and subsamples from 21 studies published between 1979 and 2019 (Table). All included studies were conducted in the US. The retained studies had a combined sample size of 154 818. Eleven studies were conducted with various national survey data. The studies used samples of children (0-12 years; 8 studies), adolescents (13-17 years; 1 study), both children and adolescents (13 studies), and adults (18 years or older; 2 studies). The age ranges or the mean ages of the samples reported in the Table refer to the entire sample in the respective studies. One sample was of economically fragile families,5 and 2 were of juvenile offenders.21 Samples included either Black, African American, or non-Hispanic Black participants. In all 21 studies included, race was self-reported or parent-reported.
The pooled prevalence of ADHD among participants was 14.54% (95% CI, 10.64%-19.56%). Figure 2 shows a forest plot of the pooled prevalence of ADHD among Black people. The Kendall τ rank-order correlation was not significant (r = 0.08; P > .05), which indicated that there was no asymmetry in the funnel plot. This result provided evidence that there was no publication bias in the present meta-analysis. The I2 statistic (I2 = 99.76%) indicated high heterogeneity in the results.43 Given the heterogeneity in the results, it would have been ideal to conduct moderation analyses to identify factors that might be associated with the differences in prevalence. We had initially planned to consider sex, age, and perceived racism as potential moderators. However, the studies did not provide enough information about these factors to be able to conduct these analyses.
The analysis was also performed without the 2 adult samples and without the 3 samples of youths in the juvenile justice system, and those results are provided in the eFigure in the Supplement. The pooled prevalence for 19 studies assessing Black people younger than 18 years was 13.87% (95% CI, 9.59%-19.64%), which did not differ substantially from the results that included the adult samples and samples of youths in the juvenile system.
Narrative Review of Risk Factors Associated With ADHD Among Black Individuals
In a narrative review of the studies in this analysis, some studies found risk factors associated with ADHD, such as sociodemographic characteristics (age, sex, race, and socioeconomic status), familial factors, environmental factors, and risk behaviors, but the data did not permit a moderation analysis to assess these findings in this study. The most-reported risk factors included sex, race, and socioeconomic status.
One included study showed that receiving a diagnosis of ADHD was commonly found among Black children in the fifth grade (11-12 years) and lower.19 However, the results of studies indicated an increase in ADHD diagnoses among older age groups, mainly children aged 10 to 17 years.26 A study with a sample from the New York State public mental health system showed that children aged 8 to 12 years were significantly more likely to receive a diagnosis of ADHD than those aged 3 to 7 years or those aged 13 to 17 years.37
Consistent with the literature, most included studies reported that male individuals were more likely than female individuals to develop symptoms of ADHD in Black minority populations.5,19,20 Male individuals also received more medical prescriptions compared with female individuals.19 However, a study found a high prevalence (55%) in the diagnosis of ADHD among females.26
Studies including racial comparisons found varied results.5,20,21,37,38 In studies conducted with subsamples and convenience samples or with at-risk populations, such as juvenile offenders, Black individuals were less likely to receive a diagnosis of ADHD.5,21 However, studies conducted with representative samples typically showed a higher prevalence of ADHD among Black individuals.20,37,38 Studies also indicated racial disparities when ADHD symptoms were reported by teachers.23,44 Teachers reported more symptoms among Black youths. Contrarily, Black parents were less likely to report ADHD symptoms in their children for fear of exposing them to racial discrimination.22,23,44
Low SES has been highlighted as a risk factor associated with ADHD among Black individuals.5,19,23,34-36,45 Higher SES is an apparent protective factor for White families but not for Black families.5 Lower SES has also been tied to familial factors; Black youths are more likely than White youths to be born to young unmarried mothers at birth.5 Moreover, being a single head of a household, mainly led by single mothers with 4 or more children, is an additional risk factor for Black youths. In addition, Black children who receive a diagnosis of ADHD within a lower SES do not have access to insurance in the US.19,26 One study noted that certain families with limited access to insurance do not speak English as a primary language, which serves as a barrier to care.26 Contrarily, another study found that families living in suburban areas, in contrast to urban areas, have a higher chance of receiving a diagnosis of ADHD due to accessibility to medical care.20
Within a sample of youths in the juvenile justice system, it has been shown that youths who have experienced adverse life events (eg, violent death of a relative) or who have had a history with child welfare were more likely to have received a diagnosis of ADHD.21 Genetic factors also heighten odds of receiving a diagnosis of ADHD.36,37 Parents also have negative views on the effect an ADHD diagnosis can have on their child’s future prospects. One study found that Black families with negative views on ADHD are less preoccupied by ADHD-related school problems and believe that ADHD diagnoses are accompanied by social stigma.22
All results presented in this section involve youths in the juvenile justice system. A study found that those diagnosed as having ADHD at an earlier age received teacher ratings of behavioral and learning problems and lower standardized test scores.21,34 Teachers’ ratings were associated with exclusionary discipline.34 Certain risk factors in conduct, such as gang affiliation, alcohol and drug use, and impulsivity, have also been associated with ADHD diagnoses.21 Behavioral problems, such as refusing to accept responsibility for actions and believing that verbal or physical aggression is acceptable to resolve conflicts, were associated with an ADHD diagnoses.21 That study also found an association between ADHD and suicidal ideations, suicidal attempts, and self-mutilation.
Environmental or Health-Associated Factors
Birth conditions, such as premature birth, low birth weight, and maternal use of drugs (eg, antidepressant medications), have been raised as possible risk factors associated with ADHD among Black youths.36,38 In utero or childhood exposure to toxic substances, such as tobacco smoke, lead, pesticides, and artificial food additives, has also been identified as risk factors.36-38
We conducted, to our knowledge, the first meta-analysis on the prevalence and risk factors associated with ADHD among Black individuals in the US. This study presented a meta-analysis of 24 independent samples and subsamples of Black individuals from 21 studies. The results of this meta-analysis indicated a pooled prevalence estimate of 14.54% (95% CI, 10.64%-19.56%) for ADHD diagnoses among Black individuals, with a Kendall τ rank-order correlation that was not significant (r = 0.08, P > .05), providing evidence that there was no publication bias in our meta-analysis. The prevalence rate in the present meta-analysis was high compared with other systematic reviews and meta-analyses conducted in the general population.2-4,46 The prevalence of ADHD in meta-analyses conducted among youths often varies between 2% and 7%, with a mean of approximately 5%.46 First, 2 previous systematic reviews found a pooled worldwide prevalence of 5.3% and 7.2%, respectively.2,3 Second, meta-analyses and national surveys conducted among populations in which Black people constitute a minority, such as North America and Western Europe, found prevalence rates ranging from 1.7% to 12.0%.46-50 Although it has often been assumed in the scientific literature that Black individuals are at lower risk than White individuals, the only 2 reviews of ADHD among Black people showed that they tend to present a higher prevalence than White people.6,7 Contrarily, although the DSM-5 states that African Americans are less likely to develop ADHD than the general population,1 results from previous studies and from the present meta-analysis indicate that Black persons have a higher prevalence of ADHD.2-4,6,7,46
Despite these observations, it is possible that the higher prevalence is because many studies included in this meta-analysis were conducted with Black youths with low SES, compared with studies conducted with national samples or with meta-analyses.2-4,46 In this regard, a recent study has shown that, whereas high SES appears to be a protective factor for ADHD diagnoses among White youths, this does not appear to be true for Black youths.5 Therefore, while low SES is a major risk factor associated with ADHD among Black individuals, high SES is not a protective factor. The results of the present meta-analysis also showed that SES was a major risk factor associated with receiving a diagnosis of ADHD among Black individuals.5,19,23,26,34,36 This observation may be associated with diminished returns specific to Black individuals that may be explained by racial discrimination, racism, stress, and the greater effort made by Black individuals to access social mobility.5 Moreover, other factors might explain the higher prevalence observed among Black individuals. First, disadvantaged families have less access to insurance to obtain the best services and diagnostics based on appropriate tools and methods.19,26 Second, discrepancies between the symptoms reported by teachers and those by parents should be considered.23 Not only do teachers report more symptoms for Black youths, but reporting is even higher for Black youths with low SES.6,23,51 This discrepancy could be explained by 3 main factors: parents’ lack of knowledge of ADHD symptoms, parents’ fear of racial discriminations associated with a diagnosis of ADHD, and prejudices based on race and SES by teachers.6-8,23,44 Third, in the US, where all the studies included in this meta-analysis were conducted, studies have shown that disadvantaged Black families, high rates of single parenthood, low SES, and violence in schools are factors that may be associated with the high prevalence of ADHD.5,6,19,23 Recent research has indicated that experiences of stress and racial discrimination may better account for this observation.5,8,23
Other risk factors associated with ADHD observed in the scientific literature were also found: being male, being older, experiencing adversities early in life, being placed in child welfare, engaging in risk behaviors, and being subjected to environmental factors during pregnancy and birth. These results show that Black individuals face the same risk factors for ADHD diagnoses as other individuals. However, aspects related to the intersection of race, low SES, racial marginalization and discrimination, and racist microaggressions may exacerbate the symptoms of ADHD.5-7,19,20,26,36,38
Implications for Research and Clinical Practice
This meta-analysis has implications for both research and clinical practice. First, the results of this study highlighted the need for more specific studies on associations between race and race-associated experiences and the diagnosis, prevalence, and risk factors associated with ADHD. In fact, studies that have shown that high SES benefits White people in terms of protective factors and not Black people5 warrant clarification to improve services offered to Black people. Second, all studies included in this meta-analysis were conducted in the United States, indicating the need for research on ADHD that takes into account ethnicity in other Western countries. This observation also raises questions about the level of services offered to Black individuals in these countries and the racial disparities often observed.6 We can also question the role of this observation in the distrust of Black individuals in institutions and the diagnoses and services offered by mental health professionals.8 In terms of clinical evaluation, these observations question the validity of the tools used and their cultural adaptation to evaluate social and racial experiences. These observations should guide future research and clinical practice, both in terms of diagnosis and intervention.52
Although this meta-analysis provides important insights into the prevalence and factors associated with ADHD among Black individuals, it also has some limitations. First, no published research has been conducted in countries other than the United States. Although Canada, France, England, and other Western countries have significant Black communities, none of the studies analyzed samples or subsamples of Black individuals. The absence of studies in other Western countries may be explained by “color-blind” policies that may influence academic and research communities (because of a lack of training on racial issues) that do not collect or prohibit collection of data on race or ethnicity but that nevertheless perpetuate racial discrimination and racism.53-55 For example, in France, researchers are prohibited from collecting data on skin color and ethnicity.56 Second, the lack of data prevented in-depth analyses of all the moderators that were planned to be examined: sex, age, location of where the study was conducted, and perceived racial discrimination. This limitation also highlights the need for studies to report sociodemographic data to provide a better understanding of associations between individuals’ experiences and mental health problems.
This meta-analysis on the prevalence and risk factors associated with the diagnosis of ADHD among US Black individuals makes an important contribution to the scientific literature. It challenges generally accepted statements that Black individuals have a lower prevalence of ADHD compared with others.1 Although there is still much work to be done to better understand these data and to study the barriers associated with culturally appropriate ADHD diagnoses and care for Black individuals, the present study provides important insights for both research and clinical practice. It offers key avenues to consider the reduction of disparities associated with ADHD diagnoses among Black individuals. These considerations include research that can help to establish accurate diagnoses and culturally appropriate care for Black youth with ADHD symptoms. We believe that such efforts should be the responsibility of each researcher and clinician working with youths.52
Accepted for Publication: July 13, 2020.
Corresponding Author: Jude Mary Cénat, PhD, School of Psychology, University of Ottawa, 136 Jean-Jacques-Lussier, 4017, Vanier Hall, Ottawa, ON K1N 6N5, Canada (jcenat@uottawa.ca).
Published Online: September 9, 2020. doi:10.1001/jamapsychiatry.2020.2788
Author Contributions: Drs Cénat and Blais-Rochette had full access to all the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis.
Concept and design: Cénat, Blais-Rochette, Noorishad, Kogan, Labelle.
Acquisition, analysis, or interpretation of data: Cénat, Blais-Rochette, Morse, Vandette, Noorishad, Ndengeyingoma, Labelle.
Drafting of the manuscript: Cénat, Blais-Rochette, Noorishad, Labelle.
Critical revision of the manuscript for important intellectual content: Blais-Rochette, Morse, Vandette, Noorishad, Kogan, Ndengeyingoma.
Statistical analysis: Cénat, Blais-Rochette.
Obtained funding: Cénat, Kogan, Ndengeyingoma.
Administrative, technical, or material support: Cénat, Morse, Noorishad, Kogan, Labelle.
Supervision: Cénat, Blais-Rochette, Noorishad.
Conflict of Interest Disclosures: None reported.
Funding/Support: This article was supported by grant 1920-HQ-000053 from the Public Health Agency of Canada (PHAC).
Role of the Funder/Sponsor: The PHAC had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.
Additional Information: Pari-Gole Noorishad is a PhD student.
1.American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. 5th ed. American Psychiatric Association; 2013.
18.Alegría
M, Lin
JY, Green
JG, Sampson
NA, Gruber
MJ, Kessler
RC. Role of referrals in mental health service disparities for racial and ethnic minority youth.
J Am Acad Child Adolesc Psychiatry. 2012;51(7):703-711.e2. doi:
10.1016/j.jaac.2012.05.005
PubMedGoogle ScholarCrossref 20.Reyes
N, Baumgardner
DJ, Simmons
DH, Buckingham
W. The potential for sociocultural factors in the diagnosis of ADHD in children.
WMJ. 2013;112(1):13-17.
PubMedGoogle Scholar 21.Baglivio
MT, Wolff
KT, Piquero
AR, Greenwald
MA, Epps
N. Racial/ethnic disproportionality in psychiatric diagnoses and treatment in a sample of serious juvenile offenders.
J Youth Adolesc. 2017;46(7):1424-1451. doi:
10.1007/s10964-016-0573-4
PubMedGoogle ScholarCrossref 23.Lawson
GM, Nissley-Tsiopinis
J, Nahmias
A, McConaughy
SH, Eiraldi
R. Do parent and teacher report of ADHD symptoms in children differ by SES and racial status?
J Psychopathol Behav Assess. 2017;39(3):426-440. doi:
10.1007/s10862-017-9591-0
Google ScholarCrossref 24.Bazargan
M, Calderón
JL, Heslin
KC,
et al. A profile of chronic mental and physical conditions among African-American and Latino children in urban public housing.
Ethn Dis. 2005;15(4)(suppl 5):S5-S3, 9.
PubMedGoogle Scholar 33.Osland
ST, Steeves
TDL, Pringsheim
T. Pharmacological treatment for attention deficit hyperactivity disorder (ADHD) in children with comorbid tic disorders.
Cochrane Database Syst Rev. 2018;6(6):CD007990. doi:
10.1002/14651858.CD007990.pub3
PubMedGoogle Scholar 35.Froehlich
TE, Lanphear
BP, Epstein
JN, Barbaresi
WJ, Katusic
SK, Kahn
RS. Prevalence, recognition, and treatment of attention-deficit/hyperactivity disorder in a national sample of US children.
Arch Pediatr Adolesc Med. 2007;161(9):857-864. doi:
10.1001/archpedi.161.9.857
PubMedGoogle ScholarCrossref 42.Stijnen
T, Hamza
TH, Özdemir
P. Random effects meta-analysis of event outcome in the framework of the generalized linear mixed model with applications in sparse data.
Stat Med. 2010;29(29):3046-3067. doi:
10.1002/sim.4040
PubMedGoogle ScholarCrossref 49.Schlack
R, Hölling
H, Kurth
B-M, Huss
M. The prevalence of attention-deficit/hyperactivity disorder (ADHD) among children and adolescents in Germany: initial results from the German Health Interview and Examination Survey for Children and Adolescents (KiGGS). Article in German.
Bundesgesundheitsblatt Gesundheitsforschung Gesundheitsschutz. 2007;50(5-6):827-835. doi:
10.1007/s00103-007-0246-2PubMedGoogle ScholarCrossref 50.Vasiliadis
H-M, Diallo
FB, Rochette
L,
et al. Temporal trends in the prevalence and incidence of diagnosed ADHD in children and young adults between 1999 and 2012 in Canada: a data linkage study.
Can J Psychiatry. 2017;62(12):818-826. doi:
10.1177/0706743717714468
PubMedGoogle ScholarCrossref