Influence of relative age on diagnosis and treatment of attention-deficit/hyperactivity disorder in children

Systematic review and meta-analysis: relative age in attention-deficit/ hyperactivity disorder and autism spectrum disorder

Youngest students in their class, with birthdates just before the school entry cut-off date, are overrepresented among children receiving an Attention-Deficit/Hyperactivity Disorder (ADHD) diagnosis or medication for this. This is known as the relative age effect. This systematic review and meta-analysis summarises the evidence on the influence of relative age on ADHD symptoms, diagnosis and medication prescribing. As no review to date has investigated the association with autism spectrum disorder (ASD) diagnosis, this is also examined. Following prospective registration with PROSPERO, we conducted a systematic review according to the PRISMA guidelines. We searched seven databases: Medline, Embase, PsycInfo, Web of Science Core Collection, ERIC, Psychology and Behavioural Sciences Collection, and Cochrane Library. Additional references were identified from manual search of retrieved reviews. We performed a meta-analysis of quantitative data. Thirty-two studies were included, thirty-one investigated ADHD and two ASD. Younger relative age was associated with ADHD diagnosis and medication, with relative risks of 1.38 (1.36-1.52 95% CI) and 1.28 (1.21-1.36 95% CI) respectively. However, risk estimates exhibited high heterogeneity. A relative age effect was observed for teacher ratings of ADHD symptoms but not for parent ratings. With regard to ASD, the youngest children in their school year were more likely to be diagnosed with ASD. This review confirms a relative age effect for ADHD diagnosis and prescribed ADHD medication and suggests that differences in teacher and parent ratings might contribute to this. Further research is needed on the possible association with ASD.

The relative age effect and its influence on athletic performance in Chinese junior female' tennis players

The relative age effect (RAE) has been the focus of numerous studies; however, there are still fewer studies in women's sports than in men's sports. In this study, all female players (N = 2,255) who participated in Chinese junior tennis competitions (U12, U14, U16, and the National Junior Team) from 2014 to 2019 were investigated in terms of competitors' birth dates and year-end rankings. For the purposes of the analysis, the birth dates were also separated into quarters and half years. The study's objectives were to analyze the prevalence of the RAE among young Chinese female tennis players and to further examine how the RAE affects athletic performance. Differences between the observed and expected distributions of birth dates were tested using the chi-square statistic, and subsequent calculations were tested using odds ratios. The RAE was discovered to be present in every group of Chinese junior female tennis players (p < 0.001), with the proportions of those born in the first half of the year being 56.4% (U12), 53.1% (U14), and 57.0% (U16), respectively. The RAE for athletes selected for the National Women's Junior Tennis Team was even more significant, with the percentage of birth dates in the first half of the year at 61.2%. Finally, we observed a tendency for the effect of the RAE on the athletic performance of adolescent female tennis players to diminish with age.

The ability to maintain rhythm is predictive of ADHD diagnosis and profile

Attention deficit hyperactivity disorder (ADHD) is the most prevalent neuropsychiatric disorder in the world. Currently, the diagnosis is based mainly on interviews, resulting in uncertainties in the clinical assessment. While some neuropsychological tests are used, their specificity and selectivity are low, and more reliable biomarkers are desirable. Previous research indicates that ADHD is associated with morphological changes in the cerebellum, which is essential for motor ability and timing. Here, we compared 29 children diagnosed with ADHD to 96 age-matched controls on prism adaptation, eyeblink conditioning, and timed motor performance in a finger tapping task. Prism adaptation and timing precision in the finger tapping task, but not performance on eyeblink conditioning, differed between the ADHD and control groups, as well as between children with and without Deficits in Attention, Motor control, and Perception (DAMP) - a more severe form of ADHD. The results suggest finger tapping can be used as a cheap, objective, and unbiased biomarker to complement current diagnostic procedures.

Association between relative age at school and persistence of ADHD in prospective studies: an individual participant data meta-analysis

BACKGROUND

The youngest children in a school class are more likely than the oldest to be diagnosed with ADHD, but this relative age effect is less frequent in older than in younger school-grade children. However, no study has explored the association between relative age and the persistence of ADHD diagnosis at older ages. We aimed to quantify the association between relative age and persistence of ADHD at older ages.

METHODS

For this meta-analysis, we searched MEDLINE, Embase, CINAHL, PsycINFO, and PubPsych up to April 1, 2022, with terms related to "cohort" and "ADHD" with no date, publication type, or language restrictions. We gathered individual participant data from prospective cohorts that included at least ten children identified with ADHD before age 10 years. ADHD was defined by either a clinical diagnosis or symptoms exceeding clinical cutoffs. Relative age was recorded as the month of birth in relation to the school-entry cutoff date. Study authors were invited to share raw data or to apply a script to analyse data locally and generate anonymised results. Our outcome was ADHD status at a diagnostic reassessment, conducted at least 4 years after the initial assessment and after age 10 years. No information on sex, gender, or ethnicity was collected. We did a two-stage random-effects individual participant data meta-analysis to assess the association of relative age with persistence of ADHD at follow-up. This study was registered with PROSPERO, CRD42020212650.

FINDINGS

Of 33 119 studies generated by our search, we identified 130 eligible unique studies and were able to gather individual participant data from 57 prospective studies following up 6504 children with ADHD. After exclusion of 16 studies in regions with a flexible school entry system that did not allow confident linkage of birthdate to relative age, the primary analysis included 41 studies in 15 countries following up 4708 children for a period of 4 to 33 years. We found that younger relative age was not statistically significantly associated with ADHD persistence at follow-up (odds ratio 1·02, 95% CI 0·99-1·06; p=0·19). We observed statistically significant heterogeneity in our model (Q=75·82, p=0·0011, I2=45%). Participant-level sensitivity analyses showed similar results in cohorts with a robust relative age effect at baseline and when restricting to cohorts involving children with a clinical diagnosis of ADHD or with a follow-up duration of more than 10 years.

INTERPRETATION

The diagnosis of ADHD in younger children in a class is no more likely to be disconfirmed over time than that of older children in the class. One interpretation is that the relative age effect decreases the likelihood of children of older relative age receiving a diagnosis of ADHD, and another is that assigning a diagnostic label of ADHD leads to unexplored carryover effects of the initial diagnosis that persist over time. Future studies should be conducted to explore these interpretations further.

FUNDING

None.

Quantifying Potential Bias Resulting From Child Age on Screening for Hyperactive/Impulsive Presentations of ADHD

OBJECTIVE

This study aims to quantify the potential age bias in screening of hyperactive/impulsive presentations of ADHD in children ages 5 to 12 through comparison of age-based and overall percentiles in screening.

METHOD

A referred clinical sample of 307 children ages 5 to 12 with behavioral concerns completed the Vanderbilt Attention Deficit-Hyperactivity Disorder Diagnostic Parent Rating Scale (VADPRS) and were formally evaluated for ADHD with a diagnostic interview. Analysis utilizing logistic regression and receiver operating characteristic (ROC) curves was performed to compare the screening performance of agebased and overall percentiles.

RESULTS

The age-based percentiles demonstrated no improvement in the analyzed models compared to overall percentiles in hyperactive presentation ADHD screening. This finding was present in the overall sample and in the sub analysis of the 5 to 6 year old children.

CONCLUSIONS

This study identifies no improvement in modeling of hyperactive/impulsive ADHD screening when considering a child's age using age-based percentiles.

The Prevalence of Risk Factors Among Children Diagnosed With Attention-Deficit/Hyperactivity Disorder, Aged 4-17 Years: A Cross-Sectional Study

INTRODUCTION

Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder commonly observed in children. Although the etiology of ADHD is still unclear, many risk factors have been shown to increase the prevalence of ADHD, such as genetics, environmental factors, socioeconomic status, maternal smoking, and low birth weight.

AIM

The current cross-sectional study aimed to assess the prevalence of several risk factors associated with ADHD-diagnosed children aged 4-17 years using parent-reported data.

METHODS

An observational cross-section study was conducted between December 2022 and February 2023 using a self-constructed questionnaire that we sent to parents whose children were diagnosed with ADHD. The questionnaire included socioeconomic information (income, gender, parent education, number of children), child information (age, ADHD type, academic achievement), pregnancy and neonatal period (smoking status, gestation age, mode of delivery, child weight), and if there is a history of ADHD in the family.

RESULTS

A total of 306 parents responded to the questionnaire. The majority of our study population was males (77.8%). The combined type, which includes symptoms of both hyperactivity and inattention, represented 70% of the population in our study, which is higher than the inattention type (23%) and the hyperactivity type (6%). The prevalence of several risk factors known to be associated with ADHD, such as family income, parental education, complications during pregnancy, and the low birth weight of the child, were also reported.

CONCLUSION

To the best of our knowledge, this is the first study that examines the frequency of risk factors among children diagnosed with ADHD in Saudi Arabia. The study revealed that males are more likely to be diagnosed with ADHD than females. We also found that the combined type is the most diagnosed ADHD among children. Furthermore, there are no significant differences in the prevalence of the risk factors during the gestational or neonatal period among ADHD-diagnosed children. Therefore, a large-scale prospective study is needed to aid in evaluating the frequency and significance of various risk factors among diagnosed children.

The relative age effect among Chinese junior men's tennis players and its impact on sports performance

The relative age effect (RAE) has been the subject of many studies, but no relevant literature has discussed the phenomenon of RAE in Chinese tennis. Numerous studies have demonstrated that RAE significantly contributes to brain drain and other occurrences that create inequity. This paper analyzes the birth dates and year-end rankings of all male players (N = 2697) who participated in China's junior tennis tournaments (U12, U14, U16) between 2014 and 2019 and who were selected for China's National Junior Team in 2019 and 2020; the paper classifies the birth dates into quarters and semesters. One of the research objectives of this study is to analyze whether RAE exists in Chinese junior men's tennis and whether RAE exerts an effect on athletes' performance. Differences between the observed and expected birthdate distributions were tested using chi-square statistics, and subsequent calculations were tested using odds ratios. The study found that RAE was present in all Chinese junior male tennis sports groups (p<0.001). The percentages of athletes born in the first half of the year were 56.4% (U12), 60.4% (U14), and 60.4% (U16), and the percentages of those born in the first quarter were 34.1% (U12), 36.4% (U14), and 37.1% (U16). Athletes with birth dates closer to the beginning of the year had a higher probability of achieving excellent athletic performance as a result of RAE, whereas those who were born near the end of the year had a more difficult time achieving strong athletic performance.

The relative age effect on fundamental movement skillsl in Chinese children aged 3-5 years

BACKGROUND

The cut-off date in the education system causes a relative age difference, with developmental advantages for children who are born on the "early side" of the cut-off date and disadvantages for those born later, which is known as the relative age effect (RAE). Very few studies have examined whether there is a RAE on the development of fundamental movement skills (FMSs) in preschool children, and no studies have been conducted in China. The purpose of this study is to identify whether a RAE exists on FMS in Chinese preschool children, comparing RAEs according to gender and age.

METHODS

From a total of 378 invited preschool children regularly registered at one Chinese kindergarten, a total of 288 healthy and typically developing preschoolers (4.33 ± 0.84 years-old; 56.6% boys) were included in this study. All children were required to take part in anthropometry and FMS assessments. Analysis of covariance (ANCOVA) was applied to examine the difference in each of the FMS items across quarter categories, year and gender groups, controlling for body mass index (BMI).

RESULTS

For the overall sample, the data show the significant main effects on the quarter of birth factor in locomotor skills (LC; F (3, 265) = 2.811, p = 0.04, η_p² = 0.031), object control skills (OB; F (3, 265) = 6.319, p = 0.04, η_p² = 0.031), and total test score (TTS; F (3, 265) = 5.988, p = 0.001, η_p² = 0.063). There were also significant differences in the age effect on all the domains of FMS (F_LC (2, 265) = 100.654, p < 0.001, η_p² = 0.432; F_OB (2, 265) = 108.430, p < 0.001, η_p² = 0.450; F_TTS (2, 265) = 147.234, p < 0.001, η_p² = 0.526) but a gender effect only in LC (F (1, 265) = 20.858; p < 0.001; η_p² = 0.073). For gender and quarter of birth groups, RAEs in LC only exists in girls. Moreover, regarding age and quarter of birth factors, RAEs are only found at younger ages.

CONCLUSIONS

This study suggests the existence of RAEs in the FMS of Chinese preschool children. Teachers need to be aware of the effect of RAEs on the FMS when approaching development, evaluation, and teaching approaches in preschools.

Relative Age and Psychotropic Drug Use in Preterm and Term-Born Children and Young Adults

BACKGROUND AND OBJECTIVES

Being among the youngest within a school class is linked to disadvantages in various educational and mental health domains. This study aimed to investigate whether preterm born infants are particularly vulnerable to relative age effects on mental health, not previously studied.

METHODS

We used registry data on all Norwegians born between 1989 and 1998 to compare prescription status for psychostimulants, antidepressants, hypnotics, anxiolytics, and antipsychotics per year from age 10 to 23 years (2004-2016) between exposure groups with different time of birth in the year (relative age) and different gestational age (preterm versus term).

RESULTS

Of 488 470 individuals, 29 657 (6,1%) were born preterm. For term born in November/December, the adjusted odds ratio (aORs) for psychostimulant prescription compared with peers born in January/February was 1.80 (95% confidence interval [CI], 1.69-1.91) at ages 10 to 14 years, and 1.17 (95% CI, 1.08-1.27) at ages 20 to 23 years. Within preterm born, the corresponding results were 1.39 (95% CI, 1.13-1.69) and 1.34 (95% CI, 1,00-1.78) at ages 10 through 14 and 20 through 23 years, respectively.

CONCLUSIONS

Being relatively young within the school group was associated with increased psychostimulant prescription in the preterm as well as the term population. In contrast to term peers, the relative age effect for psychostimulant prescription seemed to persist to young adulthood for the preterm population. The results suggest that preterm individuals are vulnerable to long-term effects of relative immaturity and that they require careful consideration from both health care professionals and the school system.

Effect of relative age on diagnosis of autism spectrum disorder in children: a nationwide study in Taiwan

BACKGROUND

The annual cut-off birthdate for entry into school in Taiwan is August 31. Thus, children and adolescents born in August are typically the youngest in their grades. The potential effect of relative age on the diagnosis of autism spectrum disorder (ASD) remains uncertain.

METHODS

A total of 9,548,393 individuals aged 3-17 years during the study period (from September 1, 2001, to August 31, 2011) identified from the Taiwan National Health Insurance Research Database were enrolled into our study. Logistic regression analysis was used to examine the likelihood of receiving ASD diagnosis for those who were born in August (the youngest) compared with those who were born in September (the oldest).

RESULTS

Both boys and girls born in August had a higher likelihood of being diagnosed with ASD (odds ratio [OR]: 1.24, 95% confidence interval [CI]: 1.16-1.32; OR: 1.23, 95% CI 1.06-1.42) than did those born in September. Sensitivity analysis conducted over different periods revealed consistent findings.

DISCUSSION

Relative age, as an indicator of neurocognitive maturity, is a crucial contributor to the risk of being diagnosed with ASD among children and adolescents. Our findings highlight the importance of considering the age of a child within a grade when diagnosing ASD.

ADHD misdiagnosis: Causes and mitigators

ADHD diagnoses increase discontinuously by a child's school starting age, with young-for-grade students having much higher ADHD diagnostic rates. Whether these higher rates reflect over-diagnosis or under-diagnosis remains unknown. To decompose this diagnostic discrepancy, we exploit differences in parent and teacher pre-diagnostic assessments within a regression discontinuity strategy based on school starting age. We show that being young-for-grade or male generates over-assessment of symptoms specifically from teacher assessment. However, under-assessments of the oldest students in a grade, especially the oldest females, account for a large part of the observed school starting age assessment gap. We argue that this difference by sex and higher school starting age effects in lower-income schools may exacerbate known gaps in educational attainment by gender and socioeconomic status. Importantly, we fail to find evidence that teachers who receive special education training make such errors.

Children's Relative Age and Medicine Treatment for Attention-Deficit/Hyperactivity Disorder Across Australian Jurisdictions with Different School Enrolment Policies

Background: Children who are relatively young for their school grade are more likely to receive treatment for attention-deficit/hyperactivity disorder (ADHD). It is unclear whether the phenomenon also exists across Australia or is impacted by the school enrolment policy in place. Objective: We evaluated the association between children's relative age and initiation of ADHD medicines across Australian jurisdictions with different school enrolment policies and rates of delayed school entry. Methods: We used Australia-wide dispensing data for a 15% random sample of children 4-9 years of age in 2013-2017 to create a nationwide cohort. Due to high rates of delayed school entry in New South Wales (NSW), we used linked prescribing and education data for a cohort of NSW residents starting school in 2009 and 2012. We estimated incidence rate ratios (IRRs) for ADHD medicine across children's birth month, sex, and jurisdiction. We used asthma medicines as a negative control. Results: For girls, we observed a relative age effect in three out of five jurisdictions, with an IRR ranging from 1.3 to 2.8, comparing the youngest versus oldest birth month thirds. We observed more modest effects among boys, ranging from null to 1.5-fold. In NSW, the relatively youngest boys were less likely to initiate stimulant medicines than the oldest (IRR = 0.5, 95% confidence interval 0.29-0.78). We did not observe a relative age effect for initiation of asthma medicines. Conclusions: In jurisdictions with low rates of delayed entry, relatively young children were more likely to initiate ADHD medicines than their older classmates. We observed the inverse association in NSW where delayed entry was highest, likely reflecting the characteristics and needs of children who delay school entry for 1 year and become the oldest children in the grade. Increased awareness around children's maturity differences and school readiness may enhance appropriate diagnosis and treatment of ADHD.

Relative Age Effect in Attention Deficit/Hyperactivity Disorder at Various Stages of the Medicalization Process

Diagnosis and pharmacological treatment of ADHD are more common among the youngest children in a classroom, born in the months immediately preceding the school entry cutoff date. The mechanisms behind this phenomenon, called the relative age effect (RAE), are not yet well understood. Nearly all hypotheses involve the school system, various teachers’ actions, and concern children’s immaturity. However, most previous studies have been based on reports of health professionals’ diagnoses and prescriptions found in official databases rather than on reports of teachers’ behavior identification or suspicion of ADHD, despite their being at the first stages of the medicalization process. Our study overcomes this limitation by using reports of parents’ and teachers’ behavior identification or suspicion of ADHD within a three-level multilevel survey design, comprising 1294 children, 130 teachers, and 17 elementary public schools. The goal of our study was to investigate whether RAE stems (1) from adults’ judgement of the child’s expression of immaturity or (2) from the consequences associated with the child’s double burden of being immature and exhibiting ADHD behaviors. Our multilevel analyses put forward the first hypothesis only, supporting the medicalization of immaturity. RAE in ADHD seems mostly initiated by teachers’ pre-diagnostic actions toward younger children.

Variations in the relative age effect with age and sex, and over time-Elite-level data from international soccer world cups

The relative age effect (RAE) is a statistical bias observed across sport contexts and consists of a systematic skewness in birth date distribution within an annual-age cohort. In soccer, January 1st is the common cut-off date when categorizing players in competitions according to their chronological age, which potentially disadvantages those within the cohort who were born later in the year. Thus, relatively older soccer players in their cohort can be favored in talent identification, selection, and development. The aim of the current study was to investigate the variations in RAE in male and female international youth world-cup tournaments (U17 and U20) in the period from 1997-2019 and in international senior world-cup-tournaments from 2006-2019. A total of 20,401 soccer players participating in 47 different tournaments were analyzed. The birthdate distributions were categorized into four quartiles (January-March, Q1; April-June, Q2; July-September, Q3; October-December, Q4) and compared to a uniform distribution using Chi-square analysis with Cramer's V (Vc) as a measure of effect size. Based on the existing data concerning RAE in elite junior and senior soccer, it was hypothesized that: (I) the RAE is present in youth soccer world cup tournaments but is stronger in male players than in female players; (II) the younger the soccer players, the stronger the RAE; and (III) the RAE in world cup soccer tournaments has strengthened over time. All these hypotheses were supported by the data; novel findings included that the effect has now entered women's soccer, and in men's soccer it persists into senior world cup tournaments. Thus, a strong RAE bias occurs in selection among elite soccer players competing in international world cup tournaments.

Influence of sex on tic severity and psychiatric comorbidity profile in patients with pediatric tic disorder

AIM

To investigate sex-related differences in tic severity, tic-related impairments, and psychiatric comorbidities in childhood.

METHOD

In this cross-sectional study, tic severity/impairment and demographic factors were collected from 270 children and young people (aged 5-17y, mean 10y 6mo, SD 3y 4mo; 212 males and 58 females) with a tic disorder diagnosis at a specialty clinic. Psychiatric diagnoses and corresponding screening questionnaire scores were collected for attention-deficit/hyperactivity disorder (ADHD), obsessive-compulsive disorder (OCD), major depressive disorder, and anxiety disorders. Logistic regression was used to compare the effect of sex and age on psychiatric comorbid diagnoses. The Mann-Whitney U test and t-tests were used to assess differences in questionnaire score distribution between sexes.

RESULTS

Females had more severe motor tics (12.55 vs 10.81, p=0.01) and higher global severity scores (38.79 vs 32.66, p=0.03) on the Yale Global Tic Severity Scale. Females were less likely to be diagnosed with ADHD (odds ratio=0.48, 95% confidence interval=0.26-0.89). No significant sex difference was observed in diagnosis rates or symptom severity scores for anxiety or OCD. Females had significantly higher scores than males on the Children's Depression Inventory, Second Edition.

INTERPRETATION

The higher level of motor tic severity and global severity in females further supports the differential natural history of tic disorders in females. Females with tic disorders may be underdiagnosed for ADHD.

Extended-release methylphenidate for attention deficit hyperactivity disorder (ADHD) in adults

BACKGROUND

Attention deficit hyperactivity disorder (ADHD) is a psychiatric diagnosis increasingly used in adults. The recommended first-line pharmacological treatment is central nervous system (CNS) stimulants, such as methylphenidate, but uncertainty remains about its benefits and harms.

OBJECTIVES

To assess the beneficial and harmful effects of extended-release formulations of methylphenidate in adults diagnosed with ADHD.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, nine other databases and four clinical trial registries up to February 2021. We searched 12 drug regulatory databases for clinical trial data up to 13 May 2020. In addition, we cross-referenced all available trial identifiers, handsearched reference lists, searched pharmaceutical company databases, and contacted trial authors.

SELECTION CRITERIA

Randomised, double-blind, parallel-group trials comparing extended-release methylphenidate formulations at any dose versus placebo and other ADHD medications in adults diagnosed with ADHD.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data. We assessed dichotomous outcomes as risk ratios (RRs), and rating scales and continuous outcomes as mean differences (MDs) or standardised mean differences (SMDs). We used the Cochrane risk of bias tool to assess risks of bias, and GRADE to assess the certainty of the evidence. We meta-analysed the data using a random-effects model. We assessed three design characteristics that may impair the trial results' 'generalisability'; exclusion of participants with psychiatric comorbidity; responder selection based on previous experience with CNS stimulants; and risk of withdrawal effects. Our prespecified primary outcomes were functional outcomes, self-rated ADHD symptoms, and serious adverse events. Our secondary outcomes included quality of life, ADHD symptoms rated by investigators and by peers such as family members, cardiovascular variables, severe psychiatric adverse events, and other adverse events.

MAIN RESULTS

We included 24 trials (5066 participants), of which 21 reported outcome data for this review. We also identified one ongoing study. We included documents from six drug regulatory agencies covering eight trials. Twenty-one trials had an outpatient setting and three were conducted in prisons. They were primarily conducted in North America and Europe. The median participant age was 36 years. Twelve trials (76% of participants) were industry-sponsored, four (14% of participants) were publicly funded with industry involvement, seven (10% of participants) were publicly funded, and one had unclear funding. The median trial duration was eight weeks. One trial was rated at overall unclear risk of bias and 20 trials were rated at overall high risk of bias, primarily due to unclear blinding of participants and investigators, attrition bias, and selective outcome reporting. All trials were impaired in at least one of the three design characteristics related to 'generalisability'; for example, they excluded participants with psychiatric comorbidity such as depression or anxiety, or included participants only with a previous positive response to methylphenidate, or similar drugs. This may limit the trials' usefulness for clinical practice, as they may overestimate the benefits and underestimate the harms. Extended-release methylphenidate versus placebo (up to 26 weeks) For the primary outcomes, we found very low-certainty evidence that methylphenidate had no effect on 'days missed at work' at 13-week follow-up (mean difference (MD) -0.15 days, 95% confidence interval (CI) -2.11 to 1.81; 1 trial, 409 participants) or serious adverse events (risk ratio (RR) 1.43, CI 95% CI 0.85 to 2.43; 14 trials, 4078 participants), whereas methylphenidate improved self-rated ADHD symptoms (small-to-moderate effect; SMD -0.37, 95% CI -0.43 to -0.30; 16 trials, 3799 participants). For secondary outcomes, we found very low-certainty evidence that methylphenidate improved self-rated quality of life (small effect; SMD -0.15, 95% CI -0.25 to -0.05; 6 trials, 1888 participants), investigator-rated ADHD symptoms (small-to-moderate effect; SMD -0.42, 95% CI -0.49 to -0.36; 18 trials, 4183 participants), ADHD symptoms rated by peers such as family members (small-to-moderate effect; SMD -0.31, 95% CI -0.48 to -0.14; 3 trials, 1005 participants), and increased the risk of experiencing any adverse event (RR 1.27, 95% CI 1.19 to 1.37; 14 trials, 4214 participants). We rated the certainty of the evidence as 'very low' for all outcomes, primarily due to high risk of bias and 'indirectness of the evidence'. One trial (419 participants) had follow-up at 52 weeks and two trials (314 participants) included active comparators, hence long-term and comparative evidence is limited.

AUTHORS' CONCLUSIONS

We found very low-certainty evidence that extended-release methylphenidate compared to placebo improved ADHD symptoms (small-to-moderate effects) measured on rating scales reported by participants, investigators, and peers such as family members. Methylphenidate had no effect on 'days missed at work' or serious adverse events, the effect on quality of life was small, and it increased the risk of several adverse effects. We rated the certainty of the evidence as 'very low' for all outcomes, due to high risk of bias, short trial durations, and limitations to the generalisability of the results. The benefits and harms of extended-release methylphenidate therefore remain uncertain.

Associating school doctor interventions with the benefit of the health check: an observational study

BACKGROUND

The benefits of school doctor interventions conducted at routine general health checks remain insufficiently studied. This study explored the associations of school doctor interventions with the doctor-evaluated and parent-evaluated benefits of routine health checks.

METHODS

Between August 2017 and August 2018, we recruited a random sample of 1341 children from grades 1 and 5 from 21 Finnish elementary schools in 4 municipalities. Doctors routinely examined all children, who were accompanied by parents. The doctor-reported interventions were categorised into six groups: instructions and/or significant discussions, prescriptions, laboratory tests and/or medical imaging, scheduling of follow-up appointments, referrals to other professionals and referrals to specialised care. Doctors evaluated the benefit of the appointment using predetermined criteria, and parents provided their subjective perceptions of benefit. Interventions and reported benefit were compared using multilevel logistic regression.

RESULTS

Doctors reported 52% and parents 87% of the appointments with interventions beneficial. All interventions were independently associated with doctor-evaluated benefit (ORs: 1.91-17.26). Receiving any intervention during the appointment was associated with parent-evaluated benefit (OR: 3.25, 95% CI 2.22 to 4.75). In analyses of different interventions, instructions and/or significant discussions (OR: 1.71, 95% CI 1.20 to 2.44), prescriptions (OR: 7.44, 95% CI 2.32 to 23.91) and laboratory tests and/or medical imaging (OR: 3.38, 95% CI 1.34 to 8.55) were associated with parent-evaluated benefit. Scheduled follow-up appointments and referrals to other professionals showed no significant association with parent-evaluated benefit.

CONCLUSIONS

Doctors and parents valued the appointments with interventions. Parents especially appreciated immediate help and testing from the doctor.

TRIAL REGISTRATION NUMBER

NCT03178331.

Age at school entry and reported symptoms of attention-deficit/hyperactivity in first graders: results of the prospective cohort study ikidS

Young age at school entry (ASE) is related to attention-deficit/hyperactivity disorder in higher grades. The reason for this association is unclear, but medical oversupply and stress-related factors are discussed. We aimed to investigate whether ASE is associated with reported symptoms of attention-deficit/hyperactivity (ADH) already in first grade. Data of a population-based prospective cohort study (N = 2003; Mainz-Bingen region; Rhineland-Palatinate; Germany) with baseline assessments prior to school entry and two follow-ups during first grade were analysed. ADH symptoms were assessed by parent and teacher versions of the Strengths and Difficulties Questionnaire. Associations between ASE and scores of the hyperactivity/inattention subscale (range 0-10) were investigated by regression analysis and adjusted for potential confounders and baseline symptoms prior to school entry. In total, 1633 children (52% boys, mean ASE 6.5 years) were included. There were no relationships between ASE and parent-reported scores of the hyperactivity/inattention subscale prior to school entry and 3 months thereafter. However, at the end of first grade, ASE was negatively associated with the hyperactivity/inattention subscale in parent (- 0.7 subscale points per year ASE, standard error = 0.16, p < 0.0001) and teacher reports (- 1.2 subscale points per year ASE, standard error = 0.25, p < 0.0001). This ASE effect appeared more pronounced in girls than in boys. Young ASE is related to more reported symptoms of ADH at the end of first grade, but not before. The evolvement of this effect during first grade may be a clue to ASE-related stress factors.

ADHD diagnosis and methylphenidate consumption in children and adolescents: A systematic analysis of health databases in France over the period 2010-2019

CONTEXT

ADHD is the most common mental disorder in school-aged children. In France, methylphenidate is the only drug authorized for ADHD. Here, we describe the pattern of ADHD diagnosis and methylphenidate prescription to children and adolescents from 2010 to 2019.

METHODS

We conducted a retrospective cohort study of all beneficiaries of the French general health insurance scheme (87% of the population, 58 million people). We extracted information for all children and adolescents aged 0-17 years who received: (1) A diagnosis of ADHD (34,153 patients). (2) At least one methylphenidate prescription (144,509 patients). We analyzed the clinical, demographic, institutional, and social parameters associated with ADHD diagnosis and methylphenidate consumption in France.

RESULTS

The ADHD diagnosis among children and adolescents increased by 96% between 2010 and 2019. ADHD diagnosis affects more boys than girls. About 50.6% of children hospitalized with a diagnosis of ADHD in 2017 also had another psychiatric diagnosis. The rate of children hospitalized with an ADHD diagnosis and treated with MPH varied between 56.4 and 60.1%. The median duration of MPH treatment for a 6-year-old ADHD child initiated in 2011 is 7.1 years. In 2018, 62% of ADHD children were receiving at least one psychotropic medication. Between 2010 and 2019, methylphenidate prescription increased by +56% for incidence and +116% for prevalence. The prevalence of methylphenidate prescription reached between 0.61 and 0.75% in 2019. Boys are predominantly medicated. The median duration of treatment among 6-year-olds in 2011 was 5.5 years. The youngest children received the longest treatment duration. Diagnoses associated with methylphenidate prescription did not always correspond to the marketing authorization. Among children receiving the first prescription of methylphenidate, 22.8% also received one or more other psychotropic drugs during the same year. A quarter of initiations and half of renewals were made outside governmental recommendations. Educational and psychotherapeutic follow-up decreased from 4.1% in 2010 to 0.8% in 2019. French children and adolescents, who were the youngest in their class were more likely to be diagnosed (55%) and prescribed methylphenidate (54%). Children from disadvantaged families had an increased risk of ADHD diagnosis (41.4% in 2019) and methylphenidate medication (25.7% in 2019).

Relative Age Effect on Problematic Alcohol Use in Adolescents

Objective: Relative age refers to a difference in age between peers in the same academic year. Although younger age of alcohol use is associated with a higher risk of lifetime problematic alcohol use, the potential effects of relative age are poorly understood. We hypothesized that a younger relative age would be associated with a younger chronological age of testing positive for alcohol in a medical setting. Methods: Problematic alcohol use was operationalized and identified as a positive alcohol test (PAT) in a medical setting. This was a retrospective population study of all 12 to 18-year-old residents (n = 4610) of Olmsted County, Minnesota (USA), who were tested for alcohol in a medical care setting from 1998 through 2016. Cox regression models examined the relationship between relative age and the age at testing positive for alcohol. Results: Relative age was not associated with age at first PAT. Results remained nonsignificant after stratifying by gender, and after adjusting for race, number of nonalcohol-related psychiatric comorbidities, and type of alcohol testing. Conclusions: The results did not support a relative age effect as a risk factor for alcohol use in adolescents in Olmsted County, Minnesota. These results contrast with findings from previous studies on this topic, which suggested older relative age increases risk of alcohol use in adolescence.

Clinical trials were missing from regulatory documents of extended-release methylphenidate for ADHD in adults: a case study of public documents

OBJECTIVES

To assess whether drug regulatory agencies decided on applications for extended-release methylphenidate for use in adult ADHD based on select samples of trials.

STUDY DESIGN AND SETTING

Case series of publicly available regulatory documents. We matched an index of extended-release methylphenidate trials for adult ADHD with trials appearing in regulatory documents of extended-release methylphenidate applications. Trials and regulatory documents were identified as part of this systematic review (https://doi.org/10.1002/14651858.CD012857). We sought to identify missing trials in the regulatory documents and to clarify regulatory submission requirements.

RESULTS

We indexed 18 trials and matched those with 13 drug applications (11 approved, 2 rejected) published by 7 agencies. There were trials missing in 7 (54%) of 13 applications, median 4 trials (range 1-6). The median proportion of missing trial participants was 45% (range 23% - 72%). Regulators seemingly require that all trials must be included in new drug applications, but wording is ambiguous.

CONCLUSION

In this sample of extended-release methylphenidate drug applications for adult ADHD, 7 of 13 regulatory decisions were missing entire trials according to public documents, even though regulatory requirements seem to stipulate that all available trials should be included in drug applications.

ADHD overdiagnosis and the role of patient gender among Iranian psychiatrists

BACKGROUND

Regarding the controversy about the overdiagnosis of Attention Deficit/Hyperactivity Disorder (ADHD) in children and adolescents there are two main directions addressed as issue of age bias and issue of gender bias. In this relation, replication of findings demonstrating significant overdiagnosis is of importance which make the systematic evaluation of such occurrence necessary.

OBJECTIVE

The seminal study by Bruchmüller, Margraf & Schneider, 2012 is replicated here, although in a different cultural context, in this case Iran, as ADHS might be perceived differently there. We assessed both gender bias and the impact of potential overdiagnosis on treatment recommendations.

METHODS

A total of 344 licensed Iranian psychiatrists (mean age = 45.17, SD = 9.50) participated in this study. Each psychiatrist received a cover letter that introduced the study as well as a case vignette. Overall, there are eight different cases, one child with ADHD and three non-ADHD children, for both a boy (Ali) and a girl (Sara). Participants also received a questionnaire requesting their particular diagnosis, treatment recommendation and the therapist's sociodemographic information. Chi square tests and multiple logistic regression were applied for data analyses.

RESULTS

Overdiagnosis occurred in both girl and boy children, although overdiagnosis was 2.45 more likely in boys than in girls (p < 0.01). With respect to the psychiatrist's gender, we detected no difference between males or females, as both overdiagnosed ADHD in boys (p_female < 0.01 and p_male < 0.01). Furthermore, ADHD overdiagnosis had a direct impact on medication prescription (p < 0.01).

CONCLUSION

This study suggests that diagnosticians should strictly adhere to diagnostic criteria to minimize diagnostic error.

Incidence of Attention Deficit Hyperactivity Disorder (ADHD) Diagnoses in Navarre (Spain) from 2003 to 2019

(1) Background: Attention deficit hyperactivity disorder (ADHD) constitutes one of the leading mental health and behavioral disorders in childhood and adolescence. The main objective of this study was to analyze the time trend in the incidence of ADHD diagnoses in Navarre (Spain) from 2003 to 2019 in children and adolescents from 5 to 19 years old. Additionally, the seasonal trends of ADHD incidence and ADHD prevalence were determined. (2) Methods: A population-based observational retrospective study, which included people born between 1991 and 2011 and who attended compulsory education between 2007 and 2017 in Navarre (Spain), was carried out with data from both the Education and Health Department databases. (3) Results: The incidence rate increased from 4.18 cases per 1000 person-years in 2003 to 7.43 cases per 1000 person-years in 2009, before decreasing progressively to 2.1 cases per 1000 person-years in 2019. A peak incidence rate at 7–8 years of age was observed, which is consistent across the study period and for both genders. Males were more than twice as likely to be diagnosed with ADHD than females, with similar time trends in both. A seasonal pattern in ADHD diagnosis was found, with peaks in February–March and the lowest rates in the summer months. Inattentive cases were much more frequent than hyperactive cases, whereas combined cases remained low across the study period. (4) Conclusions: In this age-period-cohort analysis, a clear period and age effect was observed. We found a decreasing trend in the ADHD incidence rate since 2015. Further research is needed to confirm whether a change of trend is occurring globally.

Do German Children Differ? A Validation of Conners Early Childhood™

Objective: The present study aimed to validate the German version of the Conners Early Childhood (EC)™ among German-speaking children. Method: A total of 720 parental and 599 childcare provider ratings of 2- to 6-year-old children were surveyed throughout Germany. Validity was assessed by calculating exploratory factor analyses (EFAs) and confirmatory factor analyses (CFAs), and a series of multivariate analyses of variance (MANOVAs) to analyze associations between Conners EC™ symptom ratings and sociodemographic variables. In addition, parent and childcare provider ratings of Conners EC™ scales were correlated with a number of other well-validated German measures assessing preschoolers' behaviors. Results: Although the EFA yielded different factors than the original scales, CFA revealed acceptable to good model fits. Conclusion: Overall, we confirmed the factor structure of the Conners EC's™ American original within the German validation. The use of the American factor structure is justified and can be recommended to facilitate international research on psychopathology in early childhood.

Month of birth and mental disorders: A population-based study and validation using global meta-analysis

OBJECTIVE

Month of birth (MOB) is associated with specified mental disorders (MDs). However, whether these relationships extend to all MDs remains unclear. We investigate the association using a population-based cohort study and a meta-analysis.

METHODS

First, we examined patients with 34 DSM-5-classified MDs in the Taiwan national database. We estimated the relative risk ratios (RR) of each illness in each MOB relative to that in the general population and assessed the periodicity, with six further sensitivity analyses. Second, we searched PubMed, Embase, and Cochrane for related articles through 31 December 2020. We used a random-effects model, pooled RRs with 95% confidence intervals of each MOB from the identified studies, and transformed them from MOB to relative age in a year or season.

RESULTS

The cohort included 1,951,777 patients. Except for posttraumatic stress disorder, dissociative disorders, feeding/eating disorders, gender dysphoria, and paraphilic disorders, the other MDs had significant MOB periodicity. The meta-analysis included 51 studies investigating 10 MDs. The youngest age at the start of school owing to MOB was associated with the highest RRs of intellectual disability (1.13), autism (1.05), attention-deficit/hyperactivity disorder (1.13). Winter births had significant risks of schizophrenia (1.04), bipolar I disorder (1.02), and major depressive disorder (1.01), and autumn births had a significant risk of alcohol use disorder (1.02). No significant associations between season of birth and Alzheimer's disease, or eating disorders were found.

CONCLUSIONS

MOB is related to the risks of certain MDs. This finding provides a reference for future research on the etiology of MDs.

Emotions or attention – what are predictors for the development of childhood psychopathology? A longitudinal study with pre- and elementary school children

Current debate has identified the factors emotion knowledge (EK) and attention as specific trajectories longitudinally influencing psychopathological development in childhood. The “Emotion Knowledge Hypothesis” assumes that children with great emotion skills have high self-regulating abilities that result in lower cognitive load and stronger attention capacities. Attention problems are thus perceived as a consequence of reduced EK. According to the competing “Attention Effect Hypothesis”, attention problems and EK deficits are associated because of impaired learning capacities due to attention problems. According to this hypothesis, attention problems are predictive of impaired EK. If those specific trajectories are disrupted, this might attenuate the development of later behavior problems. The present study tests those competing hypotheses replicating previous studies in this field to shed light on potential psychopathology trajectories. A total of 136 pre- and elementary school children as well as their teachers participated in this study. Children’s symptoms of inattention as well as their emotional competences were assessed 3 times over a 12-month period. We applied multilevel structural equation modelling and cross-lagged panel models for data analysis. Overall, we noted a drop in inattention scores and rise in emotional competences over the one-year course, indicating maturation effects. There was a significant but very small effect for attention scores predicting emotional competences. With respect to the question whether interventions should focus on the “Emotion Knowledge” or “Attention Effect” hypothesis, our findings imply that none of them has superiority over the other. Therefore, both emotion knowledge and attention are crucial for development, and that children with deficits in either domain should receive targeted interventions in order to disrupt potentially harmful developmental pathways.

Overdiagnosis of Attention-Deficit/Hyperactivity Disorder in Children and Adolescents: A Systematic Scoping Review

IMPORTANCE

Reported increases in attention-deficit/hyperactivity disorder (ADHD) diagnoses are accompanied by growing debate about the underlying factors. Although overdiagnosis is often suggested, no comprehensive evaluation of evidence for or against overdiagnosis has ever been undertaken and is urgently needed to enable evidence-based, patient-centered diagnosis and treatment of ADHD in contemporary health services.

OBJECTIVE

To systematically identify, appraise, and synthesize the evidence on overdiagnosis of ADHD in children and adolescents using a published 5-question framework for detecting overdiagnosis in noncancer conditions.

EVIDENCE REVIEW

This systematic scoping review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) Extension for Scoping Reviews and Joanna Briggs Methodology, including the PRISMA-ScR Checklist. MEDLINE, Embase, PsychINFO, and the Cochrane Library databases were searched for studies published in English between January 1, 1979, and August 21, 2020. Studies of children and adolescents (aged ≤18 years) with ADHD that focused on overdiagnosis plus studies that could be mapped to 1 or more framework question were included. Two researchers independently reviewed all abstracts and full-text articles, and all included studies were assessed for quality.

FINDINGS

Of the 12 267 potentially relevant studies retrieved, 334 (2.7%) were included. Of the 334 studies, 61 (18.3%) were secondary and 273 (81.7%) were primary research articles. Substantial evidence of a reservoir of ADHD was found in 104 studies, providing a potential for diagnoses to increase (question 1). Evidence that actual ADHD diagnosis had increased was found in 45 studies (question 2). Twenty-five studies showed that these additional cases may be on the milder end of the ADHD spectrum (question 3), and 83 studies showed that pharmacological treatment of ADHD was increasing (question 4). A total of 151 studies reported on outcomes of diagnosis and pharmacological treatment (question 5). However, only 5 studies evaluated the critical issue of benefits and harms among the additional, milder cases. These studies supported a hypothesis of diminishing returns in which the harms may outweigh the benefits for youths with milder symptoms.

CONCLUSIONS AND RELEVANCE

This review found evidence of ADHD overdiagnosis and overtreatment in children and adolescents. Evidence gaps remain and future research is needed, in particular research on the long-term benefits and harms of diagnosing and treating ADHD in youths with milder symptoms; therefore, practitioners should be mindful of these knowledge gaps, especially when identifying these individuals and to ensure safe and equitable practice and policy.

Predictors of ADHD persistence in elementary school children who were assessed in earlier grades: A prospective cohort study from Istanbul, Turkey

BACKGROUND

Attention-deficit hyperactivity disorder (ADHD) is the most common neurodevelopmental disorders among school-age children worldwide. In a more recent follow-up study, Biederman et al. found that 78% of children diagnosed with ADHD between the ages of 6-17 years continued to have a full (35%) or a partial persistence after eleven years.

OBJECTIVE

In this study, it was aimed to identify the factors contributing to the persistence of ADHD symptoms in elemantary school children who were prospectively assessed both in their earlier and upper grades.

METHODS

The sample was drawn from a previous community-based study where ADHD symptoms in 3696 first/or second graders were examined in regard to their school entry age. Two years after, the families of the children that participated in the initial study were called by phone and invited to a re-evaluation session. Among those who were reached, 154 were consequently eligible and were assessed with Swanson, Nolan and Pelham questionnaire (SNAP-IV), Conners' rating scales (CRS) and the Kiddie schedule for affective disorders and schizophrenia (K-SADS).

RESULTS

Of the 154 children, 81 had been evaluated to have "probable ADHD" by the initial interview. Among these 81 children, 50 (61.7%) were indeed diagnosed with ADHD after two years. Initial scores of the teacher reported SNAP-IV inattention subscale predicted the ADHD diagnosis after two years, with an odds ratio of 1.0761 (p = 0.032, Wald: 4.595).

CONCLUSIONS

Our results suggest that high inattention symptom scores reported by the teacher in the earlier grades, might predict an ADHD diagnosis in upper grades.

Influence of the month of birth on persistence of ADHD in prospective studies: protocol for an individual patient data meta-analysis

INTRODUCTION

Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder with symptoms, especially the hyperactive ones, that tend to decrease in severity with age. Interestingly, children born just before the school-entry cut-off date (ie, the youngest pupils of a classroom) are at higher risk of being diagnosed with ADHD compared with children born just after the cut-off date. Noteworthy, this month-of-birth effect tends to disappear with increasing absolute age. Therefore, it is possible that young children erroneously diagnosed with ADHD due to their month of birth present a lower chance to have their diagnosis confirmed at a later age, artificially reinforcing the low persistence of ADHD across the lifespan. This protocol outlines an individual patient data (IPD) meta-analysis of prospective observational studies to explore the role of the month of birth in the low persistence of ADHD across the lifespan.

METHODS AND ANALYSIS

Five databases will be systematically searched in order to find prospective observational studies where the presence of ADHD is assessed both at baseline and at a follow-up of at least 4 years. We will use a two-stage IPD meta-analytic approach to estimate the role of the month of birth in the persistence of ADHD. Various sensitivity analyses will be performed to assess the robustness of the results.

ETHICS AND DISSEMINATION

No additional data will be collected and no de-identified raw data will be used. Ethics approval is thus not required for the present study. Results of this IPD meta-analysis will be submitted for publication in a peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD42020212650.

Children's Relative Age and ADHD Medication Use: A Finnish Population-Based Study

OBJECTIVES

The youngest children in a classroom are at increased risk of being medicated for attention-deficit/hyperactivity disorder (ADHD). We examined the association between children's birth month and ADHD medication rates in Finland.

METHODS

Using a population-based study, we analyzed ADHD medication use among children born in 2005 to 2007. Cases (n = 7054) were identified from the first purchase of medication for ADHD. Cox proportional hazard models and hazard ratios (HRs) were examined by birth month and sex. Finnish children start first grade in the year of their seventh birthday. The cutoff date is December 31.

RESULTS

Risk of ADHD medication use increased throughout the year by birth month (ie, January through April to May through August to September through December). Among boys born in September to December, the association remained stable across cohorts (HR: 1.3; 95% confidence interval [CI]: 1.1-1.5). Among girls born in September to December, the HR in the 2005 cohort was 1.4 (95% CI: 1.1-1.8), whereas in the 2007 cohort it was 1.7 (95% CI: 1.3-2.2). In a restricted follow-up, which ended at the end of the year of the children's eighth birthday, the HRs for boys and girls born in September to December 2007 were 1.5 (95% CI: 1.3-1.7) and 2.0 (95% CI: 1.5-2.8), respectively.

CONCLUSIONS

Relative immaturity increases the likelihood of ADHD medication use in Finland. The association was more pronounced during the first school years. Increased awareness of this association is needed among clinicians and teachers.

Relative Age and Attention-Deficit/Hyperactivity Disorder: Data From Three Epidemiological Cohorts and a Meta-analysis

OBJECTIVE

To investigate the effect of relatively younger age on attention-deficit/hyperactivity disorder (ADHD) symptoms and diagnosis through three population-based cohorts and a meta-analysis.

METHOD

This study included participants of three community-based cohorts in Brazil: 1993 Pelotas Cohort (N = 5,249), 2004 Pelotas Cohort (N = 4,231), and Brazilian High-Risk Study for Psychiatric Disorders (HRC study) (N = 2,511). We analyzed the effect of relatively younger age on ADHD symptoms and diagnosis. For the meta-analysis, we searched MEDLINE, PsycINFO, and Web of Science from inception through December 25, 2018. We selected studies that reported measures of association between relative immaturity and an ADHD diagnosis. We followed the Meta-analysis Of Observational Studies in Epidemiology guidelines. The protocol for meta-analysis is available on PROSPERO (CRD42018099966).

RESULTS

In the meta-analysis, we identified 1,799 potentially eligible records, from which 25 studies including 8,076,570 subjects (164,049 ADHD cases) were analyzed with their effect estimates. The summarized relative risk of an ADHD diagnosis was 1.34 (95% CI, 1.26-1.43, p < .001) for children born in the first 4 months of the school year (relatively younger). Heterogeneity was high (I² = 96.7%). Relative younger age was associated with higher levels of ADHD symptoms in the 1993 Pelotas Cohort (p = .003), 2004 Pelotas Cohort (p = .046), and HRC study (p = .010).

CONCLUSION

Children and adolescents who are relatively younger compared with their classmates have a higher risk of receiving an ADHD diagnosis. Clinicians should consider the developmental level of young children when evaluating ADHD symptoms.

Association between exposure to polycyclic aromatic hydrocarbons and attention deficit hyperactivity disorder in children: a systematic review and meta-analysis

Some studies have shown that exposure to polycyclic aromatic hydrocarbons (PAHs) is a dangerous factor for attention deficit hyperactivity disorder (ADHD). This systematic review and meta-analysis aimed to clarify this relationship, and to collect and analyze all the relevant evidences in published reports of epidemiologic studies. PubMed, Science Direct, Web of Science, Scopus, and Google Scholar databases were searched through September 31, 2018. The study quality was evaluated using the Newcastle-Ottawa Scale. Moreover, fixed- and random-effect models were used. The data in this meta-analysis were presented as adjusted odds ratio (AOR). From 959 articles, six articles were included in the systematic review, and for meta-analysis, one study (that was not AOR) was excluded. The participants included in the studies were 2799 with the age range of 5-15 years old, and 93.6% were living in America. Four of the studies were placed in one group, due to having a common author (Perera). Moreover, a significant association was found between PAH exposure and ADHD in these studies (odds ratio = 2.57, 95% CI = 1.75-3.78); however, in all studies, there was no significant association between PAH exposure and ADHD for children (overall odds ratio = 1.99, 95% CI = 0.96-4.11) with low heterogeneity (I² = 28.73%; P value < 0.001). This study provided a systematic review and meta-analytic evidence for the association between PAH exposure and ADHD by a small number of studies. Further research study can be conducted in various countries. Graphical Abstract.

2019 Update on Pediatric Medical Overuse: A Systematic Review

IMPORTANCE

Medical overuse is common in pediatrics and may lead to unnecessary care, resource use, and patient harm. Timely scrutiny of established and emerging practices can identify areas of overuse and empower clinicians to reconsider the balance of harms and benefits of the medical care that they provide. A literature review was conducted to identify the most important areas of pediatric medical overuse in 2018.

OBSERVATIONS

Consistent with prior methods, a structured MEDLINE search and manual table of contents review of selected pediatric journals for the 2018 literature was conducted identifying articles pertaining to pediatric medical overuse. The structured MEDLINE search consisted of a PubMed search for articles with the Medical Subject Headings term health services misuse or medical overuse or article titles containing the term unnecessary, inappropriate, overutilization, or overuse. Articles containing the term overuse injury or overuse injuries were excluded, along with articles not published in English and those not constituting original research. The same search was performed using Embase with the additional Emtree term unnecessary procedure. Each article was evaluated by 3 independent raters for quality of methods, magnitude of potential harm, and number of patients potentially harmed. Ten articles were identified based on scores and appraisal of overall potential harm. This year's review identified both established and emerging practices that may warrant deimplementation. Examples of such established practices include antibiotic prophylaxis for urinary tract infections, routine opioid prescriptions, prolonged antibiotic courses for latent tuberculosis, and routine intensive care admission and pharmacologic therapy for neonatal abstinence syndrome. Emerging practices that merit greater inspection and discouragement of widespread adoption include postdischarge nurse-led home visits, probiotics for gastroenteritis, and intensive cardiac screening programs for athletes.

CONCLUSIONS AND RELEVANCE

This year's review highlights established and emerging practices that represent medical overuse in the pediatric setting. Deimplementation of disproven practices and careful examination of emerging practices are imperative to prevent unnecessary resource use and patient harm.

What Differentiates Children with ADHD Symptoms Who Do and Do Not Receive a Formal Diagnosis? Results from a Prospective Longitudinal Cohort Study

ADHD diagnoses are increasing worldwide, in patterns involving both overdiagnosis of some groups and underdiagnosis of others. The current study uses data from a national longitudinal study of Irish children (N = 8568) to examine the sociodemographic, clinical and psychological variables that differentiate children with high hyperactivity/inattention symptoms, who had and had not received a diagnosis of ADHD. Analysis identified no significant differences in the demographic characteristics or socio-emotional wellbeing of 9-year-olds with hyperactivity/inattention who had and who had not received a diagnosis of ADHD. However, by age 13, those who had held a diagnosis at 9 years showed more emotional and peer relationship problems, worse prosocial behaviour, and poorer self-concept. Further research is required to clarify the developmental pathways responsible for these effects.

Evidence of potential overdiagnosis and overtreatment of attention deficit hyperactivity disorder (ADHD) in children and adolescents: protocol for a scoping review

INTRODUCTION

Worldwide, attention deficit hyperactivity disorder (ADHD) diagnosis rates in children and adolescents have been increasing consistently over the past decades, fuelling a debate about the underlying reasons for this trend. While many hypothesise that a substantial number of these additional cases are overdiagnosed, to date there has been no comprehensive evaluation of evidence for or against this hypothesis. Thus, with this scoping review we aim to synthesise published evidence on the topic in order to investigate whether existing literature is consistent with the occurrence of overdiagnosis and/or overtreatment of ADHD in children and adolescents.

METHODS AND ANALYSIS

The proposed scoping review will be conducted in the context of a framework of five questions, developed specifically to identify areas in medicine with the potential for overdiagnosis and overtreatment. The review will adhere to the Joanna Briggs Methodology for Scoping Reviews. We will search Medline, Embase, PsycINFO and the Cochrane Library electronic databases for primary studies published in English from 1979 onwards. We will also conduct forward and backward citation searches of included articles. Data from studies that meet our predefined exclusion and inclusion criteria will be charted into a standardised extraction template with results mapped to our predetermined five-question framework in the form of a table and summarised in narrative form.

ETHICS AND DISSEMINATION

The proposed study is a scoping review of the existing literature and as such does not require ethics approval. We intend to disseminate the results from the scoping review through publication in a peer-reviewed journal and through conference presentations. Further, we will use the findings from our scoping review to inform future research to fill key evidence gaps identified by this review.

Cross-Country Differences in Parental Reporting of Symptoms of ADHD

Previous studies within the United States suggest there are cultural and contextual influences on how Attention-Deficit/Hyperactivity Disorder (ADHD) symptoms are perceived. If such influences operate within a single country, they are likely to also occur between countries. In the current study, we tested whether country differences in mean ADHD scores also reflect cultural and contextual differences, as opposed to actual etiological differences. The sample for the present study included 974 participants from four countries tested at two-time points, the end of preschool and the end of 2^nd grade. Consistent with previous research, we found lower mean ADHD scores in Norway and Sweden in comparison to Australia and the United States, and we tested four explanations for these country differences: 1) Genuine etiological differences, 2) Slower introduction to formal academic skills in Norway and Sweden than in the United States and Australia that indicated a context difference, 3) Under-reporting tendency in Norway and Sweden, or 4) Over-reporting tendency in the United States and Australia. Either under-or over-reporting would be examples of cultural differences in the perception of ADHD symptoms. Of these explanations, results of ADHD measurement equivalence tests across countries rejected the first three explanations and supported the fourth explanation: an over-reporting tendency in the United States and Australia. These findings indicate that parental reporting of ADHD symptoms is more accurate in Norway and Sweden than in Australia and the United States, and thus have important clinical and educational implications for how parental reporting informs an ADHD diagnosis in these countries.

Attention deficit hyperactivity disorder late birthdate effect common in both high and low prescribing international jurisdictions: a systematic review

BACKGROUND

Multiple studies have found that the youngest children in a classroom are at elevated risk of being diagnosed with, or medicated for, ADHD. This systematic review was conducted to investigate whether this late birthdate effect is the norm and whether the strength of effect is related to the absolute risk of being diagnosed/medicated.

METHODS

A literature search of the PubMed and ERIC databases and snowball and grey literature searching were conducted.

RESULTS

A total of 19 studies in 13 countries covering over 15.4 million children investigating this relationship were identified. Three other studies exploring related topics were identified. The diversity of methodologies prevented a meta-analysis. Instead a systematic review of the 22 studies was conducted. A total of 17 of the 19 studies found that the youngest children in a school year were considerably more likely to be diagnosed and/or medicated than their older classmates. Two Danish studies found either a weak or no late birth date effect. There was no consistent relationship between per-capita diagnosis or medication rates and the strength of the relative age effect, with strong effects reported in most jurisdictions with comparatively low rates.

CONCLUSIONS

It is the norm internationally for the youngest children in a classroom to be at increased risk of being medicated for ADHD, even in jurisdictions with relatively low prescribing rates. A lack of a strong effect in Denmark may be accounted for by the common practice of academic 'redshirting', where children judged by parents as immature have a delayed school start. Redshirting may prevent and/or disguise late birthdate effects and further research is warranted. The evidence of strong late birthdate effects in jurisdictions with comparatively low diagnosis/medication rates challenges the notion that low rates indicate sound diagnostic practices.

Where to find accurate information on attention-deficit hyperactivity disorder? A study of scientific distortions among French websites, newspapers, and television programs

Attention-deficit/hyperactivity disorder is the most frequent mental disorder among school-age children. This condition has given rise to a large mediatic coverage, which contributed to the shaping of the lay public's perceptions. We therefore conducted two studies on the way attention-deficit/hyperactivity disorder was portrayed in the TV programs and the lay-public press in France between 1995 and 2015, but the growing part played by the Internet required an additional study to analyze and compare the scientific material which is available to the French lay public depending on the source of information used. We studied the 50 first French websites dedicated to attention-deficit/hyperactivity as indexed by Google^® search engine using a structured quantitative content analysis for the web. We illustrate our results with excerpts derived from the websites. The conceptions of attention-deficit/hyperactivity disorder available on the Internet are essentially biomedical and comprise an important level of scientific distortion. Findings concerning other mass media such as television programs and the press also demonstrate massive and systematic distortions caused by the role of experts and the pharmaceutical industry. Furthermore, the most consulted media present the highest level of scientific distortions.

Prevalence and comorbidity of attention deficit hyperactivity disorder in Spain: study protocol for extending a systematic review with updated meta-analysis of observational studies

BACKGROUND

Attention deficit hyperactivity disorder (ADHD) is a childhood-onset disorder characterized by a persistent pattern of symptoms of developmentally inappropriate and impaired inattention and/or hyperactivity/impulsivity, with difficulties often continuing into adulthood. ADHD can come with other comorbid conditions. The aim of this study will be to quantify the prevalence and comorbidity of ADHD among children, adolescent, and adult population in Spain.

METHODS/DESIGN

We designed and registered a study protocol for an update and expansion of a systematic review and meta-analysis of pooled prevalence data. We will include cross-sectional observational studies reporting prevalence of ADHD in Spain and conducted in the general population, outpatient, and/or school settings. The primary outcome will be the prevalence of ADHD. Secondary outcomes will be the prevalence of any physical or mental comorbidity in association with ADHD. No limitations will be imposed on publication status, study conduct period, and language of dissemination. Comprehensive literature searches will be conducted in multiple electronic databases, including PubMed/MEDLINE, EMBASE, Scopus, Web of Science, PsycINFO, IME - Spanish Medical Index, and IBECS - Spanish Bibliographic Index of Health Sciences. We will also search Google Scholar, dissertation databases, and conference abstracts. Two team members will independently screen all citations, full-text articles, and abstract data. Potential conflicts will be resolved through discussion. The methodological quality (or risk of bias) of individual studies will be appraised using an appropriate tool. If feasible, we will conduct random effects meta-analysis. Prevalence estimates will be stratified according to gender, age, and geographical location. Additional analyses will be conducted to explore the potential sources of heterogeneity (e.g., methodological quality, sample size, diagnostic criteria).

DISCUSSION

This systematic review and meta-analysis of observational data will provide an updated synthesis of the prevalence and comorbidity of ADHD in Spain. This study will also examine factors that may explain potential variations in prevalence data. The findings of this study will be published in a peer-reviewed journal.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42018106082 .

Relative age and ADHD symptoms, diagnosis and medication: a systematic review

There is a growing international literature investigating the relationship between attention-deficit/hyperactivity disorder (ADHD) and younger relative age within the school year, but results have been mixed. There are no published systematic reviews on this topic. This study aimed to systematically review the published studies on the relative age effect in ADHD. Systematic database searches of: Medline, Embase, PsycINFO, Web of Science, ERIC, Psychology and Behavioral Sciences Collection and The Cochrane Library were conducted. Studies were selected which investigated the relative age effect in ADHD in children and adolescents. Twenty papers were included in the review. Sixteen (of 20) papers reported a significantly higher proportion of relatively younger children being diagnosed with ADHD and/or receiving medication for this. Meta-analyses involving 17 of these 20 papers revealed a modest relative age effect in countries with higher prescribing rates, risk ratio = 1.27 (95% CI 1.19-1.35) for receipt of medication. The relative age effect is well demonstrated in countries with known higher prescribing rates. Amongst other countries, there is also increasing evidence for the relative age effect, however, there is high heterogeneity amongst studies. Further research is needed to understand the possible reasons under-pinning the relative age effect and to inform attempts to reduce it.

Attention Deficit-Hyperactivity Disorder and Month of School Enrollment

BACKGROUND

Younger children in a school grade cohort may be more likely to receive a diagnosis of attention deficit-hyperactivity disorder (ADHD) than their older peers because of age-based variation in behavior that may be attributed to ADHD rather than to the younger age of the children. Most U.S. states have arbitrary age cutoffs for entry into public school. Therefore, within the same grade, children with birthdays close to the cutoff date can differ in age by nearly 1 year.

METHODS

We used data from 2007 through 2015 from a large insurance database to compare the rate of ADHD diagnosis among children born in August with that among children born in September in states with and states without the requirement that children be 5 years old by September 1 for enrollment in kindergarten. ADHD diagnosis was determined on the basis of diagnosis codes from the International Classification of Diseases, 9th Revision. We also used prescription records to compare ADHD treatment between children born in August and children born in September in states with and states without the cutoff date of September 1.

RESULTS

The study population included 407,846 children in all U.S. states who were born in the period from 2007 through 2009 and were followed through December 2015. The rate of claims-based ADHD diagnosis among children in states with a September 1 cutoff was 85.1 per 10,000 children (309 cases among 36,319 children; 95% confidence interval [CI], 75.6 to 94.2) among those born in August and 63.6 per 10,000 children (225 cases among 35,353 children; 95% CI, 55.4 to 71.9) among those born in September, an absolute difference of 21.5 per 10,000 children (95% CI, 8.8 to 34.0); the corresponding difference in states without the September 1 cutoff was 8.9 per 10,000 children (95% CI, -14.9 to 20.8). The rate of ADHD treatment was 52.9 per 10,000 children (192 of 36,319 children; 95% CI, 45.4 to 60.3) among those born in August and 40.4 per 10,000 children (143 of 35,353 children; 95% CI, 33.8 to 47.1) among those born in September, an absolute difference of 12.5 per 10,000 children (95% CI, 2.43 to 22.4). These differences were not observed for other month-to-month comparisons, nor were they observed in states with non-September cutoff dates for starting kindergarten. In addition, in states with a September 1 cutoff, no significant differences between August-born and September-born children were observed in rates of asthma, diabetes, or obesity.

CONCLUSIONS

Rates of diagnosis and treatment of ADHD are higher among children born in August than among children born in September in states with a September 1 cutoff for kindergarten entry. (Funded by the National Institutes of Health.).

Teachers' perceptions of behavioral problems in Dutch primary education pupils: The role of relative age

A growing number of studies suggest that relatively young behavior of pupils gives them a much greater likelihood of being diagnosed with a disorder such as ADHD. This 'relative age effect' has also been demonstrated for special educational needs, learning difficulties, being bullied, and so on. The current study investigated the relationship between relative age of pupils in primary education and teachers' perception of their behavior. The study sample included 1973 pupils, aged between 6 and 12. Six linear mixed models were carried out with birth day in a year as predictor variable and 'total problem score', 'problems with hyperactivity', 'behavioral problems', 'emotional problems', 'problems with peers' and 'pro-social behavior' as dependent variables. Random intercepts were added for school and teacher level. Cluster-mean centering disaggregated between-school effects and within-school effects. We found no associations between relative age of pupils and teacher perceptions of their behavior. Several explanations are postulated to account for these findings which contradict prior studies on relative age effects.