 |
|
Prevalence of Mental Disorders in Children Living in Alberta, Canada, as Determined From Physician Billing Data
Donald W. Spady, MD;
Donald P. Schopflocher, PhD;
Lawrence W. Svenson, BSc;
Angus H. Thompson, PhD
Arch Pediatr Adolesc Med. 2001;155:1153-1159.
ABSTRACT
| |
Background The prevalence of mental disorders is often assessed using survey techniques.
Although providing good estimates of prevalence, these techniques are time-consuming
and expensive.
Objective To estimate the prevalence of mental disorders among children aged 0
to 17 years living in Alberta, Canada, using health care administrative data.
Design This was a cross-sectional study. International Classification
of Diseases, Ninth Revision, Clinical Modification chapter 5 diagnostic
codes from physician billing data were used. Codes were grouped into 10 categories.
Prevalence rates for each category were calculated, stratified by age, sex,
and premium subsidy status (a proxy for socioeconomic status). The age pattern,
times of greatest risk, and the effect of sex on type and prevalence of mental
disorder were estimated.
Setting All fee-for-service health care venues in Alberta between April 1, 1995,
and March 31, 1996, providing services to children registered with the Alberta
Health Care Insurance Commission on March 31, 1996.
Results Prevalence of mental disorders varied by disorder category, age, sex,
and premium subsidy status. For boys, maximum prevalence of 9.5% occurred
at age 10 years; for girls, maximum prevalence of 12.0% occurred at age 17
years. Mental disorders were most common in young boys and adolescent girls
and among children receiving welfare. Distinct patterns of disorder were evident
and comorbidity was common.
Conclusions Administrative data can be used to estimate the prevalence of mental
disorders in a pediatric population. The estimates made are lower than those
obtained by using surveys of similar populations, perhaps indicating the difference
between treated and untreated prevalence. Strengths of this study are that
the estimates reflect the entire population, are more easily and obtained
at less cost, and are useful for the planning of mental health services.
INTRODUCTION
IN A SUMMARY of 52 studies exploring the prevalence of psychopathologic
disorders among children and adolescents, Roberts et al1
noted that estimates of prevalence varied widely. They attributed these differences
to problems in sampling, case ascertainment, case definition, and data analysis.
Samples were often small, usually only a narrow range of ages was studied,
suitable sampling procedures were uncommon, and case detection lacked sensitivity
and specificity because of inconsistent types and use of diagnostic tools.
This study presents another estimate of the prevalence of mental disorders
in children. It uses the diagnosis provided by physicians when submitting
billing data for reimbursement. Herein, these data are used to describe the
prevalence of mental disorders in children aged 0 to 17 years living in Alberta,
Canada, from April 1, 1995, through March 31, 1996.
Although physician diagnostic data have been used before,2, 3, 4, 5
usually as adjuncts to other estimates of mental disorder, data from such
a large and diverse population are rare, particularly when an accurate denominator
is available reflecting the total population at risk. This study uses cross-sectional
data to develop estimates of the times of greatest risk and the differing
effect of sex on prevalence. Data also were available to estimate the socioeconomic
status of the children in this study. Many studies suggest that mental disorders
are more prevalent among children living in poor socioeconomic circumstances,4, 6, 7, 8, 9, 10
and one purpose of this study was to determine whether our data showed similar
findings. The research purpose was to address the following questions: (1)
What are the patterns of mental disorder seen in Alberta children? (2) How
do these patterns vary with the child's age and sex? and (3) Do patterns vary
between children of differing economic means? To our knowledge, no other Canadian
study exists that uses health care administrative data and no study has captured
virtually the entire population of children and adolescents in a large defined
geographical and administrative area.
MATERIALS AND METHODS
Alberta is Canada's westernmost prairie province, and has a population
of about 2.8 million people. The majority of residents are of European descent,
but there are a considerable number of aboriginal Canadians and individuals
of Asian descent. About 75% of children and adolescents live in an urban setting,
and the remainder live in rural areas, mainly small towns, farms, and ranches.
Extreme poverty is relatively rare. Health care in Alberta is universal, with
all medically necessary procedures and investigations being provided through
health insurance administered by the Alberta Health Care Insurance Plan. The
data consisted of all the fee-for-service records submitted by physicians
to this agency between April 1, 1995, and March 31, 1996, for all children
registered with Alberta Health and Wellness on March 31, 1996. The data were
provided to one of us (D.W.S.) by Alberta Health and Wellness for the purpose
of describing patterns of morbidity of Alberta children as determined from
administrative data. The present article is the first public published report
arising from this study.
With the exception of children moving to Alberta during the study year
(about 1.68%; data provided by L.W.S.) and children born during the year and
subsequently registered with Alberta Health and Wellness, all children in
the data set had been registered for at least the preceding 12 months. Children
moving out of the province during the study year were not included. The date
of March 31, 1996, as the time when the population was to be counted was determined
by Alberta Health and Wellness, as were the ages 0 to 17 years.
The data reflect every patient service for which a physician was reimbursed
by fee-for-service and, except for a few small subspecialty programs, such
as intensive care units, all patient services are provided this way. For this
report, all physician contacts for mental health services would be reflected
in the fee-for-service data. Nonphysician contacts, such as psychologists
or mental health counselors, would not be considered and we cannot estimate
their use. Most parents would likely take their children initially to a physician
for assessment and the physician could refer the family for counseling if
it was believed necessary. Children could have received medical services out
of the province and if they were registered with Alberta Health and Wellness,
these services would have been recorded and are part of the data set.
Data were available regarding the service date, the specialty of the
service provider, and the International Classification of
Diseases, Ninth Revision, Clinical Modification (ICD-9-CM)11 diagnostic code. The fee-for-service form provided
for up to 3 diagnoses to be recorded; however, the majority of submissions
contained only 1 diagnosis, thus we used only the primary diagnosis provided.
Each diagnosis could be reported at up to 4 digits (eg, 300.1), and any diagnostic
code in the ICD-9-CM lexicon could be used. Only
diagnostic data were provided; no data regarding prescription drugs or therapy
used were available. Diagnoses could not be validated by reviewing charts
or by interviewing patients. Only records where the ICD-9-CM code reflected "Chapter 5: Mental Disorder" were used. Each ICD-9-CM code was grouped into 1 of 10 categories of disorder,
reflecting a blend of common patterns of presentation and major categories
of psychopathology. These categories and their associated ICD-9-CM codes are shown in Table
1, which also shows the number of patient contacts and individual
patients affected for each ICD-9-CM code. The categories
were created by one of us (A.H.T.), a child psychologist.
|
|
|
|
Categories of Mental Disorders
|
|
|
Demographic data were obtained for all children aged 0 to 17 years inclusive
from a registration file listing individuals registered with Alberta Health
and Wellness as of March 31, 1996. The child's "study age" was the integer
age on March 31, 1996. Although Canada has universal health care, in Alberta
it is administered as an insurance program and individuals pay premiums. Those
with a family income of under about $14 000 (Canadian) per year have
their premium subsidized in full or in part by the government. Individuals
receiving welfare have their premium paid by Alberta Family and Social Services.
Treaty status aboriginal Canadians have their premium paid by the Government
of Canada. This results in 4 levels of premium subsidy for analysis: no subsidy,
part/full subsidy, treaty status, and welfare. These 4 levels were used as
a proxy for socioeconomic status.
Rates for a 1-year prevalence of psychopathology and for each category
of disorder were created using the total number of registered children for
any given age, sex, and premium subsidy status as the denominator. The numerator
was the number of appropriately stratified children affected with a specific
disorder; thus, a child with 5 visits for depression and 3 visits for reactive
disturbances would be counted once each for depression and reactive disturbance.
Data analysis was primarily descriptive. Logistic regression using Stata statistical
software12 was used to assess the effect of
premium subsidy status on the prevalence of specific categories of mental
disorder (the dependent variables). Independent variables were sex (female
as the referent), age (10 years as the referent), and premium subsidy status.
Ten years was chosen as the age reference because it reflects a transition
time between childhood and adolescence. The reference group for premium subsidy
status was no subsidy because this was the largest group and the most affluent.
Psychiatric comorbidity was investigated briefly by determining those children
having more than 1 psychiatric disorder during the same year and summarizing
the data regarding frequency of comorbidity and the disorders most commonly
linked.
This research was approved by the University of Alberta Faculty of Medicine
Ethics Review Committee. Confidentiality of subjects was maintained by using
anonymized personal identifiers. Only one of us (L.W.S.), an employee of Alberta
Health and Wellness and under a bond of confidentiality, had access to the
code that encrypted the identifiers.
RESULTS
There were 749 924 (49% female) children registered with Alberta
Health and Wellness. This number is estimated by Alberta Health and Wellness
to be more than 99.5% of the total population13;
thus, the "sample" is effectively the entire population at risk. Most (77%)
children came from families receiving no premium subsidy. Families of 12.6%
of the children received a partial or full premium subsidy; these families
could be construed as the "working poor." The remaining children were divided
into those whose families were receiving welfare (4.6%) or who were treaty
status aboriginal Canadians (5.6%).
There were 143 226 health care services attributed to mental disorders
among 40 592 children. General practitioners provided services to 59%
of children, pediatricians to 35%, and psychiatrists to 22%. Other specialists,
such as emergency department physicians or internal medicine physicians, saw
about 4% of children. Nearly 18% of children were seen for their problem by
more than 1 type of practitioner. Psychiatrists provided 55.5% of all services
to children older than 9 years and saw individual children an average of 7.4
times, compared with an average of less than 2.1 times for pediatricians and
family practitioners. Psychiatrists saw children with all categories of disorder;
the most common categories were depression, with 39% of children being seen
by a psychiatrist, followed by anxiety/neurotic disorders (24%), psychoses
(64%), and personality problems (34%).
Figure 1 shows that the prevalence
of psychopathologic disorders varies by age and sex. In boys, the maximum
prevalence of disorder (9.5%) is at about age 10 years, whereas for girls
the maximum prevalence (12.0%) is at age 17 years.
|
|
|
|
Figure 1. Prevalence of mental disorders
in children living in Alberta, Canada, as recorded on physician fee-for-service
submissions, April 1, 1995, through March 31, 1996.
|
|
|
Figure 2 shows that although
differences appear to exist between each premium subsidy group, the welfare
group is quite distinct from the rest. At almost any age, a child receiving
welfare is nearly twice as likely to have a mental disorder than is a child
in any other group. For treaty status children, the prevalence of disorder
rises rapidly during adolescence to more than twice that at age 9 years.
|
|
|
|
Figure 2. Prevalence of mental disorders
in children living in Alberta, Canada, stratified by premium subsidy group,
April 1, 1995, through March 31, 1996. Error bars reflect 1 SE.
|
|
|
Figure 3 shows the age and
sex patterns of 9 categories from Table
1. The category "Special Symptoms NEC [not elsewhere classified]"
is not included as it is composed of disorders not easily classified and without
common features. Boys and girls have patterns that differ in kind or degree
and with age. Depression, reactive disturbances, anxiety/neurotic disorders,
and psychoses are all more common in younger boys than in girls, gradually
increase with increasing age, and become substantially more common in girls
during adolescence. In contrast, attention-deficit disorder is substantially
more common in boys than girls (odds ratio, 3.8; 95% confidence interval [CI],
3.6-4.0) but the general age-related pattern of prevalence is similar for
both sexes. A third pattern is seen with conduct disorder, where prevalence
is consistently higher in boys. Other distinct patterns are seen with developmental
delay and with alcohol and drug problems.
|
|
|
|
Figure 3. Selected examples of patterns
of mental disorders in children living in Alberta, Canada, stratified by type
of disorder and sex, April 1, 1995, through March 31, 1996. The vertical scale
varies for each graph, thus rates are not directly comparable.
|
|
|
The prevalence of disorder was examined with respect to subsidy status.
For the most part, the pattern seen in Figure
2 was maintained for each disorder (results not shown). Except for
the categories mind-body problems and special symptoms NEC, where differences
were not significant, the age- and sex-adjusted odds of disorder were at least
2 times as likely in the welfare group relative to the no subsidy group. For
children with alcohol and drug problems, treaty status children were 5.2 (95%
CI, 4.4-6.2) and children receiving welfare 4.2 (95% CI, 3.5-5.1) times as
likely as the no subsidy group to have the disorder.
About 20.8% of children with at least 1 psychiatric disorder were diagnosed
as having more than 1 mental disorder during the year; 16.0% were diagnosed
as having 2 disorders, 3.7% as having 3 disorders, and the remaining 1.1%
were diagnosed as having more than 3 disorders. For 7014 children with more
than 4 visits due to mental disorder, comorbidity was diagnosed in 59%. Comorbidity
was more common among older children. Boys were 1.3 (95% CI, 1.2-1.4) times
more likely than were girls to have comorbidity, and children receiving welfare
were the most likely group to exhibit comorbidity (odds ratio, 1.6; 95% CI,
1.5-1.7). The 5 most common pairings were attention-deficit disorder + (anxiety/neurotic
disorder or conduct disorder or developmental delay) and anxiety/neurotic
+ (depression or conduct disorder).
COMMENT
This study used physician diagnostic codes to describe the patterns
of mental disorder prevalence among virtually all children in a Canadian province.
The data provide good supportive evidence of the presence of significant mental
disorders in children where little other evidence exists at a population level.
Although the only contextual data provided are age, sex, and subsidy status,
good insight can still be gained into the epidemiology of mental disorder.
These results suggest that health care administrative data can be a useful
aid to planning mental health policy and programs.
These data report the prevalence of medically reported childhood mental
disorders. They do not reflect disorders in the community that are seen by
other health practitioners, nor do they reflect untreated disorders that might
be detected in individuals using screening surveys of the general population.
Nevertheless, the data have significant strengths. They span all of childhood
and the whole population of a defined area is included, thus sampling properties
and sampling error are not at issue. Also, all physician-generated diagnoses
of mental disorder are captured. Since the demographic makeup of Alberta is
similar to many provinces in Canada, and probably many states in the United
States, the results are reasonably generalizable to similar populations.
The results suggest that the prevalence of mental disorder varies with
age and sex, and that either figure for prevalence is inappropriate—both
age and sex must be considered. They also demonstrate that there are specific
patterns for different mental disorders and that these disorders have specific
age and sex relationships. For example, boys are more likely than girls to
be affected with depression in preadolescence and its prevalence in girls
rises significantly in their early teens, at about the presumed time of menarche.
This observation agrees with the findings of Patton et al,14
who demonstrated that menarche marks a transition in the risk of depression
and anxiety in girls and with those of Angold et al,15, 16
who noted that after the transition to mid-puberty, girls were more likely
than boys to be depressed. The pattern seen in attention-deficit disorder,
where boys are nearly 4 times more likely to be affected than girls and where
the problem is most common in the early school years, is consistent with Szatmari
et al,17 who found that prevalence of attention-deficit/hyperactivity
disorder was 9.0% in boys and 3.3% in girls.
Figure 3 suggests a key role
for adolescence to affect the prevalence of disorder. The prevalence of depression,
reactive disturbances, anxiety/neurotic disturbances, alcohol and drug problems,
and psychoses increases with the onset of adolescence, whereas the prevalence
of attention-deficit disorder declines. These findings are consistent with
those of Newman et al,18 who surveyed a birth
cohort of young adults at ages 11, 13, 15, 18, and 21 years, and found that
mental disorders increased longitudinally from late childhood through middle
to late adolescence and young adulthood. The observed decline in developmental
delay, which is a relatively static problem, may reflect the fact that developmental
delay per se may not be the reason why an adolescent is visiting a physician.
The patterns of disorder observed in this study are similar to those reported
by Cohen et al19 for young persons aged 10
to 20 years. They found age and sex differences between disorders and also
found that major depression showed a pattern suggestive of a role for the
onset of puberty, but their results suggested that the prevalence of depression
in girls declines in later adolescence whereas our findings suggest a rise.
In all instances, the prevalence of disorder is greater in the study of Cohen
et al. Possibly the problem of dissimilar patterns and increased prevalence
lies in part in the definition used for a specific disorder and the method
used to make the diagnosis.
An important finding of this study was the relationship of socioeconomic
status to the prevalence of disorder. Rates of prevalence among families receiving
welfare were generally twice that of the rest of the population. This finding
is consistent with the findings of Costello et al20
and Lipman et al.21 Costello et al found that
poverty was the strongest demographic correlate of diagnosis, in both urban
and rural children. Lipman et al, using data from the Ontario Child Health
Study, found similar results and reported that the odds of psychiatric disorder
among children with a family income of less than $10 000 was more than
twice that of children with higher family incomes. They noted the independent
contribution of family dysfunction in influencing the development of childhood
psychiatric disorder and, in a later report,7
argued that eliminating poverty per se would not necessarily reduce psychiatric
morbidity in children. Other factors such as low maternal education and family
conflict may be more influential. Shaw et al22
suggested that multiple family stressors adversely affect a child's psychosocial
development. The present study appears to agree with the idea that increased
risk is associated with more than just economics. Many families of children
in the part/full subsidy group and much of the treaty status group would have
had incomes only slightly better than families receiving welfare and yet children
from these groups appear consistently to be much less likely than those receiving
welfare to have mental disorders. Clearly, something unique about the welfare
group sets these children apart, but it is unclear just what this "something"
is. Likely factors relate to family structure and stability, parenting skills,
employment status, and parental lifestyles.
The question arises as to how comparable are these results with others.
The estimates obtained seem to be in fair agreement with those of other physicians
working in clinics but are less than those derived using surveys. This is
consistent with the findings of Costello et al,3
who noted that pediatricians have low sensitivity but high specificity to
the diagnosis of mental disorder. The results are also consistent with the
observation that, in adults, treated prevalence rates are lower than survey
estimated prevalence rates.2, 23
The closest comparisons would be with those of other physicians working
in clinics. In this regard, several studies have suggested that pediatricians
diagnose psychopathologic conditions in about 4% to 7% of their patients,
compared with survey estimates of at least twice that.2, 24
Costello2 reviewed 12 studies in which physician
diagnosis was used to estimate prevalence of psychopathologic disorders. Among
5 studies reviewed by Costello and where the denominator included everyone
enrolled in a health care plan, the prevalence of disorder ranged from 3.4%
to 10.1%. Clinic physician–derived figures are often lower than survey
estimates and may reflect the possibility that impairment could be an important
factor when a physician opts for a diagnosis of mental disorder, or when a
parent chooses to bring their child to the physician for assessment.25 The lower figure could also be due to physician reluctance
to attend to behavior complaints because of inexperience, physician feelings
of inadequacy, the recognized difficulty in management of behavior disorder,
or time constraints.26
The rates of disorder in this study are similar to estimates of 4% to
8% for serious emotional disturbance reported in the Great Smoky Mountains
Study of Youth6 but are less than the same
authors' estimate of 20.3% for any DSM-III-R Axis
I disorder.20 The results are consistent with
those of Rutter et al,27 who estimated a prevalence
of disorder of about 6.8% in 10-year-old children on the Isle of Wight, but
are less than his estimates of mental disorder in 10-year-old inner-city London
children28 but neither sample really reflects
a general population. Verhulst et al,29 using
multiple informants, estimated the prevalence of mental disorder in 13- to
18-year-old adolescents to be between 4% to more than 20%. In a companion
study of children aged 8 to 11 years, the prevalence of moderate or severe
disorder was 26%.30 Steinhausen et al31 used multiple informants and estimated the prevalence
of disorder in Swiss children aged 6 to 17 years to be about 22.5%. Offord
and coworkers32 surveyed a combination of Canadian
parents, teachers, and children and found a 6-month prevalence of 18.1% for
4 child psychiatric disorders among children 4 to 16 years old.
More specific studies that used surveys to determine prevalence may
well be more accurate; however, they have the problems of small, nonrepresentative,
sample sizes. They often cover a narrow age range and age-related differences
cannot be assessed.1 Some studies32
cover large age ranges but have too few children at any age to make age specific
estimates. As well, the criteria used for case ascertainment are inconsistent.
Some studies focus on sensitivity and thus may overestimate prevalence; others
focus on specificity and may underestimate prevalence. In some instances,
multiple informants are used to assess the prevalence of morbidity.29 With respect to comparability with the present study,
there are problems with case definition and the question arises "whether community
or epidemiologic ‘cases' are cases in the same sense as the cases of
children brought to clinical settings."1
A further question arises as to the accuracy of the diagnoses provided.
Given the variation in psychiatric expertise among physicians, misdiagnosis
clearly exists. We tried to minimize this problem by using categories of disorder
reflecting common symptom patterns and then estimated the prevalence of these
categories. The categories are based on the experience of one of the authors
and discussions with colleagues; others may use a different grouping. Similar
approaches have been used in studies of pediatric morbidity,33
but we could not find clear evidence of the use of similar classification
schemes for describing psychiatric morbidity. Validity can also be inferred
somewhat from the comparison of patterns of disorder with other studies. In
this instance, the patterns of depression and attention-deficit disorder are
similar to the findings of others.
The estimate of the presence of psychiatric comorbidity of 20.8% is
less than some reports34 and similar to others.25 Comorbidity is probably more common than this study
implies since usually only one diagnosis was provided at a physician visit;
thus, a child had to attend 2 visits to have any comorbidity detected. This
may reflect the diagnostic practices of different practitioners, the consequences
of referral to a psychiatrist, or the demonstration over time of more than
1 psychiatric problem in a child. The nature of the comorbid disorders is
similar to those found by Verhulst et al29
and Steinhausen et al,31 although not examined
in the present study, it is also likely that various other illnesses of childhood
are also associated with mental disorder.
In a review of 50 years of epidemiologic studies in child and adolescent
psychiatry, Cederblad wrote
Most studies state that boys have more behavior deviances than
girls before puberty. Girls have more problems during adolescence, especially
depressions and psychosomatic symptoms. Girls have more internalizing symptoms,
while boys display more acting-out behaviors.35
The results of this study are consistent with this generalization and
extend it by describing the patterns of mental disorder more completely. They
demonstrate the important role of adolescence in determining the prevalence
of mental disorder and also the role of socioeconomic status as a determinant
of mental health in children. Estimating the prevalence of mental disorders
is difficult. Accurate estimates may require a number of sophisticated approaches
with different perspectives. The data presented herein reflect one such approach
that can act as an adjunct to help mental health workers plan services and
detect groups at high risk.
AUTHOR INFORMATION
Accepted for publication May 14, 2001.
What This Study Adds
Mental disorder affects a significant proportion of the population of
children in a society. The distribution of mental disorder varies by age,
sex, and socioeconomic status. Measuring the prevalence of disorder is time-consuming,
expensive, and rarely reflects an entire population, thus the data that are
available are often spotty and describe only a segment of a population or
a particular age group. The present study uses health care administrative
data to provide an estimate of the prevalence of mental disorders among virtually
all children and adolescents aged 0 to 17 years living in the province of
Alberta, Canada. The estimate obtained likely underestimates the true prevalence,
but the patterns of prevalence described for various mental disorders are
likely fair representations of reality. The article also describes the strong
relationship of socioeconomic status to the prevalence of mental disorder.
From the Departments of Pediatrics (Dr Spady) and Psychiatry (Dr Thompson)
and Public Health Sciences (Drs Spady and Thompson), University of Alberta;
and Health Surveillance Branch, Alberta Health and Wellness, Government of
Alberta (Dr Schopflocher and Mr Svenson), Edmonton, Alberta.
Corresponding author and reprints: Donald W. Spady, MD, Department
of Pediatrics, 2C3.00 WMC, University of Alberta, Edmonton, Alberta, Canada
T6G 2R7 (e-mail: dspady{at}ualberta.ca).
REFERENCES
| |
1. Roberts RE, Attkisson CC, Rosenblatt A. Prevalence of psychopathology among children and adolescents. Am J Psychiatry. 1998;155:715-725.
FREE FULL TEXT
2. Costello EJ. Primary care pediatrics and child psychopathology: a review of diagnostic,
treatment, and referral practices. Pediatrics. 1986;78:1044-1051.
FREE FULL TEXT
3. Costello EJ, Edelbrock C, Costello AJ, Dulcan MK, Burns BJ, Brent D. Psychopathology in pediatric primary care: the new hidden morbidity. Pediatrics. 1988;82(3, pt 2):415-424.
4. Goldberg ID, Roghmann KJ, McInerny TK, Burke JDJ. Mental health problems among children seen in pediatric practice: prevalence
and management. Pediatrics. 1984;73:278-293.
FREE FULL TEXT
5. Jacobson AM, Goldberg ID, Burns BJ, Hoeper EW, Hankin JR, Hewitt K. Diagnosed mental disorder in children and use of health services in
four organized health care settings. Am J Psychiatry. 1980;137:559-565.
FREE FULL TEXT
6. Costello EJ, Angold A, Burns BJ, Erkanli A, Stangl DK, Tweed DL. The Great Smoky Mountains Study of Youth: functional impairment and
serious emotional disturbance. Arch Gen Psychiatry. 1996;53:1137-1143.
FREE FULL TEXT
7. Lipman EL, Offord DR, Boyle MH. What if we could eliminate child poverty? the theoretical effect on
child psychosocial morbidity. Soc Psychiatry Psychiatr Epidemiol. 1996;31:303-307.
ISI
| PUBMED
8. Offord DR. Child psychiatric disorders: prevalence and perspectives. Psychiatr Clin North Am. 1985;8:637-652.
ISI
| PUBMED
9. Offord DR, Boyle MH, Racine Y. Ontario Child Health Study: correlates of disorder. J Am Acad Child Adolesc Psychiatry. 1989;28:856-860.
ISI
| PUBMED
10. Velez CN, Johnson J, Cohen P. A longitudinal analysis of selected risk factors for childhood psychopathology. J Am Acad Child Adolesc Psychiatry. 1989;28:861-864.
ISI
| PUBMED
11. ICD-9-CM: International Classification of Diseases,
Ninth Revision, Clinical Modification. 3d ed. Vols 1-3. [Official authorized
addendum effective October 1, 1990; Health Care and Financing Administration]. J Am Med Rec Assoc. 1990;61(suppl 35).
12. StataCorp. Stata Statistical Software: Release 7.0. College Station, Tex: Stata Corporation; 2001.
13. Svenson LW, Woodhead SE, Platt GH. Estimating the prevalence of asthma in Alberta: a study using provincial
health care records. Chron Dis Can. 1993;14:28-33.
14. Patton GC, Hibbert ME, Carlin J, et al. Menarche and the onset of depression and anxiety in Victoria, Australia. J Epidemiol Community Health. 1996;50:661-666.
FREE FULL TEXT
15. Angold A, Costello EJ, Worthman CM. Puberty and depression: the roles of age, pubertal status and pubertal
timing. Psychol Med. 1998;28:51-61.
FULL TEXT
|
ISI
| PUBMED
16. Angold A, Costello EJ, Erkanli A, Worthman CM. Pubertal changes in hormone levels and depression in girls. Psychol Med. 1999;29:1043-1053.
FULL TEXT
|
ISI
| PUBMED
17. Szatmari P, Offord DR, Boyle MH. Ontario Child Health Study: prevalence of attention deficit disorder
with hyperactivity. J Child Psychol Psychiatry. 1989;30:219-230.
ISI
| PUBMED
18. Newman DL, Moffitt TE, Silva PA, Caspi A, Magdol L, Stanton WR. Psychiatric disorder in a birth cohort of young adults: prevalence,
comorbidity, clinical significance, and new case incidence from ages 11 to
21. J Consult Clin Psychol. 1996;64:552-562.
FULL TEXT
|
ISI
| PUBMED
19. Cohen P, Cohen J, Kasen S, et al. An epidemiological study of disorders in late childhood and adolescence,
I: age- and gender-specific prevalence. J Child Psychol Psychiatry. 1993;34:851-867.
ISI
| PUBMED
20. Costello EJ, Angold A, Burns BJ, et al. The Great Smoky Mountains Study of Youth: goals, design, methods, and
the prevalence of DSM-III-R disorders. Arch Gen Psychiatry. 1996;53:1129-1136.
FREE FULL TEXT
21. Lipman EL, Offord DR, Boyle MH. Relation between economic disadvantage and psychosocial morbidity in
children. CMAJ. 1994;151:431-437.
ABSTRACT
22. Shaw DS, Vondra JI, Hommerding KD, Keenan K, Dunn M. Chronic family adversity and early child behavior problems: a longitudinal
study of low income families. J Child Psychol Psychiatry. 1994;35:1109-1122.
ISI
| PUBMED
23. Wernicke TF, Linden M. Clinical recognition and drug treatment of depression in cases found
by standardized assessment. Pharmacopsychiatry. 1994;27(suppl 1):54-57.
24. Dulcan MK, Costello EJ, Costello AJ, Edelbrock C, Brent D, Janiszewski S. The pediatrician as gatekeeper to mental health care for children:
do parents' concerns open the gate? J Am Acad Child Adolesc Psychiatry. 1990;29:453-458.
ISI
| PUBMED
25. Costello EJ, Costello AJ, Edelbrock C, et al. Psychiatric disorders in pediatric primary care: prevalence and risk
factors. Arch Gen Psychiatry. 1988;45:1107-1116.
FREE FULL TEXT
26. Starfield B, Borkowf S. Physicians' recognition of complaints made by parents about their children's
health. Pediatrics. 1969;43:168-172.
FREE FULL TEXT
27. Rutter M, Tizard J, Whitmore K. Education, Health, and Behavior. Harlow, England: Longman Group; 1970.
28. Rutter M, Cox A, Tupling C, Berger M, Yule W. Attainment and adjustment in two geographical areas, I: the prevalence
of psychiatric disorder. Br J Psychiatry. 1975;126:493-509.
FREE FULL TEXT
29. Verhulst FC, Van der Ende J, Ferdinand RF, Kasius MC. The prevalence of DSM-III-R diagnoses in a
national sample of Dutch adolescents. Arch Gen Psychiatry. 1997;54:329-336.
FREE FULL TEXT
30. Verhulst FC, Berden GF, Sanders-Woudstra JA. Mental health in Dutch children, II: the prevalence of psychiatric
disorder and relationship between measures. Acta Psychiatr Scand Suppl. 1985;324:1-45.
PUBMED
31. Steinhausen HC, Winkler Metzke C, Meier M, Kannenberg R. Behavioral and emotional problems reported by parents for ages 6 to
17 in a Swiss epidemiological study. Eur Child Adolesc Psychiatry. 1997;6:136-141.
ISI
| PUBMED
32. Offord DR, Boyle MH, Szatmari P, et al. Ontario Child Health Study, II: six-month prevalence of disorder and
rates of service utilization. Arch Gen Psychiatry. 1987;44:832-836.
FREE FULL TEXT
33. Freid VM, Makuc DM, Rooks RN. Ambulatory health care visits by children: principal diagnosis and
place of visit. Vital Health Stat 13. 1998;137:1-23.
34. Anderson JC, Williams S, McGee R, Silva PA. DSM-III disorders in preadolescent children:
prevalence in a large sample from the general population. Arch Gen Psychiatry. 1987;44:69-76.
FREE FULL TEXT
35. Cederblad M. Fifty years of epidemiologic studies in child and adolescent psychiatry
in Sweden. Nordic J Psychiatry Suppl. 1996;50:55-66.
 CiteULike  Connotea  Del.icio.us  Digg  Reddit  Technorati
What's this?
THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES
Medical and Psychiatric Comorbidity and Health Care Use Among Children 6 to 17 Years Old
Spady et al.
Arch Pediatr Adolesc Med 2005;159:231-237.
ABSTRACT
| FULL TEXT
Mental Illness Hospitalizations of Youth in Washington State
Garrison et al.
Arch Pediatr Adolesc Med 2004;158:781-785.
ABSTRACT
| FULL TEXT
|
