JAMA news releases are made available to the public after 3 pm US Central time on the first 4 Tuesdays of each month. the Archives of Journals news releases are made available to the public after 3 pm Central time on Mondays. We also provide a list of previous news releases.
THIS WEEK'S CONTENTS
ARCHIVES OF PEDIATRICS & ADOLESCENT MEDICINE NEWS RELEASES
(Embargoed Until: 3 P.M. (CT), Monday, April 7, 2008)
CHILDHOOD SLEEP DIFFICULTIES ASSOCIATED WITH FUTURE MENTAL AND PHYSICAL HEALTH PROBLEMS
SLEEPING LESS IN INFANCY ASSOCIATED WITH BEING OVERWEIGHT IN PRESCHOOL
SLEEP PROBLEMS COMMON IN CHILDREN WITH ADHD
CHILDREN'S SLEEP DISTURBANCES ASSOCIATED WITH CERTAIN PARENTING BEHAVIORS
SLEEP PROBLEMS IN CHILDREN MAY BE ASSOCIATED WITH EMOTIONAL AND BEHAVIORAL DIFFICULTIES LATER IN LIFE
ARCHIVES OF PEDIATRICS & ADOLESCENT MEDICINE Audio Interviews
Interview with Michelle Cao, D.O., co-author of "Sleep Difficulties and Behavioral Outcomes in Children" (Arch Pediatr Adolesc Med. 2008;162[4]:385-389.)
Interview with Elsie M. Taveras, M.D., M.P.H., first author of "Short Sleep Duration in Infancy and Risk of Childhood Overweight" (Arch Pediatr Adolesc Med. 2008;162[4]:305-311.)
ARCHIVES OF GENERAL PSYCHIATRY NEWS RELEASES
(Embargoed Until: 3 P.M. (CT), Monday, April 7, 2008)
SYMPTOMS OF DEPRESSION DO NOT APPEAR TO INCREASE IN EARLY STAGES OF ALZHEIMER'S DISEASE
MALTREATMENT DURING CHILDHOOD ASSOCIATED WITH COMBINATION OF INFLAMMATION AND DEPRESSION IN ADULTS
STUDY SUGGESTS GENETIC FACTORS ASSOCIATED WITH COMMON FEARS
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Media Advisory: For more information, contact JAMA/Archives Media Relations at 312-464-JAMA (5262) or email mediarelations{at}jama-archives.org.
CHILDHOOD SLEEP DIFFICULTIES ASSOCIATED WITH FUTURE MENTAL AND PHYSICAL HEALTH PROBLEMS
Sleep research highlighted in Archives of Pediatrics & Adolescent Medicine theme issue
CHICAGO—"Sleep takes up about one-fourth to two-thirds of the lives of young children, but how we recognize, define and treat sleep disorders in children is still a process that we have not mastered," write Michelle Cao, D.O., and Christian Guilleminault, M.D., Biol.D., in an editorial in the April issue of Archives of Pediatrics & Adolescent Medicine, a theme issue on children and sleep.
The issue contains a number of articles focusing on the later implications of childhood sleep difficulties, Drs. Cao and Guilleminault note. Articles in the issue focus on:
- Effects of parents' behaviors on children's sleep
- Weekend vs. weeknight bedtimes
- Sleep problems in children with ADHD
- The relationship between sleep duration and childhood obesity
- Long-term mental health effects of not sleeping enough
- Sleep-disordered breathing and behavior
"A recurring theme from these articles focuses on early childhood sleep problems and later consequences of emotional and behavioral changes in adolescent and teenage years to adulthood," Drs. Cao and Guilleminault write. "With this in mind, we need to do a better job of recognizing, defining and treating sleep disorders in children. One message that we can take from these studies is clear: more attention should be given to sleep and sleep-related disorders."
(Arch Pediatr Adolesc Med. 2008;162[4]:385-389. Available to the media pre-embargo at www.jamamedia.org).
Editor's Note: Please see the article for additional information, including author contributions and affiliations, financial disclosures, funding and support, etc.
PLEASE NOTE: A podcast interview and radio actualities from Michelle Cao, D.O., are available in mp3 format below.
For more information, contact JAMA/Archives media relations at 312/464-JAMA (5262) or e-mail mediarelations{at}jama-archives.org.
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EMBARGOED FOR RELEASE UNTIL 3 P.M. (CT), MONDAY, April 7, 2008
Media Advisory: To contact Elsie M. Taveras, M.D., M.P.H., call David Cameron at 617-432-0442.
SLEEPING LESS IN INFANCY ASSOCIATED WITH BEING OVERWEIGHT IN PRESCHOOL
CHICAGO—Infants who sleep less than 12 hours per day have an increased risk of being overweight as preschoolers than those who sleep 12 hours or more, according to a report in the April issue of Archives of Pediatrics & Adolescent Medicine, a theme issue on children and sleep.
About one-fourth of children age 2 through 5 years are overweight or at risk for being overweight, according to background information in the article. Previous studies in adults, adolescents and older children have shown that restricting sleep changes hormone levels, which could stimulate hunger and increase weight gain.
Elsie M. Taveras, M.D., M.P.H., of Harvard Medical School and Harvard Pilgrim Health Care, Boston, and colleagues studied 915 children whose mothers visited a group practice in eastern Massachusetts for prenatal health care. Children were weighed and measured in person immediately after birth and again six months and three years later. Mothers reported their children's sleep habits at these visits and on questionnaires one and two years after birth. Based on these reports, the researchers calculated each child's average daily sleep duration between age 6 months and 2 years.
Overall, the infants slept an average of 12.3 hours per day. As 3-year-olds, 83 children (9 percent) in the study were overweight. After adjusting for other factors that influence weight—including their mothers' body mass index (BMI) before pregnancy—infants who slept less than 12 hours per day had a higher BMI for age and sex, higher skinfold thickness (another measure of overweight) and were more likely to be overweight at age 3 than children who slept 12 hours or more per day as infants.
Adjusting for the amount of television viewed only minimally changed the associations between sleep and overweight, the authors note. However, the combination of little sleep and more hours spent watching television conferred the highest risk of being overweight. "Our findings lend support to childhood overweight prevention interventions that target both reduction in television viewing and ensuring adequate sleep duration," the authors write.
"The mechanisms underlying the association between sleep duration and adiposity [amount of body fat] are unclear," the authors write. In addition to altering hormone levels, sleeping less at night may lead to daytime sleepiness and reduced activity levels during waking hours, they note. Finally, more time spent awake could offer more opportunities to eat.
"Strategies to improve sleep duration among young children may be an important component of behavioral interventions that promote childhood overweight prevention," the authors conclude. "Our findings suggest that clinicians and parents may wish to use evidence-based sleep hygiene techniques to improve sleep quality and perhaps increase sleep duration."
(Arch Pediatr Adolesc Med. 2008;162[4]:305-311. Available to the media pre-embargo at www.jamamedia.org).
Editor's Note: This study was supported in part by grants from the National Institutes of Health. Dr. Taveras is supported in part by the Harold Amos Medical Faculty Development Program, Robert Wood Johnson Foundation. Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.
PLEASE NOTE: A podcast interview and radio actualities from Elsie M. Taveras, M.D., M.P.H., are available in mp3 format below.
For more information, contact JAMA/Archives media relations at 312/464-JAMA (5262) or e-mail mediarelations{at}jama-archives.org.
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EMBARGOED FOR RELEASE UNTIL 3 P.M. (CT), MONDAY, April 7, 2008
Media Advisory: To contact Valerie Sung, M.B.B.S., e-mail: valerie.sung{at}rch.org.au.
SLEEP PROBLEMS COMMON IN CHILDREN WITH ADHD
CHICAGO—Children with attention-deficit/hyperactivity disorder (ADHD) appear likely to experience sleep problems, according to a report in the April issue of Archives of Pediatrics & Adolescent Medicine, a theme issue on children and sleep. Sleep problems in these children may be associated with poorer child psychosocial quality of life, child daily functioning, caregiver mental health and family functioning.
Attention-deficit/hyperactivity disorder is a behavioral disorder, usually first diagnosed in childhood, that is characterized by inattention, impulsivity and hyperactivity. "ADHD is the most common mental health disorder in childhood, affecting up to 11 percent of Australians aged 6 to 17 years," according to background information in the article. About half of parents of children with ADHD report that their children have difficulty sleeping, feel tired on waking or have nightmares or other sleep problems such as disordered breathing and restless leg syndrome. Parents of children with ADHD are more likely to experience stress, anxiety and depression than those of children without ADHD.
Valerie Sung, M.B.B.S., of the Centre for Community Child Health, Parkville, Australia, and colleagues studied families of 239 schoolchildren (average age 11.7) with ADHD to determine the prevalence and broad effects of sleep problems in these children. The association of sleep problems with child health-related quality of life, daily functioning, school attendance, primary caregiver mental health and work attendance and family impacts were also noted.
Sleep problems affected 175 (73.3 percent) of the children, with a 28.5 percent prevalence of mild sleep problems and 44.8 percent prevalence of moderate or severe sleep problems. Some of the most commonly occurring sleep patterns were difficulty falling asleep, resisting going to bed and tiredness on waking.
"Compared with children without sleep problems, those with sleep problems were more likely to miss or be late for school, and their caregivers were more likely to be late for work," the authors write. "Forty-five percent of caregivers reported that their pediatricians had asked about their children's sleep and, of these, 60 percent reported receiving treatment advice."
"In summary, sleep problems in schoolchildren with ADHD are extremely common and strongly associated with poorer quality of life, daily functioning and school attendance in the child and poorer caregiver mental health and work attendance," the authors conclude. "Implementation of a sleep intervention in children with ADHD could feasibly improve outcomes beyond treatment of ADHD alone. It is possible that such intervention could reduce the need for medication in some children."
"In the meantime, clinicians caring for children with ADHD should ask about their sleep, and if a problem is present, this should be addressed."
(Arch Pediatr Adolesc Med. 2008;162[4]:336-342. Available to the media pre-embargo at www.jamamedia.org).
Editor's Note: Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.
For more information, contact JAMA/Archives media relations at 312/464-JAMA (5262) or e-mail mediarelations{at}jama-archives.org.
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EMBARGOED FOR RELEASE UNTIL 3 P.M. (CT), MONDAY, April 7, 2008
Media Advisory: To contact Valérie Simard, M.Sc., M.Ps., call Sylvain-Jacques Desjardins at 514-343-7593.
CHILDREN'S SLEEP DISTURBANCES ASSOCIATED WITH CERTAIN PARENTING BEHAVIORS
CHICAGO—Parental behaviors at bedtime when a child is age 29 to 41 months appear to be associated with sleep disturbances both earlier in childhood and later on in preschool years, according to a report in the April issue of Archives of Pediatrics & Adolescent Medicine, a theme issue on children and sleep.
"Except for cosleeping [when parents and infants share a bed], few studies have investigated parental sleep practices and their consequences for children's sleep," the authors write as background information in the article.
Valérie Simard, M.Sc., M.Ps., of the Hôpital du Sacré-Coeur de Montréal and Université de Montréal, and colleagues administered questionnaires to 987 parents of children who were 5 months old at the beginning of the study. Each year until the children reached age 6 years, mothers or fathers answered questions about their child's sleeping habits and disturbances (such as bad dreams, short total sleep time and delays in falling asleep), psychological characteristics and sociodemographic factors.
Parents also reported their behavior at children's bedtime (including whether they lulled children to sleep, laid them down awake or stayed with them until they fell asleep) and during nighttime awakenings (including comforting children in bed, taking them out of bed, giving them food or bringing them to the parental bed for cosleeping).
"Early (age 5 to 17 months) sleep disturbances predicted maladaptive parenting behaviors (e.g., mother present at sleep onset, giving food/drink after child awakens) at ages 29 and 41 months," the authors write. "Some parental behaviors in turn predicted future bad dreams, total sleep time of less than 10 hours per night and sleep-onset latency [delays in falling asleep] of 15 minutes or more. However, most relationships did not remain significant in adjusted models that controlled for early sleep problems." Cosleeping after nighttime awakening remained associated with more than 15-minute delays in returning to sleep, while the mother's presence at the beginning of sleep appeared protective against such delays.
The results support the notion that some parental behaviors develop in response to early sleep problems, the authors note. However, they also indicate that such parental behaviors could have negative effects. "Parental strategies that were effective for early sleep difficulties (e.g. giving food or drink) may later become inappropriate to the child's age and needs. Mothers might adopt the inappropriate response of giving food or drink to 29- to 41-month-old children awakening (which is associated with bad dreams and shorter total sleep time at age 50 months) because they commonly attribute infant cries to hunger and come to believe that infants cry only when hungry," the authors write.
"Our findings clarify the long-debated relationship between parental behaviors and childhood sleep disturbances," the authors conclude. "They suggest that cosleeping and other uncommon parental behaviors have negative consequences for future sleep and are thus maladaptive."
(Arch Pediatr Adolesc Med. 2008;162[4]:360-367. Available to the media pre-embargo at www.jamamedia.org)
Editor's Note: Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.
For more information, contact JAMA/Archives media relations at 312/464-JAMA (5262) or e-mail mediarelations{at}jama-archives.org.
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Media Advisory: To contact Alice M. Gregory, Ph.D., e-mail: a.gregory{at}gold.ac.uk.
SLEEP PROBLEMS IN CHILDREN MAY BE ASSOCIATED WITH EMOTIONAL AND BEHAVIORAL DIFFICULTIES LATER IN LIFE
CHICAGO—Children who sleep less may be more likely to report symptoms of anxiety, depression and aggression later in life, according to a report in the April issue of Archives of Pediatrics & Adolescent Medicine, a theme issue on children and sleep.
"Sleep problems are risk indicators of later emotional difficulties in childhood and adolescence and in adulthood," according to background information in the article. "For knowledge concerning links between sleep problems and later emotional and behavioral difficulties to be maximally beneficial to the physician, clarification of which particular sleep problems are associated with later difficulties is paramount."
Alice M. Gregory, Ph.D., of the University of London, and colleagues collected sleep data on 2,076 children who were ages 4 to 16 at the beginning of the study. Parents rated their children's sleep and behaviors on various scales and children later reported their own emotional and behavioral symptoms at ages 18 to 32.
Children having parental reports of sleeping less than others had high scores on scales measuring anxiety, depression and aggressive behavior. "There was some (albeit less robust) support for links between other reported sleep difficulties [such as overtiredness and trouble sleeping] and later problems," the authors note. "Parental reports of sleeping more than others and nightmares were not associated with later difficulties."
"The results suggest that children reported to sleep for short periods may be at risk for later difficulties," the authors conclude. "Physicians should inquire about sleep problems during child development and should be aware that some, but perhaps not others, may constitute risk indicators of later difficulties."
(Arch Pediatr Adolesc Med. 2008;162[4]:330-335. Available to the media pre-embargo at www.jamamedia.org)
Editor's Note: Dr. Gregory was supported by a grant from the University of London Central Research Fund. Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.
For more information, contact JAMA/Archives media relations at 312/464-JAMA (5262) or e-mail mediarelations{at}jama-archives.org.
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ARCHIVES OF PEDIATRICS & ADOLESCENT MEDICINE AUDIO INTERVIEWS
Interview with Michelle Cao, D.O., co-author of "Sleep Difficulties and Behavioral Outcomes in Children"
(Arch Pediatr Adolesc Med. 2008;162[4]:385-389.)
PODCAST (mp3 file)
CLIP 1 (mp3 file)
CLIP 2 (mp3 file)
Transcript:
Clip 1: Problems that a child may face when the child isn't getting enough sleep as he or she goes into adulthood would be health-related reasons such as obesity and metabolic complications as well as behavior disorders such as attention deficit disorder, which will persist into adulthood. Runs :23
Clip 2: If a parent notices the child's behavior that's abnormal—whether it's inattention or daytime fatigue or sleepiness or irritability or aggression—and this is a persistent problem in the daytime that becomes a problem in school as well as in the home environment, then that is when the parents should seek a sleep specialist. Runs :24
Interview with Elsie M. Taveras, M.D., M.P.H., first author of "Short Sleep Duration in Infancy and Risk of Childhood Overweight"
(Arch Pediatr Adolesc Med. 2008;162[4]:305-311.)
PODCAST (mp3 file)
CLIP 1 (mp3 file)
CLIP 2 (mp3 file)
Transcript:
Clip 1: We found that this relationship of lack of sleep and obesity was especially marked among children who are watching more than two hours of TV per day. So the particular combination that was hazardous for these children in terms of their risk of later obesity was the combination of sleeping less than twelve hours per day and watching two or more hours of TV per day. Runs :31
Clip 2: Infants who were sleeping less than 12 hours per day were more likely to be overweight at 3 years of age. Actually, the risk of being obese—and that is having a body mass index over the 95th percentile at 3 years of age—was almost two-fold higher for children who slept less than 12 hours per day compared to children who were sleeping twelve hours or more. Runs :30
EMBARGOED FOR RELEASE UNTIL 3 P.M. (CT), MONDAY, April 7, 2008
Media Advisory: To contact Robert S. Wilson, Ph.D., call Kimberly Waterman at 312-942-7820.
SYMPTOMS OF DEPRESSION DO NOT APPEAR TO INCREASE IN EARLY STAGES OF ALZHEIMER'S DISEASE
CHICAGO—Although individuals with depression may be more likely to develop Alzheimer's disease, symptoms of depression do not appear to increase in the years before a diagnosis is made, according to a report in the April issue of Archives of General Psychiatry, one of the JAMA/Archives journals. This suggests that depression is not a consequence of developing Alzheimer's disease but may instead be a risk factor for dementia.
Previous studies have found higher levels of depressive symptoms (such as feeling sad) among patients with Alzheimer's disease and its precursor, mild cognitive impairment, according to background information in the article. "The basis of this association is uncertain, however," the authors write. "A leading hypothesis is that depressive symptoms do not constitute a true risk factor but rather a consequence of the disease." If this were the case, symptoms of depression would likely increase during the early stages of Alzheimer's disease.
Robert S. Wilson, Ph.D., of Rush University Medical Center, Chicago, and colleagues studied 917 older Catholic nuns, priests and monks who did not have dementia beginning in 1994. Participants had a yearly clinical evaluation that included a neurological examination, cognitive (thinking, learning and memory) testing and classification of Alzheimer's disease or mild cognitive impairment. They also completed a 10-item scale assessing their symptoms of depression.
At the beginning of the study, 53.6 percent of participants reported no symptoms of depression, 23.9 percent reported one symptom, 9.7 percent reported two, 6.1 percent reported three and 6.8 percent reported four or more. During follow-up, 190 individuals developed Alzheimer's disease. Those with more symptoms of depression at the beginning of the study were more likely to develop Alzheimer's disease.
However, "those who developed Alzheimer's disease showed no increase in depressive symptoms before the diagnosis was made, and this finding was not modified by age, sex, education, memory complaints, vascular burden or personality," the authors write. "Among those without cognitive impairment at baseline, depressive symptoms did not increase in those who subsequently developed mild cognitive impairment."
Symptoms of depression may be associated with changes in the brain that reduce its resistance to dementia, the authors write. "Understanding the mechanisms linking depressive symptoms with dementia could suggest novel approaches to delaying dementia onset because animal research suggests diverse means by which the adverse effects of chronic stress may be modified."
(Arch Gen Psychiatry. 2008;65[4]:439-446. Available to the media pre-embargo at www.jamamedia.org)
Editor's Note: This study was supported by grants from the National Institute on Aging. Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.
For more information, contact JAMA/Archives media relations at 312/464-JAMA (5262) or e-mail mediarelations{at}jama-archives.org.
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Media Advisory: To contact corresponding author Avshalom Caspi, Ph.D., e-mail: a.caspi{at}iop.kcl.ac.uk.
MALTREATMENT DURING CHILDHOOD ASSOCIATED WITH COMBINATION OF INFLAMMATION AND DEPRESSION IN ADULTS
CHICAGO—A history of neglect or abuse in childhood appears to be associated with depression and inflammation in adulthood, a combination that may increase cardiovascular risk, according to a report in the April issue of Archives of General Psychiatry, one of the JAMA/Archives journals.
"Major depression is a multisystemic disorder that affects both brain and bodily functions," the authors write as background information in the article. Depression and cardiovascular disease often occur simultaneously, and inflammation (chronic activation of the immune system) has been linked to both. "However, not all individuals with depression have elevated levels of inflammation. Those who do could be at highest risk for cardiovascular disease."
Andrea Danese, M.D., M.Sc., of King's College London, and colleagues studied 1,000 New Zealand residents born between 1972 and 1973. Assessments were carried out every two years between ages 3 and 15, then again at ages 18, 21, 26 and 32. Childhood maltreatment—including rejection by a child's mother, harsh discipline, physical or sexual abuse or disruptive changes in caregivers—was identified through parental reports during childhood years, objective observations of behavior and participants' own reports once they reached adulthood. At age 32, participants underwent physical examinations as well as clinical interviews to diagnose depression.
Individuals with current depression and a history of childhood maltreatment were more likely to have a high level of inflammation at age 32, as measured by the presence of the chemical high-sensitivity C-reactive protein in the blood. Those with depression but no history of childhood maltreatment did not have this increased risk. "The elevated inflammation levels in individuals who were both depressed and maltreated were not explained by correlated risk factors such as depression recurrence, low socioeconomic status in childhood or adulthood, poor health or smoking," the authors write.
"Information about experiences of childhood maltreatment may help to identify depressed individuals with elevated inflammation levels and, thus, greater risk of cardiovascular disease," the authors conclude. "In turn, the early recognition of the health risk associated with maltreatment history might help to address pressing needs for the care of depressed individuals such as the reduction of the effect of depression on comorbid [co-occurring] medical illness."
(Arch Gen Psychiatry. 2008;65[4]:409-416. Available to the media pre-embargo at www.jamamedia.org)
Editor's Note: Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.
For more information, contact JAMA/Archives media relations at 312/464-JAMA (5262) or e-mail mediarelations{at}jama-archives.org.
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Media Advisory: To contact Kenneth S. Kendler, M.D., call Sathya Achia Abraham at 804-827-0890.
STUDY SUGGESTS GENETIC FACTORS ASSOCIATED WITH COMMON FEARS
CHICAGO—Genetic factors that are associated with fears appear to change as children and adolescents age, with some familial factors declining in importance over time while other genetic risk factors arise in adolescence and adulthood, according to a report in the April issue of Archives of General Psychiatry, one of the JAMA/Archives journals.
The nature of common fears changes during childhood and adolescent development, according to background information in the article. Two hypotheses have been proposed regarding genetic risk factors for these fears. "The 'developmentally stable' hypothesis predicts that a single set of genetic risk factors impacts the level of fears at age 8 years and these same genes constitute the only genetic influences on fear-proneness throughout development," the authors write. "By contrast, the 'developmentally dynamic' hypothesis predicts that genetic effects on fear-proneness will vary over time."
Kenneth S. Kendler, M.D., of the Virginia Commonwealth University School of Medicine, Richmond, and colleagues studied 2,490 twins born in Sweden between 1985 and 1986. The twins were assessed for their level of fear four times: at age 8 to 9 by a questionnaire mailed to parents, at ages 13 to 14 and 16 to 17 with questionnaires mailed to twins and parents and at age 19 to 20 with questionnaires only to the twins.
Fears naturally divided into three categories: situational fears (such as fear of closed spaces, flying or the dark), animal fears (including rats, dogs and snakes) and blood or injury fears (fears of dentists, injections and blood). Overall, genetic factors influenced all three types of fears, but did not remain stable over time. "We identified one set of genetic risk factors that act in childhood and have a steep decline in influence with age," the authors write. "Furthermore, we see evidence for new sets of genetic risk factors 'coming on line' in early adolescence, late adolescence and early adulthood."
As the twins aged, the effects of their shared environment on their fears diminished and the influence of their individual environment increased. "This is an expected pattern given that adolescence is a time of declining influence of the home environment as individuals spend less time with family and progressively make their own world, spending more time with friends," the authors write.
Further research is needed to determine the exact mechanisms by which genetics influences fears, they note—for example, if genes influence mental processes such as sensitivity to disgust or are more closely linked to changes in neurobiology, including alterations in the brain circuits through which fear is processed.
(Arch Gen Psychiatry. 2008;65[4]:421-429. Available to the media pre-embargo at www.jamamedia.org)
Editor's Note: This study was supported in part by National Institutes of Health grants, the Swedish Council for Working Life and Social Research and the Swedish Research Council. Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.
For more information, contact JAMA/Archives media relations at 312/464-JAMA (5262) or e-mail mediarelations{at}jama-archives.org.
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