COMMENTARIES 499
the issue with parents. However, at present the lack
of unanimity on the part of those who have critically
examined the available data, coupled with rapidly
emerging research findings in this area, argues that
parents should be presented with the evidence of the
potential risks and benefits of both positions.
Given the preliminary epidemiologic and
physio-logic evidence, we urge pediatricians to recommend avoidance of sheepskins and other soft bedding ma-terials. Unlike recommending a change in sleeping position, which may be followed by both anticipated
and unanticipated risks, a recommendation
regard-ing bedding materials would offer likely benefit without any appreciable risk; further, such a
recom-mendation represents an extension of existing US
policy (ie, the St Louis and US Consumer Product Safety Commission warnings against use of polysty-rene-filled cushions for infants).
SUSAN R. ORENSTEIN, MD
Dept of Pediatrics, Division of Pediatric Gastroenterology
University of Pittsburgh School of Medicine Children’s Hospital of Pittsburgh
Pittsburgh, PA
ALLEN A. MITCHELL, MD
Boston University School of Medicine Slone Epidemiology Unit
Brookline, MA
SALLY DAVIDSON WARD, MD Dept of Pediatrics
Division of Neonatology and Pediatric Pulmonology Children’s Hospital Los Angeles
Los Angeles, CA
REFERENCES
1. American Academy of Pediatrics, Task Force on Infant Positioning and SIDS. Positioning and SIDS. Pediatrics. 1992;89:1120-1126
2. Taylor BJ. A review of epidemiological studies of sudden infant death syndrome in southern New Zealand. IPaediatr Child Health. 1991;27:344-348
3. Kemp JS, Kowalski RM, Graham MA, Thach BT. Positional ventila-tory impairment in a serial study of 23 SIDS cases. Pediatr Res. 1992;31(4, pt 2):360A
4. Ramenofsky ML, Leape LL. Continuous upper esophageal pH monitor-ing in infants and children with gastroesophageal reflux, pneumonia, and apneic spells. IPediatr Surg. 1981;16:374-378
5. Vandenplas Y, Sacre SL. Seventeen-hour continuous esophageal pH monitoring in the newborn: evaluation of the influence of position in asymptomatic and symptomatic babies. I Pediatr Gastroenterol Nutr.
1985;4:356-361
6. Yu V. Effect of body position on gastric emptying in the neonate. Arch Dis Child. 197550:500-504
7. Blumenthal I, Lealman GT. Effect of posture on gastro-oesophageal
reflux in the newborn. Arch Dis Child. 1982;57:555-556
8. Hewitt V. Effect of posture on the presence of fat in tracheal aspirate in neonates. Aust Paediatr J.1976;12:267-271
9. Herbst JJ,Book LS, Bray PF. Gastroesophageal refiux in the ‘near miss’ sudden infant death syndrome. /Pediatr. 197892:73-75
10. Herbst JJ, Minton SD, Book LS. Gastroesophageal reflux causing respi-ratory distress and apnea in newborn infants. IPediatr. 197995(5, pt 1):763-768
II. Newman U, Russe J,Glassman MS. et al. Patterns of gastroesophageal reflux (GER) in patients with apparent life-threatening events. IPediatr Gastroenterol Nutr. 1989;8:157-160
12. Jolley 5, Halpern L, Tunnell W,Johnson D, Sterling C. The risk of sudden infant death from gastroesophageal reflux. IPediatr Surg. 1991;26:691-696
13. See CC, Newman U, Berezin 5, et al. Gastroesophageal reflux-induced
hypoxemia in infants with apparent life-threatening event(s). AJDC.
1989;143:951-954
14. Sondheimer JM. Clearance of spontaneous gastroesophageal reflux in awake and sleeping infants. Gastroenterology. 1989;97:821-826
15. Sondheimer J. Electroencephalogram patterns during sleep reflux in infants. Gastroenterology. 1991 ;101 :1007-1011
16. Walsh JK, Farrell MK, Keenan WI, Lucas M, Kramer M. Gastroesoph-ageal reflux in infants: relation to apnea. IPediatr. 1981;99:197-201 17. Jeffery H, Heacock H. Impact of sleep and movement on
gastro-oesoph-ageal reflux in healthy, newborn infants. Arch Dis Child. 1991;66:1136-1139
18. Ariagno RL, Guilleminault C, Baldwin R, Owen BM. Movement and gastroesophageal reflux in awake term infants with ‘near miss’ SIDS, unrelated to apnea. IPediatr. 1982;100:894-897
19. Menon AP, Scheift GL, Thach BT. Apnea associated with regurgitation in infants. IPediatr. 1985;106:625-629
20. Spitzer AR, Boyle JT, Tuchman DN, Fox WW. Awake apnea associated with gastroesophageal reflux: a specific clinical syndrome. I Pediatr.
1984;104:200-205
21. Hashimoto T, Hiura K, Endo 5, et al. Postural effects on behavioral states of newborn infants: a sleep polygraphic study. Brain Dcv. 19835:286-291 22. Brackbill Y, Couthitt T, West H. Psychophysiologic effects in the neonate
of prone versus supine placement. IPediatr. 1973;82:82-84
23. Keitel H, Cohn R, Harnish D. Diaper rash, self-inflicted excoriations, and crying in full-term newborn infants kept in the prone or supine position. IPediatr. 1960;57:884-886
TV
or Not
TV: Fat Is the
Question
The manuscript entitled “Does television viewing
increase obesity and reduce physical activity?” pub-lished by Robinson and coauthors in this issue of
Pediatrics1 is a careful and well-written study of the effect of television viewing on adiposity and physical activity among sixth- and seventh-grade adolescent girls. In contrast to two other large studies of chil-dren,2’3 the authors failed to find a significant
asso-ciation between hours of television viewed and
adiposity, measured by body mass index. Physical activity was weakly and inversely correlated to time spent viewing television. The latter observation is consistent with prior data which demonstrate a re-ciprocal relationship of fitness and television view-ing,4 perhaps because television viewing displaces more vigorous physical activities.5 The authors argue that their observation “refutes previous suggestions that...television viewing is causally related to obesity” and that “statistically significant results may not have clinical, practical, or policy significance and may primarily reflect a large sample size.”1
Before the relationship between television viewing
and fatness observed in previous studies is
dis-missed, several important methodologic problems in the Robinson et al study require closer examination. Concerns about the study include the generalizabil-ity of findings from the particular sample studied, the measure selected to assess the duration of televi-sion viewing, and the use of epidemiologic studies to establish public health policy.
Received for publication Sep 2, 1992; accepted Sep 2, 1992. Reprint requests to (W.H.D.) Dept of Pediatric Gastroenterology/Nutrition, Boston Floating Hospital, Box 213, 750 Washington St. Boston, MA 02111. PEDIATRICS (ISSN 0031 4005). Copyright © 1993 by the American Acad-emy of Pediatrics.
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500 COMMENTARIES
The population samples examined in the two
stud-ies that found an association between television
viewing and obesity were nationally representative
samples, whereas the population sample examined
by Robinson and coworkers was derived from four
northern California middle schools. Although their
population was ethnically heterogeneous, it clearly
does not represent the pediatric population of the
United States. At most, one could argue from this
study that no significant relationship existed
be-tween television viewing and fatness in sixth- and
seventh-grade girls in northern California.
The most significant problem with all studies that
have examined the effects of television viewing on
behavior is that reports of television viewing time
cannot be validated. In Robinson and coworkers’
study, estimates of television time were based on the
question of how much time after school was spent
viewing television. Whether after-school viewing
in-cludes evening television or represents a surrogate measure for total daily television time remains
un-clear. Although the television viewing estimates in
this study corresponded to hours of television
viewed by the Neilsen sample between 3 PM and 11
PM, the Neilsen samples may also be biased. The
Neilsen ratings of television time are derived from direct measures of household viewing. However, ap-proximately half of the families asked to participate in the Neilsen survey refuse to do so.6 The parental
and subject reports of television time reported in
the National Health Examination Survey on which
we relied2 also lacked validation. In the absence of
valid measures, any conclusions must be cautiously
advanced.
Finally, Robinson et al argue that the “weak”
as-sociation between obesity and television viewing
re-futes the causal relationship between television viewing and obesity that we proposed2 and that our results may have reflected a large sample size. We agree that our results have been overemphasized and
misinterpreted. Clearly television viewing is not the only cause of obesity. Furthermore, our clinical
expe-rience suggests that obesity is not invariably associ-ated with excessive television viewing. However, the importance of a statistically significant finding depends not only on the magnitude of the associa-tion, but also on the rarity of the event, and on whether we can know or measure other modifiable causes. For example, an energy imbalance clearly ac-counts for obesity. However, the repeated failures to demonstrate differences in caloric intake between obese and nonobese individuals should not lead us to dismiss increased food intake or reduced expen-diture as the mechanism that underlies the develop-ment of obesity.
The relationship between smoking and lung cancer offers a pertinent example. An early 4-year prospec-tive study7 of smoking and lung cancer conducted in
almost 200000 men found a significant correlation
coefficient of
4
= 048 Although this associationre-flected in part a large sample size, the importance of the observation cannot and should not be dismissed
as a refutation of the causal association between
smoking and lung cancer, simply because the num-bers involved make the small correlation coefficient significant. Abundant supporting evidence supports the inference that smoking causes lung cancer.
Among the adolescents in our sample, the
correla-tion coefficient for the association between obesity, measured by triceps skinfold thickness, and televi-sion viewing was
4
= .08. If we use the groupwatch-ing 0 to I hours of television per day as the case
referent category, the etiologic fraction of cases9 of
obesity associated with television viewing was 29%. An alternative interpretation of this finding is that 29% of the cases of obesity could be prevented by
reducing television viewing to 0 to I hours per week.
Subsequent analys&#{176} have demonstrated a signifi-cant association between the lack of remission of obe-sity and television viewing
(4
= .26) and themci-dence of obesity and television viewing
(4
= .08). Aswith smoking, we would expect that these effects would increase with time. Furthermore, as with
smoking and lung cancer, a strong and logical case
underlies the argument that television viewing
causes obesity. Television viewing could cause obe-sity by either increasing food intake or reducing en-ergy expenditure. Both effects are supported by a variety of 12 Because adiposity has so many
determinants, and few determinants are as
poten-tially modifiable as television viewing, we would hesitate to dismiss the implications of even a low order correlation for public policy, even though this observation may have only a small effect on patient care.
Regardless of whether no, weak, or strong
epide-miologic associations exist between television
view-ing and obesity, the other effects of television on the health of children and adolescents, as well as corn-mon sense, would suggest that television viewing among children should be limited to I to 2 hours per day. Robinson et a! agree.1 As Robinson and his coworkers suggest, school-based curricula, criti-cal viewing skills, and family or peer characteristics may have a major impact on how reductions in tele-vision time can be achieved or how the effects of television on behavior can be modified. These are
deservedly the subjects for further research.
ACKNOWLEDGMENTS
We gratefully acknowledge Bonni Pear and Jennifer Fairlamb, formerly of the American Dietetic Association Office of Public
Relations, who first thought of the title of this commentary.
WILUAM H. Dwrz, MD, PHD
New England Medical Center
Boston, MA
STEVEN L. GORTMAKER, PHD
Harvard School of Public Health
Boston, MA
REFERENCES
1. Robinson TN, Hammer LD, Killen JD, et al. Does television viewing increase obesity and decrease physical activity? Cross-sectional and longitudinal analyses among female adolescents. Pediatrics. 199391:273-280
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COMMENTARIES 501 2. Dietz WH, Gortmaker SL. Do we fatten our children at the television
set? Obesity and television viewing in children and adolescents.
Pedi-atrics. 1985;75:807-812
3. Pate RR, Ross JG. The national children and youth fitness study, II: factors associated with health-related fitness. I Phys Educ Recreation
Dance. 198758:93-95
4. Tucker LA. The relationship oftelevision viewing to physicalfitness and obesity. Adolescence. 198621:797-806
5. Williams TM, Handford AG. Television and other leisure activities. In: Williams TM, ed. The Impact of Television: A Natural Experiment in Three Communities. Orlando, FL: Academic Press mc; 1988:143-213
6. Gerard J.TV networks want Neilsen to change rating methods. New York Times. December 14, 1989
7. Hammond EC, Horn D. Smoking and death rates-report on forty-four months of follow-up of 187783 men, II: death rates by cause. JAMA.
1958;166:1294-1308
8. Fleiss JL. Statistical Methods forRates and Proportions. 2nd ed. New York, NY: John Wiley and Sons; 1981:60
9. Miettinen OS. Proportion of disease caused or prevented by a given exposure, trait or intervention. Am JEpidemiol. 197499:325-332
10. Gortmaker SL, Dietz WH, Cheung L Inactivity, diet and the fattening of
America. IAm Diet Max. 199090:1247-1255
11. Dietz WH, Strasburger VC.Children, adolescents, and television. Curr Probl Pediatr. 1991;21:S-31
12.Dietz WH. Prevention of childhood obesity. Pediatr Clin North Am.
198633:823-834
Effects
of Technologic
and
Sociocultural
Changes
on the
Practice
of Neonatal
Medicine:
A
View
From
France
ABBREVIATIONS. MAP, medically assisted procreation; IVF, in vitro fertilization; ECMO, extracorporeal membrane oxygenation.
When one considers the changes that have oc-curred in trends of perinatal mortality or the propor-tion of severe handicap in infants or adults in most Western countries in the past 20 years, there has been
a profound change in the prognosis for life and for
long-term sequelae after perinatal distress. The
tech-nical reasons for this extraordinary progress are
straightforward. But it is much more difficult to
Un-derstand the profound effects on the quality of the lives that have come into being as a result of these advances. Indeed, it is hard to assess the precise con-sequences directly related to the new technology as opposed to effects related to the long separation of mother and child after an abnormal birth and in pathologic states of the newborn. In this paper, Iwill review the present status of these issues as seen from
a French point of view. This outlook takes into
ac-count the principal technical advances that have re-sulted in the survival of increasingly immature and
seriously ifi neonates. It is based on improved means of assessing the neonate that have come about with a
better understanding of the perceptive capacities during fetal life, as well as the importance of cultural
Received for publication Aug 7, 1992; accepted Oct 20, 1992.
Reprint requests to (J.P.R) Professor of Paediatrics, Service de M#{233}decine N#{233}onatale, Maternite Port-Royal, 123, Boulevard de Port-Royal, F-75014 Paris, France.
PEDIATRICS (ISSN 0031 4005). Copyright ©1993 by the American Acad-emy of Pediatrics.
changes in developed countries that have been made possible by new techniques of procreation. Above all, the current view recognizes the increase in na-tional and personal wealth that has made it possible for parents to consider obtaining “a child at any
price . . .“-a child-object to be purchased like any
other desired possession. The last notion raises the question of restraints on the cost of perinatal medi-cine in particular, and medical care in general. What are the limiting factors in aggressive modern medi-cine, ever more technical, but ever less human?
ANALYSIS OF TECHNICAL PROGRESS
There can be little doubt that the most significant technical progress in neonatal medicine has occurred in the present era. There were very few changes be-tween 1900, when Pierre Budin’s manual on the care of premature newborns was published,’ and 1965 to
1970, when the first successful attempts were made
at artificial ventilation of sick neonates. Budin dem-onstrated that simple measures to keep small new-borns (weighing less than 2500 g) clean, warm, and fed with human milk reduced neonatal mortality from about 70% to 25%.’ Budin’s views on the im-portance of reducing heat loss and on the need for cleanliness to protect the neonate from the risk of nosocomial infections are still valid today.
Beginning in 1965, many neonatal teams in West-ern countries began to intubate and ventilate neo-nates with respiratory distress. Up to 1970, the
mor-tality
rate remained high in premature neonatesweighing less than 1200 g at birth. Between 1970 and 1980, the transformation from passive to intensive neonatal care was virtually complete at the Port-Royal center which was the first unit to routinely admit premature newborns with respiratory distress syndrome. Before 1970, about 80% of neonates
weighing less than 1200 g at birth died. In the next 10 years the numbers were reversed: after 1980, about 80% survived in good condition. This remarkable change came about as the result of considerable ad-vances in knowledge about fetal and neonatal phys-iology and because of the physical means made available to French obstetricians and pediatricians for the purpose of improving the condition of the fetus in utero and of the neonate after birth.
The period of rapid change, fascinating because of the large number of lives saved, was dominated, nev-ertheless, by the coldest aspects of technology and science. The fetus and the neonate were looked on and, indeed, were treated as marvelous experimental models that might confirm or refute the insights gained from extensive animal research. Nonetheless,
there is little doubt that the care of the newborn, and particularly of the premature newborn, has been greatly improved because of a deeper understanding of pulmonary and cardiovascular pathophysiology, increased effectiveness of artificial ventilation and the use of surfactants, and wider use of parenteral nutrient solutions to promote growth. Similarly, progress in understanding the wide range of physi-ologic handicaps of extremely premature infants has made it possible to use potent drugs much more safely and effectively than in the past.
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1993;91;499
Pediatrics
WILLIAM H. DIETZ and STEVEN L. GORTMAKER
TV or Not TV: Fat Is the Question
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1993;91;499
Pediatrics
WILLIAM H. DIETZ and STEVEN L. GORTMAKER
TV or Not TV: Fat Is the Question
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