On 03 Dec 2002 12:31:02 GMT, foxglove54321 at aol.commaps (Foxglove54321) wrote:
>> I suggest the "secular trend" is
>>evidence of this
>>http://members.aol.com/warpcoresf>Free sci-fi stories, reviews and news.
>>http://members.aol.com/foxglove54321/>Inside the Bubble - autism information
Here is the abstract of latest article on the secular trend in the United
Secular Trends in Height Among Children During 2 Decades
The Bogalusa Heart Study
David S. Freedman, PhD; Laura Kettel Khan, PhD; Mary K. Serdula, MD; Sathanur
R. Srinivasan, PhD; Gerald S. Berenson, MD
Objective To examine trends in height among 5- to 17-year-old children between
1973 and 1992.
Design A panel design consisting of 7 cross-sectional surveys.
Participants All schoolchildren residing in Bogalusa, La, were eligible. A
total of 24 070 examinations were performed.
Results During the study period, the mean height of schoolchildren increased by
0.70 cm per decade independently of race, sex, and age. Trends were most
pronounced among preadolescents, blacks, and boys, with 9- to 12-year-old black
boys showing a height increase of 1.8 cm per decade. We observed a decrease in
the number of relatively short children (<10th percentile of height) and an
increase in the number of tall children (>90th percentile of height). Because a
secular trend was not seen among the 15- to 17-year-old children, our findings
likely reflect an acceleration of maturation.
Conclusions It has generally been assumed that secular increases in height
among schoolchildren in the United States ceased by the mid-1900s. Our findings,
which may be due to various environmental factors, demonstrate that care must be
taken when using nonconcurrent reference data to assess the growth of children.
Additional study is needed to determine if these secular trends are continuing
and to examine possible explanations and consequences of these trends.
Archives of Pediatric and Adolescent Medicine. 2000;154:155-161