Factors in low birth weight
CMAJ 1997;157:1737
Re: "Recent trends in infant mortality rates and proportions of low-birth-weight live births in Canada" (CMAJ 1997;157[5]:535-41 [abstract / résumé]), by Drs. K.S. Joseph and Michael S. Kramer
"A warning from the cradle? Because they may signal a deterioration in the nation's health, trends in infant mortality and low birth weight bear watching" (CMAJ 1997;157[5]:549-51 [full text / résumé]), by Dr. Graham Chance
In response to: A.T. Shennan
Dr. Shennan describes the experience at a tertiary perinatal facility and argues that the proportion of low-birth-weight babies in Toronto has increased, inaccuracies in the reporting mechanism notwithstanding. As we mentioned in our paper, the truncation of birth weights does not fully address other findings suggestive of an increase in low-birth-weight live births in Ontario. In fact, correction of the erroneous birth weights only halves the documented increase between 1987 and 1994, from 22% to 11%;1 the latter increase remains highly significant statistically. Clearly, the truncation error is only a partial explanation for the increase. Nevertheless, our experience with Ontario data leaves us uncertain as to whether the increase is real or artifactual.
Shennan further proposes increased immigration from non-European countries as a likely cause of the increase. We agree that this is a plausible explanation, although it and competing hypotheses need to be carefully examined. Whereas a few of the potential explanations for the increase in low-birth-weight live births could be tested with existing data, obtaining accurate and comprehensive answers to such questions necessitates an improved system of perinatal surveillance, such as that currently being set up by the Laboratory Centre for Disease Control, the provinces and territories, and other concerned parties.
K.S. Joseph, MD, PhD
Consultant Epidemiologist
Bureau of Reproductive and Child Health
Laboratory Centre for Disease Control
Ottawa, Ont.
Michael S. Kramer, MD
Professor
Department of Pediatrics and
Epidemiology and Biostatistics
Faculty of Medicine
McGill University
Montreal, Que.
Reference
- Singh I, Hagey J. Error corrected, conclusions the same. CMAJ 1997;157[6]:646-7.
 |
Send a letter to the editor responding to this letter
Envoyez une lettre à la rédaction au sujet de cette lettre |
Letters