Joseph: Comparing international infant mortality rates [CMAJ

Comparing international infant mortality rates

CMAJ 2000;163(5):497-8

See also: eLetters

A report in CMAJ provided an international comparison of infant mortality rates based on data recently published by the Organization for Economic Cooperation and Development (OECD) [News and Analysis].¹ Although the OECD and other international organizations such as UNICEF publish international comparisons using data they obtain from Statistics Canada and other national bodies, their estimates are sometimes erroneous.² For instance, the OECD reported the 1996 infant mortality rate in Canada to be 6.0 per 1000 live births. In fact, in 1996 the infant mortality rate in Canada was 5.6 per 1000 live births,³ whereas that in the United States was 7.3 per 1000 live births.⁴ In 1997, infant mortality rates in Canada and the United States were 5.5 and 7.2 per 1000 live births respectively.^5,6

International comparisons of infant mortality are compromised by a lack of standardization with regard to birth registration practices. Studies have documented wide variation in the rate at which extremely small babies at the borderline of viability (e.g., < 500 g) are registered in different countries.^7,8 In fact, recent secular trends and interprovincial comparisons of infant mortality within Canada are also affected by such differences in birth registration [Original Research].⁹ As a potential solution, the World Health Organization has recommended that international comparisons of infant mortality be restricted to live births in which the newborn weighs 1000 g or more.¹⁰ Such a restriction would eliminate a substantial proportion of neonatal deaths from the infant mortality counts of most industrialized countries, however. This and other challenges inherent in birth- weight-specific comparisons mean that international infant mortality rankings will continue to be based on crude rates and will favour industrialized countries, which tend not to register extremely small live births.

K.S. Joseph
Perinatal Epidemiology Research Unit
Department of Obstetrics & Gynecology and Pediatrics
Dalhousie University
Halifax, NS
and
Associate Editor, CMAJ
KS.Joseph@np.iwkgrace.ns.ca

References

    1.    Martin S. Canada among leaders in OECD health results. CMAJ 2000;162(7):1032.

    2.    Joseph KS. The state of the world’s children 1996 [book review]. Chron Dis Can 1996;17:77-8.

    3.    Health Statistics Division. Births and deaths 1996. Ottawa: Statistics Canada; 1999. Cat no 84F0210XPB.

    4.    Peters KD, Kochanek KD, Murphy SL. Deaths: final data for 1996. vol 47 (no 9) of National vital statistics reports series. Hyattsville (MD): National Center for Health Statistics; 1998.

    5.    Health Statistics Division. Births and deaths 1997. Ottawa: Statistics Canada; 1999. Cat no 84F0210XPB.

    6.    Hoyert DL, Kochanek KD, Murphy SL. Deaths: final data for 1997. vol 47 (no 19) of National vital statistics reports series. Hyattsville (MD): National Center for Health Statistics; 1999.

    7.    Howell EM, Blondel B. International infant mortality rates: bias from reporting differences. Am J Public Health 1994;84:850-2. [MEDLINE]

    8.    Sepkowitz S. International rankings of infant mortality and the United States vital statistics natality data collecting system — failure and success. Int J Epidemiol 1995;24:583-8. [MEDLINE]

    9.    Joseph KS, Kramer MS. Recent trends in Canadian infant mortality rates: effect of changes in registration of live newborns weighing less than 500 g [Abstract]. CMAJ 1996;155(8):1047-52. [MEDLINE]

    10.    International statistical classification of diseases and related health problems. vol 2. 10th rev ed. Geneva: World Health Organization; 1993. p. 129-33.