Growth and development of children as a positive health indicator
For the purpose of monitoring child health, the vast majority of countries, and even international agencies (1-2) use indicators such as infant mortality and morbidity (prevalence or incidence of specific diseases): AIDS, TBC, etc). In our opinion, these indicators are very important and should continue to be used by public health offices. However, they fail to give a comprehensive picture of the status of the whole population under observation, since they express the occurrence of an undesirable (negative) condition with regards to a reference population not suffering the condition. The indicator says very little about this reference population. For example, when we say that infant mortality in a given country is 9 per thousand, we do not know what happens to the health of the denominator, the remaining 991 children who do not die. We certainly know they are alive, but this information is not enough for child health monitoring. What we want to know in the case of child health is how they grow and develop.
These considerations are not original, the use of physical growth for the monitoring of child population health has been proposed several decades ago by James Tanner (3) who coined the phrase “Growth is a mirror of society”, meaning that physical growth of population groups (and certainly not of individuals) express better than any other indicator the nutritional, health and even socioeconomic situation of the group. They express how social and biological determinants of health (4) are distributed among the populations, and the variation of inequalities over time. At present, countries use proportion on individuals below certain cut off points of height for age, weight for age, and BMI. These indicators are certainly useful, but yet they express the status of a group of affected individuals and not that of the whole population. On the contrary, Simple auxological values such as mean height of child population groups at different ages, and data on physical maturation (age of menarche) are the most commonly used indicators of population groups. There is a vast body of information on the scientific literature on this broad and important issue. As an example, we can mention the educational and social class differences in height in several countries from Europe (5), America (6-7), Asia (8), secular trends in height and weight witnessed in many countries during the XXth century all over the world (9), and contemporary world - wide studies on correlations between gross national product and physical growth of populations (10).
Also psychomotor development has been proved to be sensible to social categories and inequalities, there being abundant literature on general psychomotor development and specific intellectual functions related to population groups (11 – 12), and related to the wealth of nations (13). Recently, psychomotor development has been proposed as another possible tool for child health monitoring (14 - 15), with specific statistical handling different from that used for physical growth data.
Both sets of data, on growth and on development should, in our opinion, be called positive indicators for two main reasons: first, they express a desirable process, we want children to growth and develop properly, positively. Second, they express the situation of the whole population and not only that of a damaged group. The indicators used are global figures, showing for example, mean height or average reference population. They can be shown as gradients (related to social, educational, labor or any other social stratification), or as trends, (changes over time), generally called secular trends. This is a relevant way of measuring child health (16).
This recommendation certainly imposes technical difficulties, such as the way the information is obtained. This is an important point, subject to discussion, but several alternatives can be found, for example, the growth surveillance inserted within the local program of medical care could regularly provide information about growth of all children under program. Periodic surveys can also be an alternative.
In the XXIst century, the reduction of infant mortality should not be the only purpose of public health actions; we must promote a positive growth and development of children and for this end we need adequate, proper indicators. Consequently, the International Association for the Study of Human Growth and Clinical Auxology strongly recommends the use of positive health indicators based on data on growth and development for measuring child health in population groups, as a complement of mortality and morbidity indicators.
1) UNICEF. The state of world´s children report. 2012.
2) WHO. The world health report 2010. Geneva.
3) Tanner JM. Growth as a mirror of the condition of the society: secular trends and class distinctions, In: Human Growth: a Multidisciplinary Review ,ed. A Demirdjian pp 34. London, Taylor and Francis. 1986.
4) WHO.A conceptual framework for action on the social determinants of health. Discussion Paper II Debates, Policy and Practice. Series on Social Determinants of Health, Geneva 2010. ISBN: 978 92 4 150085 2
5) Bielicki T. Physical growth as a measure of the economic well – being of populations- The twentieth Century. In: Tanner and Falkner Human Growth. a comprehensive treatise. Vol. 3, Ch 14. 283-306. 1986.
6) Fogel RW. ¨ Auxology and economics. In: Gigli G, Schell CL, and Benso L. Human Growth form conception to maturity. Chapter I, 1-11, 2002. Smith-Gordon, UK
7) Lejarraga H, Physical growth in Argentina. en: Hauspie, Lindgren and Falkner, “Essays on Auxology”. James Mourylan Tanner Festschrift. Castlemead publ. 232-245, 1995, London, UK.
8) Graham, MJ, Larsen U, Xiping Xu. Secular trend in age at menarche in China: a case study of two rural counties in Anhui Province. Journal of Biological Science 31,257-267, 1999.
9) Van Wieringen JC, Secular growth changes, In: Tanner and Falkner Human Growth a comprehensive treatise, ch. 15, vol II, 307-332, 1986. Steckel RH. Social and economic effect on growth. In: Noël Cameron and Barry Bogin, ch 9, pp 225 - 244, Elsevier, London, 2nd edition, 2012.
10)Steckel RH. Social and economic effect on growth. In: Noël Cameron and Barry Bogin, ch 9, pp 225 - 244, Elsevier, London, 2nd edition, 2012.
11)Starkey P. Klein A. Economic and cultural differences in early mathematical development. In: Parker FL, Robinson R, Sombrano S, Piotrowski C, Hagen J, Randolph S.Baker A. (Eds.) New directions in child and family research: shaping head start in the 90s. National Council of Jewish Womem. 1992.
12)Griffin SA, Case R, Siegler RS. Rightstart: providing the central conceptual prerequisites for the first formal learning on aritmetics to students at risk for school failure. In: K McGuilly (Eds). Classroom lessons: integrating cognitive theory and classroom practice (pp 1-50). Cambridge, MA, MIT Press / Bradford Books. 1994.
13)Keating DP, Hertzman C. Developmental health and the wealth of nations. Social, biological and educational dynamics. The Guilford Press, NY,99.
14)Lejarraga H, Kelmansky H, Pascucci MC, Lejarraga C, das Neves P, Masautis A, Charrúa G, Insua I, Nunes F. Growth and psychomotor development in children under 6 years as a public health indicator in population groups. XIII International Congress of Human Growth and Clinical Auxology. ISGA. Maribor, Slovenia, Abstracts, pp 74. Sept. 17-19, 2014.
15)Lejarraga H, Kelmansky D, Masautis A, Pascucci C, Insua I, Nunes F. Child psychomotor development as a positive health indicator. Sent for publication to Archives of Disease in Childhood, November 2014.
16) Schlaepfer Pedrazzini L, Infante Castañeda C. La medición de la salud. Perspectivas teóricas, y metodológicas. (Health measurement: theoric and methodological perspectives) Salud Publica de Mexico 1990;32:141-155.