What is Neyzi 2008?
Neyzi 2008 is a national growth reference developed to assess the growth of Turkish children and adolescents. It provides percentile and z-score values by age and sex for height, weight, head circumference and body mass index (BMI). Because these values are derived from the measurements of large numbers of Turkish children, it is regarded as the fundamental source for growth assessment in Turkey.
The reference is named after pioneering work in paediatric endocrinology and growth in Turkey, and it represents updated national data.
Why does a national reference matter?
A percentile and a z-score are always calculated relative to a “comparison group”. Whichever population is taken as the basis, the same child’s percentile can come out slightly differently. Comparing a child with the distribution of children in their own country gives the most accurate and fair result; because genetic and environmental factors differ between populations.
For this reason, a child in Turkey is most accurately assessed with Neyzi 2008. The international WHO charts, on the other hand, provide a common standard especially for ages 0–5 and are often preferred in this age group.
Consistency in follow-up
One of the most important rules when tracking a child’s growth is to use the same reference consistently. When the reference is changed, percentile values can shift, and this can create a false impression of a “drop” or “rise” when there has been no real change. The platform ensures this consistency by basing its calculations for Turkey on Neyzi 2008.
Neyzi 2008 forms the basis not only for percentile and z-score calculation but also for derived assessments such as BMI percentile; in this way height, weight and weight-for-height balance are read from the same national framework.
The background of the Neyzi reference
The value of a growth reference depends on which children it was obtained from and when. Neyzi 2008 is based on updated measurements collected from Turkish children and adolescents; in this respect it reflects the real distribution of height, weight and head circumference in children in Turkey. Because the growth pattern of populations can change over time with genetic and environmental factors, using a current and local reference gives a more accurate result.
The international WHO charts provide an “ideal growth” standard based on healthy breastfed infants, especially for ages 0–5, and are widely preferred in this age group. At school age and in adolescence, however, the national reference is more representative. What matters is to use the same reference consistently in a child’s follow-up and to interpret percentiles within this framework; when references are mixed, percentile shifts that are not real can be seen.