Comparison of estimates of under-nutrition for pre-school rural Pakistani children based on the WHO standard and the National Center for Health Statistics (NCHS) reference

Objective: To compare estimates of under-nutrition among pre-school Pakistani children using the WHO growth standard and the National Center for Health Statistics (NCHS) reference. Design: Prevalence of stunting, wasting and underweight as defined by WHO and NCHS standards are calculated and compared. Setting: The data are from two cross-sectional surveys conducted in the early 1990s, the time frame for setting the baseline for the Millennium Development Goals: (i) National Health Survey of Pakistan (NHSP) assessed the health status of a nationally representative sample and (ii) Thatta Health System Research Project (THSRP) was a survey in Thatta, a rural district of Sindh Province. Subjects: In all, 1533 and 1051 children aged 0-35 months from national and Thatta surveys, respectively. Results: WHO standard gave a significantly higher prevalence of stunting for both national [36.7 (95% CI 33.2, 40.2)] and Thatta surveys [52.9 (95% CI 48.9, 56.9)] compared to the NCHS reference [national: 29.1 (95% CI 25.9, 32.2) and Thatta: 44.8 (95% CI 41.1, 48.5), respectively]. It also gave significantly higher prevalence of wasting for the Thatta survey [22.9 (95% CI 20.3, 25.5)] compared to the NCHS reference [15.7 (95% CI 13.5, 17.8)]. Differences due to choice of standard were pronounced during infancy and for severely wasted and severely stunted children. Conclusions: Pakistan should switch to the robustly constructed and up-to-date WHO growth standard for assessing under-nutrition. New growth charts should be introduced along with training of health workers. This has implications for nutritional intervention programmes, for resetting the country's targets for Millennium Development Goal 1 and for monitoring nutritional trends.