Percentiles division: Refers to the value of measurement of that particular number in a series of hundred, when they are arranged in an ascending order. 50th percentile – (Median) referes to the 50th value in a series of 100. 3rd percentile indicates that 3% of children are below the value and 97% above that value. Common percentiles are – 3, 5, 10, 25, 50, 75, 90, 95 & 97th.

Standard deviation (SD) The relationship of percentiles to S.D in a normally distributed characteristic is shown in figure below. 3rd & 97th percentile include 94% of the population and coincide with values + or – S.D from the mean. Conventionally -2 S.D units are taken as cut offs to determine retardation in growth.

S.D classification Standard deviation (S.D) classification is shown in table below.

Percentage deviation from the median of standard To classify children into Nutrition grades or grades of deficit (mild, moderate, severe) – by establishing arbitrary cut-off points. Ex: Gomez Classification

Velocity of growth Velocity is the rate of growth per unit time, usually one year and is referred to as annual increment. It is the difference in the measurements obtained at initial point of time (T1) and at the end of one year (T2), in a longitudinal study. Distance Charts: are prepared using data collected in cross sectional studies. Children belonging to different ages are measured at one point of time. Means for different ages are plotted on graphs and are joined by a smoothened curve.

Last modified: Tuesday, 29 November 2011, 11:24 AM