The z-score in malnutrition is a statistical measure that compares a child's weight, height, or weight-for-height to the average for their age and sex. It indicates how many standard deviations a child's measurement is above or below the average.
- Positive z-scores indicate that the child is above average for their age and sex.
- Negative z-scores indicate that the child is below average for their age and sex.
Z-scores are used to:
- Identify children who are at risk of malnutrition.
- Monitor the growth and development of children.
- Evaluate the effectiveness of interventions to improve nutrition.
Different z-scores are used to assess different aspects of malnutrition:
- Weight-for-age z-score (WAZ): Measures a child's weight relative to their age.
- Height-for-age z-score (HAZ): Measures a child's height relative to their age.
- Weight-for-height z-score (WHZ): Measures a child's weight relative to their height.
Cut-off points for z-scores:
- -2 SD or below: Indicates that a child is severely malnourished.
- -1 to -2 SD: Indicates that a child is moderately malnourished.
- -1 SD or above: Indicates that a child is adequately nourished.
Example:
A child with a WAZ of -2.5 is 2.5 standard deviations below the average weight for their age and sex. This indicates that the child is severely malnourished.
It is important to note that z-scores are just one tool for assessing malnutrition. Other factors, such as the child's overall health and diet, should also be considered.
