WIC Nutrition Risk Criteria: A Scientific Assessment (1996)
Chapter: Appendix D Definitions of Yield and Sensitivity of Cutoff Points for Nutrition Risk
Appendix D
Definitions of Yield and Sensitivity of Cutoff Points for Nutrition Risk
Efficacy of WIC interventions: the proportion of individuals selected for WIC whose bad outcomes will be prevented or reduced = 
where
Y = those identified who have the risk and will benefit
w = those identified who have the risk and will not benefit
|
|
Overall benefit from WIC |
|
|
Identified by criterion |
Yes |
No |
|
Yes |
Y |
w |
Yield of risk1: the proportion of those identified at risk who are at risk = 
where
B = those identified at risk who are at risk
o = those identified at risk who are not at risk
|
|
At risk of bad outcome |
|
|
Identified by criterion |
Yes |
No |
|
Yes |
B |
o |
|
No |
b |
O |
Not all those who have the risk and are identified at risk (B) will benefit, thus: 
Combining equations D-2 and D-3: 
Yield of benefit: proportion of those identified at risk who will benefit = 
Sensitivity for risk2 = 
Sensitivity for benefit: 
References
Habicht, J-P. 1980. Some characteristics of indicators of nutritional status for use in screening and surveillance. Am. J. Clin. Nutr. 33:531-535.
Habicht, J-P., L.D. Meyers, and C. Brownie. 1982. Indicators for identifying and counting the improperly nourished. Am. J. Clin. Nutr. 35:1241-1254.
Last, J.M. 1988. A Dictionary of Epidemiology. London: Oxford University Press.
