Development of a Mathematical Model That Will Predict the Mean Daily Dietary Intake of Pregnant Women Based upon Sociological, Psychological and Physiological Factors Assumed to be Related to the Mean Daily Dietary Iron Intake

The purpose of this investigation was to develop a mathematical model using linear stepwise regression analysis that would predict the dietary iron intake of pregnant women. Development of the mathematical model was based upon sociological, psychological and physiological factors assumed to be related to the dietary iron intake of pregnant women.

Fifty-seven pregnant women participated in the study. They were private outpatients of two obstetricians at the Macomb Clinic, Macomb, Illinois.

The dependent variable used in the development of the models was the seven-day mean daily dietary iron intake for each pregnant woman which was obtained during the second and/or third trimester of pregnancy. Independent variables used were eight socioeconomic factors, one personality score, two food and nutrition variables and four blood level determinations.

Linear stepwise multiple regression analysis was done using the total sample of 57 cases. Two subsamples of 53 cases and 34 cases were also. analyzed by stepwise multiple regression analysis.

It was found that in using 34 cases, two variables were entered into the equation at both the 1 and 5 percent F levels. The food frequency history score entered first and the hematocrit level entered second. In the 53 case run, two variables were entered at the 5 percent F level; the first variable entered was the food frequency history score, and the second variable entered was the educational level. of the spouse. At the I percent.!: level the only variable entered was the food frequency history score. In the 57 case run, the only variable used was the food frequency history score; it was entered at the I percent F level.

When using this model as a case-finding tool in nutrition programs, the equation to use would be the one with only the food frequency history score which was developed in the 57 case run. The mathematical model would be:

Estimated Mean Daily Dietary Iron Intake = 0.00125 (food frequency history score) + 5.93705

This equation has a standard error of estimate of ±2.3 mg of iron. The mathematical model may apply to other pregnant women in a different locality, but further study would be needed to test the reliability and validity of the model under various settings.