U.S. Department of Health and Human Services Office of Disease Prevention and Health Promotion

Increase the proportion of women of childbearing age who get enough folic acid — MICH‑12 Data Methodology and Measurement

On this page:  About the National Data  |  Methodology  |  History

About the National Data

Data

Data Source:  National Health and Nutrition Examination Survey (NHANES), CDC/NCHS

Baseline: 82.6 percent of non-pregnant women aged 15 to 44 years had optimal red blood cell folate concentrations in 2013-16

Target: 86.2 percent

Numerator
Number of non-pregnant women aged 15 to 44 years with optimal red blood cell (RBC) folate concentrations (>=748 nmol/L).
Denominator
Number of non-pregnant women aged 15 to 44 years with RBC folate concentrations.
Target-setting method
Percentage point improvement
Target-setting method details
Percentage point improvement from the baseline using Cohen's h effect size of 0.10.
1
Target-setting method justification
Trend data were not available for this objective. A percentage point improvement was calculated using Cohen's h effect size of 0.1. This method was used because it was a statistically significant improvement from the baseline. Due to the decision by the Food and Drug Administration to approve the voluntary fortification of corn masa flour with folic acid starting in 2016, an increase is expected in the proportion of U.S. women of childbearing age achieving the recommended daily intake of folic acid and optimal blood folate status for the prevention of neural tube defects, which are birth defects affecting the brain and spinal cord.

Methodology

Methodology notes

RBC folate concentration is a population weighted estimate from the blood specimens collected from women aged 15 to 44 years as part of the standard NHANES protocol. According to data from NHANES, median RBC folate concentrations increased substantially between 1988-94 and 1999-2000, pre- and post-fortification with folic acid, and then declined slightly in the post-fortification period (Pfeiffer et al., 2007, CDC, 2007).

History

Comparable HP2020 objective
Modified, which includes core objectives that are continuing from Healthy People 2020 but underwent a change in measurement.
Changes between HP2020 and HP2030
This objective differs from Healthy People 2020 objective MICH-15 in that this objective has been modified to align with the most recent World Health Organization (WHO) guidelines. Objective MICH-15 tracked women of childbearing potential with low red blood cell folate concentrations, while this objective tracks women with optimal red blood cell folate concentrations.

1. Effect size h=0.1 was chosen to correspond with 10% improvement from a baseline of 50%.