Screening for iron deficiency in young women: the predictive validity of a five-item screening instrument (IRON-5)

BACKGROUND: Iron deficiency is the most common micronutrient deficiency worldwide, negatively affecting quality of life and health. Young women are at particularly high risk due to increased iron demands during growth, menstrual blood losses, and dietary habits. There are no official guidelines recommending screening for iron deficiency in healthy young women. This study aimed to develop a screening instrument (IRON-5) to predict iron deficiency in this group, with relevance for use in primary care and school health services. METHODS: In 2023, a cross-sectional study was conducted to assess the prevalence of iron deficiency and associated factors in high school girls. A questionnaire assessing dietary habits, menstrual bleeding patterns, iron supplement use, and hormonal contraceptive use was administered. Iron deficiency was defined as serum ferritin <15 µg/L. A post-hoc analysis identified the strongest predictors of iron deficiency and incorporated them into a risk-scoring model. RESULTS: The final instrument included five predictors: a non-omnivorous diet, heavy menstruation causing discomfort, avoidance of activities due to menstruation, no iron supplementation, and non-use of hormonal contraceptives. A scoring system (0-5) was developed. Using a threshold score of ≥ 3, the model achieved a sensitivity of 74% and specificity of 57% for detecting iron deficiency. CONCLUSION: The IRON-5 is a concise and user-friendly screening instrument designed to identify young women at risk of iron deficiency. It demonstrated good sensitivity and may serve as a cost-effective method to prioritize individuals for blood testing. IRON-5 could support identification and prevention strategies in school-based and primary care settings.