Validity of self-reported vitamin D deficiency among midlife Arab women living in Qatar.
Academic Article
Overview
abstract
OBJECTIVES: This study evaluates the level of agreement between self-reported vitamin D deficiency and serum vitamin D measured within the previous calendar year. METHODS: In a study in which serum 25(OH)D levels were retrieved from electronic health records, 523 women were asked whether they considered themselves to have vitamin D deficiency. Serum vitamin D levels were categorized as vitamin D deficiency if serum 25(OH)D was <20 ng/ml and as insufficiency if <30 ng/ml. The kappa statistic was computed to assess the level of agreement between serum 25(OH)D level and self-report responses. RESULTS: Agreement between self-reported and measured 25(OH)D levels was poor. The kappa statistic was -0.041 when using a cutpoint of <20 ng/ml and -0.008 using the cutpoint of <30 ng/ml. Among women with levels ≥20 ng/ml, 82.4% believed that they were vitamin D deficient, while 13.3% who were below <20 ng/ml did not self-report deficiency. Among women who did not report vitamin D deficiency, 46.3% (37/80) had levels <20 ng/ml while 82.5% (66/80) had levels <30 ng/ml. CONCLUSIONS: These findings suggest that, although the prevalence of 25(OH)D <20 and <30 ng/ml was quite high (53.2% and 84.7%, respectively), there was little agreement between measured levels and self-report of vitamin D deficiency. This may be due to belief in this region that low levels of serum vitamin D is widespread. Better communication is needed between healthcare providers and patients regarding transmission of laboratory results.
