Validity of self-reported vitamin D deficiency among midlife Arab women living in Qatar.
OBJECTIVE
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.
Department of Healthcare Policy and Research, Weill Cornell Medical College, New York, New York.
Linda M
LM
Gerber
Department of Healthcare Policy and Research, Weill Cornell Medical College, New York, New York.
Ashley E
AE
Giambrone
Weill Cornell Medical College in Qatar, Doha, Qatar.
Hala M
HM
Al-Ali
Weill Cornell Medical College in Qatar, Doha, Qatar.
Mohamud A
MA
Verjee
D000328:Adult; D018912:Arabs; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008875:Middle Aged; D015995:Prevalence; D011780:Qatar / Q000453:epidemiology; D057566:Self Report / Q000592:standards*; D014807:Vitamin D / Q000097:blood*; D014808:Vitamin D Deficiency / Q000453:epidemiology / Q000523:psychology*
D014807:Vitamin D