Physicians underestimate calcium intake in women.
OBJECTIVE
Personalized nutritional counseling about calcium intake during office encounters requires rapid estimation of calcium intake. We compared the accuracy of physician estimates to a validated calcium intake measure and characterized women whose intakes were incorrectly deemed inadequate by physicians.


METHODS
As part of a controlled trial of brief, office-based calcium intake counseling of women, family physicians estimated calcium intake from patients' self-reported intake of dairy food/beverage intake and from their supplement use. We compared estimates to the Short Calcium Questionnaire (SCQ), a validated 7-day dietary recall measure completed by patients. Sensitivity/specificity of physician-estimated calcium intake was estimated by comparison with the SCQ.


RESULTS
For 97 women, SCQ rated 32 (33%) as inadequate, 55 (57%) as adequate, and 10 (10%) as excessive. When compared to SCQ, the sensitivity of physician-estimated calcium intake inadequacy was 97% (95% confidence interval [CI]: 94%-100%), specificity was 51% (95% CI: 41%-61%), and positive predictive value was 49% (95% CI: 39%-59%). Women with underestimated intakes were more likely to report a family history of osteoporosis and take a daily multivitamin. The major source of physician underestimation of calcium intake was underestimate of dairy product contribution.


CONCLUSIONS
More accurate estimates of dairy-based calcium intake will lead to greater specificity in identifying inadequate calcium intake.
Department of Family Medicine, Medicine Institute, Cleveland Clinic, Cleveland, Ohio, USA. sandra.snyder@fairviewhospital.org
Sandra M
SM
Snyder
Carl V
CV
Tyler
Vanessa
V
Panaite
Michael J
MJ
Smolak
Brenda L
BL
Powell
Christopher W
CW
Young
Jessica L
JL
Conway
Donald B
DB
Ford
Stephen J
SJ
Zyzanski
D000328:Adult; D002136:Calcium, Dietary / Q000008:administration & dosage* / Q000592:standards; D003376:Counseling; D003611:Dairy Products; D019587:Dietary Supplements; D005260:Female; D006801:Humans; D008875:Middle Aged; D015596:Nutrition Assessment; D010821:Physicians, Family; D015203:Reproducibility of Results; D016387:Women's Health; D055815:Young Adult
D002136:Calcium, Dietary