Evaluation of quality control procedures for 24-h dietary recalls: results from the Girls Health Enrichment Multisite Studies.
BACKGROUND
Quality control methods are key components of dietary assessment, but have rarely been evaluated.


METHODS
One hundred forty-four 8-10-year-old African-American girls at three field centers completed two 24-h dietary recalls at baseline before a pilot weight gain prevention intervention (one recall collected in-person and one by telephone). The dietary recall data were initially reviewed by the dietary interviewer (Phase 1), then by a local lead nutritionist at the field center (Phase 2), and then by the Nutrition Coordinating Center (NCC) (Phase 3); any differences identified by NCC were reconciled (Phase 4). Bland-Altman and generalizability theory methods were used to assess agreement of consumption for selected food variables and nutrients between phases.


RESULTS
Only small differences occurred. Quality control procedures primarily reduced the variances of nutrients rather than caused the means to shift. Most of the variability among phases was due to individual level variability in dietary intake.


CONCLUSIONS
Decisions to review dietary recall data beyond local review should be based on the level of precision and accuracy required for the study outcomes and the availability of financial resources.
Cullen
Karen W
KW
Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030-2600, USA. kcullen@bcm.tcm.edu
Watson
Kathy
K
Himes
John H
JH
Baranowski
Tom
T
Rochon
James
J
Waclawiw
Myron
M
Sun
Wanjie
W
Stevens
Mary
M
Slawson
Deborah Leachman
DL
Matheson
Donna
D
Robinson
Thomas N
TN
D001741:Black or African American; D002648:Child; D015981:Epidemiologic Factors; D005247:Feeding Behavior; D005260:Female; D006801:Humans; D011939:Mental Recall; D015337:Multicenter Studies as Topic / Q000706:statistics & numerical data; D015596:Nutrition Assessment; D009765:Obesity / Q000517:prevention & control; D010865:Pilot Projects; D011786:Quality Control; D016032:Randomized Controlled Trials as Topic / Q000706:statistics & numerical data; D014481:United States