Context: Self-reported health data are used by health insurance companies to assess risk. Most studies show underreporting compared with clinical measurements.
Objective: To compare self-reported height, weight, blood pressure, waist circumference, and dietary intake with registered dietitian's (RD's) measures of the same parameters.
Design: This is a secondary analysis of data collected in a larger study on the benefits of Medical Nutrition Therapy from an RD for overweight and obese patients when provided free of charge through an insurance benefit.
Setting: Participants completed a health risk assessment survey at home, from which the self-reported measures were extracted. The clinical measurements were taken by an RD in the office during a visit for Medical Nutrition Therapy.
Participants: Participants were 81.4% female, with a mean body mass index of 35.0. All were insured and had a least 1 visit with an RD.
Main Outcome Measure(s): Main outcomes were correlation between self-reported and RD-measured height, weight, body mass index, blood pressure, and waist circumference. Blood pressure was categorized as normal or high and the κ statistic was used to examine category agreement between the 2 measures. Servings of food groups were compared between the 2 measures by examining cumulative percent within 0, 1, or 2 servings of the RD-measured value.
Results: The 2 measures of height and weight were highly correlated (0.974 and 0.986, respectively). Blood pressure was more weakly correlated and when categorized had low κ scores, as did servings of food groups.
Conclusions: Height and weight were more closely correlated than in previous studies. In an insured population enrolled in a weight management program, self-reported measures may be accurate for determining program impact. Blood pressure may be better collected categorically than continuously. The necessity of food intake assessment on a risk assessment should be reconsidered.
This study aims at comparing self-reported height, weight, blood pressure, waist circumference, and dietary intake with registered dietitian's measures of the same parameters.
Community Health Division of the Community and Family Medicine Department, Duke Medical School, Duke University, Durham, North Carolina (Dr Murphy); Community and Behavioral Health, and Epidemiology, College of Public Health, University of Iowa, Iowa City, Iowa (Dr Snetselaar); Academy of Nutrition and Dietetics, Chicago, Illinois (Dr Myers); Healthcare Program Development, BlueCross BlueShield of North Carolina, Durham, North Carolina (Ms LaForge); BlueCross BlueShield of North Carolina, Durham, North Carolina (Ms Qualls and Dr Blackwelder); Dietetics Practice Based Research Network, Academy of Nutrition and Dietetics, Chicago, Illinois (Ms Hand); and BlueCross BlueShield of North Carolina, Durham, North Carolina (Dr Bradley). Ms Qualls is now with Duke Clinical Research Institute, Durham, North Carolina, and Dr Blackwelder is now with Cornerstone Health Enablement Strategic Services, High Point, North Carolina.
Correspondence: Gwendolyn Murphy, MS, PhD, Community Health Division of the Community and Family Medicine Department, Duke Medical School, Duke University, Room 319, 411 W Chapel Hill St, Durham, NC 27701 (Gwen.firstname.lastname@example.org).
Funding was provided by the Academy of Nutrition and Dietetics Foundation, Commission on Dietetic Registration, the Academy of Nutrition and Dietetics, and BlueCross BlueShield of North Carolina.
The authors acknowledge Tracy Lewis for data preparation for analysis and Lisa Spence, Mina Silberberg, and Alison Steiber for their assistance in preparing this manuscript. In addition, they acknowledge all of the registered dietitians who were part of the Dietetics Practice Based Research Network and were part of this study including the following: Barbara Bapst, Denise Barratt, Tricia Beasley, Susan Blomeley, Garren Brannon, Lisa Cooper, Kay Craven, Karen Donelson, Bonnie Elber, Karen Gantt, Shelia Garner, Susan Gregory, Janie Hoag, Barbara Hughes, Johnnie Jackson, Carol Johnson, Kristen Klecha, Jaime Lynn Lewis, Cathie Ostrowski, Karen Pfohl, Deborah Rosenquist, Jessica Seymour, Millicent Simmons, Kathy Simons, Rebecca Subbiah, Kay Sullivan, Joye Willcox, Wilda Wade, Karen Smith, Donna Hollinger, Jan Foster, and Dru Mueller.
The authors declare no conflicts of interest.