BMC Public Health 2007, 7:277 http://www.biomedcentral.com/1471-2458/7/277 its kind. Because a large number of questionnaires were sent with a high return rate achieved, the SHIELD survey achieved a large sample that is representative of the over- all US population. SHIELD provides information that is unique from data more commonly reported, especially regarding the longitudinal follow-up on a large sample, which may allow correlation of RFs with the future diag- nosis of DM. Competing interests Dr. Harold Bays, in almost two decades of clinical research, has served as a Clinical Investigator for (and has received research grants from) pharmaceutical companies such as Abbott, Alteon, Arena, AstraZeneca, Aventis, Bayer, Boehringer Ingelheim, Boehringer Mannheim, Bristol Myers Squibb, Eli Lilly, Esperion, Fujisawa, Ciba Geigy, GelTex, Glaxo, Genentech, Hoechst Roussel, KOS, Kowa, Lederle, Marion Merrell Dow, Merck, Merck Scher- ing Plough, Miles, Novartis, Parke Davis, Pfizer, Pliva, Purdue, Reliant, Roche, Rorer, Regeneron, Sandoz, San- kyo, Sanofi, Searle, Shionogi, Schering Plough, SmithK- line Beecham, Takeda, TAP, UpJohn, Upsher Smith, Warner Lambert, and Wyeth-Ayerst. He has also served as a consultant, speaker, and/or advisor to and for pharma- ceutical companies such as Arena, AstraZeneca, Aventis, Bayer, Bristol Myers Squibb, KOS, Merck, Merck Schering Plough, Metabasis Therapeutics, Microbia, Novartis, Nicox, Ortho-McNeil, Parke Davis, Pfizer, Roche, Sandoz, Sankyo, Sanofi Aventis, Shering Plough, SmithKline Bea- cham, Takeda, UpJohn, and Warner Lambert. Dr. James Gavin has served as a consultant to Sanofi-Aventis, Merck, Novartis, Eli Lilly, LifeScan, and Mannkind; on advisory boards for AstraZeneca, Novartis, Eli Lilly, and Novo Nor- disk; on speakers' bureaus for Eli Lilly, Novartis, Sanofi- Aventis; and as a director for Amylin. Ms. Bazata and Drs. Clark, Green, Lewis and Stewart serve on advisory boards for AstraZeneca LP. Drs. Michael Reed, Richard Chapman and Kathleen Fox received funding for research and con- sulting from AstraZeneca LP. Dr. Susan Grandy is an employee of AstraZeneca LP. SHIELD, the SHIELD Advi- sory Board, and the preparation of this manuscript were supported by funding from AstraZeneca LP. Authors' contributions HB chairs the SHIELD Advisory Board, and helped to draft the manuscript. DDB, NGC, JRG, AJG, SJL, MLR, and WS were members of the SHIELD Advisory Board, which par- ticipated in the design and ongoing direction of this study. RHC participated in the design and coordination of this study, analysis of the results, and drafting of the manu- script. KF participated in analysis of the results and draft- ing of the manuscript. SG participated in the design and coordination of this study and drafting of the manuscript. All the authors have read and approved the final manu- script. Additional material Additional file 1 Sociodemographic characteristics of respondents to the SHIELD baseline survey (unweighted). Click here for file [http://www.biomedcentral.com/content/supplementary/1471- 2458-7-277-S1.doc] Acknowledgements The following individuals also contributed to the work reported in this manuscript: Tina Fanning (data collection and analysis) of Vedanta Research; and Craig Wood (data analysis) of Geisinger Health System. Results from this study were presented as posters at the 7th Scientific Forum on Quality of Care and Outcomes Research in Cardiovascular Disease and Stroke, Washington, DC, May 7–9, 2006, and at the American Diabetes Association 66th Annual Scientific Sessions, Washington, DC, June 9–13, 2006. References 1. Mokdad AH, Ford ES, Bowman BA, Nelson DE, Engelgau MM, Vinicor F, Mark JS: Diabetes trends in the U.S.: 1990–1998. Diabetes Care 2000, 23:1278-1283. 2. Mokdad AH, Bowman BA, Ford ES, Vinicor F, Marks JS, Koplan JP: The continuing epidemics of obesity and diabetes in the United States. JAMA 2001, 286:1195-1200. 3. Kanjilal S, Gregg EW, Cheng YJ, Zhang P, Nelson DE, Mensah G, Beckles GL: Socioeconomic status and trends in disparities in 4 major risk factors for cardiovascular disease among US adults, 1971–2002. Arch Intern Med 2006, 166:2348-2355. 4. Stewart WF, Lipton BB, Celentano DD, Reed ML: Prevalence of migraine headaches in the United States: relation to age, income, race and other sociodemographic factors. JAMA 1992, 267:64-69. 5. Lipton RB, Stewart WF, Diamond S, Diamond ML, Reed M: Preva- lence and burden of migraine in the United States: data from the American Migraine Study II. Headache 2001, 41:646-657. 6. Hirschfeld RM, Calabrese JR, Weissman MM, Reed M, Davies MA, Frye MA, Keck PE Jr, Lewis L, McElroy SL, McNulty JP, Wagner KD: Screening for bipolar disorder in the community. J Clin Psychi- atry 2003, 64:53-59. 7. Lipton RB, Stewart WF, Celentano DD, Reed ML: Undiagnosed migraine headache: a comparison of symptom-based and reported physician diagnosis. Arch Intern Med 1992, 152:1273-1278. 8. Lipton RB, Diamond S, Reed M, Diamond ML, Stewart WF: Migraine diagnosis and treatment: results from the American Migraine Study II. Headache 2001, 41:638-645. 9. Calabrese J, Hirschfeld MA, Reed M, Davies MA, Frye MA, Keck PE, Lewis L, McElroy SL, McNulty JP, Wagner KD: Impact of bipolar disorder on a US community sample. J Clin Psychiatry 2003, 64:425-432. 10. Ettinger A, Reed M, Cramer J: Depression and comorbidity in community-based patients with epilepsy or asthma. Neurol- ogy 2004, 63:1008-1014. 11. Ware JE, Kosinski M, Dewey JE: How to Score Version Two of the SF-36 Health Survey Lincoln, RI: QualityMetric, Incorporated; 2000. 12. Rabin R, de Charro F: EQ-5D: a measure of health status from the EuroQol Group. Ann Med 2001, 33:337-343. 13. Szende A, Williams A, Eds: Measuring Self-Reported Population Health: An International Perspective Based on EQ-5D Budapest: SpringMed Pub- lishing Ltd; 2004. 14. Drummond MF, O'Brien B, Stoddart GL, Torrance GW: Methods for the Economic Evaluation of Health Care Programs 2nd edition. New York: Oxford Medical Publications; 1997:163-164. 15. EuroQol Group: EuroQoL – a new facility for the measure- ment of health-related quality of life. Health Policy 1990, 16:199-208. Page 8 of 9 (page number not for citation purposes)