Underreporting the use of dietary supplements and nonprescription medications among patients undergoing a periodic health examination.
OBJECTIVE
To compare the use of dietary supplements and nonprescription medications as reported on a written medical questionnaire with use reported during a structured interview.


METHODS
We conducted a prospective study of 200 subjects randomly selected among patients undergoing a periodic health examination in two divisions of the Department of Internal Medicine at Mayo Clinic Rochester--100 patients from a national cohort of executives and 100 community patients.


METHODS
Written information on self-reported use of supplements and nonprescription medications was obtained as part of a comprehensive medical questionnaire. Subjects were then interviewed and asked about the use of supplements and nonprescription medications. In addition, the reason for using supplements was elicited and recorded.


RESULTS
The prevalence of use of dietary supplements was 30.5% by written self-report in comparison with 61.0% reported during the structured interview. The results were consistent between executive and community patients. In response to questions about taking nonprescription medications, 24.5% of patients reported such use on the medical questionnaire in comparison with 42.5% when interviewed. The most common dietary supplements taken were multivitamins (41.5%), followed by vitamin E (24.0%) and vitamin C (23.0%). The most common nonprescription medications taken were aspirin (16.5%) and ibuprofen (13.0%). Most frequently, patients indicated that they were using supplements to promote health.


CONCLUSIONS
In this study, half the patients who took dietary supplements and almost half who took nonprescription medications did not report them to their healthcare provider on a written questionnaire, even though this information was requested. Patients should be specifically asked about use of dietary supplements and nonprescription medications, even if written information about such use is provided.
D003142:Communication; D019587:Dietary Supplements / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008910:Minnesota; D004366:Nonprescription Drugs / Q000627:therapeutic use*; D010507:Periodicity; D010808:Physical Examination; D015995:Prevalence; D011446:Prospective Studies; D012651:Self Medication / Q000706:statistics & numerical data*; D012737:Sex Factors; D011795:Surveys and Questionnaires