Learn More about Surrogate Reporting
When a person cannot report for him or herself, another person who is knowledgeable about that person's diet can be asked to report. These surrogate reports generally are not totally accurate because the surrogate seldom knows everything the study participant consumed. Surrogate reports may contain additional error due to the surrogate reporter's assumptions and biases, such as social desirability (Learn More about Social Desirability). In the case of spouses reporting each other’s diets, one study found that the individual's report for oneself is more accurate than the spouse's report for that individual.
When surrogate reports are necessary (e.g., young children or disabled persons), the surrogate reporter who is most knowledgeable about the participant's diet should be asked to report. Questions for the surrogate reporter about his perception of how accurate his report is, and his relationship to the study participant may be useful for data cleaning, stratification of data, or sensitivity analyses.
For More Information
Metzner HL, Thompson FE, Lamphiear DE, Oh MS, Hawthorne VM. Correspondence between perceptions of change in diet and 15-year change in diet reports in the Tecumseh Diet Methodology Study. Nutr Cancer 1988;11(1):61-71. [View Abstract]
Samet JM, Alberg AJ. Chapter 8. Surrogate sources of dietary information, in Willett W, Nutritional Epidemiology. Oxford University Press: New York, NY. 1998