Pica.

At 36, 54, 65, 77, and 115 months, mothers were asked, “How often does the child eat coal, dirt, or other non-nutritious substances?” Response options included “every day,” “at least once a week,” “less than once a week,” and “not at all.” Pica behavior in the current study was defined as any respondent option that indicated pica occurred “every day,” “at least once a week,” and “less than once a week.” When examining differences in pica between subgroups, a binary “yes/no” pica variable was created. When mothers answered “yes,” to the pica item, they were required to include what the child consumed so that the provider could confirm the parent interpreted the question correctly. This strengthens the validity of the single-item measure.