For example, Taiwan FBS listed green leaves, roots, bulbs and tubers, flowers and fruits, and mushroom as subgroups of the vegetables group, while FAO assigned the vegetable subgroup items as tomatoes, onions, beans, peas, aquatic plants, and other vegetables; therefore, we compared the whole vegetables group only, not the vegetable subgroup items.
No significant correlations were found for the other CAP subgroups, items or total score.
For the reliability analysis for the 2 to 4 age subgroups, items on the School Functioning Scale were excluded from the analysis given that toddlers do not necessarily attend school or daycare and thus, depending on whether their child was enrolled in school or daycare, parent proxy respondents were given the option of completing the School Functioning items.
None of the Korean RCTs reported the critical criteria of subgroup analyses (item #18) including the use of subgroup variables measured at baseline, the prespecification of subgroup hypotheses, and the statistical significance of interaction tests.
18 Most studies used all the CONSORT-harms criteria with the exception of the subgroup analysis item; one study 16 however, discarded the use of recommendation eight, since it was captured elsewhere within the data extraction, and recommendation 10, which was considered too vague to assess with any objectivity.
Subsequently, these factors were categorized into subgroups for item bias analyses, aiming for an equivalent distribution of participants among the subgroups (25 33% per subgroup).
Table 1 listed the serving quantities of the six food groups and some important subgroup food items, which were derived from 2007 FBS data.
We calculated combined and subgroup internal reliability, item statistics, and performance.
The difference in expected scores on items 3, 7 and 19 was not considered a problem, because differences between expected scores were not extreme, the place of this difference on the disability continuum was near the extremes, and DIF was only found for one subgroup variable per item.
DIF refers to the situation when the individuals across subgroups rate an item differently (e.g., item score three by one subgroup and four by another) given the same underlying construct.
