Table 4 Criteria used to develop items for complementary medicine questionnaires ¹

1 Literacy level of questions at 8^th grade or below

2. Specific questions are generally easier to answer than broad ones

8. Questions covering multiple concepts are decomposed into single questions

3. Question captures what researcher intended (i.e. every respondent answering the same question)

9. Questions are designed to avoid social desirability effects

4. Question interpreted as intended by persons in a range of socio-demographic groups

10. Avoid:

   a. questions worded in the negative

5. Response categories fit the question and are non-overlapping, clear and unambiguous

   b. complex questions

   c. questions combining two items in one (double barreled)

6. Reference periods are clear and match respondent’s ability to recall

   d. jargon

   e. ambiguous terms

7. Terms and definitions are defined

   f. questions that lead respondents toward a particular answer