Table 2.

Category	Sub-category
1. Recall difficulty	Recall of events Recall of frequency of asthma-related difficulties Recall of severity of asthma-related difficulties Recall of frequency of medication use
2. Respondent bias	Social desirability Embarrassment Lying to appear truthful or honest Lying to hide illness severity from parent Fear of punishment
3. Interviewer bias	Cultural bias A priori expectations/hypotheses Judgment
4. Frustration	Irrelevant questions Respondent burden
5. Coercion/parental influence	Strong parental opinion Overriding child’s answers Answering for child
6. Inter-relational conflict	Conflict avoidance Conflict aversion Laying blame
7. Psychic discomfort for health states	Concerns about past, present and future health and ability
8. Emotional sensitivity	Anxiety induction Physical burden of illness Psychological burden of illness
9. Parent as advocate	Providing interviewer with additional relevant information about child Checking with child to ensure comfort with the interview process
10. Parent as enabler	Ensuring child’s learning and other needs are met by disclosing them to interviewer Encouraging child to answer based on their own feelings and perceptions Providing child with examples of past events and activities to enable them to answer standardized questions Providing child with positive feed back Interpreting question/statement for child in words the child understands Repeating question Discussing and negotiating answer with child Providing child with examples that help put the question into context
11. Comprehension	Difficulty understanding the meaning of a particular word Difficulty understanding the meaning of a question or statement