Sometimes it is not possible to have a parent (or a professional) complete a questionnaire all at one time. It may be better not to complete the ASQ all on one home visit and tire the child and parent. As long as the questionnaire is completed within a week or two from the start date, the results should still be valid. With 4- to 5-year-old children, completion of the questionnaire within a 3- or 4-week timeframe is acceptable.
However, if a child’s score falls in the monitoring zone or below the cutoff on ASQ-3, it would be good to go over the items with “sometimes” and “not yet” answers with families to see if the child has acquired these skills during the time between visits. If so, then the score should be recalculated. If a child transitions to a new age interval (from the 6 month questionnaire to the 8 month questionnaire, for example) during the time period between visits, it makes it very difficult to continue the earlier questionnaire. When we researched test-retest reliability with a 2- to 3-week time frame, we did find that some infants and toddlers had learned new skills during the timeframe and thus didn’t get exactly the same score on the questionnaire.