Impact of verb tense on response to the Four-Dimensional Symptom Questionnaire (4DSQ)

The verb tense of a questionnaire hypothetically might influence the way people respond to its items. We examined the effects of the verb tense on the response to the Four-Dimensional Symptom Questionnaire (4DSQ) in a population-based sample (N = 4,959; present tense N = 605; past tense N = 4,354). We determined whether the verb tense impacted the overall response rate, the scale structure, differential item functioning, reliability, proportions of respondents scoring above a range of cut-offs, and mean scale scores. The verb tense did not influence response rate, scale structure, item functioning, and reliability. The present tense increased the number of respondents scoring above very low cut-offs for distress and somatization. The effect on mean scale scores was limited and of little clinical importance.
Keywords: verb tense, questionnaire response, confirmatory factor analysis, differential item functioning, measurement properties