Using visual analogue scales in ehealth: Non-response effects in a lifestyle intervention

Background: Visual analogue scales (VASs) have been shown to be valid measurement instruments and a better alternative to Likert-type scales in Internet-based research, both empirically and theoretically [1,2]. Upsides include more differentiated responses, better measurement level, and less error. Their feasibility and properties in the context of eHealth, however, have not been examined so far. Objective: The present study examined VASs in the context of a lifestyle study conducted online, measuring the impact of VASs on distributional properties and non-response. Method: A sample of 446 participants with a mean age of 52.4 years (standard deviation (SD) = 12.1) took part in the study. The study was carried out as a randomized controlled trial, aimed at supporting participants over 8 weeks with an additional follow-up measurement. In addition to the randomized questionnaire, participants were further randomly assigned to either a Likert-type or VAS response scale version of the measures. Results: Results showed that SDs were lower for items answered via VASs, 2P (Y ≥ 47