OBJECTIVES : Discrete choice experiments (DCEs) are valuable for understanding and quantifying participant preferences of health interventions and their associated attributes. Choice tasks can be taxing on the respondent and engagement is necessary to produce reliable results. However, when in-person interviews are infeasible, participant-led, portal-based surveys may be conducted. Often, patient recruitment is achieved through online patient panels; in this setting, survey “speedsters” are common. We evaluated two methods of sensitizing DCE respondents to the importance of respondent engagement.

METHODS : We tested two sensitizing methods in the context of a DCE evaluating patient preferences towards toenail fungus treatments. First, we added text describing the importance of carefully considering each preference task, and the potential end-stage implications of this research, just prior to the DCE. In the second, participants were contacted via phone to relay similar information. A third control group without sensitization was included. Time to survey completion was recorded in all cases and the distributions of times were compared using the Wilcoxon rank sum test as data were not normally distributed.

RESULTS : Median (Q1 – Q3) completion time (minutes) for the no sensitization group (n = 31) was 9.7 (5.2 – 14.9); the text sensitization group (n = 31) was 10.7 (8.3 – 16.4); and the phone sensitization group (n = 187) was 16.8 (12.4 – 25.4). Compared with no sensitization, the difference in the distribution of completion times for text sensitization was not statistically significant (p = 0.20); however, for those who received phone sensitization, there was a statistically significant difference in the distribution of completion times compared to those with no sensitization (p < 0.0001).

CONCLUSIONS : Sensitization methods involving in-person phone calls prior to conducting self-led, internet portal based DCEs may increase participant engagement producing more reliable results. The implications are widespread given the increasing necessity of conducting research using online surveys.