This study is a randomized controlled trial, nested in the SKETHIS e-cohort, aiming to evaluate whether adding a modest, narrative-driven, strorytelling introduction to a Patient-Reported Outcome questionnaire increases completion without compromising data quality.

This trial is led by SKEZI, a DeepTech start-up which markets a data collection solution and carries out the InnoPRO program, aimed at generating new knowledge in the field of e-cohorts.

SKETHIS is a national e-cohort that serves as an observatory of health-related quality of life in France. Launched in September 2023 by SKEZI, the cohort is built as a secure health-data warehouse hosted on the SKEZIA data-collection solution. While its primary aim is to monitor health-related quality of life, its trajectories and determinants, SKETHIS is also the opportunity for SKEZI to carry out its InnoPRO program, an initiative dedicated to generate new knowledge in the field of e-cohorts.

Gamification, i.e. the integration of game-design elements, such as points, levels, or badges into non-game contexts, has been shown to increase usage, prolong retention and improve adherence to e-health services. Storytelling is a specific gamification tool that employs narrative techniques (voices, story characters, suspense, etc.) to structure a coherent, accessible and engaging participants' experience.

Improving and maintaining participant engagement is a major challenge for large-scale e-cohorts. Although gamification and storytelling have been empirically used to boost participation, the effect of storytelling on self-administered patient reported outcome questionnaires has not been evaluated in a rigorously designed randomized clinical trial.

Purpose of the study To determine whether adding a modest, narrative-driven storytelling introduction to a Patient-Reported Outcome questionnaire increases questionnaire completion without compromising data quality.

How the study will be done

This study is a parallel-group randomized controlled trial nested within SKETHIS. All eligible SKETHIS participants (i.e. participants who have completed the first questionnaire and socio-demographic questionnaire) will be randomly assigned to one of two groups:

1. Intervention: Patient-Reported Outcome Questionnaire with storytelling
2. Control: Patient-Reported Outcome Questionnaire without storytelling The same Patient-Reported Outcome questionnaire (French version of the Global Physical Activity Questionnaire [GPAQ]) will be used in both groups (with the same questions). The introduction page and design of the questionnaire will differ between the two groups: short narrative with minimal visual design (color palette, icons, illustrations) for the intervention group; neutral (plain text, no narrative, no visual embellishment) for the control group.

Questions the study will answer

• Does the storytelling increase completion rate of the questionnaire (proportion of participants who fully completed the questionnaire) within 30 days, compared to the neutral (control) version?
• Does the storytelling improve participants' self reported satisfaction (Net Promoter Score) after questionnaire completion?
• Does the storytelling reduce the drop out (abandonment) rate - i.e., the proportion of participants who start the questionnaire but do not finish it - within 30 days of receipt?
• Does the storytelling affect the quality of the data collected?

Hypothesis Investigators hypothesized that the integration of storytelling in self-reported Patient-Reported Outcome questionnaire will increase completion rates and participants' satisfaction, without negatively impacting data quality.

Why this matters Finding ways to increase engagement in SKETHIS, and other online cohorts, will help improving the quantity and quality of the data that can be used for future health research. The results will be shared in a peer reviewed scientific article and could guide the design of future e cohort studies worldwide.

Inclusion Criteria:

• Being a current SKETHIS participant (eligibiliy criteria: being 18 or older, living in France, reading and understanding French, having a digital device with internet access and a valid e-mail address)
• Having completed the main SKETHIS questionnaire and the socio-demographic information questionnaire
• Providing consent to participate to the study

Exclusion Criteria:

- Answering "I am unable to walk out" to the EQ-5D mobility item part of the main SKETHIS questionnaire (cannot complete Global Physical Activity Questionnaire)

Participants are unaware that the trial was being conducted, and the researchers and data analysts were blind to participants' assigned groups.