JMIR Publications

ABSTRACT

Background:

Autonomous motivation, grounded in Self-Determination Theory (SDT), is critical for sustaining diabetes self-care behaviors. While mobile health (mHealth), gamification, and peer support are increasingly used to foster motivation, evidence on the long-term trajectory and the temporal dynamics of these psychological changes remains limited. However, it is unclear whether motivation increases linearly or follows a more complex non-linear course, such as peaking and then declining. Understanding how motivation changes over time is crucial for designing adaptive interventions to support diabetes self-care.

Objective:

The objective of this study was to characterize the one-year developmental trajectory of autonomous motivation following the real-world introduction of a commercially available team-based gamification app.

Methods:

This prospective, single-arm longitudinal study involved adults with type 1 or type 2 diabetes recruited from outpatient clinics in Japan. Participants were instructed to use a team-based gamification app promoting self-care through peer support, for at least seven days. The primary outcome, autonomous motivation, was assessed using the Treatment Self-Regulation Questionnaire (TSRQ-AM) at baseline, 6 weeks, 6 months, and 1 year. Secondary measures included HbA1c and psychological scales (eg, PCDS, SDSCA, PAID-5, WHO-5). To analyze the trajectory, we used Linear Mixed-effects Models (LMMs) with random intercepts for participants. The final model included fixed effects for time (as both linear and quadratic terms), age, sex, employment status, family structure, baseline BMI, and baseline HbA1c.

Results:

Of 32 enrolled participants, 29 completed follow-up assessments and were included in the main analysis. For the primary outcome, the LMM analysis revealed that a model including a quadratic term for time provided a significantly better fit than a linear-only model (χ²(1) = 4.96, p = .026). The LMM identified a significant quadratic effect of time (β = –7.9, p = .028), indicating that autonomous motivation increased after baseline, peaked at 6 months, and modestly declined by 1 year while remaining above baseline. The model explained 83% of variance (conditional R² = 0.83). Among the covariates, higher baseline BMI was significantly and independently associated with lower autonomous motivation across all time points (β = –1.0, p = .001). The secondary outcome, HbA1c, showed no significant change (p =.395).

Conclusions:

This formative study provides preliminary evidence of a non-linear, one-year trajectory of autonomous motivation following introduction of a team-based app. The observed curvilinear pattern suggests that app-supported motivation may peak around 6 months, underscoring the importance of adaptive intervention designs to maintain engagement over time. Moreover, the inverse association between baseline BMI and motivation highlights the need to tailor mHealth strategies for individuals with higher BMI. Clinical Trial: Although this study was not a randomized controlled trial, it was prospectively registered with the UMIN Clinical Trials Registry (UMIN000044874; https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000051253).