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Longitudinal Evaluation of a Cross-Device Platform for Anhedonia Trend Visualization Using Ecological Momentary Assessment and Moving Averages (Part 2): Protocol for a 24-Week Multicenter Prospective Observational Study
ABSTRACT
Background:
Repeated assessment can describe anhedonia over time, but interpretable temporal signals require evaluation under realistic missingness and participant burden. Moving averages compare recent experience with longer-term patterns without assuming that a smoothed trajectory is a validated clinical warning.
Objective:
This second-year study will evaluate the feasibility and temporal information of 7-, 14-, and 30-day moving averages in a cross-device anhedonia monitoring platform, extending the published Part I methodological protocol.
Methods:
This prospective observational study in Taiwan targets 202 participants: 101 psychiatric outpatients and 101 university students. A separate implementation cohort comprises 30 hospitalized service members. Participants undertake 24 weeks of ecological momentary assessment using a current-state adaptation of the Snaith-Hamilton Pleasure Scale, targeting 3 participant-initiated assessments per day with 5-hour spacing. Optional evening LINE reminders depend on noncompletion, while participants can view descriptive weather and trend feedback. One daily mean will support calendar-defined moving averages. Three crossover pairs will be compared in 100 northern participants, with a selected rule evaluated without retuning in 102 central participants. The target is a first observed sustained threshold-state transition within the subsequent 14 days. Evaluation includes computational availability, event capture, false-signal burden, lead time, and comparison with the current score. Missingness sensitivities and continuous level, slope, and instability features are secondary analyses.
Results:
The funded project began on August 1, 2026. As of September 22, 2026, recruitment is ongoing and no outcome analyses have been conducted. The grant work plan schedules recruitment through March 2027 and analysis activities during April-July 2027. Final analysis will follow completion of the relevant 24-week observation periods; enrollment continuing through March would extend final follow-up to September 2027.
Conclusions:
The study will establish the achievable observation density and assess whether moving-average signals add temporal information beyond current anhedonia severity. Forecasting within the same symptom series will be interpreted separately from independently verified clinical deterioration or clinical benefit.
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