A Randomized Controlled Trial to Evaluate the Efficacy of a Sleep Intervention by To-Do Application (Keepee) for Improving Insomnia Symptoms

INTERVENTION: Behavioral : Study Intervention Design This study is designed as a double‐blind, two‐arm parallel, randomized controlled trial. The total study duration is 9 weeks, consisting of three phases: screening/adaptation period (Weeks 0–1), intervention period (Weeks 2–5), and follow‐up period (Weeks 6–9). Group Assignment Component Experimental Group Control Group Keepee app (general To‐Do + basic AI) O O Insomnia subtype classification + personalized sleep To‐Do O X Sleep‐specialized AI agent O X Sleep diary (brief CSD) O O Sleep education materials (once weekly, 4 sessions total) O O Randomization Stratified block randomization will be employed. Stratification variables are ISI severity (mild: 8–14 vs. moderate or greater: 15–28) and se X(male vs. female), yielding a total of 4 strata. Permuted block randomization with variable block sizes (4 or 6) will be applied within each stratum to prevent allocation prediction. The allocation ratio is 1:1 (intervention:control). Randomization will be performed by an independent statistician according to a computer‐generated randomization table. Blinding This study adopts a double‐blind design. Although complete blinding of participants and study personnel is not feasible given the nature of the intervention, the following measures will be applied to minimize bias. Participant partial blinding: Participants will be informed that the study compares "two types of sleep management programs," without disclosure of which arm constitutes the intervention group. Statistical analyst blinding: The statistical analyst will perform the primary analysis using a dataset coded only with group allocation codes (A/B), with code disclosure occurring after analysis completion. CONDITION: Mental and behavioural disorders PRIMARY OUTCOME: Insomnia Severity Index, ISI SECONDARY OUTCOME: Pittsburgh Sleep Quality Index‐Korean (PSQI‐K) Patient Health Questionnaire‐9 (PHQ‐9) Generalized Anxiety Disorder‐7 (GAD‐7) Korean Version of Epworth Sleepiness Scale (KESS) Sleep Health Inde X(SHI) Sleep Hygiene and Practices Scale (SHPS) Dysfunctional Beliefs and Attitudes about Sleep‐16 (DBAS‐16) Morningness‐Eveningness Questionnaire (MEQ) Bedtime Procrastination Scale (BPS) Ford Insomnia Response to Stress Test (FIRST) Body Sensations Questionnaire (BSQ) Korean Resilience Quotient‐53 (KRQ‐53) Multidimensional Fatigue Scale (MFS) Alcohol Use Disorders Identification Test (AUDIT‐K) Smartphone Overuse Screening Questionnaire (SOS‐Q) Seasonal Pattern Assessment Questionnaire (SPAQ) Biological Rhythms Interview of Assessment in Neuropsychiatry (K‐BRIAN) Spiritual Well‐Being Scale (SWBS) International Physical Activity Questionnaire‐Short Form (IPAQ‐SF) Nightmare Severity Inde X(NSI‐K) World Health Organization Quality of Life‐BREF (WHOQOL‐BREF) Berlin Questionnaire (BQ) International Restless Legs Syndrome Rating Scale (IRLS) Insomnia Subtype Classification Questionnaire (20 items) Sleep Literacy Quiz‐12 (SLQ‐12) Brief Sleep Diary (sleep efficiency, sleep onset latency, wake after sleep onset, total sleep time) App usage log (daily access frequency, To‐Do completion rate, AI agent interaction frequency) User Satisfaction Questionnaire (System Usability Scale, SUS; meCUE) Adverse Event Assessment INCLUSION CRITERIA: Adults aged 19 to 75 years Individuals reporting marked dissatisfaction with sleep quantity or quality, with at least one of the following symptoms occurring = 3 nights per week for = 3 months: difficulty initiating sleep, frequent nocturnal awakenings, or early morning awakening Insomnia Severity Inde X(ISI) score = 8 (mild or greater insomnia symptoms) Possession of a smartphone (Android or iOS) with the ability to use basic app functions Individuals who voluntarily agree to participate in the study and have signed a written informed consent form