Efficacy of CBT-I With Adjuvant Melatonin in Older Adults Chronic Insomnia

Insomnia symptoms measured by Insomnia Severity Index (ISI). ISI is a 5-item self-rated scale. Possible scores range from 0 to 20, with higher scores indicating greater insomnia severity.

Defined as a decrease of ≥ 8 points on the ISI (self-reported)

Insomnia remission is defined as an ISI score less than 8. The outcome will be reported as the number and percentage of participants meeting remission criteria.

Pittsburgh Sleep Quality Index (PSQI) is a self-rated scale consisting of 19 questions. All items are combined to form seven component scores on different aspects of sleep quality, each of which ranges from 0 to 3 points with higher scores representing more sleep disturbance. The seven component scores are added to one global score, which ranges from 0 to 21, with higher scores indicating more difficulties with sleep.

The Munich Chronotype Questionnaire (MCTQ) is a self-report measures of sleeping patterns during weekdays and weekends separately. The Mid-Sleep Time (MSF/MSFsc) are used to as an indicator of chronotype, where individuals with earlier mid-sleep time reflect a morning chronotype and later mid-sleep time reflect an evening chronotype.

The Morningness-Eveningness Questionnaire (MEQ) is a 19-item self-assessment tool used to determine an individual's chronotype with a total score between 16 and 86. A higher score indicates a morning chronotype (e.g., "morning type"), a lower score indicates an evening chronotype (e.g., "evening type"), and a mid-range score indicates an intermediate chronotype.

Hospital Anxiety and Depression Scale (HADS), a 14-item self-report questionnaire used to screen for anxiety and depression in a patient's recent past week. The depression subscale ranges in scores from 0 to 21, with higher scores indicating more severe states of depression. Similarly, the anxiety subscale ranges in scores from 0-21 with higher scores indicating more severe states of anxiety.

Epworth sleepiness scale, a short self-assessment to identify how likely you are to fall asleep during the daytime. Scores range from 0 to 24, a higher score indicates a higher level of excessive daytime sleepiness.

Multidimensional Fatigue Inventory (MFI) is a 20-item self-rated scale on fatigue symptoms. There are three subscales, measuring the physical (possibly scored from 7 to 35), mental (possibly scored from 6 to 30), and spiritual (possibly scored from 7 to 35), dimensions of fatigue. A grand total score can be calculated by summing up the three sub scores. In all cases, a higher score represents higher fatigue symptoms.

Clinical Global Impression (CGI) Scale is a clinician-rated scale, comprised of two one-item subscales: Severity of Illness (CGI-S) subscale evaluating the severity of psychopathology, and Clinical Global Improvement Scale (CGI-I) evaluating change from the initiation of treatment. In both cases, the score is given on a seven-point scale, with higher values indicating higher severity of illness and larger improvement, respectively. CGI-S will be used to evaluate the overall severity of clinical symptoms.

Clinical Global Impression (CGI) Scale is a clinician-rated scale, comprised of two one-item subscales: Severity of Illness (CGI-S) subscale evaluating the severity of psychopathology, and Clinical Global Improvement Scale (CGI-I) evaluating change from the initiation of treatment. In both cases, the score is given on a seven-point scale, with higher values indicating higher severity of illness and larger improvement respectively. Overall treatment response is defined as CGI-I <3 (clinician-rated)

The SF-36, or Short Form 36 Health Survey, is a 36-item patient-reported questionnaire that measures health status and quality of life. It assesses eight different health domains, including physical functioning, bodily pain, vitality, general health, role-physical, role-emotional, social functioning, and mental health. Total scores range from 0 to 100, where higher scores indicate better health.

The stop-signal task is a behavioural task that measures a person's ability to inhibit a pre-programmed response. The main measure of inhibitory control is the stop-signal reaction time (SSRT), which estimates the time it takes to cancel a response. A longer SSRT indicates a slower ability to inhibit a response.

Psychomotor Vigilance Task (PVT) is a reaction-time test that measures sustained attention by having a person respond as quickly as possible to a visual stimulus that appears at random intervals. Reaction Time (RT): The primary measurement is how quickly the participant responds to the stimulus. Lapses: A lapse is a failure to respond to the stimulus within a certain time frame, often defined as a reaction time longer than 500 milliseconds.

N-back Task for assessing working memory capacity and manipulation. In N-back Task, a d prime score will be calculated based on the signal detection theory, where a higher score indicates better working memory performance.

Wisconsin Card Sorting Test for assessing problem solving. In Wisconsin Card Sorting Test, lower executive functioning is indicated by a higher percentage of persistent errors and a higher number of trials taken to complete the first category.

Chinese Auditory Verbal Learning Task for assessing episodic memory, where a higher number of recalled words indicates better episodic memory performance.

Multifactorial Memory Questionnaire (MMQ) is a 57-item self-report assessing memory satisfaction, ability and strategy use (three subscales).For each subscale, score ranges: for each subscale: Satisfaction (0-72), Ability (0-80), and Strategy (0-76). A higher score generally indicates better self-reported memory functioning, higher satisfaction with memory, and greater use of memory strategie

Beck Depression Inventory-II (BDI-II) is 21-item self-report of depressive-symptom severity during the past two weeks (0-63). Higher scores indicate more severe depressive symptoms

The Hamilton Rating Scale for Depression (HAM-D17) is a 17-item interview to assess the severity of depression symptoms. Scores are interpreted based on a range: 0-7 indicates no depression, 8-16 is mild, 17-23 is moderate, and 24 or higher is severe depression.

Dysfunctional Beliefs and Attitudes about Sleep Scale (DBAS): 16 statements evaluating maladaptive sleep-related cognitions (0-160). A higher score indicates a higher level of dysfunctional, unhelpful, or rigid beliefs about sleep.

Cognitive Failures Questionnaire; 25 items indexing self-reported failures in attention, memory and action execution, 0-100. Indicates a higher frequency of everyday cognitive failures.

Pre-Sleep Arousal Scale (PSAS): 16 items measuring somatic and cognitive arousal at bedtime (8 each; 1-5 Likert, total score range 8-40). Higher scores indicate greater pre-sleep physical distress.

Ford Insomnia Response to Stress Test (FIRST): 9-item trait measure of likelihood that stress will provoke insomnia (0-36).

Sleep Hygiene Practices Scale (SHPS): 30 items assessing frequency of behaviours affecting sleep quality (0-120). Higher scores indicate more maladaptive (unhealthier) sleep hygiene practices

Daily sleep diary for consecutive seven days. Sleep parameter estimated by daily sleep diary: time in bed (TIB) in hours

Daily sleep diary for consecutive seven days. Sleep parameter estimated by daily sleep diary: total sleep time (TST) in hours

Daily sleep diary for consecutive seven days. Sleep parameter estimated by daily sleep diary: sleep onset latency (SOL) in mins

Daily sleep diary for consecutive seven days. Sleep parameter estimated by daily sleep diary: wake after sleep onset (WASO) in mins

Daily sleep diary for consecutive seven days. Sleep parameter estimated by daily sleep diary: sleep efficiency (SE), which is calculated by total sleep time divided by total time in bed, %

The duration of time spent in bed attempting to sleep, estimated from 7-night wrist actigraphy. Reported as mean minutes per night across the recording period.

The total amount of sleep obtained during a sleep period, estimated from 7-night wrist actigraphy. Reported as mean minutes per night across the recording period.

The amount of time it takes to fall asleep after attempting to do so, estimated from 7-night wrist actigraphy. Reported as mean minutes per night across the recording period.

The amount of time spent awake after initially falling asleep, estimated from 7-night wrist actigraphy. Reported as mean minutes per night across the recording period.

The standard deviation of the sleep midpoint, defined as (sleep onset + sleep offset) / 2, across the 7-night recording. Higher values reflect more irregular sleep timing across nights.

The percentage of time spent asleep while in bed, calculated as (TST / TIB) × 100, estimated from 7-night wrist actigraphy.

The clock time of maximum activity estimated from a cosinor model fitted to the 7-day rest-activity record. Represents the timing of peak daily activity.

The difference between the peak and nadir of the cosinor-fitted rest-activity curve across the 7-day recording. Reflects the overall strength of the circadian rest-activity rhythm.

An index ranging from 0 to 2 quantifying the degree of rest-activity rhythm fragmentation. Higher values reflect greater fragmentation, indicating more daytime napping or nocturnal awakening.

An index ranging from 0 to 1 reflecting the synchronisation of the rest-activity rhythm to the 24-hour light-dark cycle. Higher values reflect stronger synchronisation.

The clock time of onset of the 5 least active consecutive hours across the 7-day recording, presumed to represent the habitual sleep window.

Actigraphic assessment for consecutive seven days. Circadian parameters computed by the nonparametric circadian rhythm analysis method - start times and average activity of M10 (i.e. 10 h with maximal activity).

Actigraphic assessment for seven consecutive days. The standard deviation of the midpoint of sleep will be derived from actigraphy, defined as sleep onset + sleep offset) / 2, across the 7-night recording.

DLMO time to sleep-onset phase angle: Interval (min) from DLMO time to diary-determined sleep-onset time. Sleep-onset time will be calculated as the mean sleep-onset time across valid diary nights.

Dim-light melatonin onset (express as time value hh:mm) is determined by 6-hours salivary melatonin collected at 30-minutes interval. Melatonin is assayed by gas chromatography-mass spectrometry.

DLMO time: Clock time (hh:mm) at which salivary melatonin first exceeds the 3 pg mL-¹ threshold under < 10 lux illumination.

DLMO time to sleep-midpoint phase angle is the initerval (min) from DLMO time to diary-determined sleep midpoint. Sleep midpoint will be calculated as halfway between sleep onset and final sleep offset/waketime.

Interval (min) from DLMO time to diary-determined lights-off/bedtime; indexing the timing of attempted sleep relative to biological night onset. Lights-off/bedtime will be calculated as the mean diary-reported lights-off/bedtime across valid diary nights.

T75 recovery time is the seconds from stimulus offset to 75% return toward baseline pupil diameter, reflecting the post-illumination pupil response (PIPR), a melanopsin-mediated circadian biomarker.

Objective sleep parameter derived from overnight polysomnography: time in bed (TIB) in hours, measuring the total duration from lights-out to lights-on.

Objective sleep parameter derived from overnight polysomnography: total sleep time (TST) in hours.

Objective sleep parameter derived from overnight polysomnography: sleep efficiency (SE) expressed as a percentage, calculated as total sleep time divided by time in bed.

Objective sleep parameter derived from overnight polysomnography: sleep latency in minutes, measuring the time interval from lights-off to the onset of the first scored sleep stage.

Objective sleep parameter derived from overnight polysomnography: wake after sleep onset (WASO) in minutes, measuring the total duration of wakefulness recorded after initial sleep onset.