Cost-utility Study of Cognitive-behavioral Management of Auditory Hallucinations in Schizophrenic Disorder

Incremental cost-utility ratio (ICUR) at 12 months, of the management of auditory hallucinations by CBT compared to usual treatment. The preferred outcome criterion is the QALY (Quality Adjusted Life Years) unit of measurement of the duration of life weighted by the quality of life related to health (HAS 2020), calculated from the utilities derived from the EuroQuality of life 5 dimensions questionnaire (EQ5D-5L).

Using the Psychotic Symptom Rating Scales - Auditory Hallucinations (PSYRATS-AH; Haddock et al., 1999; Favrod et al., 2012 for French validation), a hetero-questionnaire consisting of 11 items designed to measure the severity of various dimensions of the auditory hallucination experience. The items are grouped into four factors: distress (negative content, distress, and control), frequency (frequency, duration, and disruption), attribution (location and origin of the auditory hallucinations), and intensity of sound. Each item is rated on a scale from 0 ("not at all") to 4 ("always"). The total score ranges from 0 to 44.

Using The Beliefs About Voices Questionnaire (BAVQ-R, Chadwick and al, 2000) a self-report questionnaire that assesses beliefs, emotional, and behavioral consequences related to auditory hallucinations (AHs). It initially contains 35 items, each rated from 0 ("strongly disagree") to 3 ("strongly agree"), and is divided into 5 subscales: Power, Malevolence, Benevolence, Resistance, and Engagement. We will consider the total score for the four subscales: Power, Malevolence, Resistance, and Engagement (total score ranging from 0 to 12).

The Maastricht Semi-structured Interview, developed by Romme and Escher (2000), is a precursor to the early work on the experience of AVHs in the Netherlands. It allows for the assessment of this phenomenological experience through a variety of individual variables such as intensity, volume, and number of AVHs, while also addressing the individual's environmental spheres and potential journey through different psychiatric care services.

Auditory Hallucination Rating Scale (AHRS), French validation by Dondé et al., 2020. This scale includes 7 questions regarding the frequency, intensity, or intentional valence of AVHs.

Hallucination Relationship Scale (Approve Questionnaire, Hayward et al., 2020). This scale consists of 30 items measuring both assertiveness in relation to AVHs and assertiveness in everyday life in human relationships.

For the psychotic symptoms, the "Positive And Negative Syndrome Scale" (PANSS): The PANSS is a 30-item hetero-assessment scale, rated from 1 to 7, which measures the symptomatology specific to psychotic disorders, particularly schizophrenic disorders. It calculates scores for 3 syndromic dimensions: positive (7 items), negative (7 items), and general psychopathology (16 items), from both a categorical and dimensional perspective.

For the comorbidities,the "Mini International Neuropsychiatric Interview" (M.I.N.I) is a structured diagnostic interview, with a short duration (approximately 20 minutes) exploring in a standardized way, the main psychiatric disorders according to the DSM IV. The M.I.N.I version 5.0 is divided into identified modules, each corresponding to a diagnostic category. We will use modules A, D, E, F, G, H, I, M, N, O.

Calgary Depression Scale for Schizophrenia (CDSS, Addington & Addington, 1990). This scale is designed to assess depression in individuals with schizophrenia. The questionnaire consists of 9 items (depressed mood, despair, self-deprecation, reference ideas with a theme of guilt, pathological guilt, morning depression, early awakening, suicidal thoughts, and observed depression) covering the past two weeks. Each item is rated on a 4-point Likert scale ranging from: "Absent" (0) to "Severe" (3). The total score is obtained by adding the items and provides a score out of 27.

Columbia Suicide Severity Rating Scale (C-SSRS, Posner et al., 2011). The C-SSRS measures four dimensions. The first is the severity of suicidal ideation, which is assessed on a 5-point ordinal scale. The second is the subscale of intensity of suicidal thoughts, which includes 5 items, each rated on a 5-point ordinal scale: frequency, duration, controllability, deterrents, and reason for ideation. The third is the behavioral subscale, assessed on a nominal scale, which includes actual, aborted, and interrupted attempts, preparatory behavior, and non-suicidal self-injury. The fourth is the lethality subscale, which evaluates actual attempts; actual lethality is rated on a 6-point ordinal scale. Suicidal risk is ultimately determined by the clinician's judgment when administering the scale.

PERMA Psychological Well-Being Scale (Seligman, 2011). This scale consists of 10 items encompassing four factors: positive emotion, relationships, having a sense of purpose in life, and personal accomplishment. Each question is rated on an 11-point Likert scale, ranging from "0 = never" to "10 = always," "0 = not at all" to "10 = completely," or "0 = very poor" to "10 = excellent," depending on the content of the question.

The EQ-5D-5L (EuroQol) is a multi-attribute health status classification system consisting of 5 attributes: mobility, self-care, usual activities, pain/discomfort, and anxiety/depression. The EQ-5D-5L will be used to measure the effectiveness of the innovation in terms of QALYs (Quality-Adjusted Life Years), which is an which is an indicator where health states are weighted by quality of life.

The Global Assessment of Functioning (GAF) is a numerical scale (ranging from 0 to 100) used in psychiatry to assess an individual's psychological, social, and occupational functioning.

The Functional Remission of General Schizophrenia (FROGS) scale will be used to assess patients' functioning (Llorca et al., 2009).

Premorbid IQ by the fNART (French version of the National Adult Reading Test, Mackinnon & Mulligan (2005)). The ƒNART is based on the ability to pronounce 40 words with irregular spelling. It offers clinicians and researchers an easy method of estimating premorbid intelligence using a robust test in the face of cognitive decline.

Using the Insomnia Severity Index (ISI), developed to assess the severity of insomnia complaints and their daytime repercussions on daily activities. The first item evaluates the intensity of insomnia complaints such as difficulty falling asleep, maintaining sleep, and early awakening, each separately. One item assesses the overall satisfaction of the subject with their sleep, and another item evaluates concerns about insomnia. Finally, two items assess the impact on daily activities. Each item is rated by the patient on a scale from 0 to 4. The total score is obtained by adding the scores for each item. The total score ranges from 0 to 28.

The "Medication Adherence Rating Scale" (MARS) will assess adherence to medication treatment. This is a self-administered questionnaire of 10 items, yes/no answer