Self-guided Acceptance and Commitment Therapy-based Digital Smartphone Application for Management of Fibromyalgia

The FIQR includes 21 items that are answered on a 0-10 numerical scale in which higher scores indicate greater functional impairment. The FIQR assesses the impact of FM symptoms over the past 7 days. The questionnaire consists of items that cover three domains: physical impairment, overall impact, and symptom severity. These items inquire about various aspects such as pain, energy levels, stiffness, sleep quality, depression, memory problems, anxiety, sensitivity to touch, balance issues, and heightened sensitivity to noises, lights, smells, or temperatures. The total FIQR score is calculated by summing the scores of the three subscales, resulting in a range of 0 to 100. Higher scores indicate a greater level of impairment. The Spanish version of the FIQR has an excellent internal consistency (α = 0.91-0.95)

This instrument is an indicator of meaningful clinical change in treatments for chronic pain. The PGIC is one item (on a 7-point numerical scale, from 1 = 'Much better' to 7 = 'Much worse') referred to the participants' perception of global improvement due to treatment. It has undergone validation in the context of psychologically-based treatments for chronic pain. Additionally, the PSIC evaluates (also on a 7-point Likert scale) changes in specific domains, including physical and social functioning, work-related activities, mood, and pain. Both the PGIC & PSIC scales will be completed by participants assigned to STANZA and FM-ST treatments.

It discriminates between features of depression, anxiety and stress in clinical and non-clinical samples. Responders are required to indicate the presence of several symptoms over the previous week. Each item is scored from 0 (´Did not apply to me at all over the last week') to 3 ('applied to me very much or most of the time over the past week'). There are 7 items on each of the three subscales: depression, anxiety and stress. Therefore, total scores in each scale can range from 0 to 21, with higher scores indicating more severe levels of depression, anxiety and stress. The Spanish version has excellent psychometric properties.

It is a 10-item self-report measure of subjective cognitive dysfunction in FM during the last week. Each item is scored from 1 ('Not at all/Never') to 5 ('Very much/Always') and the total score ranges from 10 to 50. Lower scores indicate higher cognitive dysfunction. The MISCI was developed through classical test theory and item response theory from cognitive functioning item banks developed within the Patient Reported Outcomes Measurement Information System (PROMIS). The Spanish version of the MISCI has excellent internal reliability (α = 0.91)

Scale of 13 items comprising three dimensions: rumination over pain, magnification of pain and helplessness in the face of pain symptoms. The PCS total score and subscale scores are computed as the sum of ratings for each item.

This study uses the total score, which can vary from 0 to 52 with higher scores indicating greater pain catastrophising.

12-item scale that assesses psychological inflexibility in patients with pain and includes two factors: avoidance and cognitive fusion with pain. For this study, only the total score is used; it ranges from 12 to 84, with higher scores indicating higher level of psychological inflexibility.

This brief 6-item questionnaire assesses psychological flexibility during the past week. It is based on the Acceptance and Commitment Therapy model (ACT; Hayes et al.), which identifies six core dimensions of psychological flexibility: acceptance, cognitive defusion, contact with the present moment, self-as-context, values, and committed action. Each item is answered on a 5-point Likert scale, ranging from 1 ("very rarely") to 5 ("very frequently"). The total score is obtained by summing the responses of the six items; higher scores reflect a higher level of psychological flexibility.

This scale is composed of 12 items and it measures measure psychological inflexibility in people with chronic pain. It consists of two subscales: avoidance and cognitive fusion in relation to pain. Each item is answered on a 7-point Likert scale, where 1 means "never true" and 7 "always true". The total score ranges between 12 and 84, and higher scores indicate a greater degree of psychological inflexibility.

Instrument for evaluating health-related quality of life. The EQ-5D-5L scores will be used to calculate the Quality-Adjusted Life Years (QALYs) for the cost-utility analysis

The version used in this study is designed to retrospectively collect information on the use of health and social services during the previous six months. This instrument does not provide total or sub-scale scores, only collects information about use of services and medication consumption.

It consists of 21 items grouped into three dimensions: usability and satisfaction, system information arrangement, and efficiency. Responses are recorded on a 7-point Likert scale, ranging from 1 ("strongly agree") to 7 ("strongly disagree"). Values closer to 1 indicate higher usability of the application. For this study, only the usability and satisfaction dimension will be used.

Qualitative ad hoc measure to check the presence of negative effects of the therapies

The PHQ-9 is a 9-item questionnaire that assesses the presence and severity of depressive symptoms over the last two weeks. Each item is scored from 0 ("not at all") to 3 ("nearly every day"), resulting in a total score ranging from 0 to 27. For this study, only item 9 will be used, which evaluates the presence of thoughts related to death or suicidal ideation/intent.

Gender, date of birth, marital status, living arrangements, educational level, employment status, and years lived with fibromyalgia

Serum levels of IL-4, IL-6, CXCL8, IL-10, IL-17A, brain-derived neurotrophic factor (BDNF), and high sensitivity C-reactive protein (hs-CRP)

Participants' experience will be recorded during the focus group discussion, guided by the semi-structured questionnaire.