Interventional Study on the Effects of Forest Therapy in Fibromyalgia Patients

Level of perceived pain assessed using the Visual Analog Scale (VAS), a validated gold standard for fibromyalgia and allowing for direct and comparable measurement. The Visual Analogue Scale is the most widely used method in medicine to measure the intensity of pain subjectively perceived by the patient. It is usually represented as a continuous line 10 centimetres long, the ends of which indicate two opposite conditions: left end (0): no pain ; right end (10): the worst pain imaginable. The patient fills in the instrument by making a mark on the line at the point corresponding to the pain he or she feels. The operator then measures the distance in millimetres (from 0 to 100) to obtain the score. Interpretation of the Scores (cut-off): based on various clinical studies, the values of the scale are generally divided into 4 ranges: 0 - 4 mm: no pain ; 5 - 44 mm: mild pain ; 45 - 74 mm: Moderate pain; 75 - 100 mm: Severe pain.

The Revised Fibromyalgia Impact Questionnaire (FIQR) is a self-assessment questionnaire used to measure the impact of fibromyalgia on quality of life.

The FIQR has 21 individual questions. All questions are based on an 11-point numeric rating scale of 0 to 10, with 10 being 'worst'. All questions are framed in the context of the past 7 days. The FIQR is divided into 3 linked sets of domains (symptoms, function and overall impact of the disease) and the final score (0-100) is obtained by summing the values of the 3 domains. Four severity categories and their corresponding cutoffs have been identified: remission if final score ≤30, mild if final score >30 and ≤45, moderate if final score >46 and ≤65, severe if final score >65. The study will evaluate the change in the score of the FIQR in the 2 arms.

The Widespread Pain Index (WPI) is one of two key parameters used for the assessment and diagnosis of fibromyalgia. It measures the extent of body pain . The questionnaire asks the patient to indicate in which specific areas of the body they have felt pain during the last week. The list consists of 19 body areas. One point is assigned for each area where pain is present. The total score therefore ranges from 0 (no area) to 19 (all the body).

The State-Trait Anxiety Inventory (STAI) is a standardized psychometric scale for measuring anxiety. It is divided into two parts: 20 questions to assess trait anxiety (STAI-T) and 20 questions to assess state anxiety (STAI-S). The STAI is a 60-point scale (from 20 to 80) where 20 indicates the lowest level of anxiety and 80 the highest possible score.

The Profile of Mood States" (POMS) questionnaire is a psychological and psychiatric questionnaire used to assess mood and emotional states. It is used in the management of fibromyalgia to quantify the psychological impact (e.g., anxiety, depression, fatigue) and stress related to chronic pain. The test consists of a list of adjectives (typically 65 in the standard version) that describe feelings and emotions experienced "including today." The patient rates each adjective on a scale from 0 (not at all) to 4 (extremely). The questionnaire measures 6 mood dimensions: Tension-Anxiety (e.g., tense, anxious, nervous); Depression-Disappointment (e.g., unhappy, sad, hopeless); Truth-Hostility (e.g., angry, resentful, offended); Vigor-Activity (e.g., active, energetic, lively); Fatigue-Inertia (e.g., tired, exhausted, listless); Confusion-Disconcertment (e.g., confused, disoriented, forgetful).

Changes in systolic and diastolic blood pressure in mmHg

Heart Rate in ms

Heart Rate Variability Variation in ms

Possible change in pain medication use at the end of the study (intervention groups vs. control groups).

Dependence of the variation of the aforementioned scores and parameters on environmental variables (meteorological comfort, volatile organic pollutants and biogenic volatile organic compounds), assessed during the forestry therapy sessions for the intervention groups only

The Symptom Severity Scale (SSS) is one of the two main measures used to evaluate and diagnose fibromyalgia. It measures the overall severity of symptoms. It is commonly calculated in conjunction with the WPI scale. The SSS scale assigns a score from 0 to 12, adding the two values: severity of the 3 main syntoms e general somatic syntoms:

• Severity of the 3 main symptoms (score from 0 to 3 for each): the level of disturbance perceived in the last week is assessed:

• Asthenia (chronic tiredness).
• Sleep seizures or non-restorative sleep.
• Cognitive symptoms (difficulty with memory or concentration, mental fog) (Assigned values: 0 = No problem; 1 = Mild/Moderate; 2 = Moderate/Considerable; 3 = Severe/Continuous) 2) General somatic symptoms (score from 0 to 3): the presence of other related disorders is assessed (e.g. headache/migraine, abdominal pain or cramps, depression). (Assigned values: 0 = No symptoms; 1 = Few symptoms; 2 = Moderate symptoms; 3 = Severe symptoms)