Validation of the Turkish Brief Inventory of Treatment Expectations in Chronic Pain

The purpose of this study is to conduct the Turkish cross-cultural adaptation, validity, and reliability study of the "Brief Inventory of Treatment Expectations in Chronic Pain" (BITEC) scale. Chronic pain is a complex, multidimensional experience that affects a significant portion of the adult population. Treatment expectations play a critical role in predicting clinical outcomes and directly influencing placebo/nocebo responses. While several tools exist to evaluate expectations, there is a lack of a concise, clinician-friendly, and Item Response Theory (IRT)-based instrument adapted for Turkish chronic pain populations. The BITEC is a 9-item scale that evaluates biological, psychological, and social/interactional expectation domains. This methodological and cross-sectional study will be conducted with adult patients diagnosed with chronic pain for at least three months at Bingöl State Hospital. The study will be carried out in four consecutive stages: cross-cultural adaptation (forward and backward translation), comprehensibility pre-testing (with 30-40 volunteers), main data collection (with at least 200 participants), and statistical analyses. Data will be collected through printed forms and an online survey platform (Kobotoolbox), involving no clinical interventions. Participants will complete a sociodemographic information form, the Turkish version of the BITEC (BITEC-TR), the Treatment Expectations in Chronic Pain Scale (TEC-TR), the Pain Catastrophizing Scale (PCS), the Numerical Pain Rating Scale (NPRS), and the Hospital Anxiety and Depression Scale (HADS). Additionally, a subgroup of approximately 60 participants will recomplete the BITEC-TR 7-10 days after the initial session to evaluate test-retest reliability. Psychometric evaluation will include construct validity through exploratory and confirmatory factor analyses, and internal consistency and stability measurements.

Inclusion Criteria: * Aged 18-70 years * Having chronic pain for at least 3 months according to the International Association for the Study of Pain (IASP) criteria * Diagnosed with any chronic pain condition (e.g., fibromyalgia, nociceptive pain, neuropathic pain, etc.) * Being literate * Currently receiving any medical treatment Exclusion Criteria: * Presence of cancer-related pain * Diagnosis of acute pain * Being unable to fill out the questionnaire due to a diagnosed cognitive impairment or psychiatric illness * Presence of visual or motor disabilities that prevent completing the questionnaire