Validation of the Turkish Brief Inventory of Treatment Expectations in Chronic Pain (BITEC-TR)

This study is a methodological and cross-sectional research project aimed at the cultural adaptation and psychometric evaluation of the Brief Inventory of Treatment Expectations in Chronic Pain (BITEC) into Turkish. The study will be conducted at Bingöl University Faculty of Physical Therapy and Rehabilitation and Bingöl State Hospital Physical Medicine and Rehabilitation Outpatient Clinic. Data collection involves no clinical interventions and will be carried out using printed forms and an online survey platform (Kobotoolbox).

Procedure and Stages

The research will be executed in four consecutive stages:

Stage 1 - Cross-Cultural Adaptation: The BITEC will be adapted into Turkish following the ISPOR guidelines. Two independent native Turkish translators (one health professional, one linguist) will perform the forward translation. An expert panel will synthesize these translations into a consensus version. A native English speaker fluent in Turkish and blind to the original scale will perform the backward translation. The back-translated version will be compared with the original scale to eliminate semantic discrepancies.

Stage 2 - Comprehensibility Pre-testing: The provisional Turkish version will be administered to 30-40 volunteers diagnosed with chronic pain. Items will be rated on a scale from 0 (not comprehensible at all) to 10 (completely comprehensible). Items with a mean score below 8 will be revised.

Stage 3 - Main Data Collection: Eligible participants will be recruited to reach a target sample size of 200 to 250 individuals. Participants will complete a battery of assessments, including a sociodemographic and clinical information form, the 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). For test-retest reliability, a subgroup of approximately 60 participants whose clinical status and treatment remain unchanged will recomplete the BITEC-TR 7-10 days after the initial assessment.

Stage 4 - Statistical Analysis: Data analysis will be performed using SPSS software (v.25). Normality will be assessed via the Shapiro-Wilk test. Construct validity will be examined using exploratory factor analysis (EFA) and confirmatory factor analysis (CFA), reporting model fit indices such as CFI, NFI, RMSEA, and chi-square/df. Internal consistency will be evaluated using Cronbach's alpha, and test-retest reliability will be measured using the intra-class correlation coefficient (ICC). Measurement error will be calculated using the standard error of measurement (SEM) and minimal detectable change (MDC 95). Convergent, discriminant, and known-groups validities will be analyzed using Spearman correlation analyses based on pre-established hypotheses registered on the Open Science Framework (OSF). Ceiling and floor effects will also be evaluated.