Turkish Validation of the HOOS-12

\## Detailed Description

Hip osteoarthritis (HOA) is one of the leading causes of pain, disability, and reduced health-related quality of life among older adults worldwide. Patient-reported outcome measures (PROMs) are essential for evaluating symptoms, functional limitations, treatment effectiveness, and patient-centered outcomes in both clinical practice and research. The Hip Disability and Osteoarthritis Outcome Score-12 (HOOS-12) is a concise, multidimensional PROM developed to assess pain, physical function, and hip-related quality of life while substantially reducing respondent burden compared with the original HOOS questionnaire.

Although the HOOS-12 has been validated in several languages and populations, no culturally adapted and psychometrically validated Turkish version is currently available. The absence of a validated Turkish HOOS-12 limits its use in clinical practice, multicenter studies, and international research involving Turkish-speaking patients with hip osteoarthritis. Therefore, a rigorous cross-cultural adaptation and psychometric evaluation is required before the instrument can be recommended for clinical and research applications in Türkiye.

The primary objective of this study is to translate and culturally adapt the HOOS-12 into Turkish and to evaluate its psychometric properties in patients with hip osteoarthritis who are scheduled to undergo primary total hip arthroplasty. The translation and cross-cultural adaptation process will be conducted in accordance with internationally accepted guidelines for patient-reported outcome measures, including forward translation, synthesis, backward translation, expert committee review, and pilot testing to ensure semantic, idiomatic, experiential, and conceptual equivalence between the original and Turkish versions.

Following the adaptation process, the psychometric performance of the Turkish HOOS-12 will be evaluated according to the COSMIN recommendations. Internal consistency will be assessed using Cronbach's alpha, while test-retest reliability will be examined using the intraclass correlation coefficient (ICC) in clinically stable participants who complete the questionnaire twice before surgery without any therapeutic intervention between assessments. Measurement error will be determined by calculating the standard error of measurement (SEM) and the minimal detectable change (MDC). Structural validity will be evaluated using confirmatory factor analysis (CFA). Construct validity will be examined by testing predefined hypotheses regarding the relationships between the Turkish HOOS-12 and the Short Form-12 Health Survey (SF-12). Floor and ceiling effects will also be investigated.

To determine responsiveness, participants will complete the Turkish HOOS-12 and SF-12 before surgery and again three months after primary total hip arthroplasty. Changes in questionnaire scores over time will be analyzed to evaluate the instrument's ability to detect clinically meaningful improvement following surgical treatment.

The results of this study are expected to provide a reliable, valid, and responsive Turkish version of the HOOS-12 for evaluating patient-reported outcomes in individuals with hip osteoarthritis. The availability of this instrument will facilitate standardized outcome assessment in routine clinical practice, clinical trials, and multicenter research involving Turkish-speaking populations.

• Patient-Reported Outcome Assessment (Other): Participants will complete the Turkish version of the Hip Disability and Osteoarthritis Outcome Score-12 (HOOS-12) and the Short Form-12 Health Survey (SF-12) at predefined assessment time points. No therapeutic intervention will be assigned or administered as part of this observational study. Primary total hip arthroplasty will be performed as part of routine clinical care and will not be assigned by the investigators.

Primary outcomes

• Internal Consistency of the Turkish HOOS-12 [Baseline]: Internal consistency of the Turkish Hip Disability and Osteoarthritis Outcome Score-12 (HOOS-12) will be assessed using Cronbach's alpha coefficient. The HOOS-12 is a 12-item patient-reported outcome measure assessing hip-related pain, physical function, and hip-related quality of life. The HOOS-12 summary score ranges from 0 to 100, where 0 represents the worst possible hip-related health and 100 represents the best possible hip-related health. Higher scores indicate better hip-related health. Internal consistency will be evaluated using baseline data.
• Test-Retest Reliability [Baseline and Day 7]: Test-retest reliability of the Turkish Hip Disability and Osteoarthritis Outcome Score-12 (HOOS-12) will be assessed in clinically stable participants who complete the questionnaire at baseline and again on Day 7. The HOOS-12 summary score ranges from 0 to 100, where 0 represents the worst possible hip-related health and 100 represents the best possible hip-related health. Higher scores indicate better hip-related health. Test-retest reliability will be evaluated using the intraclass correlation coefficient (ICC). Participants with a substantial therapeutic intervention or clinically relevant change in their condition between the two assessments will not be included in the test-retest reliability analysis.
• Construct Validity With SF-12 Physical Component Summary [Baseline]: Construct validity of the Turkish Hip Disability and Osteoarthritis Outcome Score-12 (HOOS-12) will be evaluated by examining the correlation between the HOOS-12 summary score and the Physical Component Summary (PCS) score of the 12-Item Short Form Health Survey (SF-12), according to a predefined hypothesis. Higher scores on both measures indicate better health status.
• Construct Validity With SF-12 Mental Component Summary [Baseline]: Construct validity of the Turkish Hip Disability and Osteoarthritis Outcome Score-12 (HOOS-12) will be evaluated by examining the correlation between the HOOS-12 summary score and the Mental Component Summary (MCS) score of the 12-Item Short Form Health Survey (SF-12), according to a predefined hypothesis. Higher scores on both measures indicate better health status.
• Structural Validity [Baseline]: Structural validity of the Turkish Hip Disability and Osteoarthritis Outcome Score-12 (HOOS-12) will be evaluated using confirmatory factor analysis (CFA). The HOOS-12 consists of 12 items assessing hip-related pain, physical function, and quality of life. The HOOS-12 summary score ranges from 0 to 100, where 0 represents the worst possible hip-related health and 100 represents the best possible hip-related health. Higher scores indicate better hip-related health. Model fit will be evaluated using the Comparative Fit Index (CFI), Tucker-Lewis Index (TLI), Root Mean Square Error of Approximation (RMSEA), and Standardized Root Mean Square Residual (SRMR). CFI, TLI, RMSEA, and SRMR will be interpreted jointly as complementary model-fit indices to evaluate the overall fit of the prespecified measurement model rather than as separate outcome measures.
• Responsiveness [From baseline until primary total hip arthroplasty, assessed up to 12 months; responsiveness assessed 3 months after surgery.]: Responsiveness will be evaluated in participants who undergo primary total hip arthroplasty within 12 months after baseline assessment. The Hip Disability and Osteoarthritis Outcome Score-12 (HOOS-12) will be administered before surgery and again 3 months after surgery. The HOOS-12 summary score ranges from 0 to 100, with higher scores indicating better hip-related health. Changes in scores will be used to evaluate the ability of the Turkish HOOS-12 to detect clinically meaningful change.

Secondary outcomes

• Standard Error of Measurement of the Turkish HOOS-12 [Baseline and Day 7]: Measurement error of the Turkish Hip Disability and Osteoarthritis Outcome Score-12 (HOOS-12) will be quantified using the Standard Error of Measurement (SEM), based on scores obtained from clinically stable participants at baseline and Day 7.
• Minimal Detectable Change of the Turkish HOOS-12 [Baseline and Day 7]: The Minimal Detectable Change at the 95% confidence level (MDC95) of the Turkish Hip Disability and Osteoarthritis Outcome Score-12 (HOOS-12) will be calculated using scores obtained from clinically stable participants at baseline and Day 7.
• Floor Effect of the Turkish HOOS-12 [Baseline]: The floor effect will be determined as the percentage of participants achieving the minimum possible HOOS-12 summary score of 0 at baseline.
• Ceiling Effect of the Turkish HOOS-12 [Baseline]: The ceiling effect will be determined as the percentage of participants achieving the maximum possible HOOS-12 summary score of 100 at baseline.
• Physical Health-Related Quality of Life [Baseline and Month 3]: Physical health-related quality of life will be assessed using the Physical Component Summary (PCS) score of the 12-Item Short Form Health Survey (SF-12). Higher PCS scores indicate better physical health-related quality of life.
• Mental Health-Related Quality of Life [Baseline and Month 3]: Mental health-related quality of life will be assessed using the Mental Component Summary (MCS) score of the 12-Item Short Form Health Survey (SF-12). Higher MCS scores indicate better mental health-related quality of life.

Sex: All, ages: 18 Years to any

Inclusion Criteria:

* Age 18 years or older.
* Native Turkish speaker or able to read and understand Turkish fluently.
* Diagnosed with primary hip osteoarthritis based on clinical and radiographic evaluation.
* Scheduled to undergo primary total hip arthroplasty.
* Able to complete the study questionnaires independently or with standardized assistance.
* Clinically stable during the test-retest period.
* Willing to participate in the study and provide written informed consent.

Exclusion Criteria:

* Previous total hip arthroplasty on the affected side.
* Scheduled for revision hip arthroplasty.
* Hip arthroplasty indicated for conditions other than primary hip osteoarthritis, including hip fracture, inflammatory arthritis, avascular necrosis, congenital hip disorders, or malignancy.
* History of major lower-extremity surgery within the previous six months.
* Neurological or neuromuscular disorders that may substantially affect mobility or lower-extremity function.
* Severe cognitive impairment, psychiatric disorder, or communication difficulty that prevents reliable questionnaire completion.
* Severe visual or hearing impairment that prevents completion of the assessment procedures.
* Presence of another acute musculoskeletal condition that substantially affects pain or physical function.
* Any therapeutic intervention, significant change in medication, acute clinical deterioration, or surgery occurring between the baseline and test-retest assessments.
* Incomplete questionnaire data or inability to complete the planned follow-up assessments.