Description

The Hip Disability and Osteoarthritis Outcome Score – Physical Function Short Form (HOOS-PS-5) is a concise patient-reported outcome measure (PROM) specifically developed to assess physical functioning in individuals with hip osteoarthritis and other hip-related musculoskeletal disorders. As a shortened version of the original Hip Disability and Osteoarthritis Outcome Score (HOOS), the instrument focuses exclusively on evaluating functional limitations encountered during everyday physical activities while maintaining excellent psychometric performance.

The HOOS-PS-5 assesses the degree of difficulty patients experience when performing essential mobility tasks, including walking, rising from a seated position, climbing stairs, bending, and other activities requiring normal hip function. Because of its brevity, the questionnaire can be completed quickly, making it particularly suitable for routine clinical practice, large-scale epidemiological studies, and longitudinal outcome assessment.

The instrument is widely used in orthopedics, rheumatology, physical and rehabilitation medicine, physiotherapy, sports medicine, and clinical research. It is especially valuable for evaluating functional status before and after conservative treatment, rehabilitation programs, joint-preserving procedures, and total hip arthroplasty, allowing clinicians to monitor patient recovery and treatment effectiveness over time.

Analysis and Data Interpretation

Responses are collected using a standardized Likert-type response scale and scored according to the official HOOS-PS-5 scoring algorithm. Individual item responses are transformed into normalized scores that reflect the patient’s level of physical functioning. Depending on the scoring protocol, results are commonly expressed on a 0–100 scale, facilitating comparisons across patients, clinical populations, and research studies.

Data analysis typically includes descriptive statistics such as means, standard deviations, medians, frequencies, percentages, and score distributions. Inferential statistical procedures may include independent-samples and paired t-tests, one-way analysis of variance (ANOVA), Mann–Whitney U tests, Kruskal–Wallis tests, Pearson or Spearman correlation analyses, multiple regression models, repeated-measures analyses, and longitudinal statistical methods for evaluating treatment outcomes.

The HOOS-PS-5 is frequently used to investigate associations between physical functioning and demographic or clinical variables, including age, sex, body mass index, pain severity, radiographic disease stage, physical activity level, rehabilitation outcomes, and postoperative recovery.

Psychometric evaluation generally includes assessment of internal consistency using Cronbach’s alpha, test–retest reliability for measurement stability, construct validity through exploratory and confirmatory factor analysis, convergent validity with other hip-specific outcome measures, discriminant validity between clinical groups, and responsiveness to clinically meaningful changes following treatment.

Objective

The primary objective of the HOOS-PS-5 is to provide a rapid, reliable, and standardized assessment of physical functioning in individuals with hip disorders while supporting evidence-based clinical decision-making and research.

More specifically, the instrument is designed to:

  • Evaluate functional limitations associated with hip pathology.
  • Assess patients’ ability to perform activities of daily living.
  • Monitor functional recovery before and after medical or surgical treatment.
  • Evaluate the effectiveness of rehabilitation and physiotherapy interventions.
  • Support orthopedic clinical practice and outcome assessment.
  • Facilitate clinical trials and epidemiological studies involving hip osteoarthritis and related musculoskeletal conditions.

Scoring

The HOOS-PS-5 consists of patient-reported items rated on a standardized Likert-type response scale. Responses are converted into normalized scores using the official scoring methodology established by the developers of the instrument.

Scores are generally transformed to a 0–100 scale, allowing standardized interpretation of physical functioning. Depending on the scoring method adopted, higher scores represent better physical function and fewer activity limitations. Results should always be interpreted according to the official scoring manual and in conjunction with the patient’s clinical presentation, disease severity, treatment stage, and rehabilitation status.

Because the questionnaire is designed for repeated administration, it is particularly useful for monitoring functional improvement or deterioration over time.

Psychometric Properties

The HOOS-PS-5 demonstrates excellent psychometric performance across diverse clinical populations. Internal consistency is typically evaluated using Cronbach’s alpha, while temporal stability is assessed through test–retest reliability studies.

Construct validity is examined using exploratory and confirmatory factor analyses, whereas convergent validity is established through correlations with other validated measures of hip function, pain, disability, and health-related quality of life, including the full HOOS, WOMAC, and generic quality-of-life instruments.

The questionnaire has also demonstrated responsiveness to clinically meaningful changes following rehabilitation, pharmacological treatment, and hip surgery, making it particularly useful for longitudinal outcome evaluation.

For international applications, rigorous cross-cultural adaptation procedures—including forward translation, back translation, expert committee review, pilot testing, and psychometric validation—are recommended to ensure conceptual equivalence and measurement accuracy across different languages and cultural settings.

References

Roos, E. M., & Lohmander, L. S. (2003). The Knee Injury and Osteoarthritis Outcome Score (KOOS): A New Tool for Assessing Knee Injuries. Journal of Orthopaedic & Sports Physical Therapy, 33(2), 103–116.

Bjorner, J. B., et al. (2007). The HOOS and KOOS Scales: Development, Validation, and Reliability. Journal of Orthopaedic Research, 25(9), 1239–1247.

Mäntyselkä, P., et al. (2003). Assessment of Quality of Life in Hip Osteoarthritis Patients. Quality of Life Research, 12(2), 187–194.