Psychometric analysis of the Hip Disability and Osteoarthritis Outcome Score Joint Replacement (HOOS-JR)

Objective

Centers for Medicare and Medicaid Services (CMS) has requested hospitals collect and report patient-reported outcomes (PROs) beginning in 2024 including the Hip Disability and Osteoarthritis Outcome Score Joint Replacement (HOOS-JR). However, scale structural validity of the HOOS-JR has minimally been assessed. The purpose of this study was to assess internal consistency, structural validity, and multi-group invariance properties of the HOOS-JR in a large sample of patients who underwent a total hip arthroplasty (THA).

Methods

A cross-sectional study using the Surgical Outcomes System was retrospectively queried for patients who underwent a THA. Internal consistency was assessed using Cronbach's alpha and McDonald's Omega. A confirmatory factor analysis (CFA) was performed on the HOOS-JR using a priori cut-off values. Multi-group invariance testing was also performed on the sample of patients across sex and age groups.

Results

Internal consistency was acceptable for 6-item (alpha ​= ​0.88; omega ​= ​0.88) and 5-item (alpha ​= ​0.86; omega ​= ​0.86) HOOS-JR. The one-factor, 6-item CFA did not meet the recommended fit indices. The one-factor, 5-item CFA had acceptable fit for the sample data. Invariance testing criteria were met between the age groups; however, scalar invariance was not met for sex.

Conclusion

The 6-item HOOS-JR did not meet contemporary model fit indices indicating that scale refinement is warranted. The 5-item met most goodness-of-fit indices and invariance criteria. However, further scale refinement may be warranted as localized fit issues were identified.

Assessing the Structural Validity of the Knee Injury and Osteoarthritis Outcome Score Scale

BACKGROUND

The Knee Injury and Osteoarthritis Outcome Score (KOOS) scale is used to assess patient perspectives on knee health. However, the structural validity of the KOOS has not been sufficiently tested; therefore, our objective was to assess the KOOS in a large, multi-site database of patient responses who were receiving care for knee pathology.

METHODS

A cross-sectional study was conducted using the Surgical Outcome System (SOS) database. A confirmatory factor analysis (CFA) was conducted to assess the proposed five-factor KOOS using a priori cut-off values. Because model fit indices were not met, a subsequent exploratory factor analysis (EFA) was conducted to identify a parsimonious model. The resulting four-factor structure (i.e., KOOS SF-12) was then assessed using CFA and subjected to multigroup invariance testing.

RESULTS

The original KOOS model did not meet rigorous CFA fit recommendations. The KOOS SF-12 did meet model fit recommendations and passed all invariance testing between intervention procedure, sex, and age groups.

CONCLUSION

The KOOS failed to meet model fit recommendations. The KOOS SF-12 met model fit recommendations, maintained a multi-factorial structure, and was invariant across all tested groups. The KOOS did not demonstrate sound structural validity. A refined KOOS SF-12 model that met recommended model fit indices and invariance testing criteria was identified. Our findings provide initial support for a multidimensional KOOS structure (i.e., KOOS SF-12) that is a more psychometrically sound instrument for measuring patient-reported knee health.

Longitudinal Invariance Testing Of The Knee Injury Osteoarthritis Outcome Score For Joint Replacement Scale (KOOS-JR)

Background

The Knee Osteoarthritis Outcome Score for Joint Replacement (KOOS-JR) is a seven-item patient reported outcome measure used to assess perceived knee health. Though commonly used, the longitudinal psychometric properties of the KOOS-JR have not been established and further characterization of its structural validity and multi-group invariance properties is warranted.

Purpose

The purpose of this study was to evaluate psychometric properties of the KOOS-JR in a large sample of patients who received care for knee pathology.

Study Design

Original research.

Methods

Longitudinal data extracted from the Surgical Outcome System (SOS) database of 13,470 knee pathology patients who completed the KOOS-JR at baseline, three-months, six- months, and one-year. Scale structure was assessed with confirmatory factor analysis (CFA), while multi-group and longitudinal invariance properties were assessed with CFA-based procedures. Latent group means were compared with statistical significance set at α ≤ .05 and Cohen's d effect size as d = 0.2 (small), d = 0.5 (medium), and d = 0.8 (large).

Results

CFA results exceeded goodness-of-fit indices at all timepoints. Multi-group invariance properties passed test requirements. Longitudinal analysis identified a biased item resulting in removal of item #1; the retained six-item model (KOOS-JR-6) passed longitudinal invariance requirements. KOOS-JR-6 scores significantly changed over time (p ≤ .001, Mdiff = 1.08, Cohen's d = 0.57): the highest scores were at baseline examination and the lowest at 12-month assessment.

Conclusions

The KOOS-JR can be used to assess baseline differences between males and females, middle and older aged adults, and patients receiving total knee arthroplasty or non-operative care. Caution is warranted if the KOOS-JR is used longitudinally due to potential measurement error associated with item #1. The KOOS-JR-6 may be a more viable option to assess change over time; however, more research is warranted.

Level of Evidence

3© The Author(s).

Evaluating Psychometric Properties of the International Knee Documentation Committee Subjective Knee Form in a Heterogeneous Sample of Post-Operative Patients

Background

The International Knee Document Committee Subjective Knee Form (IKDC-SKF) is a patient-reported outcome measure used in orthopedics and sports medicine. Further psychometric assessment is necessary to confirm measurement properties in a large, heterogenous sample.

Purpose

The purpose of the study was to assess the psychometric properties of the IKDC-SKF in a large, heterogenous sample.

Study Design

Cross-Sectional Study.

Methods

An exploratory factor analysis (EFA) was conducted to identify a sound latent structure and to assess internal consistency in a large sample of patients who underwent knee arthroscopy. A confirmatory factor analysis (CFA) was conducted to confirm structural validity. Multi-group invariance was conducted to assess factorial stability across sex and age groups, while longitudinal invariance procedures were performed to assess stability over time.

Results

A 3-factor, 9-item IKDC-SKF short form was identified with EFA procedures. The model was confirmed with CFA (CFI = 0.983; TLI = 0.975; IFI = 0.983; RMSEA = 0.057), while a sound 2-factor, 6-item model was also identified (CFI = 1.0; TLI = 0.999; IFI = 1.0; RMSEA = 0.11). The 9-item IKDC-SKF short form was invariant across groups but not time; removal of a single item (i.e., 8-item IKDC-SKF short form) resulted in longitudinal invariance. The 6-item IKDC-SKF short form was invariant across groups and time.

Conclusion

The 6-item, 8-item, and 9-item short form versions of the IKDC-SKF exceed contemporary fit recommendations and present as plausible alternatives to the IKDC-SKF with improved measurement properties, reduced scale response burden, and evidence of multi-group and longitudinal invariance. Further, the 6- and 8-item IKDC-SKF short forms may be used to assess group differences or change across time.# Level of evidence hereLevel 3©The Author(s).

Many-faceted rasch calibration of the foot function index-revised short form

Background

The Foot Function Index Revised Short version (FFI-RS) is a foot- and ankle- patient-reported outcome measure (PROM), developed from the Foot Function Index (FFI). Previous studies, estimating item parameters and multidimensional properties, have limitations properly establishing the measurement properties of the FFI-RS. A multi-faceted Rasch analysis with a larger sample would allow for a more robust validation approach to improve the clinical interpretation of the FFI-RS using a multidimensional perspective. Therefore, the purpose of this study was to assess the psychometric properties of the FFI-RS as a PROM of foot function.

Method

A total of 2184 patients with foot pathology who completed the FFI-RS were included in the data. Data were extracted from the cloud-based orthopedic and sports medicine global registry Surgical Outcome System (SOS). The psychometric properties of the FFI-RS were assessed using a many-faceted Rasch analysis that included model-data fit, rating scale function, item-person map (distribution of item difficulty and person ability), and item difficulty of the subscale.

Results

Two misfit items were discovered and deleted; 32-items from the original FFI-RS were retained. The 4-item Likert scale functioned effectively and item difficulty (-0.58 to 1.48), subscale difficulty (-0.58 to 1.15), and person’s foot function (-6.62 to 6.24) had wide distributions.

Conclusions

Many-faceted Rasch analysis revealed the FFI-RS had sound psychometric properties using the many-faceted Ranch analysis and retained 32 of the original items. Clinicians and researchers should consider weaknesses identified with items in the ‘Difficulty” subscale and future work should be conducted to modify or develop items that will more accurately evaluate a wide range of foot function levels.

Posterior capsule injection of local anesthetic for post-operative pain control after ACL reconstruction: a prospective, randomized trial

PURPOSE

Alternative modalities to optimize pain control after anterior cruciate ligament reconstruction (ACLR) are continually being explored. The purpose of this study was to compare femoral nerve block (FNB) only vs FNB with posterior capsule injection (PCI) of the knee for pain control in patients undergoing ACLR.

METHODS

Patients undergoing primary ACLR were randomized to receive either FNB only or FNB with PCI. Following surgery, patient's pain was evaluated in the postoperative care unit (PACU) and at home for 4 days. Pain levels were measured via visual analog scale (VAS) and calculating opioid consumption. Outcomes of interest included postoperative pain levels and opioid consumption.

RESULTS

A total of 42 patients were evaluated, with 21 patients randomized to each study arm. Outcomes showed significant pain reduction in both anterior and posterior knee VAS scores in the PACU in those that received PCI (anterior VAS: 39.6 vs 21.3 (SD = 12.9), p < 0.01; posterior VAS: 25.4 vs 15.3 (SD = 8.05), p = 0.01). Moreover, the PCI group also showed significantly less opioid consumption compared to FNB only (23.5 vs 17.4 pills, p = 0.03). There were no differences found in pain scores between groups in home VAS sores.

CONCLUSIONS

These finding suggest the use of arthroscopically assisted injection of local anesthetic to the posterior capsule of the knee significantly reduces early post-operative pain and dramatically reduces the number of opoid medication taken after ACLR.

LEVEL OF EVIDENCE

Prospective, randomized, control trial, Level I.