Validation of the Polish versions of the Lower Limb Task Questionnaire, Lower Limb Functional Index, and Lower Limb Functional Index-10

BACKGROUND

Physicians who treat patients with lower limb diseases should pay attention not only to the patients' clinical condition but also to their individual needs and expectations. For this purpose, many different questionnaires can be employed. This study aimed to validate the Lower Limb Task Questionnaire (LLTQ), Lower Limb Functional Index (LLFI), and Lower Limb Functional Index-10 (LLFI-10) for their use in Polish conditions and to perform a mutual comparison and analysis of differences in subjective assessments by patients who undergo hip or knee arthroplasty.

METHODS

The LLTQ, LLFI, and LLFI-10 were translated into Polish. A total of 103 patients who qualified for hip or knee arthroplasty at a University Hospital in from 2019 to 2021 were included in this study. The patients were asked to complete the Polish versions of the LLTQ, LLFI, LLFI-10, Lower Extremity Functional Scale (LEFS), and Short Form-36 four times - twice before and twice after their surgeries.

RESULTS

The Polish versions of the LLTQ, LLFI, and LLFI-10 had good psychometric properties. One year after surgery, the Cohen's standard response mean revealed high improvement of limb functionality and thus quality of life among all patients. We observed better treatment outcomes among patients who had hip osteoarthritis.

CONCLUSIONS

The questionnaires were validated and can be used both in everyday health practice and in further research in Poland.

Ten-Item Lower Extremity Functional Scale (LEFS-10): Instrument Reduction Based on Brazilian Patients With Lower Limb Dysfunction

OBJECTIVE

To propose a short version of the lower extremity functional scale (LEFS), to compare our short version with the different structures proposed for the LEFS by the specialized literature, and to verify the criterion validity of the best structure of the LEFS identified in our study.

DESIGN

Cross-sectional observational study.

SETTING

Physiotherapy clinics.

PARTICIPANTS

We included 140 patients with lower limb dysfunction (N=140).

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

We used confirmatory factor analysis (CFA), χ²/degree of freedom (DF), comparative fit index (CFI), Tucker-Lewis index (TLI), root mean square error of approximation (RMSEA), standardized root mean squared residual (SRMR), Akaike information criterion (AIC), and Bayesian information criterion (BIC). The method of reducing the number of items of the LEFS considered the modification indices and factor loadings.

RESULTS

The body site most affected by pain was the knee (71.4%), and the most common diagnoses were knee osteoarthritis (55%) and anterior knee pain (11.4%). LEFS reduction generated a 1-dimensional structure of the LEFS with 10 items (LEFS-10). When compared with other structures, the LEFS-10 presented the best fit indices (χ²/DF=1.88, CFI=0.975, TLI=0.968, RMSEA=0.079, and SRMR=0.058) and the lowest values of AIC (3287.063) and BIC (3345.896). LEFS-10 presents a high correlation (Spearman's correlation coefficient [ρ]=0.911, P<.001) with the 20-item LEFS.

CONCLUSION

LEFS-10 is the proposal for a short version of the instrument with the most adequate internal structure, in addition to being satisfactorily correlated with the longer version of the instrument.

Patient reported outcome measures for ankle instability. An analysis of 17 existing questionnaires

BACKGROUND

Patient reported outcome measures (PROMs) are essential for evaluating treatment of ankle instability (AI). The aim was to assess the content validity and the measurement properties of all relevant PROMs for AI.

METHODS

Relevant PROMs were identified from PubMed and SCOPUS. The development and validation quality of the PROMs was assessed according to established scientific standards.

RESULTS

Seventeen PROMs and 56 validation studies were analyzed. Content validity, which ensures the PROM measures what is relevant, is obtained by involving target patients in the development process. Only three PROMs identified had some degree of patient involvement (Cumberland Ankle Instability Tool (CAIT), Lower Extremity Function Scale (LEFS), and the Foot and Ankle Ability Measure (FAAM)). Of these, only FAAM was somewhat rigorously validated using modern psychometric validation methods, and exhibited superior measurement properties (construct validity).

CONCLUSION

No existing PROM is completely adequate to evaluate AI. However, FAAM is the best choice.

Longitudinal Validity and Minimal Important Change for the Modified Lower Extremity Functional Scale (LEFS) in Orthopedic Foot and Ankle Patients

The lower extremity functional scale (LEFS) is a patient-reported outcome measure for lower extremity disorders. Aim of this study was to assess the longitudinal validity including responsiveness and test-retest reliability of the revised 15-item version, and to define the minimal important change (MIC) of the modified LEFS in a generic sample of orthopedic foot and ankle patients who underwent surgery. Responsiveness, effect size, and standardized response mean were measured by determining the score change between the baseline and 6 months administration of the LEFS from 156 patients. There was no significant difference between preoperative (median 78, interquartile range [IQR] 64.2-90.3) and postoperative (median 75.0, IQR 61.7-95.0) scores. Both effect size and standardized response mean were low (0.06 and 0.06, respectively). Test-retest reliability of the LEFS was satisfactory. Intraclass correlation coefficient was 0.85 (95% confidence interval 0.81-0.88). MIC value could not be estimated due to the lack of significant score change. The modified LEFS presented with relatively low longitudinal validity in a cohort of generic orthopedic foot and ankle patients. The findings of this study indicate that the modified LEFS might not be the optimal instrument in assessing the clinical change over time for these patients.

Rasch Analysis of the Proactive Personality Scale

The Proactive Personality Scale (PPS) is used widely to measure proactive personality. Previous research has evaluated the psychometric properties of the 6-item PPS (hereafter called PPS-6) using classical test theory. There is a need to provide further validity evidence for the PPS-6 using modern test theory. This study evaluated the psychometric properties of the PPS-6 using Rasch analysis. A total of 429 participants completed the PPS-6. Rasch rating scale model (RSM) was used to analyse the data. RSM showed that the PPS-6 fitted the Rasch model well. RSM demonstrated that the PPS-6 functioned as a unidimensional measure with good internal consistency reliability. Items on the PPS-6 did not show any noticeable differential item functioning across gender. RSM showed that the response rating scale of the PPS-6 is suitable. Results suggest that the PPS-6 is a reliable measure for the assessment of proactive personality.