Cross cultural adaptation and validation of a Spanish version of the lower limb functional index

Abstract

BackgroundThe Lower Limb Functional Index (LLFI) is a relatively recently published regional outcome measure. The development article showed the LLFI had robust and valid clinimetric properties with sound psychometric and practical characteristics when compared to the Lower Limb Extremity Scale (LEFS) criterion standard.ObjectiveThe purpose of this study was cross cultural adaptation and validation of the LLFI Spanish-version (LLFI-Sp) in a Spanish population.MethodsA two stage observational study was conducted. The LLFI was initially cross-culturally adapted to Spanish through double forward and single backward translation; then subsequently validated for the psychometric characteristics of validity, internal consistency, reliability, error score and factor structure. Participants (n = 136) with various lower limb conditions of >12 weeks duration completed the LLFI-Sp, Western Ontario and McMaster University Osteoarthritis Index (WOMAC) and the Euroqol Health Questionnaire 5 Dimensions (EQ-5D-3 L). The full sample was employed to determine internal consistency, concurrent criterion validity, construct validity and factor structure; a subgroup (n = 45) determined reliability at seven days concurrently completing a global rating of change scale.ResultsThe LLFI-Sp demonstrated high but not excessive internal consistency (α = 0.91) and high reliability (ICC = 0.96). The factor structure was one-dimensional which supported the construct validity. Criterion validity with the WOMAC was strong (r = 0.77) and with the EQ-5D-3 L fair and inversely correlated (r = -0.62). The study limitations included the lack of longitudinal data and the determination of responsiveness.ConclusionsThe LLFI-Sp supports the findings of the original English version as being a valid lower limb regional outcome measure. It demonstrated similar psychometric properties for internal consistency, validity, reliability, error score and factor structure.

A case-series of patients with musculoskeletal conditions in an underserved community in Moca, Dominican Republic

“…We collected data using a paper and pencil questionnaire that included five sections. The questionnaire, available in English and Spanish [21][22][23][24][25][26][27][28][29][30][31][32][33] was selfadministered or completed with the assistance of a trained Spanish-native translator, the primary investigator or a family member. The following sections were included in the questionnaire:…”

“…The recall period is within the last few days. These measures have been shown to be valid (r = 0.85-0.9) and reliable (ICC = 0.93-0.96) in both the English and Spanish languages [26][27][28][29][30][31]. If a patient presented with a primary complaint of low back pain, the Spine Functional Index was completed.…”

“…First, the psychometric properties of our questionnaire were not previously tested for use in our population. However, the functional outcome measures have appropriate reliability and validity in the Spanish language [27,29,31]. Second, 62% of participants required assistance (translator, family or primary investigator) to complete study surveys.…”

Cross-cultural Adaptation and Validation of the Polish Version of the Lower Limb Functional Index

“…From the perspective of practical characteristics, the LLFI demonstrated brevity, ready transferability to a 100-point scale, ease and rapidity of completion and scoring, low missing responses, and suitable readability [11]. These clinimetric properties were reinforced with the scale's adaptation to Spanish [13] and Turkish [14].…”

“…The sample size was pre-selected on the basis of a literature review concerning the creation of the LLFI questionnaire and other language validations [11,13,14]. The sample size was also based on Altman's recommendations of > 50 subjects in a methods comparison study [23].…”