Article Text
Abstract
Objectives The evaluation of health-related quality of life and physical function is important for determining therapeutic strategies following ankle injuries. The Anglo-American Foot and Ankle Ability Measure (FAAM) is a valid and reliable self-reported measure to detect functional deficits in chronic lateral ankle instability. The purpose of this study was to translate, cross-culturally adapt and validate the FAAM questionnaire for use with German-speaking patients with chronic lateral ankle instability.
Patients/Participants Preoperative and conservatively treated patients with chronic lateral ankle instability. Sport students and volleyball athletes served as control groups.
Main Outcome Measurements The FAAM was forward and back translated, cross-culturally adapted and validated. The study population completed the FAAM-G questionnaire twice within 3–5 days. Additionally, the patients were scored with the Good ankle laxity classification system. Test–Retest reliability, construct validity and internal consistency were calculated.
Results Reliability and validity of the FAAM-G were examined in presurgical chronic ankle instability patients (n=24), conservatively treated chronic ankle instability patients (n=17), university sport students (n=31) and volleyballers (n=37).
Test–retest reliability revealed fair, good, or excellent reliability (inter-class correlation coefficient (ICC)=0.590–0.998; ρ=0.528–1.000). Construct validity, tested between the FAAM-G subscores and the Good et al ankle laxity classification system demonstrated strong correlations (ρ = −0.819 to −0.861).
Conclusions The original FAAM questionnaire was successfully translated and cross-culturally adapted from English to German. Corresponding to the Anglo-American version, the FAAM-G is a reliable and valid questionnaire for self-reported assessment of pain and disability in German-speaking patients suffering from chronic ankle instability.
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Every lower leg loading (sport) activity induces a relevant risk for ankle sprains. Especially individuals who participate in volleyball, basketball and soccer are predisposed.1 Insufficient treatment of the initial trauma often results in chronic ankle instability leading to recurrent giving way, residual pain and swelling.2,–,5
There are two major questions in evaluating treatment efficacy in clinic research: which parameters constitute a successful outcome and how can they be registered.6 Patient-assessed questionnaires are considered to be appropriate tools to identify patient impairments, disabilities and quality of life.3 These instruments are commonly used for clinical assessment and outcome measurement following treatment, and for research.7 Outcome evaluation questionnaires are usually introduced in Anglo-American language and addressed to that specific population.8 When patient-assessed questionnaires are used in different countries, they have to be not only translated to the respective language but also cross-culturally adapted and validated.9 The procedure of cross-cultural adaptation and validation has to be carried out according to recognised guidelines.10 Several patient- and disease-related questionnaires and grading scales have been constructed for the use in foot and ankle disorders.11,–,17 However, a systematic review for chronic ankle instability3 detected only four relevant, patient-assessed, self-reported questionnaires.12,–,14 18 The Foot and Ankle Disability Index (FADI)12 and the Foot and Ankle Ability Measure (FAAM) questionnaire13 19 were identified as the most suitable patient-assessed questionnaires to quantify chronic lateral ankle instability. Both questionnaires are similar and include an activity of daily life (ADL) subscale and a sport subscale as well. The FADI contains 34 items, while the FAAM consists of 29 items. As the psychometric outcome of both questionnaires is similar, the advantage of the FAAM is the less expenditure of time to fill out the questionnaire.
Currently, there is no validated patient-assessed questionnaire available in the German language to document functional deficits in chronic lateral ankle instability. Therefore, the purpose of this study was to translate, cross-culturally adapt and validate a German version of the FAAM to a German-speaking population.
Material and methods
Translation procedure
The study received ethics approval from the local ethics committee and was in compliance with the Declaration of Helsinki. The Anglo-American version of the FAAM was adapted for German use (FAAM-G) according to the recommendations for cross-cultural adaptation of self-report measures using six steps:10
Step I: Two independent native-speaking Germans (one orthopaedic surgeon specialised in foot and ankle disorders and one sport scientist) first translated the Anglo-American version of the FAAM into German. Both translators were aware of the concept.
Step II: In a consensus meeting, the German translators synthesised their versions to a preliminary FAAM-G version.
Step III: Two additional persons with English as their mother tongue then translated the preliminary German version of the FAAM back into English. Both were blinded to the concept and had no medical background.
Step IV: An expert committee consisting of the forward and back translators, a methodologist and a healthcare professional reviewed all the translations, and semantic, idiomatic, experiential and conceptual consensus was reached on all discrepancies. Thus, the prefinal version of the FAAM-G was consolidated.
Step V: The prefinal version of the FAAM-G was then tested by a cohort of 18 university sport students for accuracy of wording and for understanding of the different test items. The interviewer (sport scientist) documented any problems occurring during the completion of the prefinal FAAM-G questionnaires. Considering these issues, a final FAAM-G version was established.
Step VI: The final version of the FAAM-G and all documents reporting steps I–V were then reviewed by the developers of the FAAM-G questionnaire, and the adaptation process was appraised.
The validity and reliability of the final FAAM-G were tested on 41 patients with chronic lateral ankle instability and 68 asymptomatic people.
Foot and Ankle Ability Measure
The original FAAM questionnaire13 contains two separate subscales: the ADL and the sport subscale. The ADL subscale consists of 21 items investigating basic functional activities. The sport subscale comprises eight items referring to more skilled and intensive physical activities occurring during sport. Each item is scored on a five-point Likert scale from 4 (no difficulty at all) to 0 (unable to do), and a “non-applicable” category additionally exists. To calculate the total score of each subscale, the result of each item is added. So, the highest potential score for the ADL is 84 and for the sport subscale 32. To get a percentage value, the total score of each subscale is divided by the highest potential score and multiplied by 100. High subscores represent high physical function.
At the end of each FAAM subscale, a global function rating scale is added. The level of function has to be specified from 0% (inability to perform the listed exercises) to 100% (function before the injury). In conclusion, a four-point Likert scale from normal to severely abnormal is added to categorise the functional status of the ankle (fig 1A,B).
Test participants
Informed consent was obtained from each participant included in the study. Patients with bilateral lateral ankle instability or actually lower leg disorders were excluded from the study. Participants were classified as “healthy” or “unstable” using the Ankle Injury History Questionnaire which was initially filled out by each participant.20 The reliability and validity of the FAAM were examined in a group of presurgical chronic ankle instability patients (n=24) and in a conservatively treated chronic ankle instability patient group (n=17). A first control group included university sport students without any previous ankle and foot complaints (n=31). A second control group (no previous ankle and foot complaints) represented a high-risk target population (volleyballers) (n=37). The patient groups were selected from medical files in our institute for sports medicine. The sport students were directly contacted in the sport faculty of the local university. The volleyballers were directly addressed during their training sessions in local volleyball clubs. To test for construct validity, all participants of the study (n=109) completed the FAAM-G questionnaire and were additionally examined by one of the authors to grade lateral ankle instability by the standardised Good et al ankle laxity classification system.15 Grade 1 indicates full activity, including strenuous sport and no pain, swelling or giving way. Grade 2 demonstrates occasional aching only following strenuous exercise, no giving way or feeling of apprehension. Grade 3 includes no giving way but some remaining apprehension and taking care when walking on rough ground. Grade 4 involves recurrent instability and giving way in normal activities with episodes of pain and swelling.
Additionally, the FAAM-G results of the preoperative and conservatively treated groups were compared with the respective results of the sport student and volleyballer group.
For reliability testing, conservatively treated patients, sport students and volleyball athletes completed the FAAM-G twice within a period from 3 to 5 days. Internal consistency was analysed in all 41 patients with chronic lateral ankle instability.
Statistical analysis
Descriptive analyses were performed using mean, SD and 95% CI. Construct validity was calculated by Spearman's rank correlation coefficient (ρ) between FAAM-G questionnaire and the Good et al ankle laxity classification system.15 Reliability testing was performed by Spearman's rank correlation test (ρ), inter-class correlation coefficient (ICC) and Wilcoxon paired test for nonparametric data. According to Fleiss21 ICC values >0.75 are considered as excellent, 0.75–0.40 as fair to poor and <0.40 as poor. Internal consistency for both subscales of the FAAM questionnaire was examined using Cronbach's α. The significance level was set at p<0.05. All statistical analyses were carried out using SPSS 15.0 (SPSS GmbH, München, Germany).
Results
Cross-cultural adaption
Forward and back translation of the Anglo-American FAAM version revealed no major semantic or language difficulties. All of the discrepancies concerned synonyms for particular terms. These unclear items could be clarified during the expert committee meeting. Item 9 of the FAAM-ADL subscale “stepping up and down curbs” generated some confusion as it was unclear whether the curbs have to be stepped forward or sideward. We decided to translate the item with “Bordsteinkante auf- und absteigen”. Corresponding to the original version, this leaves the question unanswered. Additionally, the meaning of item 10 of the ADL subscale “squatting” was obscure. It could stand for the dynamic process of squatting down or for statically assuming a squatted position. Finally, we translated that item as “in die Hocke gehen”. Item 17 of the ADL subscale “home responsibilities” did not specify the content: we agreed to the German translation “Tätigkeiten im Haushalt”. Pretesting of the final FAAM-G version in 18 sport students revealed no further difficulties. So, the prefinal and the final FAAM-G versions were identical.
Study participants
The preoperative patient group included 11 female and 13 male participants with an average age of 23.8 (range 16–46) years. The conservatively treated patients (7 female and 10 male participants) were 29.8 (range 13–49) years old. In the group of sport students with 17 women and 14 men, the average age was 24.7 (range 20–35). The volleyballer group (19 women and 18 men) was 25.8 (range 17–35) years old. The preoperative patient group was significantly younger than the conservatively treated patient group (p=0.001). Also, the conservatively treated group was significantly older than the sport students group (p=0.004). The age of the sport students and volleyballers did not differ significantly (p=0.880) (table 1).
FAAM-G subscale results
Preoperative patients scored 69.3% (range 32.1–100%) on the ADL subscale. Conservatively treated patient's ADL result was 91.6% (range 71.4–98.8%). The sport students group scored 99.0% (range 91.7–100%), and the volleyballers had a mean ADL subscore of 99.0% (range 94.0–100%). On the sport subscale, the preoperative patient group reached a mean score of 34.1% (range 20.0–90.6%), the conservatively treated patient group reached 75.4% (range 34.4–90.6%), the sport students group had 93.5% (range 31.3–100%) and the volleyballers achieved 96.2% (range 75.0–100%).
In both subscales (ADL and sport subscale), only the preoperative study group differed significantly from the three other groups (p=0.000). When pooling patients (n=41) and healthy controls (n=68), the FAAM-G scores differed significantly (p=0.000).
Reliability
The test–retest reliability was excellent with respect to both subscales, comparing conservative, preoperative and volleyballer groups, respectively (ICC=0.878–0.976; p=0.000). The sport students group demonstrated fair to poor reliability results in the ADL subscale (ICC=0.590; p=0.000) and excellent reliability in the sport subscale (ICC=0.921; p=0.000). Except for the sport students demonstrating moderate correlations (ρ=0.528–0.665; p=0.002–0.000), the Spearman correlations were “strong” for all tested groups (ρ=0.896–0.949; p=0.000). The Wilcoxon test revealed no significant differences between the tested groups with respect to both subscales (p=0.062–1.000) (table 2).
The individual item reliability analyses revealed no relevant discrepancies (ICC=0.700–0.998, p=0.040–0.000; ρ=0.653–1.000, p=0.021–0.000; to get full details of the individual item reliability analysis, please contact the authors). The interobserver agreement was excellent (n=12; ICC=0.911, p=0.000, ρ=0.895, p=0.000).
Discussion
Chronic ankle instability is a frequent and potentially disturbing complication following acute ankle sprains.22 Evaluation of a given treatment seems to be more effective when clinical results are compared with patient- and disease-related outcome measures.23 Patient-administered and disease-related questionnaires examining the quality of life and physical function are increasingly used in international research.24 25 26 These instruments have to be translated and cross-culturally adapted before they are administered to different language speaking populations.10 Due to the fact that no reliable and validated chronic ankle instability questionnaire exists in the German language, we translated and cross-culturally adapted the Anglo-American version of the FAAM to German-speaking populations. This process was successfully performed by following the guidelines developed by Beaton et al.10
A systematic literature review3 detected only four patient-assessed, valid and reliable questionnaires for foot and ankle disorders.12,–,14 18 The FAAM and the FADI were announced to be most advisable research tools to quantify functional disabilities in persons with chronic ankle instability. Both patient-assessed questionnaires are similar in psychometric analyses. We decided to translate the FAAM as it consists of fewer test items and, therefore, requires less time for completion. The FAAM was created as a self-reported questionnaire to measure the changes of physical function in leg, foot and ankle disorders.13 Reliability and construct validity of the questionnaire for different foot disorders and athletes with chronic ankle instability were already demonstrated.19 27
This study demonstrates that the FAAM-G questionnaire is clearly structured, the items are easy to understand, and, therefore, the questionnaire can be used as a self-administered tool. For both subscales, test–retest reliability demonstrates excellent results for the conservative, preoperative and volleyballer groups (ICC=0.878–0.976; ρ=0.896–0.949) and for the sport students group on the sport subscale (ICC=0.921; ρ=0.528). However, the ICC for the ADL subscale for the sport students group was fair to poor (ICC=0.590; ρ=0.665, p=0.000). Even if all results of reliability testing were significant (p<0.05), it is unclear why the sport students revealed these lower correlation coefficients.
The individual item analysis reflected our fair to high reliable overall results (ICC=0.700–0.998, p=0.040–0.000; ρ=0.653–1.000, p=0.021–0.000). The construct validity was proven to be strong (ρ = −0.819 to −0.861, p=0.000). Healthy study participants scored both FAAM-G subscores significantly higher as the patient groups (p=0.000). This finding is in line with the results seen in the validation process for the original FAAM in athletes with chronic ankle instability.19 A weakness of the study is the Good et al score15 used for calculating construct validity. That grading scale is frequently used in clinical research and easy to apply. However, its validity and reliability in patients with chronic ankle instability has not been proven.
Our translation, cross-cultural adaptation and validation of the FAAM to a German-speaking population with chronic ankle instability is a first step to generate internationally comparable research in this field. Further studies are needed to validate the FAAM-G questionnaire for different diagnoses—for example, bone-related diseases and fractures, too.
Conclusion
The translation of the Anglo-American version of the FAAM into German and its cross-cultural adaptation to a German-speaking population were done carefully and without any major inconsistencies. Our results confirm that the FAAM-G questionnaire is a reliable and valid self-reported outcome measurement to evaluate patients with chronic ankle instability. For chronic lateral ankle instability testing, the FAAM-G is equivalent to the original FAAM version.
What is already known on this topic
▶ Evaluation of health-related quality of life and physical function is important for determining therapeutic strategies following ankle injuries. Instruments fulfiling those purposes are patient-administered questionnaires. Most frequently, these measures are introduced in the English language and psychometrically tested in Anglo-American populations.
What this study adds
▶ present study successfully cross-culturally adapted and validated (reliability and validity testing) the English version of the FAAM to a German-speaking population with chronic ankle instability according to the guidelines presented in literature.
Acknowledgments
The authors gratefully thank Michael Shields, Patty Schütze (back translation, expert committee), Christiane Riedel (healthcare professional, expert committee), Anja Kolb (expert committee) and Dr Hans Ackermann (statistical advice) for their substantial contribution. The authors further thank Dr RobRoy Martin for his conceptual email discussion during the cross-cultural adaptation and validation process of the FAAM-G questionnaire.
References
Footnotes
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Competing interests None declared.
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Ethics approval This study was conducted with the approval of the Ethik-Kommision Hessen, Germany.
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Provenance and peer review Not commissioned; externally peer reviewed.
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Patient consent Obtained.