This cross-sectional study was conducted over a period of almost 2 years and data were collected from(March 2019 to March 2020) The study was divided into 2 stages: Translation and cross-cultural adaptation or Psychometric testing of KOOS Urdu version. All methods were carried out in accordance with relevant guidelines and regulations [11].
Stage I: translation and cross-cultural adaptation process
Step I: initial translation
In adaptation, the first step was the forward translation. From the original language (the root language) to the target language, at least two forward translations were made of the instrument. The translations were contrasted in this manner, as it they recognize inconsistencies that might represent unclear terminology in the original language or discrepancies with how a term is interpreted. To achieve the best quality translation, the two translators belonged from different profiles or histories.
Step II: synthesis of these translations
A third, non-biased entity was added to the team to establish a combination of the two translations. This person’s function was to act as a mediator in the discussion of discrepancies in translation and to produce written evidence of the process. Working from the original questionnaire and the first version of the translator (T1) and the second version of the translator (T2), a combination of these translations. A written report was completed, meticulously describing the synthesis process, each problem discussed, and how it could have been solved. Instead of one party risking their emotions, it was crucial that all problems be settled by consensus.
Step III: Back-translation
The questionnaire was then converted back into the original language, working from the T-12 edition of the questionnaire and entirely oblivious to the original version. This was a validity testing method to make sure that the translated edition correctly represents the original version’s item information. The back translation process often magnifies unclear wording in the translations.
As with forward translations, the standard was assumed to be two back-translations. Two bilingual individuals with the source language (English) as their mother tongue have developed back-translations (BT1 andBT2). The two translators were not aware of the topics discussed nor knowledgeable of them, and ideally without medical history.
Step IV: expert committee
To obtain the cross-cultural equivalence of the interpreted instrument, the configuration of the Expert Committee was important. At least one methodologist, healthcare practitioner, language professional, as well as all translators (both forward and backward) and the translation synthesis recorder were included in minimum membership of the Expert Group. During this phase of the process, the original authors of the questionnaire were in close touch with the Expert Committee to answer questions and provide feedback.
The task of the Expert Committee was to compile all variants and components of the questionnaire, including the original instrument, instructions, scoring documents and all interpreted versions of the questionnaire (T1, T2, T12, BT1, BT2), and to create the pre-final version of the field test questionnaire. In finalizing the translated instrument, important decisions were reached by the expert committee and full written recording of the problems was made.
Step V: test of the pre-final version
Pre-test was the final step of the adaptation process. This field evaluation of the new questionnaire uses a pre-final version of subjects/patients from the goal environment, preferably between 30 and 40 participants. In this study the questionnaire was filled by 20 patients for pilot testing. The questionnaire is first completed by each subject and then questioned to explore what they think was intended by each questionnaire object and its answer. It discussed both the significance of the things and the answers. This means that the modified variant of an applied scenario still preserves its equivalence. To search for a high percentage of missed items or single answers, the distribution of responses was analyzed. The outcomes of this stage were compiled and forwarded to the AAOS Committee for approval with the other papers.
Step VI: submission of documentation to the AAOS Committee for appraisal
The final step in the adaptation process was the submission to the AAOS Committee of all the findings and formats. The Committee has confirmed that the recommended stages have been implemented and that the findings appear to be a fair reflection of this process [11].
Stage II: psychometric testing
The total sample size was 117 which was calculated by Kline method [12], out of which 54 were male participants and 63 were female patients of knee osteoarthritis. The data was gathered after Institutional review board (IRB) approval from The University of Lahore teaching hospital, department of physical therapy. All procedures were carried out in compliance with the applicable rules and regulations. Before data assemblage the informed written consent was also taken from all the participants. The inclusion criteria were male and female of age range between 40 and 75 years [13], subjects with primary knee osteoarthritis diagnosed and referred from orthopedic surgeon, those who were able to read and speak the native Urdu language and willing to participate in the study, patients that were able to understand and complete self-report questionnaires. Patients and subjects who were excluded from the study were having limb length discrepancy, musculoskeletal deformity, severe inflammatory arthritis, patients who had history of intra- articular use of corticosteroids and those who were unable to understand Urdu language.
Participants and testing
SF-12 Score, Numeric Pain Rating Scale (NPRS) for pain in addition to the Urdu version of Knee injury and Osteoarthritis Outcome score was completed by 117 patients with a variety of knee pathologies. The inclusion and exclusion criteria were the same as the pre-test stage.
Reliability
The reliability of KOOS-U version was tested among 117 patients of Knee osteoarthritis. The patients were instructed to fill KOOS-U, NPRS, SF-12 (quality of life) [14] during their first visit. Other demographic features were also acknowledged. After 48 h, same patients without any treatment were ret-tested in the same manner by filling KOOS-U, NPRS (pain), SF-12 (quality of life). The test-re-test reliability was measured by evaluating intra-class correlation coefficient (ICC) at 95% confidence interval. The internal consistency of KOOS-U was assessed through Cronbach’s alpha values and item total correlation. Internal consistency is regarded acceptable when alpha value exceeds 0.60–0.80 or excellent when it is between 0.80–0.95 [15]. The item-total correlation was evaluated by Cronbach alpha.
Validity
Convergent validity was assessed by determining correlation between KOOS-Urdu and SF-12 scale, Numeric Pain Rating Scale (NPRS. The r values are distributed as follows: r = 0–0.25, very low correlation; r = 0.26–0.49, low correlation; r = 0.5–0.69, moderate correlation; r = 0.7–0.89, high or strong correlation; r = 0.9–1.0, very high or very strong correlation [16].
Data analysis
Quantitative variables, in terms of mean ± SD and qualitative variables as frequency and percentage were taken to analyze the result by using SPSS version 23. Reliability was measured by test-retest reliability across repeated measures, internal consistency and measurement error by using an intra-class correlation coefficient (ICC2,1) and 95% confidence intervals (CIs). P < 0.05. Cronbach’s alpha was used to find Internal consistency.