Validation and cultural adaptation of the Russian version of the Pedi-IKDC questionnaire

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BACKGROUND

In contemporary traumatology and orthopedics, scales (integral point systems) are used as a standard to assess the functional status of patients and their treatment results [1–3].

The data obtained from a systematic survey of a patient using point systems are summarized to a universal indicator that is understandable to orthopedic traumatologists. It provides a concise idea about the degree of knee joint dysfunction and severity of decrease in the quality of life of patients.

The current functional status of pediatric patients with various knee joint injuries also requires assessment [4]. In global practice, the Pedi-IKDC (The Pediatric International Knee Documentation Committee) scale [5–7] is increasingly used for this purpose, since it is adapted and understandable for patients under 18 years of age. In the Russian Federation, versions developed for adult patients are used very often as a questionnaire. Some questions may not be clear to pediatric patients, which can lead to misinterpretation of questions and incorrect final results.

The presence of validated and adapted scales in the arsenal of pediatric trauma orthopedists enables Russian colleagues to interact more effectively when assessing treatment results and to use the same professional language for communication with international colleagues due to the wide occurrence of this assessment system in international literatures [8, 9].

In a study of Charlote et al. [10], they validated, adapted, and translated the Pedi-IKDC scale into Dutch and revealed which questionnaire is the best for clinical practice. The authors concluded that the Pedi-IKDC questionnaire is more suitable for patients in terms of psychometric parameters than the KOOS-Child.

Dietvorst et al. [11] conducted a systematic review of articles based on patient-reported outcomes (PROMs). PROM enables to determine the extent of patients’ satisfaction with treatment results. It was also showed that the Pedi-IKDC and KOOS-Child questionnaires based on PROM data are reliable and sensitive, and these were recommended for the assessment of the functional status of the knee joints of pediatric patients.

The clinical relevance of this review consists of adult versions of questionnaires that are not suitable for children and adolescents.

This study aimed to validate, culturally adapt, and translate the Pedi-IKDC scale from English into Russian for pediatric patients.

MATERIALS AND METHODS

Due to the need to develop assessment standards for pediatric patients, a procedure for the validation and cultural adaptation of the Pedi-IKDC questionnaire was considered. To date, the translations of the questionnaire have already been completed by an orthopedic traumatologist, a professional medical translator proficient in the English language. As part of the procedure described, a team of specialists developed a variant of the questionnaire (Appendix) for conducting clinical trials. A statistical analysis of the material was performed to study the translated questionnaire for correlation and internal consistency. The stages of validation described above are presented in detail in international sources [12].

Our study included a questionnaire survey on 100 pediatric patients with various knee joint injuries. Fifty-two patients were male, and 48 were female patients. All patients underwent surgical treatment for damage to various knee joint structures (damage to the anterior cruciate ligament, posterior cruciate ligament, and knee menisci) in a clinic of Department No. 9 of the Priorov National Medical Research Center of Traumatology and Orthopedics from August 2020 to January 2021. In addition to the Pedi-IKDC questionnaire, the subjects filled out the frequently used Lysholm questionnaire.

The statistical analysis consisted of three stages. In stage 1, a general analysis was performed, standard baseline indicators were calculated, and their distribution was assessed. Based on the information received, methods and criteria were selected to solve the tasks assigned. In stage 2, the validity of the questionnaire was determined. In stage 3, the objectivity of the results was tested.

RESULTS

In stage 1, the main statistical indicators were calculated [13–15] using the Pedi-IKDC and Lysholm methods (Table 1).

 

Table 1. Descriptive statistics of the survey results

Statistical indicator	Questionnaire
	Pedi-IKDC	Lysholm
Mean	55.97	67.89
Dispersion	263.25	274.70
Median	58.15	68.50
Excess	–0.416	0.081
Asymmetry	–0.336	–0.528

 

To select the methods for the statistical processing of the results, the type of distribution of indicators was tested according to Pearson’s chi-squared test [12]. The significance level did not exceed 0.05, which indicates a normal distribution of the survey results. Calculations were performed using the StatGraphics software package. Figures 1 and 2 shows histograms based on the results above.

 

Fig. 1. Histogram of the distribution of patient survey results according to the Pedi-IKDC questionnaire with normal distribution density curve

 

Fig. 2. Histogram of the distribution of patient survey results according to the Lysholm questionnaire with normal distribution density curve

 

Due to the normal distribution of the survey results, parametric statistical methods were used [12–17].

Then, the validity of the questionnaire was tested based on three components: feasibility, discriminatory power, and consistency of tasks, which were confirmed using Cronbach’s alpha.

Feasibility was considered normal if the condition 0.1 ≤ D_j ≤ 0.9 is true. The calculated feasibility of each question for the Pedi-IKDC questionnaire is presented in Fig. 3.

 

Fig. 3. Testing the feasibility of questions for the Pedi-IKDC questionnaire

 

The Figure 3 shows that the feasibility condition was met, so the qualitative compilation of questionnaires was confirmed in terms of feasibility.

Discriminatory power shows the extent of consistency of the survey results on a particular question with the final results obtained from the entire questionnaire.

The calculated level of discriminatory power of each question in the Pedi-IKDC questionnaire are shown in Fig. 4.

 

Fig. 4. Discriminatory power values of questions for the Pedi-IKDC questionnaire

 

Figure 4 shows that the discriminatory power of the Pedi-IKDC questionnaire for all tasks, except for question 13, is high or moderate. In general, considering the significant number of questions for each questionnaire, their quality in terms of the discriminatory power of the questions can be considered satisfactory.

The Cronbach’s alpha coefficient enables the assessment of the internal consistency of the questions. For the Pedi-IKDC scale, it was 0.902. Thus, the questions were consistent despite the unconfirmed discriminatory power of one of the questions (Table 2).

 

Table 2. Results of the Cronbach α-test

Questionnaire	M	r	a	Consistency
Pedi-IKDC	20	0.315	0.902	Very high

 

The adequacy and objectivity of the survey results were substantiated using parametric correlation analysis.

The consistency of the assessments in the Pedi-IKDC and Lysholm questionnaires are presented in Table 3.

 

Table 3. Correlation matrix of survey results by methods

Pearson correlation	Pedi-IKDC	Lysholm
Pedi-IKDC	1.000	0.690
Lysholm	0.690	1.000

 

As shown the Table 3, the correlation is high and suggests a relationship between the survey results. However, to obtain statistically sound conclusions, the correlation coefficients should be tested for significance. The critical value for a sample of 100 patients at a significance level of 0.05 was t_cr = 1.661, and at a significance level of 0.01, it was t_cr = 2.365 [18].

Table 4 presents the t-test results for the same data categories shown in Table 3.

 

Table 4. Values of Student’s t-test necessary to substantiate the significance of the correlation matrix elements in Table 3

Pearson correlation	Pedi-IKDC	Lysholm
Pedi-IKDC	–	9.445
Lysholm	9.445	–

 

The high correlation of the results to determine the condition of patients confirms the adequacy and objectivity of the assessments obtained using the Pedi-IKDC questionnaire.

DISCUSSION

The assessment of the functional status of patients very important for conservative and surgical treatments. Pedi-IKDC is an adapted version of the IKDC questionnaire for pediatric patients. The questionnaire has been translated into various languages and is often used in global practice [1, 2, 7, 10, 11]. The Russian-language version of the Pedi-IKDC questionnaire is presented in the Appendix. The data obtained can be interpreted as follows. An excellent, good, satisfactory, and poor result is >90, 80–89, 70–79, and <70, respectively. Statistical analysis was performed to check the correctness of the translation. The level of statistical relationship between the results of the questionnaires (correlation) was also determined. The advantages of the study include the use of the Cronbach’s alpha coefficient and the calculation of discriminatory power. High Cronbach’s alpha values indicate the absence of contradictions between the questions and are considered a standard when performing questionnaire validation procedures [19]. The question discriminatory power check can be used for both the created questionnaires and the adapted ones. This enables the removal of conflicting questions from the questionnaire and ensures that it is adequate and applied correctly in practice.

Lysholm was used as a “control questionnaire.” Its data were compared with the data of the tested Pedi-IKDC. Lysholm was used because it is the most frequently used in our practice, but other questionnaires (KOOS-Child, WOMET, SF-36, etc.) can also be used. It is advisable for future studies on validation and cultural adaptation to select approved questionnaires as controls to have a greater reliability for statistical analysis. Based on the results of our statistical analysis, the Russian version of Pedi-IKDC provides reliable, adequate, and objective data and represents a sensitive tool. This study involved 100 pediatric patients. The association of each test item with the overall score was high. The Cronbach’s alpha index was 0.9, which indicates the validity and reliability of the translated version of the questionnaire. The procedure performed was also done in other countries, which is the standard for translation into other languages [10, 20]. Similar procedures were used in the practice of trauma orthopedists in Russia [19–21].

CONCLUSION

The Pedi-IKDC questionnaire validated and adapted here can be used in the practice of trauma orthopedists for children aged 10 to 18 years old. Using statistical methods, the results of the quality assessment of the adapted survey using the Pedi-IKDC method were analyzed. The validity of the questionnaires was also assessed using three components. Regarding the “feasibility of question,” all tasks in the questionnaire satisfy the requirements for sufficient feasibility and can be used in practice. In terms of the “discriminatory power of questions,” all tasks have high or moderate discriminatory power and make an adequate contribution to the final grade. The general consistency analysis based on Cronbach’s alpha test revealed the high overall consistency of questions in each questionnaire. Based on the comparison of assessment results on the patients’ condition using the Pedi-IKDC method and Lysholm questionnaire, which has been proven positively in practice, there was a significantly high level of correlation, with a probability of >0.99, which confirms the adequacy and objectivity of the assessments.

 

Appendix - The Pediatric International Knee Documentation Committee (Pedi-IKDC)

 

ADDITIONAL INFORMATION

Funding. The study had no external funding.

Conflict of interest. The authors declare no conflict of interest.

Ethical considerations. The study was performed in accordance with the requirements of the Declaration of Helsinki of the World Medical Association (as revised in 2013). The study was approved by the ethical committee (02/04/2021 No. 1-2021). The consent of the developers of the questionnaire for translation was obtained.

All patients and volunteers who participated in the clinical study gave written consent to this.

Author contributions. Ya.A. Ivanov created the concept and design of the study, collected and processed the data, and wrote the text. A.G. Yeltsin collected the data, edited the text. D.S. Mininkov collected the data.

All authors made significant contributions to the research and preparation of the article, read and approved the final version before its publication.

Acknowledgments. The authors are grateful to Sergei Igorevich Moiseev for his great contribution to the data analysis.

About the authors

Iaroslav A. Ivanov

National Medical Research Center of Traumatology and Orthopedics named after N.N. Priorov

Author for correspondence.
Email: docyaroslav@gmail.com
ORCID iD: 0000-0002-6352-2784
SPIN-code: 5575-4630

MD, PhD student

Russian Federation, Moscow

Alexander G. Eltsin

National Medical Research Center of Traumatology and Orthopedics named after N.N. Priorov

Email: agyeltsin@gmail.com
ORCID iD: 0000-0002-7736-9493
SPIN-code: 6411-2484

MD, PhD

Russian Federation, Moscow

Dmitry S. Mininkov

National Medical Research Center of Traumatology and Orthopedics named after N.N. Priorov

Email: 45040311@mail.ru
ORCID iD: 0000-0002-9490-6932
SPIN-code: 1494-3179

MD, PhD

Russian Federation, Moscow

References

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