INTRODUCTION
Renal stone disease is a common urological condition. The prevalence of urinary calculi has been increasing, despite the generalization of supplying clean water and the development of treatment skills for increasing stone-free rates [1-4]. Although the development of extracorporeal shock wave lithotripsy and endoscopic surgery such as ureteroscopic removal of stone and percutaneous nephrolithotomy (PCNL) have made urinary calculi relatively easy to treat, recurrence rate remains high. Therefore, many stone formers suffer from repetitive flank pain and anxiety about going to the emergency room because of stone-related symptoms and health problems. Additionally, deterioration of renal function is induced by long-term ureter obstruction, stone-related pain, urinary tract infection, or reintervention which may adversely affect the quality of life (QoL) of patients. This emphasizes the importance of evaluating QoL of patients’ daily lives. The QoL of patients with stones would be inevitably lower than that of those without history of stones. However, studies on the QoL of patients with urinary stone are rarely conducted. Although many studies have been published about the development of new treatment methods or the efficiency of treatment, few studies have focused on QoL of patients with urinary stone. The importance of QoL for patients with urinary stone has recently begun to be acknowledged and several studies have been published up to date [5-17]. With increasing interest in QoL of patients with urinary stone, research has also focused on how to evaluate QoL more accurately. Consequently, several questionnaires have been suggested for patients with urinary stone [7,16].
Wisconsin Stone Quality of Life Questionnaire (WISQOL) developed by Penniston et al. [6] has been relatively widely used and cited. It not only evaluates QoL of stone formers, but also evaluates QoL of patients who have undergone surgery due to urinary stones [12,13]. The questionnaire consisted of 28 questions to evaluate QoL of stone formers with help from 34 stone patients. They initially generated 65 items and reduced them depending on the frequency and importance of symptoms. These 28 questions were grouped intuitively into the following 7 domains: (1) energy and fatigue, (2) sleep, (3) work and family, (4) nutrition and pharmacological therapies, (5) physical symptoms, (6) concerns related to intimacy and travel, and (7) general emotional well-being [7].
However, a qualified assessment tool for patients with urinary stone in Korea is lacking. Therefore, the objective of this study was to make a Korean version of WISQOL. The present study describes the development of Korean version of WISQOL based on the original English version with subsequent linguistic validation by a panel of Korean specialists and patients with history of urinary stone.
MATERIALS AND METHODS
Translation and Linguistic Validation
This study was approved by the Institutional Review Board. The authors followed previously designated processes (Fig. 1) designed to obtain a well-translated Korean version of WISQOL so that it would be conceptually identical to the original version [18,19]. The original version was translated or paraphrased in accordance with Korean cultural and social differences. It was carried out by project leaders (YEY and SYC) of the panel. This panel called Young Endourological Study Group consisted of 13 Korean experts who performed a typical linguistic validation process. They were urologists who were actively treating patients with urolithiasis.
Permission
Before the present study began, the panel contacted the Wisconsin group to gain permission to translate and use WISQOL with language validation process.
Forward Translation
The original version of WISQOL was translated into Korean by 2 bilingual (Korean and English) translators who did not have a medical license (ver. 1a and 1b). One was an accountant working on international affairs. The other was a doctoral student majoring in natural science in a graduate school of the United States. Only one researcher (YEY) contacted 2 translators respectively. Contacts were made only through emails. The 2 translators were unaware of each other. Discussion between the 2 translators was not allowed during the translation process.
Reconciliation by Panel
Translated WISQOL by 2 translators were combined into 1 file and reconciliated into a single version through 2 panel meetings and several electronic conversations. There was difficulty because of the existence of some honorific expression only in Korean, not in English. Thus, a lot of discussion was necessary about expressions in English without such expression in Korea due to cultural differences. After many adjustments, panel was able to complete a reconciliated Korean version of WISQOL (ver. 2).
Backward Translation
Backward translation was performed by another bilingual translator who did not know the original version of WISQOL. This translator was a graduate student majoring in biology at a university in the United States and preparing a doctorate in Korea. As before, we only contacted the translator via email. The third translator was isolated from the previous 2 translators. This translator translated reconciliated Korean version (ver. 2) back into an English version (ver. 3).
Second Reconciliation by Panel
After the third translator completed the task, all panels assembled to make the final adjustment. Several differences were detected between the original version and ver. 3. All panels including 3 translators carried out reconciliation on this. After that, all sentences were made as one questionnaire in the same shape according to the original arrangement of WISQOL (ver. 4). As the questionnaire was completed, spellings and grammars were checked by careful proofreading.
Cognitive Debriefing and Final Reconciliation
WISQOL ver. 4 was given to 5 Korean recurrent stone formers at the center of the author (SYC). Patients gave information about whether they had difficulty in reading or understanding the questionnaire without any help or whether there was ambiguous expression. After they finished the questionnaire, a well-trained interviewer who was a nurse practitioner in the center of the author (SYC) interviewed these patients. The interviewer gathered and gave their opinions to the panel. The panel finally discussed whether further correction was needed.
RESULTS
Forward Translation and Reconciliation
As experienced in previous research, the choice of words (especially nouns) was very tricky. There were some expressions that we had difficulty in word selection despite many panel meetings and discussions (Table 1). Supplementary Table 1 shows all items of forward translation and reconciliation.
The first sentence (1-A) in the first question group “My energy level during the day is less than usual.” is translated into “Nat donganui eneoji reberi pyeongsoboda natda.” (Energy levels during the day are lower than usual.) and “Pyeongsoboda giryeogi eopda.” (There is no energy than usual). However, the panel concluded that there was no Korean synonym for the English noun “energy.” It is usually called “eneoji” in Korea. However, it is very different from the meaning of energy in this sentence when Koreans use this expression. In addition, there is a high possibility that elderly patients would not understand “eneoji” because it is a loanword. Therefore, the panel reconciled that energy should be changed into “giryeok sujun” (power level).
The panel also had trouble for the second sentence (3-B) in the third question group “I force myself to go to work or school, to exercise, or to fulfill other responsibilities.” Translators translated this into “Jikjangina hakgyoe gagi wihae, undonghareo gagi wihae, hogeun dareun mateun ireul hagi wihae eokjiro noryeokaeya handa.” (I have to try hard to go to work or school, go to workout, or do other jobs.) or “Irina hakgyoe gageona, undong ttoneun dareun ildeureul hagi wihaeseoneun eokjiro haeyahanda.” (Have to force myself to go to work or school, exercise or do other things.). The main reason why this sentence is difficult to translate is because there is no proper word to replace “fulfill other responsibilities” in Korean. The panel discussed about this and it was interpreted as “dareun chaegimdeureul suhaenghanda” (carry out other responsibilities) after discussion.
Backward Translation and the Second Reconciliation
Contents of Korean WISQOL version 2 were revised for a total of 5 sentences (Table 2). The reconciled version of the WISQOL (ver. 2.) was sent to a third translator by email and the third translator performed backward translation to version 3 which was compared with the original version of WISQOL. These translated sentences showed a good agreement with the original WISQOL (Supplementary Table 2).
In question 7-2, there was an expression “everyday issues or responsibilities.” However, after backward translation, it was changed to “everyday tasks and responsibilities.” In version 2, the word “issues” was translated into Korean “ildeul.” In English, issues and tasks mean quite different meanings. However, panels concluded that there were no proper Korean words to represent “issues” through discussion. Therefore, the authors concluded that no modifications were needed in this sentence.
There were differences in backward translation due to different tense grammars of English and Korean for questions about the last 4 weeks of experience of the last session. These questions are based on past tense sentences while asking about past 4-week experiences. Backward translator translated these into sentences of present perfect tense. In panel reconciliation, panels concluded that this part was not considered to be a problem to understand and this issue was inevitable because of different tenses of English and Korean.
Cognitive Debriefing and Final Reconciliation
The translated WISQOL was given to 5 patients and tested to make sure that they understood these questions. All patients were regularly followed up in the urology outpatient clinic of the center of the author (SYC) due to urinary lithiasis. Their ages ranged from 20s to 60s. Patients were able to understand all sentences well. However, 2 of these patients aged over 60 years had to read these questions 2 or 3 times to understand these questions. Because all the questions are based on the last 4 weeks of experience, patients who underwent surgery recently wondered if they had to answer based on preoperative conditions or postoperative symptoms. All patients answered yes to the question whether these questions explained the patients’ situation well. Most of these responders answered that explanatory notes of the questionnaire were well written and the format of the questionnaire was easy to follow. They gave feedback on some expressions that were difficult to understand. One patient had difficulty in understanding “giryeok sujun” in question 1-A, which was translated from “energy level.” After short panel discussion, the ward “sujun” was decided to be eliminated. Another one pointed out the meaning of “sagyo haengsa” which was translated from “social events.” However, since this expression does not exist in Korean anyhow, panels decided to keep the original translated text. Another patient asked about the meaning of “gingeupchiryosil” (urgent care in the last session). It is a hospital facility that does not exist in the Korean medical system. No further grammatical errors or misunderstandings were found. The authors were able to confirm the completed Korean version of WISQOL (Fig. 2).
DISCUSSION
It is very important to assess the QoL of patients with urinary stone because many of them may experience recurrence after they have been properly treated. They may suffer from it like chronic diseases. The QoL of patients with urinary calculi tended to be neglected in the past. However, a questionnaire was developed to measure the inconvenience caused by ureteral stents earlier than urinary stone QoL [20]. About 10 years ago, papers about the QoL of patients with urinary stone began to be published [11,14,15]. Since then, the QoL for patients with urinary stone has been reported to be far worse and different than expected. In a prospective study assessing changes in QoL of patients who underwent PCNL for symptomatic caliceal diverticulum and deep lower-pole calculi, Staios et al. [15] concluded that, although stone-free rate was very high (87%), fewer than half of these patients experienced subjective benefit. Bryant et al. [9] have demonstrated that stone formers suffer from not only physical functioning and bodily pain, but also lower social functioning and general health compared to the general population. Moreover, Bensalah et al. [8] have reported that the number of stone episodes does not influence QoL. However, the number of ureteroscopic surgery and stent placement have impacted their mental health [11].
One of the important disadvantages in these papers was that a 36-Item Short-Form General Health Survey (SF-36) questionnaire was used as a tool for QoL assessment. The SF-36 was initially designed as a general scale to predict QoL of an individual [10]. Donnally et al. [10] reported that 18 of 96 patients (18.8%) reported a stone event within the month preceding completion of the initial questionnaire. However, these 18 patients had no stone event prior to follow-up survey or changes in any SF-36 domain between the first and follow-up questionnaires. Thus, they concluded that the absence of significant changes in SF-36 scores despite changes in stone status suggested that SF-36 might not be an adequate tool to monitor QoL in stone patients [10]. In recognition of the need for a questionnaire specific to patients with urinary stone, Penniston and Nakada [7] have developed WISQOL as an instrument to access the health-related QoL of kidney stone formers. They made 65 items at first related to stone formers and eliminated 37 questions that had less impact factor through an item reduction process [10]. The WISQOL was externally validated with 1,609 stone patients from 9 academic stone centers in the United States and English-speaking Canada [21]. It was found that WISQOL was superior to SF-36v2 in identifying health-related QoL related decrements, confirming its convergent validity. Further studies have cited and used WISQOL as a useful tool to evaluate health-related QoL of stone formers [6,12,13].
It is not easy to translate questionnaires developed in foreign languages into other languages [22]. Since a small mistake can cause a big difference in meaning, translation work must be done through several confirmation procedures. The authors were able to complete the Korean version of WISQOL through precise procedures proven previously [18,19,23]. In addition, good feedbacks were received from patients who had answered the questionnaire.
Our study has several limitations, including the small number of patients who participated in cognitive briefing. However, the authors sought to improve the accuracy of the screening by selecting patients of various ages with different educational levels. Another limitation of this study was that there was no external validation at all. This needs to be addressed in a further study. However, to our knowledge, this is the first questionnaire available in Korea to assess the QoL of urinary stone formers. Our results are significant because the Korean version of WISQOL would be a generally reliable instrument for urinary stone patients.
In conclusion, the present study describes details for the development of Korean version of WISQOL. Our results might be widely used in real practice between urologists who treat and care urinary lithiasis patients. A further large-scale validation study is needed. The use of this questionnaire is expected to have a positive impact on patient care.
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