{'fraction_non_alphanumeric': 0.028473091364205255, 'fraction_numerical': 0.017521902377972465, 'mean_word_length': 5.213452566096423, 'pattern_counts': {'":': 0, '<': 4, '<?xml version=': 0, '>': 1, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Validation of the French version of the Wisconsin Quality of Life (WISQOL) questionnaire for patients with nephrolithiasis

Introduction: The Wisconsin Stone Quality of Life (WISQOL) questionnaire has been recently developed to objectively assess QOL in patients with nephrolithiasis. However, a French version of the questionnaire was lacking. Therefore, the aim of the present study was to develop and validate the French version of this tool. Methods: The French version of the WISQOL (F-WISQOL) was developed in a multistep process involving primary translation, back-translation, and pilot testing among a group of patients (n=12). Nephrolithiasis patients from two tertiary care institutions were recruited into this study and completed the following questionnaires: the medical history form and either the WISQOL or F-WISQOL. Internal consistency was assessed using Cronbach’s α, and interdomain associations were evaluated using Spearman’s rank correlation (r). One-way ANOVA was used to compare scores from the two groups (WISQOL and F-WISQOL). Results: A total of 210 patients were enrolled in this study: 68 in the WISQOL group and 148 in the F-WISQOL group. Internal consistency was high for all domains in both groups (FWISQOL: 0.924–0.970; WISQOL: 0.888–0.965). No statistically significant difference was found between the two groups’ scores. Inter-domain association, measured by Spearman correlation, was moderate to very strong between all the domains in the F-WISQOL. Values ranged from r=0.676–0.915, with acceptable correlation between D1, D2, and D3, but weaker correlation between D4 (vitality) and the three other domains (r=0.676–0.729). CUAJ – Original Research Bhojani et al Validation of French WISQOL 2 © 2020 Canadian Urological Association Conclusions: In the present study, the French version of the WISQOL questionnaire was validated at two academic institutions. Introduction With recurrence rates of up to 50% at 5 years post a symptomatic kidney stone event, kidney stone disease is often a chronic medical condition that poses a significant burden on Quality of Life (QOL).1 Previous studies exploring the QOL of nephrolithiasis patients found pain and physical impairment to be worse in this patient population compared to their healthy counterparts.2 Mental health symptoms such as anxiety and depression were also reported to be worse amongst recurrent nephrolithiasis patients during their inter crises intervals.3,4 The number of recurrent colic episodes significantly correlated with symptoms of anxiety (P = 0.002) and depression (P < 0.001).3 While current guidelines recommend treatment options based on stonefree rates, patients’ QOL is often not included as a primary end point.5 In recent years, Health-related quality of life (HRQOL) data has gained more attention from clinicians and researchers as it has an important role in disease management. HRQOL scores are thought to provide critical information regarding patients’ expectations of their health state post-treatment, which may impact decision-making. This is particularly relevant in the management of asymptomatic stones, where information about the patients’ expectations of HRQOL improvement could influence the choice between active management versus surveillance.6 Consideration of HRQOL factors also provides vital information that allow for medical and nutritional therapies to be tailored to patients and their treatment goals. One such example in urologic oncology is the incorporation of the Bladder Utility Symptoms Scale in the management of patients with prostate and bladder cancers. 7,8,9 Another example of HRQOL questionnaire is the Ureteral Stent Symptom Questionnaire (USSQ) that was previously developed and validated to assess QOL in patients with ureteral stents. 10 One of the shortcomings of the USSQ is that the majority of the items assessed HRQOL specific to patients with ureteral stents. The Wisconsin Stone-QOL (WISQOL) self-report questionnaire was developed in 2016 to address this gap in the literature and clinical practice.11 Although general measures of QOL are important, they are often insufficient to gain a holistic and comprehensive understanding of the disease burden specifically experienced by nephrolithiasis patients. The WISQOL questionnaire’s objective is to measure patients’ QOL in the context of their disease as well as to promote and incorporate this new tool within current clinical management paradigms for nephrolithiasis. It has been previously established, through internal validity testing, that the WISQOL questionnaire successfully discriminates between patients on the basis of nephrolithiasis.6 Although, the generalizability of this tool to patients of a broader geographical area has been previously assessed in Turkey, Spain and Korea, the CUAJ – Original Research Bhojani et al Validation of French WISQOL 3 © 2020 Canadian Urological Association questionnaire had yet to be tailored to the French-speaking population in Canada and beyond.12,13,14 The purpose of this study was to develop the French version of the WISQOL (FWISQOL) and evaluate its internal consistency and psychometric properties.


Introduction
With recurrence rates of up to 50% at 5 years post a symptomatic kidney stone event, kidney stone disease is often a chronic medical condition that poses a significant burden on Quality of Life (QOL). 1 Previous studies exploring the QOL of nephrolithiasis patients found pain and physical impairment to be worse in this patient population compared to their healthy counterparts. 2 Mental health symptoms such as anxiety and depression were also reported to be worse amongst recurrent nephrolithiasis patients during their inter crises intervals. 3,4 The number of recurrent colic episodes significantly correlated with symptoms of anxiety (P = 0.002) and depression (P < 0.001). 3 While current guidelines recommend treatment options based on stonefree rates, patients' QOL is often not included as a primary end point. 5 In recent years, Health-related quality of life (HRQOL) data has gained more attention from clinicians and researchers as it has an important role in disease management. HRQOL scores are thought to provide critical information regarding patients' expectations of their health state post-treatment, which may impact decision-making. This is particularly relevant in the management of asymptomatic stones, where information about the patients' expectations of HRQOL improvement could influence the choice between active management versus surveillance. 6 Consideration of HRQOL factors also provides vital information that allow for medical and nutritional therapies to be tailored to patients and their treatment goals. One such example in urologic oncology is the incorporation of the Bladder Utility Symptoms Scale in the management of patients with prostate and bladder cancers. 7,8,9 Another example of HRQOL questionnaire is the Ureteral Stent Symptom Questionnaire (USSQ) that was previously developed and validated to assess QOL in patients with ureteral stents. 10 One of the shortcomings of the USSQ is that the majority of the items assessed HRQOL specific to patients with ureteral stents. The Wisconsin Stone-QOL (WISQOL) self-report questionnaire was developed in 2016 to address this gap in the literature and clinical practice. 11 Although general measures of QOL are important, they are often insufficient to gain a holistic and comprehensive understanding of the disease burden specifically experienced by nephrolithiasis patients. The WISQOL questionnaire's objective is to measure patients' QOL in the context of their disease as well as to promote and incorporate this new tool within current clinical management paradigms for nephrolithiasis. It has been previously established, through internal validity testing, that the WISQOL questionnaire successfully discriminates between patients on the basis of nephrolithiasis. 6 Although, the generalizability of this tool to patients of a broader geographical area has been previously assessed in Turkey, Spain and Korea, the questionnaire had yet to be tailored to the French-speaking population in Canada and beyond. 12,13,14 The purpose of this study was to develop the French version of the WISQOL (F-WISQOL) and evaluate its internal consistency and psychometric properties.

Translation method and pilot testing
The French version of the questionnaire (F-WISQOL; Appendix A) was developed in a multistep process by two authors who are both bilingual with native level written and spoken French and English. Both authors were medical students with knowledge in medical jargon in both languages. 15 The questionnaire was first translated from English to French by one of the authors (GST) and subsequently back translated from French to English by another author (NGT). The back translated version found to be consistent with the original WISQOL questionnaire, except for one question that was revised in the F-WISQOL. A final review of the latest version of the questionnaire was conducted by an endourologist (SA) to ensure the F-WISQOL was representative of the original version and that it did not include vocabulary that would be difficult for patients to understand. This second version of the F-WISQOL was then pilot tested amongst a group of 12 nephrolithiasis patients recruited in the outpatient clinic. All patients included in the pilot testing completed the second version of the F-WISQOL questionnaire in its entirety and did not raise any issues in understanding the meaning of any items. Some grammatical and punctuation adjustments were made at that point. The revised third version was used for the validation of the F-WISQOL. Final correction of minor grammatical errors took place during the review of this manuscript.

Sample size calculation
In previous translation studies, the number of patients varied between 5 and 87. 12,13,14 A correlation sample size calculation was performed using the Sample Size Calculators for designing clinical research tool (UCSF Clinical & Translational Science Institute) 16 . The calculation yielded that recruiting a total of 194 patients would be sufficient; using α (two-tailed) = 0.05, β = 0.20 and r=0.20. The goal for the present study was to recruit at least 100 patients at each of the two tertiary care centres.

Study population
Ethics board approval was obtained from both institutions and all patients were consented prior to enrolment. Adult males and females with a history of kidney stones and proficient in either English or French were approached for the study. Exclusion criteria included: illiteracy, inability to communicate in English or French, as well as severe mental or physical disability preventing informed consent and/or independent questionnaire completion. Patients with common urological comorbidities such as neurogenic bladder or benign prostatic hyperplasia were not

Study design
Enrolled patients were asked to complete either the WISQOL or F-WISQOL questionnaire based on their preference depending on whether they felt most comfortable with English or French, respectively. In addition, all patients were asked to fill a medical history form specifically developed for this study. The latter questionnaire was translated into French for those more comfortable in French. The WISQOL questionnaire is a 28-item multidimensional questionnaire measuring morbidity in four domains specific to nephrolithiasis patients: social impact, emotional impact, disease impact and impact on vitality. 6 Each item in the questionnaire is scored on a Likert-scale ranging from 1 to 5, with the maximum score being of 140. A higher score in the WISQOL indicates a higher HRQOL. The French version of the WISQOL (F-WISQOL) was constructed in the same format. The WISQOL only refers to events or symptoms occurring in the past 4 weeks. The medical history form aimed to gather information about the patients' primary occupation, medical and nephrolithiasis history and current pharmacological therapies. The questionnaires included short instructions and patients were encouraged to ask clarifying questions to the research assistant prior to beginning. Upon completion, patients were asked if they had any comments or suggestions regarding the WISQOL items.
The primary aim of this study was to develop and validate F-WISQOL. To achieve this, assessment of the internal consistency within each domain and inter-domain was performed for the F-WISQOL questionnaire. The secondary outcome was to compare the internal consistency between the French (F-WISQOL) and the previously validated English version of the WISQOL questionnaire. Both primary and secondary outcomes were assessed by means of statistical analyses.
Statistical analysis was completed using IBM SPSS Statistics version 24.0 (IBM Corp., Chicago, USA). For the purpose of the analyses, raw scores and totals were used. The level of significance was set at p<0.05. Consistency and reliability were assumed at values >0.70. Baseline demographics and clinical characteristics were compared between both groups (French and English). Student t-tests and Chi-square analyses were used as appropriate. For the primary outcome, inter-domain associations were measured using Spearman's rank correlation (r). Principal component analysis with Kaiser-Varimax rotation was done to identify the most important variables of the French version of the WISQOL and to group them into the most important components (domains). For the secondary outcome, internal consistency reliability was assessed using Cronbach's α, comparing the two versions of the questionnaire across all domains. Readability was assessed using the Flesch-Kincaid test. 19

Results
All patients enrolled (n=210) completed either the WISQOL or F-WISQOL questionnaire. At the MUHC, a total of 106 participants were recruited. Of those, 36% (n=38) completed the French version of the questionnaire, while 64% (n=68) completed the English version of the questionnaire. At the CHUM, which cares for a predominantly francophone population, 100% (n=104) of the recruited participants completed the F-WISQOL. Therefore, the French group was comprised of 142 patients whereas 68 patients were in the English group. Both WISQOL and F-WISQOL groups were comparable except for two variables: there were significantly more women who took the WISQOL questionnaire than the F-WISQOL questionnaire (50% vs. 35%; p=0.032). In addition, there were significantly more patients with history of prior stone passage in the WISQOL group than in the F-WISQOL group (67.7% vs 50%; p=0.016) ( Table 1).
On one-way analysis of variance (ANOVA), there were no significant differences in the WISQOL and F-WISQOL groups ( Table 2). Cronbach's α was used to assess the internal consistency within each domain of the WISQOL and F-WISQOL questionnaires (Table 3). Internal consistency was high for all domains for both questionnaires ranging from 0.89 to 0.97 for the WISQOL and from 0.92 to 0.97 for the F-WISQOL (Table 3). Table 4 illustrates interdomain association in the F-WISQOL, measured by Spearman correlation. Moderate to very strong associations were found between all of the domains. Values ranged from r=0.68-0.91, with acceptable correlation between D1, D2 and D3, but weaker correlation between D4 (vitality) and the 3 other domains r=0.68-0.73.
Principal components analysis generated Eigenvalues indicating that 4 factors (domains) accounted for nearly 70% of cumulative variability, which is consistent with the number identified in the original development of the WISQOL. After Kaiser-Varimax rotation, none of the 28 items of the F-WISQOL loaded <0.30 on a factor, and exploratory factor analysis revealed individual items had high communalities ranging between 0.48 and 0.87 for all 28 items (mean 0.73; median 0.72). Flesch-Kincaid score was of 10, indicating the F-WISQOL's readability is at the level of 10 th grade.