The Spanish Linguistic Validation of the Ureteral Stent Symptom Questionnaire

Abstract

Background and Purpose:

Ureteral Stent Symptoms Questionnaire (USSQ) is an intervention-specific health-related quality-of-life (HrQoL) measure. We describe development and validation of the Spanish version.

Materials and Methods:

We followed established methods to develop the Spanish version of the original USSQ. After pilot testing, we conducted a formal validation study; 70 patients, undergoing placement of ureteral stents, successfully completed the Spanish USSQ as well as the EuroQoL-5D (male and female), the ICIQ male and female lower urinary tract symptoms questionnaires at weeks 1 and 4 after stent insertions, and at week 4 after their removal. In addition, 40 healthy people acted as a control group and completed the same questionnaires twice at 3-week intervals. Statistical analyses were performed to evaluate reliability, validity, and sensitivity to change of the Spanish USSQ.

Results:

After revision of the initial two drafts after translation, back translation, and pilot testing, a final draft was developed that underwent field testing. Psychometric analyses revealed satisfactory internal consistencies (Cronbach alpha coefficients: 0.73–0. 85) and test-retest reliability (Spearman correlation coefficient: >0.6) for the domains of urinary symptom, body pain, and general health. It demonstrated satisfactory discriminant validity (sensitivity to change, p<0.01), convergent validity (good correlations between the domains of the USSQ and existing validated questionnaires), and test–retest reliability (p<0.001). Analysis of the domains of the sexual matter (21.4%) and work performance (35.7%) were limited because of the small proportion of the study population for whom it was applicable.

Conclusions:

Results of our development and validation study demonstrate that the new Spanish version of the USSQ is a psychometrically valid intervention-specific measurer for use in the second most common language in the world. It is a reliable outcome measure that could be used for both clinical and research purposes.

Introduction

Ureteral stent placement is among the most common procedures performed in the urologist's daily practice; decompression of the upper urinary tract for obstruction or renal colic, prevention of ureteral blockage after shockwave lithotripsy for large stones, and drainage of the upper urinary tract after surgical procedures are frequent indications.¹

On the other hand, ureteral stents are associated with a decrease in quality of life (QoL) in up to 80% of the patients.² In the last few years, a lot of research has been conducted to reduce the stent-related morbidity by introducing new designs and materials for stents or testing different pharmacologic agents (alpha-blocker and anticholinergic) to control the symptoms.^3
–5

Joshi and associates⁶ developed the Ureteral Stent Symptom Questionnaire (USSQ), a psychometrically valid measure to evaluate symptoms and impact on QoL of ureteral stents. It consists of six domains, exploring stent-specific matters in three (urinary symptoms, pain, and additional problems) and general matters in the other three (general health, work performance, and sexual matters).

The USSQ has been adopted as a reliable outcome measure in several trials, allowing better understanding of the results and its application for meta-analysis.^4,7
–9 No validated versions of non-English USSQ have been used in some studies, however, thus limiting the strength of their results.^10
–12 Accordingly, linguistic validation in different languages and across cultures is needed for USSQ global validation and wider use.

Currently, validated versions of the USSQ have been published in Italian and Korean, while validations in several other languages are ongoing.^13,14

This study was conducted to provide a validated version of the USSQ in Spanish, the language most widely spread in the world and the second most common language in the United States.

Materials and Methods

Translation process and pilot testing

Linguistic translations in Spanish of the USSQ in situ and poststent were developed in parallel by two independent Spanish native-speaking professional translators, with English as their first foreign language. A first draft of the questionnaire was issued after revision of the translations in a consensus meeting attended by the two translators together with the consultants of the Urolithiasis unit at Fundació Puigvert-Barcelona. The text was further refined using a plain language easily understandable by patients from different sociocultural backgrounds and by all Spanish-speaking people in the world.

This first draft of the Spanish USSQ version was sent for back-translation to two additional bilingual professional translators, with English as their native language, and blinded to the original English version.

The two back-translation versions were then reviewed by a professional English linguistic reviewer for scientific publications and compared with the original English version to highlight discordances. Accordingly, a second draft of the Spanish USSQ version was developed in a new consensus meeting; this draft was eventually sent to a member of the Royal Academy of the Spanish Language (Real Academia de la Lengua Española) for a linguistic revision.

Finally, five patients with stents were asked to review the texts and to give their opinions regarding the ease in reading and comprehending the questions. No additional remarks were generated by the second draft of the USSQ, so it was considered ready for use.

Patient selection

Between January 2012 and August 2012, 78 patients who underwent placement of a ureteral stent were recruited at two tertiary academic urological institutions in Spain (Barcelona and Zaragoza). Inclusion criteria were unilateral temporary stent insertion for acute benign ureteral obstruction or placement after diagnostic/therapeutic upper urinary tract procedures. Exclusion criteria were (1) a history of or current treatment for lower urinary tract symptoms, chronic bacterial prostatitis, chronic pelvic pain syndrome, and prostate cancer in men, (2) stress/urge/mixed urinary incontinence, lower urinary tract dysfunction, and pregnancy in women, and (3) chronic ureteral obstruction, obstruction from malignancy, bleeding diathesis, history of bladder cancer, recurrent urinary tract infections, overactive bladder syndrome, neurologic and psychiatric diseases, and concomitant medication with alpha-blockers, anticholinergics, analgesics, and other drugs, possibly interfering with lower urinary tract function or pain assessment, in men and women. We also excluded cases of complicated ureteroscopy, defined as (1) mucosal injury edema, or perforation, (2) multiple, large (more than 2 cm) or impacted stones.

In both institutions, the same type of 6F Double-J ureteral stent was inserted in all cases by experienced urologists, using three different lengths (26, 28, and 30 cm, respectively) according to ureteral length.

All subjects were fully informed about the purpose of the study, which was approved by the Institutional Review Board, and all provided written informed consent.

During the same period, 40 healthy people were recruited at Fundació Puigvert in Barcelona as a control group.

Data collection

The Spanish version of the USSQ-in situ was self-administered by all patients at weeks 1 and 4 after stent placement. The USSQ-poststent version was self-administered at week 4 after stent removal, considering this interval of time adequate for the patients to come back to the prestent condition. This was the time frame used during validation of the original questionnaire.

Scores for urinary symptoms, body pain, general health, work performance, and sexual matters domains were computed according to the original author (HBJ) instructions. No score was recorded for the additional problems domain, because this is a descriptive/qualitative domain, and the global QoL domain was scored on the basis of a single question.

In addition, all the patients were asked to complete the EuroQoL-5D, ICIQ-MLUTS (male) and ICIQ-FLUTS (female) questionnaires at the same time; all these questionnaires were validated in Spanish and provided by the corresponding authors.^15,16

Controls were evaluated with the USSQ-poststent two times, the first time with the additional questionnaires and the second time after 3 weeks with the USSQ alone.

Statistics

Sample size calculation was based on convergent validity. The minimum number of subjects with stent per sex, i.e. 35, was estimated according to different variables, which included a correlation coefficient between the USSQ and individual questions of other validated questionnaires of at least 0.56 (the lowest found in the validation of the original questionnaire2), α=0.05, β=0.10, and a response rate of at least 80%.

We used descriptive statistics to obtain participant characteristics. To evaluate if the questions could be understood by, and acceptable to, the participants, we calculated response rate for each item. Domain scores were calculated by simple addition of the scores for each question in that domain, as per the original scoring guide.

Individual's mean was used for the small number of missing data, and unanswered whole domain was omitted in the analysis.

Reliability was evaluated by internal consistency (tested by Cronbach alpha coefficient) and test-retest reliability between week 1 and 4 (tested by Spearman correlation coefficient) after stent insertion.

Spearman correlation coefficients were used to assess relations between different domains of the Spanish USSQ. Convergent validity was assessed by correlating the scores of urinary symptom domain with the MLUTS in men and FLUTS in women, and by correlating the scores of general health domain with the visual analogue scale (VAS) of the EuroQoL questionnaire. Wilcoxon-rank sum tests were used to compare scores with the stent in situ and after removal (sensitivity to change) and the results of patients at week 4 with those of the healthy group (discriminant validity).

Data were collected and analyzed under the supervision of a statistician member of the Iberoamerican Cochrane Centre at Barcelona; the software SPSS 20.0 for Windows (SPSS, Chicago, IL) was used for the study purposes and results were two-sided with p<0.05.

Results

The demographic characteristics are shown in Table 1. A total of 70 patients completed all the questionnaires; 8 patients dropped out of the study because of consent form retrieved (n=4), detection of malignancy (n=1), recurrent acute urinary retention during the observation period (n=1), displacement of the stent (n=1), and lost to follow-up before completion of the study (n=1).

Table 1.

Patient and Control Demographics

	Cases	Control
Number of subjects	70	40
Mean age (SD)	56.8 (15)	42 (12)
Male/female ratio	32:38	20:20
Nationality (%)
Spanish	58 (82)	36 (90)
Mexican	2 (2.8)
Colombian	1 (1.4)
Ecuadorian	2 (2.8)
Venezuelan	1 (1.4)
Argentinean	3 (4.3)	1 (2.5)
Cuban		1 (2.5)
N.A.	3 (4.3)	2 (5)
Employment status (%)
Student	3 (4.3)
Employed	25 (35.7)	40 (100)
Unemployed	13 (18.5)
Retired	15 (21.5)
N.A.	14 (20)

SD=standard deviation; N.A.=not applicable.

In eight (11%) cases, a small number (1 to 4) of unanswered questions were detected; the missing data were uniformly distributed throughout the domains. No entire domains remained unanswered.

Only a small proportion of the study population were sexually active [n=15 (21.4%) at week 1 and n=18 (25.75%) at week 4 with the stent in situ] when compared with n=37 after stent removal.

Although this clearly indicates difficulty with sexual function with the stent in situ, the results of the statistical analysis might not be reliable because of small numbers and hence were omitted from presentation in the final draft.

Reliability and validity

Internal consistency was high for the urinary symptoms and body pain domains, and satisfactory for general health and work performance domains (Table 2), both at weeks 1 and 4.

Table 2.

Internal Consistency and Test–Retest Reliability

	Internal consistency (Cronbach α)		Test–retest reliability
Domain	Week 1	Week 4	Spearman correlation coefficient	p-Value
Urinary symptoms	0.82	0.85	0.64	0.0001
Body pain	0.73	0.73	0.62	0.0001
General health	0.77	0.85	0.63	0.0001
Work performance	0.70	0.60	0.47	0.014
Global QoL	N.A.	N.A.	0.66	0.0001

QoL=quality of life.

Test-retest reliability was always significant for all the domains compared at weeks 1 and 4, with weaker Spearman correlation coefficients recorded for body pain and work performance domains.

Similarly, test-retest reliability was significant for all the domains in the control group, including also the sexual matter domain, which was applicable because all the subjects were sexually active (Spearman correlation coefficient 0.71, p 0.0001).

Domain structure and convergent validity

Most USSQ domains showed moderate correlations with each other (Table 3).

Table 3.

Total Domain Correlations at Weeks 1 and 4

	Urinary symptom	Body pain	General health	Work performance	Global QoL
Urinary symptom	1.00/1.00
Body pain	0.34/0.60	1.00/1.00
General health	0.45/0.51	0.35/0.51	1.00/1.00
Work performance	0.26/0.14	0.53/0.31	0.27/0.20	1.00/1.00
Global QoL	0.50/0.49	0.26/0.32	0.29/0.41	0.27/0.20	1.00/1.00

QoL=qualify of life.

For the convergent validity, when comparing the USSQ urinary symptom domains with the ICIQ male and female LUTS questionnaires, all the correlation coefficients were statistically significant, with just the exception of the comparison between the urinary symptom domain and the total incontinence score of the ICIQ FLUTS at week 1 (Spearman correlation coefficient 0.16, p=0.36).

Similarly, statistically significant correlations have been found when comparing the USSQ global health domain and the EuroQoL questionnaire (Table 4).

Table 4.

Convergent Validity

	Spearman correlation coefficient
	Week 1	p-Value	Week 4	p-Value
Urinary symptom vs
FLUTS filling score	0.40	0.014	0.65	0.0001
FLUTS voiding score	0.41	0.012	0.35	0.047
FLUTS incontinence score	0.16	0.36	0.57	0.0001
FLUTS total score	0.53	0.001	0.70	0.0001
MLUTS voiding score	0.51	0.003	0.47	0.007
MLUTS incontinence score	0.49	0.006	0.43	0.013
MLUTS total score	0.54	0.001	0.44	0.013
General health vs
EuroQoL total score	0.52	0.0001	0.62	0.0001
EuroQoL VAS	−0.41	0.001	−0.58	0.0001

FLUTS=female lower urinary tract symptoms module; MLUTS=male lower urinary tract symptoms module; EuroQoL=European quality of life.

Sensitivity to change and discriminant validity

Significant changes were observed in all the domains when comparing patients with (week 1 and 4) and without a stent (Table 5). All the patients had no pain after stent removal. Discriminant validity has been conducted comparing the domains scores of patients at week 4 after the stent placement and of healthy controls (Table 6): Each domain score was significantly different, indicating good discriminant validity of the Spanish USSQ.

Table 5.

Sensitivity to Change

	Median with stent (IQR)		Median without stent (IQR)	p-Value
	Week 1	Week 4	Week 4 poststent	Week 1 vs 4 poststent	Week 4 vs 4 poststent
Urinary symptom	29 (23–34)	27 (23–34)	19 (16–22)	0.0001	0.0001
Body pain	19.5 (15–23)	19 (17–22)	0	0.0001	0.0001
General health	13 (10–16.5)	14 (10.5–17.5)	9 (7–12)	0.003	0.0001
Work performance	6 (3–9)	7 (6–9)	3 (3–4)	0.0004	0.001
Global QoL	5 (4–6)	4 (4–4)	1.5 (1–2)	0.0001	0.0001

IQR=interquartile range; QoL=quality of life.

Table 6.

Discriminant Validity

	Cases (week 4 with stent)	Controls	p-Value
Median domain index score (IQR)
Urinary symptom	27 (23–34)	16 (13–17)	0.0001
Body pain	19 (17–22)	0	0.0001
General health	14 (10.5–17.5)	7 (6–9.5)	0.0001
Work performance	7 (6–9)	3 (3–3)	0.004

IQR=interquartile range.

Discussion

Placement of an indwelling ureteral stent is a common urologic intervention. With a wide variety of stents available, with different designs from various manufacturers, the need for a widely validated instrument to measure the stent-related discomforts is important.

The original English USSQ first captured the impact of the side effect associated with stent insertion by using a well developed questionnaire; they recorded a reduced QoL in up to 80% of patients.²

A similar result was shown in a Spanish-speaking cohort, by assessing the urinary symptoms and QoL with nonspecific questionnaires for patients with indwelling ureteral stents.¹⁷

We validated the Spanish translation of the USSQ, contributing to the diffusion of this useful tool, to objectively evaluate the impact of stents for clinical use. The Spanish language is currently estimated to be the second most widely spoken native language in the World¹⁸; Spanish has also been ranked as the second language learned by native speakers of American English.¹⁹

Psychometric properties of our validation study demonstrate that the Spanish USSQ is a reliable and valid instrument for measuring the ureteral stent-related symptoms in male and female patients.

As pointed out by the original authors, patients with an indwelling ureteral stent are affected mostly by urinary symptoms and pain that eventually affect their general health by impacting social life and limiting physical activities.^2,6 This is reflected by the fully satisfactory internal consistency coefficients found for these domains in our study (Table 1), in line with those showed in the previous publications: (urinary symptoms 0.77–0.96; body pain 0.73–0.88; general health: 0.77–0.93).^6,13,14

Sexual life and work performance are more variable domains depending on several factors not necessarily related to an indwelling ureteral stent, such as normal sexual activity, cultural behaviors, and social situation, and working status, respectively. Likewise in the Korean study, in our cohort, there were only 15 and 18 sexually active patients at weeks 1 and 4, respectively, which did not enable us to compute the internal consistency for this domain.

Similarly, a weak internal consistency for the work performance domain (0.70 and 0.60 at 1 and 4 weeks) was detected as a consequence of the relatively low number of active workers (35.7%).

Test-retest reliability was satisfactory for the urinary symptoms, body pain, general health, and global QoL domains, and weak for the work performance section. As in the original study and in the Italian validation, we chose a 3-week interval for this test, which can be biased by a maturation bias (change of conditions and higher symptom tolerance) and by a recall bias for longer or shorter intervals, respectively. Counterbalancing each other, we think that 2 (as used by the Korean group) and 3 weeks are both acceptable intervals to limit these biases for this kind of study. Test-retest reliability of sexual matters was performed in the control group as a surrogate of the study group where it was not applicable, showing a good correlation coefficient (0.71; p=0.0001).

Moderate correlations were detected in the domain correlation analysis but, as previously stated in the original and Korean articles, this is a peculiar aspect of the USSQ that reflects different components of the dynamic stent experience, at least partly unrelated to each other. Similar to the previous studies, stronger correlations were found at week 4 between urinary symptoms, body pain, and general health domains, indicating the impressions that patients with more severe urinary symptoms experience higher levels of body pain and vice versa; these clinical experiences might eventually affect the general health perceptions.

The Spanish version of USSQ showed moderate correlation with other validated symptom measures: moderate convergent validity with high statistical significance was detected when comparing urinary symptoms domains with ICIQ MLUTS in men and ICIQ FLUTS in women, with the exception of the incontinence score for female patients at week 1. These are expected findings, taking into account that even though similar, these questionnaires have been developed for different patients and with different clinical conditions. Moderate correlations were also found when comparing the general health sections with the EuroQoL total scores and VAS scores. Unlike the previous validation studies, we did not compare the global QoL single question of the USSQ to the VAS scale of the EuroQoL-5D questionnaire, preferring the general health score for this purpose. Sensitivity to change and discriminant validity were satisfactory when comparing patients with stents with poststented patients and controls, respectively.

A potential limitation of our study may be that formal validation has not been conducted in the Central or South American Spanish speaking countries. We have designed the Spanish validation of USSQ, however, taking into account the differences that can exist among the diverse accents of the Spanish language in the world. For this reason, the final draft of the questionnaires was reviewed by an official member of the Spanish Royal Academy—the official regulatory board of the Spanish language in Spain and one of the 20 permanent members of the Association of Spanish Language Academies—so that all the Spanish-speaking people around the world can easily understand the texts.

Finally, the absence of any problem with reading or comprehension of the text by overseas patients recruited in our study suggests the suitability of our Spanish USSQ for use in any Spanish-speaking country of the world.

Conclusion

The Spanish version of the USSQ is a reliable and robust instrument that can be self-administered by Spanish-speaking patients worldwide to investigate the impact of ureteral stents in different clinical aspects. Validation in other languages would be useful to increase the worldwide population of patients undergoing the placement of a ureteral stent who could be evaluated for clinical and research purposes.

Copies of the questionnaire are available from the authors on request.

Footnotes

Acknowledgments

The authors wish to sincerely thank Dr. Gianluca Giannarini (University of Udine) for his advice on study design; Mrs. Dorothy Mulvey for the bilingual translation and linguistic support; Prof. Francisco Rico (Real Academia Española) for the linguistic revision of the Spanish USSQ; Dr. Ignasi Gich (Iberoamerican Cochrane Centre, Barcelona) for statistical support.

Disclosure Statement

No competing financial interests exist.

Abbreviations Used

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