Int Urogynecol J DOI 10.1007/s00192-015-2628-6
ORIGINAL ARTICLE
Adaptation and validation of the King’s Health Questionnaire in Portuguese women with urinary incontinence Rui Viana & Sara Viana & Félix Neto & Teresa Mascarenhas
Received: 18 August 2014 / Accepted: 6 January 2015 # The International Urogynecological Association 2015
Abstract Introduction and hypothesis Urinary incontinence (UI) in women is a problem of public health with psychological repercussions in various contexts of life. The aim of this study was to adapt and validate the King’s Health Questionnaire (KHQ) in women with UI to Portugal. Methods For the adaptation, a multistep forward–back translation protocol was used. The Positive and Negative Affect Schedule and the Satisfaction with Life Scale were used to validate the KHQ. The evaluation of the psychometric properties involved the assessment of validity, reliability, and test–retest stability in 103 women. A factor analysis was conducted to explore the underlying factor structure of KHQ. Inter-domain correlation was calculated for convergent and discriminant validity assessment. Results Exploratory factor analysis identified three factors Bpersonal limitations and daily life^, Bemotions and social relationships^ and Burinary symptoms^. Indicators of test–retest stability showed almost perfect agreement with a mean intraclass correlation coefficient (ICC) of 0.937. Internal consistency was found to be high (Cronbach’s alfa>0.7). Furthermore, the Portuguese version of the KHQ significantly
correlates with the Positive and Negative Affect Schedule, supporting construct validity. Conclusions The Portuguese version of the KHQ was found to be a valid and reliable measure of the quality of life in women with UI in Portugal, being relevant to both clinical practice and research. Keywords King’s health questionnaire . Quality of life . Reliability . Subjective well-being . Urinary incontinence . Validity Abbreviations UI QoL KHQ SD Cronbach α ICC CI
Urinary incontinence Quality of life King’s Health Questionnaire Standard deviation Cronbach alfa Intraclass correlation coefficient Confidence intervals
Introduction R. Viana : S. Viana : T. Mascarenhas Hospital of S. João, Porto, Portugal R. Viana (*) : S. Viana Faculty of Health Sciences, University of Fernando Pessoa, Porto, Portugal e-mail: [email protected] F. Neto Faculty of Psychology and Educational Sciences , University Porto, Porto, Portugal T. Mascarenhas Faculty of Medicine, University Porto, Porto, Portugal
Urinary incontinence (UI) is defined by the International Continence Society as the complaint of any involuntary loss of urine [1], representing a Public Health problem of high prevalence among adult women [2]. This problem may have a negative impact on the quality of life (QoL) [3], and treatments for UI are being developed to improve symptoms, and thereby QoL [4]. Symptoms of UI and their impact on patients’ QoL can be assessed in a number of ways, but the valid way of measuring the patient’s perspective of their predicament is through the use of psychometrically robust self-completion questionnaires.
Int Urogynecol J
Scientific evidence has shown that the King’s Health Questionnaire (KHQ) [5] is relevant in assessing the QoL in people with UI and is highly recommended, with validity, reliability, and sensitivity obtained in several studies [6]. The purpose of this study was to adapt and validate the KHQ to assess QoL in Portuguese women with UI. Additionally, this study aims to explore a relationship between the Portuguese version of the KHQ with and the Positive and Negative Affect Schedule and the Satisfaction with Life Scale.
Stage 5 We sent the back-translated version of the KHQ to the authors of the original version by the MAPI Research Trust [8] and obtained their agreement.
Measures The participants were assessed using three scales, as described below, and demographic and clinical questions regarding age, marital status, education, parity, menopause, no pelvic surgery procedure, urinary frequency, nocturia, and nocturnal enuresis were performed.
Materials and methods
King’s Health Questionnaire
Participants
The KHQ [5] has been translated and validated in 37 countries [9] and assesses the impact of the UI on the QoL, comprising the assessment of the urinary symptoms and subjective severity measures. The KHQ is composed of 21 items investigating nine domains and it evaluates the agreement of the subjects on a 4- and 5-option Likert scale: general health perceptions (1 item), incontinence impact (1 item), role limitations (2 items), physical limitations (2 items), social limitations (2 items), personal relationships (3 items), emotions (3 items), sleep and energy (2 items), and severity measures (5 items). Additionally, it has an independent subscale designed as a Symptom Severity Scale, which contains 11 items, measuring the presence and severity of urinary symptoms. The KHQ is scored from a minimum of 0 (best QoL) to a maximum of 100 (worst QoL), scored by every domain and by their global score [8]. The scoring algorithm, including handling missing data, is published elsewhere [10]. Concerning the psychometric properties, this instrument has shown good validity and reliability in several observational studies and clinical trials [11–15].
One hundred and twenty-four women were recruited from the Department of Gynecology and Obstetrics of São João Hospital, Porto, Portugal. After screening, 103 women met the inclusion criteria. Inclusion criteria were being a Portuguese woman, at least 18 years old, with stress UI, and living in the community. Exclusion criteria included being pregnant, being institutionalized, having had previous pelvic surgery procedure, neurological problems, ongoing urinary tract infections, and pelvic organ prolapse. The validation of the KHQ was carried out in two phases. Phase 1 included the translation and adaptation of the questionnaire into the Portuguese language and culture and phase 2 comprised the evaluation of their psychometric properties. The translation process followed the multistep approach according to the international guidelines [7], involving five stages. Stage 1 Consisted of the translation and cultural and linguistic adaptation of the original version of the KHQ, by two bilingual translators with specific skills in terms of English and Portuguese and experience demonstrated in the health sciences. Stage 2 A panel of experts (clinical investigators and translators) that evaluated the two translations of KHQ, analyzing each item, consensually obtaining a preliminary version. Stage 3 A pilot study, which was applied to a preliminary version of the KHQ in 20 women with SUI, to assess the adequacy of the vocabulary used, the univocal understanding of items, and other problems. Stage 4 The translators proceeded to back-translate into the English language of the original version, using a similar methodology, following discussion on the appropriateness of the content of the KHQ, according to what it claims to measure (content validity).
Positive and Negative Affect Schedule The Positive and Negative Affect Schedule was built to assess the affective domain of subjective well-being [16]. This scale has 22 items and evaluates the agreement of the individuals on a 5-option Likert scale. The authors verify that it has a high internal consistency and construct validity. The scale has been extensively used and was adapted for a Portuguese population [17]. In this sample, the coefficient alfas were 0.90 for positive affect and 0.84 for negative affect. Satisfaction with Life Scale The Satisfaction with Life Scale was developed by Diener et al. [18] to measure the satisfaction with life and to assess the cognitive domain of subjective well-being. It consists of five items. Participants were asked to state how much they agreed or disagreed with each statement on a seven-point
Int Urogynecol J
Likert scale, with 1 indicating strong disagreement and 7 strong agreement. The reliability and the validity of this scale have previously been demonstrated for a Portuguese population [19]. The coefficient alfa on this measure for the current study was 0.88. Procedure The recruitment and testing of the participants was performed by a trained physiotherapist researcher. The sample was recruited at the Department of Gynecology and Obstetrics of São João Hospital, Porto, Portugal. The study was approved by the Ethics Committee of São João Hospital and all women signed the consent form before participating in the investigation. The owners of the copyright of KHQ© are Linda Cardozo and Con Kelleher, 1997, all rights reserved [5]. We had the authorization and permission of the MAPI Research Trust to use the KHQ [8]. Statistical analysis The internal consistency of the Portuguese version of the KHQ and its domains was analyzed using the Cronbach alfa (α) coefficient and by the inter-item and item-total correlation matrixes. The test–retest stability was calculated by applying KHQ in the test and retest, after 12 weeks, to the same sample and under equal conditions, using adequate agreement analysis techniques (statistics for categorical variables and intraclass correlation coefficient [ICC] for continuous variables) [20–23]. To assess the construct validity an exploratory factor analysis was also carried out, applying the methods of principal components with varimax rotation to the extraction of the factors, except for general health perceptions and Incontinence impact, which are single-item measures. There was an appropriateness of the factorial analysis, given the factors with eigenvalues equal to or greater than 1.0, through the Kaiser– Meyer–Olkin criteria [23] and the Bartlett test (p
ORIGINAL ARTICLE
Adaptation and validation of the King’s Health Questionnaire in Portuguese women with urinary incontinence Rui Viana & Sara Viana & Félix Neto & Teresa Mascarenhas
Received: 18 August 2014 / Accepted: 6 January 2015 # The International Urogynecological Association 2015
Abstract Introduction and hypothesis Urinary incontinence (UI) in women is a problem of public health with psychological repercussions in various contexts of life. The aim of this study was to adapt and validate the King’s Health Questionnaire (KHQ) in women with UI to Portugal. Methods For the adaptation, a multistep forward–back translation protocol was used. The Positive and Negative Affect Schedule and the Satisfaction with Life Scale were used to validate the KHQ. The evaluation of the psychometric properties involved the assessment of validity, reliability, and test–retest stability in 103 women. A factor analysis was conducted to explore the underlying factor structure of KHQ. Inter-domain correlation was calculated for convergent and discriminant validity assessment. Results Exploratory factor analysis identified three factors Bpersonal limitations and daily life^, Bemotions and social relationships^ and Burinary symptoms^. Indicators of test–retest stability showed almost perfect agreement with a mean intraclass correlation coefficient (ICC) of 0.937. Internal consistency was found to be high (Cronbach’s alfa>0.7). Furthermore, the Portuguese version of the KHQ significantly
correlates with the Positive and Negative Affect Schedule, supporting construct validity. Conclusions The Portuguese version of the KHQ was found to be a valid and reliable measure of the quality of life in women with UI in Portugal, being relevant to both clinical practice and research. Keywords King’s health questionnaire . Quality of life . Reliability . Subjective well-being . Urinary incontinence . Validity Abbreviations UI QoL KHQ SD Cronbach α ICC CI
Urinary incontinence Quality of life King’s Health Questionnaire Standard deviation Cronbach alfa Intraclass correlation coefficient Confidence intervals
Introduction R. Viana : S. Viana : T. Mascarenhas Hospital of S. João, Porto, Portugal R. Viana (*) : S. Viana Faculty of Health Sciences, University of Fernando Pessoa, Porto, Portugal e-mail: [email protected] F. Neto Faculty of Psychology and Educational Sciences , University Porto, Porto, Portugal T. Mascarenhas Faculty of Medicine, University Porto, Porto, Portugal
Urinary incontinence (UI) is defined by the International Continence Society as the complaint of any involuntary loss of urine [1], representing a Public Health problem of high prevalence among adult women [2]. This problem may have a negative impact on the quality of life (QoL) [3], and treatments for UI are being developed to improve symptoms, and thereby QoL [4]. Symptoms of UI and their impact on patients’ QoL can be assessed in a number of ways, but the valid way of measuring the patient’s perspective of their predicament is through the use of psychometrically robust self-completion questionnaires.
Int Urogynecol J
Scientific evidence has shown that the King’s Health Questionnaire (KHQ) [5] is relevant in assessing the QoL in people with UI and is highly recommended, with validity, reliability, and sensitivity obtained in several studies [6]. The purpose of this study was to adapt and validate the KHQ to assess QoL in Portuguese women with UI. Additionally, this study aims to explore a relationship between the Portuguese version of the KHQ with and the Positive and Negative Affect Schedule and the Satisfaction with Life Scale.
Stage 5 We sent the back-translated version of the KHQ to the authors of the original version by the MAPI Research Trust [8] and obtained their agreement.
Measures The participants were assessed using three scales, as described below, and demographic and clinical questions regarding age, marital status, education, parity, menopause, no pelvic surgery procedure, urinary frequency, nocturia, and nocturnal enuresis were performed.
Materials and methods
King’s Health Questionnaire
Participants
The KHQ [5] has been translated and validated in 37 countries [9] and assesses the impact of the UI on the QoL, comprising the assessment of the urinary symptoms and subjective severity measures. The KHQ is composed of 21 items investigating nine domains and it evaluates the agreement of the subjects on a 4- and 5-option Likert scale: general health perceptions (1 item), incontinence impact (1 item), role limitations (2 items), physical limitations (2 items), social limitations (2 items), personal relationships (3 items), emotions (3 items), sleep and energy (2 items), and severity measures (5 items). Additionally, it has an independent subscale designed as a Symptom Severity Scale, which contains 11 items, measuring the presence and severity of urinary symptoms. The KHQ is scored from a minimum of 0 (best QoL) to a maximum of 100 (worst QoL), scored by every domain and by their global score [8]. The scoring algorithm, including handling missing data, is published elsewhere [10]. Concerning the psychometric properties, this instrument has shown good validity and reliability in several observational studies and clinical trials [11–15].
One hundred and twenty-four women were recruited from the Department of Gynecology and Obstetrics of São João Hospital, Porto, Portugal. After screening, 103 women met the inclusion criteria. Inclusion criteria were being a Portuguese woman, at least 18 years old, with stress UI, and living in the community. Exclusion criteria included being pregnant, being institutionalized, having had previous pelvic surgery procedure, neurological problems, ongoing urinary tract infections, and pelvic organ prolapse. The validation of the KHQ was carried out in two phases. Phase 1 included the translation and adaptation of the questionnaire into the Portuguese language and culture and phase 2 comprised the evaluation of their psychometric properties. The translation process followed the multistep approach according to the international guidelines [7], involving five stages. Stage 1 Consisted of the translation and cultural and linguistic adaptation of the original version of the KHQ, by two bilingual translators with specific skills in terms of English and Portuguese and experience demonstrated in the health sciences. Stage 2 A panel of experts (clinical investigators and translators) that evaluated the two translations of KHQ, analyzing each item, consensually obtaining a preliminary version. Stage 3 A pilot study, which was applied to a preliminary version of the KHQ in 20 women with SUI, to assess the adequacy of the vocabulary used, the univocal understanding of items, and other problems. Stage 4 The translators proceeded to back-translate into the English language of the original version, using a similar methodology, following discussion on the appropriateness of the content of the KHQ, according to what it claims to measure (content validity).
Positive and Negative Affect Schedule The Positive and Negative Affect Schedule was built to assess the affective domain of subjective well-being [16]. This scale has 22 items and evaluates the agreement of the individuals on a 5-option Likert scale. The authors verify that it has a high internal consistency and construct validity. The scale has been extensively used and was adapted for a Portuguese population [17]. In this sample, the coefficient alfas were 0.90 for positive affect and 0.84 for negative affect. Satisfaction with Life Scale The Satisfaction with Life Scale was developed by Diener et al. [18] to measure the satisfaction with life and to assess the cognitive domain of subjective well-being. It consists of five items. Participants were asked to state how much they agreed or disagreed with each statement on a seven-point
Int Urogynecol J
Likert scale, with 1 indicating strong disagreement and 7 strong agreement. The reliability and the validity of this scale have previously been demonstrated for a Portuguese population [19]. The coefficient alfa on this measure for the current study was 0.88. Procedure The recruitment and testing of the participants was performed by a trained physiotherapist researcher. The sample was recruited at the Department of Gynecology and Obstetrics of São João Hospital, Porto, Portugal. The study was approved by the Ethics Committee of São João Hospital and all women signed the consent form before participating in the investigation. The owners of the copyright of KHQ© are Linda Cardozo and Con Kelleher, 1997, all rights reserved [5]. We had the authorization and permission of the MAPI Research Trust to use the KHQ [8]. Statistical analysis The internal consistency of the Portuguese version of the KHQ and its domains was analyzed using the Cronbach alfa (α) coefficient and by the inter-item and item-total correlation matrixes. The test–retest stability was calculated by applying KHQ in the test and retest, after 12 weeks, to the same sample and under equal conditions, using adequate agreement analysis techniques (statistics for categorical variables and intraclass correlation coefficient [ICC] for continuous variables) [20–23]. To assess the construct validity an exploratory factor analysis was also carried out, applying the methods of principal components with varimax rotation to the extraction of the factors, except for general health perceptions and Incontinence impact, which are single-item measures. There was an appropriateness of the factorial analysis, given the factors with eigenvalues equal to or greater than 1.0, through the Kaiser– Meyer–Olkin criteria [23] and the Bartlett test (p
