To evaluate the psychometric properties of the Menopause-Specific Quality of Life (MENQOL) Questionnaire in a sample of breast cancer survivors experiencing menopausal symptoms.
This was a secondary analysis of MENQOL psychometric data from two larger parent studies investigating acupuncture for the relief of menopausal symptoms among breast cancer survivors. Reliability was assessed for each subscale of the MENQOL via: 1) internal consistency reliability with Cronbach’s α, and 2) test-retest reliability at multiple follow-up points with intra-class correlation coefficients (ICCs) and r. Convergent and discriminant validity were assessed via correlations of the vasomotor and psychosocial MENQOL subscales with select items in the Kupperman Index and Daily Symptom Diary. A principal components analysis (PCA) was performed to determine construct validity.
For each subscale, Cronbach’s α was ≥ 0.70. All subscale test-retest reliabilities at first follow-up were significant and at least moderately correlated ≥ 0.450 (r’s and ICCs). Convergent validity was moderate between the vasomotor and psychosocial subscales and the symptom diary (r’s ≥ 0.410, p’s < 0.001), and larger between these domains and the Kupperman Index (r’s ≥ 0.614, p’s < 0.001). In the same subscales, discriminant validity was supported by low, non-significant correlations (r’s ≤ 0.176, p’s > 0.05). The PCA revealed a latent structure nearly identical to the pre-specified instrument domains, with the exception of the physical domain.
With results comparable to those obtained in previous psychometric work, the MENQOL appears to be a reliable and valid instrument to assess quality of life in post-menopausal breast cancer survivors.
menopause; quality of life; breast cancer; psychometrics; factor analysis
Background and aim: The psychometric properties of rating scales are sample dependent and need evaluations in different samples. The Multiple Sclerosis Impact Scale (MSIS-29), a new patient based rating scale for multiple sclerosis (MS) was predominantly developed from a community based sample derived from the MS Society. A number of important patient characteristics of this sample remain unknown. The aim of the study was to evaluate five psychometric properties of the MSIS-29 in three hospital based samples: people admitted for rehabilitation, people admitted for intravenous corticosteroid treatment for MS relapses, and people with primary progressive MS.
Methods: People with MS were recruited from the three clinical settings. They completed several health measures. MSIS-29 data were evaluated for data quality, scaling assumptions, acceptability, reliability and validity, and compared with those from a previously reported community based study.
Results: A total of 233 people (rehabilitation =53; corticosteroids =76; primary progressive =104) completed questionnaires. In all samples, missing data were low (≤2.2%), scaling assumptions were satisfied, and reliability was high (≥0.91). Correlations between the MSIS-29 and other scales were consistent with a priori hypotheses. Findings were consistent with those from the community samples.
Conclusions: The psychometric properties of the MSIS-29 are consistent across three hospital based samples, and similar to those in the community samples. These findings further support its use as an outcome measure in different clinical settings.
Measuring the impacts of oral conditions on quality of life is an important part of oral health needs assessment. For this purpose a variety of oral health-related quality of life instruments have been developed. To use a scale in a new context or with a different groups of people, it is necessary to re-establish its psychometric properties. The objectives of this study are to develop and test the reliability and validity of the Persian version of Oral Impacts on Daily Performances (OIDP) index.
The Persian version of OIDP index was developed through a linguistic translation exercise. The psychometric properties of the Persian version of OIDP were evaluated in terms of face, content, construct and criterion validity in addition to internal and test-retest reliability. A convenience sample of 285 working adults aged 20–50 living in Mashad was recruited (91% response rate) to evaluate the Persian version.
The Persian version of OIDP had excellent validity and reliability charactersitics. Weighted Kappa was 0.91. Cronbachs alpha coefficient was 0.79. The index showed significant associations with self-rated oral and general health status, as well as perceived dental treatment needs, satisfaction with mouth and prevalence of pain in mouth (P < 0.001). 64.9% of subjects had an oral impact on their daily performances. The most prevalent performance affected was eating, followed by major work or role and sleeping.
The Persian version of OIDP index is a valid and reliable measure for use in 20 to 50 year old working Iranians.
Aims: To compare the psychometric qualities of six fatigue questionnaires in a sample of working persons.
Methods: Internal consistency and test-retest reliability, content validity, convergent validity, and the dimensionality of the fatigue instruments were explored.
Results: All scales had a satisfactory internal consistency. Furthermore, based on factor analyses and Mokken scale analyses, all scales were unidimensional and appeared to measure an identical construct. The Fatigue Assessment Scale (FAS) had the highest factor loading on the one factor solution obtained in a factor analysis of the total scores of all scales.
Conclusions: All the questionnaires were unidimensional and had good reliability and validity. The FAS was the most promising fatigue measure.
To compare psychometric functioning of the Fatigue Severity Scale (FSS) and the Modified Fatigue Impact Scale (MFIS) in a community sample of persons with multiple sclerosis (MS).
A self-report survey including the FSS, MFIS, demographic and other health measures was completed by 1271 individuals with MS. Analyses evaluated the reliability and validity of the scales, assessed their dimensional structures, and estimated levels of floor and ceiling effects. Item response theory (IRT) was used to evaluate the precision of the MFIS and FSS at different levels of fatigue.
Participants had a mean score on the FSS of 5.1 and of 44.2 on the MFIS. Cronbach’s alpha values for FSS and MFIS were all 0.93 or greater. Known-groups and discriminant validity of MFIS and FSS scores were supported by the analyses. The MFIS had low floor and ceiling effects, while the FSS had low floor and moderate ceiling effects. Unidimensionality was supported for both scales. IRT analyses indicate the FSS is less precise in measuring both low and high levels of fatigue compared to the MFIS.
Researchers and clinicians interested in measuring physical aspects of fatigue in samples whose fatigue ranges from mild to moderate can choose either instrument. For those interested in measuring both physical and cognitive aspects of fatigue, and whose sample is expected to have higher levels of fatigue, the MFIS is a better choice even though it is longer. IRT analyses suggest both scales could be shortened without a significant loss of precision.
Fatigue Severity Scale; Modified Fatigue Impact Scale; multiple sclerosis; psychometrics; Item Response Theory
Background: There may be difficulties in the use of self report measurements in patients with cognitive impairment or serious mood disturbances which interfere with reliable self assessment, as may be the case in multiple sclerosis (MS). In such cases proxies may provide valuable information. However, before using any questionnaires in a proxy sample, the questionnaire should be evaluated for proxy use.
Objective: To evaluate the psychometric properties of the 29 item Multiple Sclerosis Impact Scale (MSIS-29) when used by proxies of MS patients.
Methods: A sample of 62 partners of MS patients completed the MSIS-29. The data were evaluated for the psychometric criteria of the MSIS-29, including data quality, scaling assumptions, acceptability, reliability, validity, and responsiveness.
Results: Psychometric evaluation was satisfactory; data quality was high, and scaling assumptions and acceptability were good. Reliability was high (α>0.80). Findings were consistent with results of a psychometric evaluation in a patient sample.
Conclusions: The MSIS-29 can be used reliably in proxies of patients with MS. As a next step the relation between data obtained from patients and proxies needs to be studied, focusing on factors that may affect agreement and discrepancies.
Purpose: This study provides preliminary evidence for the acceptability, reliability, and validity of the new Alzheimer's Disease Knowledge Scale (ADKS), a content and psychometric update to the Alzheimer's Disease Knowledge Test. Design and Methods: Traditional scale development methods were used to generate items and evaluate their psychometric properties in a variety of subsamples. Results: The final 30-item, true/false scale takes approximately 5–10 min to complete and covers risk factors, assessment and diagnosis, symptoms, course, life impact, caregiving, and treatment and management. Preliminary results suggest that the ADKS has adequate reliability (test–retest and internal consistency) and validity (content, predictive, concurrent, and convergent). Implications: The ADKS is designed for use in both applied and research contexts, capable of assessing knowledge about Alzheimer's disease among laypeople, patients, caregivers, and professionals.
Alzheimer's disease; Knowledge; Assessment; Psychometrics; Health education
Symptoms of heartburn has an impact on health-related quality of life (HRQL). When a questionnaire is translated into a new language, a linguistic validation is necessary but not sufficient unless the psychometric characteristics have been verified. The aim is to document the psychometric characteristics of the German translation of the Gastrointestinal Symptom Rating Scale (GSRS) and Quality of Life in Reflux and Dyspepsia (QOLRAD) questionnaire.
142 patients with symptoms of heartburn (Age: M = 47.5, ± 14.6; Males = 44.4%) completed the German translation of GSRS, the QOLRAD, the Short-Form-36 (SF-36) and the Hospital Anxiety and Depression (HAD) scale.
The internal consistency reliability of GSRS ranged from 0.53–0.91 and of QOLRAD from 0.90–0.94, respectively. The test-retest reliability of GSRS ranged from 0.49–0.73 and of QOLRAD from 0.70–0.84. The relevant domains of the GSRS and QOLRAD domain scores significantly correlated. GSRS domains of Abdominal Pain and Constipation correlated (negatively) with most of the domains of the SF-36. The relevant QOLRAD domains significantly correlated with all SF-36 domains.
The psychometric characteristics of the German translation of GSRS and QOLRAD were found to be good, with satisfactory reliability and validity. The reliability of the GSRS Abdominal Pain domain was moderate.
Reliability; Validity; Reflux; Health-Related Quality of Life; Germany
The evaluation of asthma symptoms is a core outcome measure in asthma clinical research. The Asthma Symptom Utility Index (ASUI) was developed to assess frequency and severity of asthma symptoms. The psychometric properties of the ASUI are not well characterized and a minimal important difference (MID) is not established.
We assessed the reliability, validity, and responsiveness to change of the ASUI in a population of adult asthma patients. We also sought to determine the MID for the ASUI.
Adult asthma patients (n = 1648) from two previously completed multicenter randomized trials were included. Demographic information, spirometry, ASUI scores, and other asthma questionnaire scores were obtained at baseline and during follow-up visits. Participants also kept a daily asthma diary.
Internal consistency reliability of the ASUI was 0.74 (Cronbach’s alpha). Test-retest reliability was 0.76 (intra-class correlation). Construct validity was demonstrated by significant correlations between ASUI scores and Asthma Control Questionnaire (ACQ) scores (Spearman correlation r = −0.79, 95% CI [−0.85, −0.75], P<0.001) and Mini Asthma Quality of Life Questionnaire (Mini AQLQ) scores (r = 0.59, 95% CI [0.51, 0.61], P<0.001). Responsiveness to change was demonstrated, with significant differences between mean changes in ASUI score across groups of participants differing by 10% in the percent predicted FEV1 (P<0.001), and by 0.5 points in ACQ score (P < 0.001). Anchor-based methods and statistical methods support an MID for the ASUI of 0.09 points.
The ASUI is reliable, valid, and responsive to changes in asthma control over time. The MID of the ASUI (range of scores 0–1) is 0.09.
Asthma Symptom Utility Index; reliability; validity; responsiveness; minimal important difference
The Arthritis Impact Measurement Scales 2 (AIMS2) has not been translated and validated for Persian-speaking patients with osteoarthritis of the knee. This was to provide a validated instrument to measure functional disability and health-related quality of life in patients with osteoarthritis of the knee in Iran. The aim of this study was to culturally adapt and validate the AIMS2 for Persian-speaking patients with osteoarthritis of the knee in Iran.
A consecutive sample of patients with knee osteoarthritis were asked to complete the AIMS2, the Short Form Health Survey (SF-36) and four visual analog scales for pain, joint stiffness, patient's and physician's global assessment. Internal consistency and convergent validity were applied to examine psychometric properties of the AIMS2. In addition, 30 randomly selected patients were asked to complete the questionnaire two days later for the second time for test-retest reliability. Finally factor structure of the Persian AIMS2 was performed using the principal component factor analysis.
In all 230 patients were entered into the study. The mean (SD) age of the participants was 56.9 (8.7) years and the mean (SD) duration of disease was 7.2 (3.5) years. Cronbach's alpha coefficient and intraclass correlation coefficient (ICC) for the Persian AIMS2 scales ranged from 0.74 to 0.92 and 0.85 to 0.96, respectively. The correlation between most of the Persian AIMS2 scales and the physical and mental summary scores of the SF-36 and the visual analogue scales for pain, joint stiffness, patient's and physician's global assessment were statistically significant indicating a good convergent validity (p < 0.05). The results obtained from factor analysis indicated three latent factors that jointly accounted for 67.5% of the total variance.
The results showed that the Persian AIMS2 had reasonably good internal consistency, test-retest reliability, and convergent validity in patients with osteoarthritis of the knee. It is simple and easy to use and now can be applied in the future studies in Iran. However, its sensitivity to change needs still to be studied.
The current paper reviews data from different sources to get a closer impression on the psychometric and other methodological characteristics of the Aging Males' Symptoms (AMS) scale gathered recently. The scale was designed and standardized as self-administered scale to (a) to assess symptoms of aging (independent from those which are disease-related) between groups of males under different conditions, (b) to evaluate the severity of symptoms over time, and (c) to measure changes pre- and post androgen replacement therapy. The scale is in widespread use (14 languages).
Original data from different studies in many countries were centrally analysed to evaluate reliability and validity of the AMS.
Reliability measures (consistency and test-retest stability) were found to be good across countries, although the sample size was sometimes small.
Validity: The internal structure of the AMS in healthy and androgen deficient males, and across countries was sufficiently similar to conclude that the scale really measures the same phenomenon. The sub-scores and total score correlations were high (0.8–0.9) but lower among the sub-scales (0.5–0.7). This however suggests that the subscales are not fully independent.
The comparison with other scales for aging males or screening instruments for androgen deficiency showed sufficiently good correlations, illustrating a good criterion-oriented validity. The same is true for the comparison with the generic quality-of-life scale SF36 where also high correlation coefficients have been shown.
Methodological analyses of a treatment study of symptomatic males with testosterone demonstrated the ability of the AMS scale to measure treatment effect, irrespective of the severity of complaints before therapy. It was also shown that the AMS result can predict the independently generated (physician's) opinion about the individual treatment effect.
The currently available methodological evidence points towards a high quality of the AMS scale to measure and to compare HRQoL of aging males over time or before/after treatment, it suggests a high reliability and high validity as far as the process of construct validation could be pressed ahead yet. But certainly more data will become available, particularly from ongoing clinical studies.
AMS; Aging Males Symptoms; Quality of Life; Questionnaires; Reliability; Validity
Mindful-based interventions improve functioning and quality of life in fibromyalgia (FM) patients. The aim of the study is to perform a psychometric analysis of the Spanish version of the Mindful Attention Awareness Scale (MAAS) in a sample of patients diagnosed with FM.
The following measures were administered to 251 Spanish patients with FM: the Spanish version of MAAS, the Chronic Pain Acceptance Questionnaire, the Pain Catastrophising Scale, the Injustice Experience Questionnaire, the Psychological Inflexibility in Pain Scale, the Fibromyalgia Impact Questionnaire and the Euroqol. Factorial structure was analysed using Confirmatory Factor Analyses (CFA). Cronbach's α coefficient was calculated to examine internal consistency, and the intraclass correlation coefficient (ICC) was calculated to assess the test-retest reliability of the measures. Pearson’s correlation tests were run to evaluate univariate relationships between scores on the MAAS and criterion variables.
The MAAS scores in our sample were low (M = 56.7; SD = 17.5). CFA confirmed a two-factor structure, with the following fit indices [sbX2 = 172.34 (p < 0.001), CFI = 0.95, GFI = 0.90, SRMR = 0.05, RMSEA = 0.06. MAAS was found to have high internal consistency (Cronbach’s α = 0.90) and adequate test-retest reliability at a 1–2 week interval (ICC = 0.90). It showed significant and expected correlations with the criterion measures with the exception of the Euroqol (Pearson = 0.15).
Psychometric properties of the Spanish version of the MAAS in patients with FM are adequate. The dimensionality of the MAAS found in this sample and directions for future research are discussed.
Mindfulness; MAAS; Reliability; Validity; Fibromyalgia
To evaluate the reliability and validity of the English and Spanish versions of the Strengths and Weaknesses of ADHD-symptom and Normal-behavior (SWAN) rating scale.
Parents of preschoolers completed both a SWAN and the well-established Strengths and Difficulties Questionnaire (SDQ) on two separate occasions over a span of 3 months; instruments were in the primary language of the family (English or Spanish).
Psychometric properties for the English and Spanish versions of the SWAN were adequate, with high internal consistency and moderate test–retest reliability. Skewness and kurtosis statistics for the SWAN were within the range expected for a normally distributed population. The SWAN also demonstrated adequate convergent and discriminant validity in correlations with the various subscales of the SDQ.
Psychometric properties of both the English and Spanish versions of the SWAN indicate that it is a reliable and valid instrument for measuring child attention and hyperactivity. The stability of ratings over time in this preschool sample was moderate, which may reflect the relative instability of these characteristics in preschool children.
ADHD; rating scale; SWAN; Spanish
A self-report scale of adult attention-deficit/hyperactivity disorder, the World Health Organization (WHO) Adult ADHD Self-Report Scale (ASRS) was developed and demonstrated good psychometric properties. The purpose of the present study is to investigate the psychometric properties of the ASRS in Korean samples.
The ASRS includes 18 questions regarding the frequency of recent DSM-IV Criterion A symptoms of adult ADHD. We examined the factor structure, internal consistency, and convergent validity of the ASRS in Korean samples.
The ASRS demonstrated good internal consistency and test-retest reliability. Correlations between the ASRS and other adult ADHD measures were high, providing evidence of convergent validity. A subsequent exploratory factor analysis indicated that a two-factor solution provided the best fit.
It is expected that this scale would be helpful in clinical settings and research in Korea.
ASRS; Adult ADHD; Scale; Psychometric properties; Korean
We examined data (N = 34,108) on the differential reliability and validity of facet scales from the NEO Inventories. We evaluated the extent to which (a) psychometric properties of facet scales are generalizable across ages, cultures, and methods of measurement; and (b) validity criteria are associated with different forms of reliability. Composite estimates of facet scale stability, heritability, and cross-observer validity were broadly generalizable. Two estimates of retest reliability were independent predictors of the three validity criteria; none of three estimates of internal consistency was. Available evidence suggests the same pattern of results for other personality inventories. Internal consistency of scales can be useful as a check on data quality, but appears to be of limited utility for evaluating the potential validity of developed scales, and it should not be used as a substitute for retest reliability. Further research on the nature and determinants of retest reliability is needed.
Reliability; validity; cross-national; Five-Factor Model; personality traits
Purpose: To examine the psychometric properties of six outcome measures in people with Parkinson disease (PD).
Method: Twenty-four participants completed the following twice within 2 weeks: the timed up-and-go test (TUG), Northwestern University Disability Scale (NUDS), Schwab & England ADL Scale (S&E), Activities-specific Balance Confidence (ABC) Scale, PD Questionnaire—Short Form (PDQ 8), and Stanford Self-Efficacy for Managing Chronic Disease 6-Item Scale (SSE). Internal consistency, test–retest reliability (ICC[3,1]), and minimal detectable change (MDC) scores were calculated. Convergent and discriminant validity of the ABC were examined.
Results: Cronbach's alpha scores for the NUDS, ABC, PDQ-8, and SSE were 0.47, 0.92, 0.72, and 0.91 respectively. The intra-class correlation coefficient (ICC[3,1]) for the TUG was 0.69 and could be improved by averaging two trials. ICCs for the NUDS, S&E, ABC, PDQ-8, and SSE were 0.56, 0.70, 0.79, 0.82, and 0.72 respectively. The ABC correlated with the TUG (r=−0.44, p=0.03) and with PDQ-8 (rs=0.51, p=0.01) and NUDS (rs=0.48, p=0.02) walking items. The ABC was able to discriminate between stages 1 and 3 of disease progression but not between stages 1 and 2, which suggests that the ABC can distinguish large differences in disease progression but cannot detect more subtle differences.
Conclusions: Homogeneity of the ABC, PDQ-8, and SSE is good to excellent. Test–retest reliability scores of all measures except the NUDS are moderate to good. The ABC is a valid measure for use in PD. The MDC statistic may be useful for interpreting group score changes.
outcome measures; Parkinson disease; reliability; validity; fiabilité; maladie de Parkinson; mesure de résultats; validité
The Iowa Sleep Disturbances Inventory (ISDI) is a new measure of self-reported sleep difficulties, which was designed to help facilitate research on the overlap of sleep disturbances and psychopathology. This instrument was developed in 2 large student samples using principal factor analyses; the psychometric properties of the scales then were examined in 3 additional samples (students, psychiatric patients, sleep disorder patients). The ISDI consists of 11 specific scales (Nightmares, Initial Insomnia, Fatigue, Fragmented Sleep, Nonrestorative Sleep, Anxiety at Night, Light Sleep, Movement at Night, Sensations at Night, Excessive Sleep, Irregular Schedule) and 1 general scale (Daytime Disturbances). The structure of the ISDI generalizes across both patient and non-patient samples. In addition, the ISDI scales are internally consistent, show good retest reliability, demonstrate convergent and discriminant validity with widely used measures of sleep disturbances, and display criterion validity in relation to psychiatric patient status and specific symptoms of depression and anxiety.
sleep; scale development; factor analysis; major depression; anxiety disorders
Data are scarce on the comparison of EQ-5D index scores using the UK, US, and Japan preference weights in other populations. This study was aimed to examine the differences and agreements between these three weights, psychometric properties including test-retest reliability, convergent and known-groups validity, and the impact of differences in the EQ-5D scores on the outcome of cost-utility analysis in Thai people.
A convenience sample of 303 type 2 diabetic outpatients (18 years or older) from a cross-sectional study was examined. ANOVA and pos-hoc Bonferroni tests were used to determine the differences among the three EQ-5D scores. The agreements among the EQ-5D scores were assessed employing intraclass correlations coefficients (ICCs) and Bland-Altman plots. The ICCs were utilized to examine the test-retest reliability. Spearman's rho correlation coefficients were used to assess the convergent validity between the EQ-5D scores and sociodemographic & clinical data, and health status. Mann-Whitney U tests were used to test the differences in EQ-5D scores between the known groups including HbA1c level (cut point of 7%), and the presence of diabetic complications namely neuropathy, retinopathy, nephropathy and cardiovascular diseases. Seven hypothetical decision trees were created to evaluate the impact of differences in the EQ-5D scores on the incremental cost-utility ratio (ICUR).
The US weights yielded higher scores than those of the UK and the Japan weights (p < 0.001, both), while the UK and the Japan weighted scores did not differ (p > 0.05). Both UK and US scores had more agreement with each other than with the Japan scores. Regarding psychometric properties, the Japan scheme provided better test-retest reliability, convergent and known-groups validity than both UK and US schemes. The variation in EQ-5D scores estimated from UK, US, and Japan preference weights had a marginal impact on ICUR (range: 1.23–6.32%).
Since the Japan model showed more preferable psychometric properties than the UK and the US models and the differences in these EQ-5D scores had a small impact on ICUR, we recommended that for both clinical and policy purposes the Japan scheme should be used in Thai people. However, more research needs to be done.
To validate a Chinese version of the Diabetes Distress Scale (CDDS).
RESEARCH DESIGN AND METHODS
The CDDS was derived using forward-backward translation and administered in 189 Chinese type 2 diabetic patients with evaluation of its psychometric properties.
On the basis of principal-component analysis, three factors of the 15-item version of the CDDS (CDDS-15) accounted for 63% of the variance. The correlation coefficient between the original 17-item and 15-item scales was 0.99. The Cronbach α for internal consistency was 0.90, and the test-retest reliability coefficient was 0.74. The CDDS-15 score was significantly associated with glycemic control, obesity, depressive symptoms, and quality of life.
The CDDS-15 is a valid and reliable instrument to assess diabetes-related distress.
Fatigue is a common complaint in multiple sclerosis (MS) and often interferes with daily functioning. Both clinicians and researchers may need to detect high levels of fatigue impact using a time and effort efficient tool. This study evaluates the psychometric properties of a rapid screening instrument for fatigue impact in multiple sclerosis.
Three visual analogue scales (VAS) for assessing the impact of fatigue were developed. Sixty two subjects with definite MS (mean age 52 +/- 10.5 years; 29 women) and 24 healthy controls (mean age 52 +/- 14 years; 13 women) completed all VAS scales (range 0–100), the Fatigue Severity Scale (FSS) (range 7–63), the Modified Fatigue Impact Scale (MFIS) (range 0–84) and the Guy's Neurological Disability Scale (GNDS) (range 0–5). All tests were repeated with an interval of maximum three days.
To evaluate the reproducibility, intraclass correlations (ICC) were calculated, based on one-way analysis of variance for repeated measurements. Validity was considered by means of correlation coefficients. ROC analysis was used to determine the accuracy of the VAS scales.
The ICC of the VAS scales ranged from 0.68 to 0.69. VAS scales showed low to moderate correlation with FSS, MFIS and GNDS (Kendall's tau 0.23–0.45) and were not related with physical or cognitive performance, or with depression. All VAS scales were able to discriminate between subjects with MS and controls. Twenty five subjects with MS had a Fatigue Severity Scale score of 36 or more and were classified into the "fatigue" group. ROC analysis showed that VAS_1 is most useful to classify subjects in the "fatigue" group. A cut-off value of VAS_1 of 59 displayed 76% sensitivity and 72% specificity. When using the MFIS score of 40 or more to classify the groups, VAS_1 remained the strongest tool, with 81% sensitivity and 77% specificity at a cut-off value of 59.
The VAS for the impact of fatigue on daily life (VAS_1) is a moderately reliable, though valid and useful tool to screen rapidly for fatigue impact in multiple sclerosis. A cut-off value of 59 satisfactorily classifies individuals having severe fatigue with a high impact on daily life. In clinical practice, a more comprehensive assessment of fatigue and the impact on daily life is recommended.
Pain catastrophization has recently been recognized as a barrier to the healthy development of physical functioning among chronic pain patients. Levels of pain catastrophization in chronic pain patients are commonly measured using the Pain Catastrophizing Scale (PCS).
To cross-culturally adapt and validate the South African PCS (SA-PCS) among English-, Afrikaans- and Xhosa-speaking patients with fibromyalgia living in the Cape Metropole area, Western Cape, South Africa.
The original PCS was cross-culturally adapted in accordance with international standards to develop an English, Afrikaans and Xhosa version of the SA-PCS using a repeated measures study design. Psychometric testing included face/content validity, internal consistency (Cronbach’s alpha-α), test-retest reliability (intraclass coefficient correlations-ICC), sensitivity-to-change and cross-sectional convergent validity (by comparing the adapted SA-PCS to related constructs).
The cross-culturally adapted English, Afrikaans and Xhosa SA-PCS showed good face and content validity, excellent internal consistency (with Chronbach’s α = 0.98, 0.98 and 0.97 for the English, Afrikaans and Xhosa SA-PCS, as a whole, respectively), excellent test-retest reliability (with ICC’s of 0.90, 0.91 and 0.89 for the English, Afrikaans and Xhosa SA-PCS, respectively); as well as satisfactory sensitivity-to-change (with a minimum detectable change of 8.8, 9.0 and 9.3 for the English, Afrikaans and Xhosa SA-PCS, respectively) and cross-sectional convergent validity (when compared to pain severity as well as South African versions of the Tampa scale for Kinesiophobia and the revised Fibromyalgia Impact Questionnaire).
The SA-PCS can therefore be recommended as simple, efficient, valid and reliable tool which shows satisfactory sensitivity-to-change and cross-sectional convergent validity, for use among English, Afrikaans and Xhosa-speaking patients with fibromyalgia attending the public health sector in the Western Cape area of South Africa.
Fibromyalgia; Chronic pain; Pain catastrophizing; Outcome measures; Pain catastrophizing scale; Cross-cultural adaptation; Validation; Psychometric properties; South Africa
To examine psychometric properties of the Confidence in Diabetes Self-Care (CIDS) scale, a newly developed instrument assessing diabetes-specific self-efficacy in Dutch and U.S. patients with type 1 diabetes.
RESEARCH DESIGN AND METHODS
Reliability and validity of the CIDS scale were evaluated in Dutch (n = 151) and U.S. (n = 190) outpatients with type 1 diabetes. In addition to the CIDS scale, assessment included HbA1c, emotional distress, fear of hypoglycemia, self-esteem, anxiety, depression, and self-care behavior. The Dutch sample completed additional measures on perceived burden and importance of self-care. Test-retest reliability was established in a second Dutch sample (n = 62).
Internal consistency (Cronbach's α = 0.86 for Dutch patients and 0.90 U.S. patients) and test-retest reliability (Spearman's r = 0.85, P < 0.0001) of the CIDS scale were high. Exploratory factor analysis showed one strong general factor. Spearman's correlations between the CIDS scale and other measures were moderate and in the expected directions, and high HbA1c levels were associated with low CIDS scores in the U.S. sample only. Low CIDS scores were positively associated with self-care but not with glycemic control in the original samples. CIDS scores in the U.S. and Dutch samples did not show any statistically significant differences. U.S. men had higher CIDS scores than U.S. women.
The CIDS scale is a reliable and valid measure of diabetes-specific self-efficacy for use in patients with type 1 diabetes. High psychometric similarity allows for cross-cultural comparisons.
Perception of quality of life may differ depending on the perspective. The aim of the study was to assess the psychometric properties of the Spanish version of the 'TOlerability and quality Of Life' (TOOL) questionnaire, a specific self-rated instrument to evaluate the impact of side effects of antipsychotic drugs on health-related quality of life (HRQoL). The questionnaire consists of eight items answered on a four-point Likert scale.
A psychometric study was conducted with clinically stable outpatients with schizophrenia and bipolar disorder under antipsychotic treatment. The translation and cultural adaptation of the questionnaire was performed according to international standards. Internal consistency using the Cronbach α coefficient and test-retest reliability using the intraclass correlation coefficient (ICC) was used to assess the reliability of the instrument. Patients completed generic and specific measures of quality of life and clinical severity.
A total of 238 patients were analysed, with a mean age of 42 years (SD 10.9). The mean completion time was 4.9 min (SD 4.4). Internal consistency and intraclass correlation coefficient were adequate (Cronbach α = 0.757 and ICC = 0.90). Factorial analysis showed a unidimensional structure (a single eigenvalue >1, accounting for 39.1% of variance). Significant Spearman's rank correlations between the TOOL and both generic and specific measures were found. The questionnaire was able to discriminate among the Clinical Global Impression - Severity scores (Mann-Whitney U test, P < 0.001).
The TOOL questionnaire shows appropriate feasibility, reliability, and discriminative performance as a patient-reported outcome. TOOL constitutes a valuable addition to measure the impact of adverse events of antipsychotic drugs from the patient perspective.
To assess the psychometric properties of the Valued Activity Inventory for Adults with Cancer (VAI-AC), a self-report instrument measuring activity limitations.
Fifty older adults undergoing chemotherapy.
Participants completed the VAI-AC and measures of physical and mental function, symptom intensity, and mood three days before and on the day of chemotherapy. Test-retest reliability was assessed by determining the average number of items for which the importance of an activity was rated consistently and by calculating the intraclass correlation coefficient (ICC) for the first and second VAI-AC scores. Convergent validity was assessed by correlating the VAI-AC scores with the other measures.
Participants consistently rated the importance of 90% of the items. Seventy-two hour test-retest reliability was ICC = 0.67. Participants with fewer activity limitations indicated better physical function (r = 0.58, p< 0.001), better mental function (r = 0.55, p< 0.001), lower symptom intensity (r = −0.57, p< 0.001), and fewer depressive symptoms (r = −0.68, p< 0.001).
The VAI-AC demonstrated evidence of test-retest reliability and convergent validity in this convenience sample of older adults undergoing chemotherapy for cancer.
Outcome and Process Assessment (Health Care); Human Activities
Objective: The aim of this study was to assess the psychometric properties of the Multiple Sclerosis Impact Scale (MSIS-29) for patients in the community and in a hospital setting.
Methods: During an epidemiological study, 172 people with multiple sclerosis (MS) were examined and completed the MSIS-29, the London Handicap Scale, and Beck's Depression Inventory; disability was assessed by the Kurtzke Expanded Disability Status Score (EDSS) and the Multiple Sclerosis Functional Composite. At the hospital neurology clinic, 102 MS patients completed the MSIS-29 and EDSS assessments were performed; 41 of these patients had repeat evaluations six months later. The psychometric properties of the MSIS-29 were examined.
Results: In the 172 community and the 102 hospital patients the psychometric properties of the MSIS-29 were satisfactory, with high convergent and low divergent validity. It was significantly responsive to change in the contexts of self-reported change (p<0.034) and EDSS worsening (p<0.001). The MSIS-29 physical score did not change over time when the EDSS was stable, and increased significantly in proportion to EDSS deterioration (p = 0.014).
Conclusions: The psychometric properties of the MSIS-29 are acceptable; it is a valuable outcome measure in intervention studies of patients with MS.