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PubMed1993

Two scales for measuring patients' perceptions for coercion during mental hospital admission.

Legal and extra-legal coercion are pervasive in mental hospital admission and there are sharp disputes about its appropriate role. This article presents two scales for measuring psychiatric patients' perceptions of coercion during hospital admission and reports data on these scales' internal consistency. We measure patients' perceptions of coercion by asking questions, in either an interview or questionnaire format, about their experience of lack of control, choice, influence, and freedom in hospital admission. Patients' responses to questions about their perceptions of coercion were highly internally consistent. The internal consistency of the scale was robust with respect to variation in site, instrument format, patient population, and interview procedure. Correspondence analysis was used to construct two numerical scales of perceived coercion.

Adolescent↗

PubMed2005

Test-retest reliability, internal item consistency, and concurrent validity of the wheelchair seating discomfort assessment tool.

Discomfort is a common problem for wheelchair users. Few researchers have investigated discomfort among wheelchair users or potential solutions for this problem. One of the impediments to quantitative research on wheelchair seating discomfort has been the lack of a reliable method for quantifying seat discomfort. The purpose of this study was to establish the test-retest reliability, internal item consistency, and concurrent validity of a newly developed Wheelchair Seating Discomfort Assessment Tool (WcS-DAT). Thirty full-time, active wheelchair users with intact sensation were asked to use this and other tools in order to rate their levels of discomfort in a test-retest reliability study format. Data from these measures were analyzed in SPSS using an intraclass correlation coefficient (ICC) model (2,k) to measure the test-retest reliability. Cronbach's alpha was used to examine the internal consistency of the items within the WcS-DAT. Concurrent validity with similar measures was analyzed using Pearson product-moment correlations. ICC scores for all analyses were above the established lower bound of .80, indicating a highly stable and reliable tool. In addition, alpha scores indicated good consistency of all items without redundancy. Finally, correlations with similar tools, such as the Chair Evaluation Checklist and the Short Form of the McGill Pain Questionnaire, were significant at the .05 level, and many were significant at the .001 level. These results support the use of the WcS-DAT as a reliable and stable tool for quantifying wheelchair seating discomfort. Its application will enhance the ability to assess and to research this important problem and will provide a means to validate the outcomes of specialized seating interventions for the study population of wheelchairs users.

Persons with Disabilities↗

PubMed2006

Measurement properties of the WOMAC LK 3.1 pain scale.

OBJECTIVE: The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) is applied extensively to patients with osteoarthritis of the hip or knee. Previous work has challenged the validity of its physical function scale however an extensive evaluation of its pain scale has not been reported. Our purpose was to estimate internal consistency, factorial validity, test-retest reliability, and the standard error of measurement (SEM) of the WOMAC LK 3.1 pain scale. METHOD: Four hundred and seventy-four patients with osteoarthritis of the hip or knee awaiting arthroplasty were administered the WOMAC. Estimates of internal consistency (coefficient alpha), factorial validity (confirmatory factor analysis), and the SEM based on internal consistency (SEM(IC)) were obtained. Test-retest reliability [Type 2,1 intraclass correlation coefficients (ICC)] and a corresponding SEM(TRT) were estimated on a subsample of 36 patients. RESULTS: Our estimates were: internal consistency alpha=0.84; SEM(IC)=1.48; Type 2,1 ICC=0.77; SEM(TRT)=1.69. Confirmatory factor analysis failed to support a single factor structure of the pain scale with uncorrelated error terms. Two comparable models provided excellent fit: (1) a model with correlated error terms between the walking and stairs items, and between night and sit items (chi2=0.18, P=0.98); (2) a two factor model with walking and stairs items loading on one factor, night and sit items loading on a second factor, and the standing item loading on both factors (chi2=0.18, P=0.98). CONCLUSION: Our examination of the factorial structure of the WOMAC pain scale failed to support a single factor and internal consistency analysis yielded a coefficient less than optimal for individual patient use. An alternate strategy to summing the five-item responses when considering individual patient application would be to interpret item responses separately or to sum only those items which display homogeneity.

Aged↗

PubMed2001

Interpreting change on the WAIS-III/WMS-III in clinical samples.

Clinicians should note that there is considerable variability in the reliabilities of the index and subtest scores derived from the third editions of the Wechsler Adult Intelligence Scale (WAIS-III) and the Wechsler Memory Scale (WMS-III). The purpose of this article is to review these reliabilities and to illustrate how they can be used to interpret change in patients' performances from test to retest. The WAIS-III IQ and Index scores are consistently the most reliable scores, in terms of both internal consistency and test-retest reliability. The most internally consistent WAIS-III subtests are Vocabulary, Information, Digit Span, Matrix Reasoning, and Arithmetic. Information and Vocabulary have the highest test-retest reliability. On the WMS-III, the Auditory Immediate Index, Immediate Memory Index, Auditory Delayed Index, and General Memory Index are the most reliable, in terms of both internal consistency and test-retest reliability. The Logical Memory I and Verbal Paired Associates I subtests are the most reliable. Data from three clinical groups (i.e., Alzheimer's disease, chronic alcohol abuse, and schizophrenia) were extracted from the Technical Manual [Psychological Corporation (1997). WAIS-III/WMS-III Technical Manual. San Antonio: Harcourt Brace] for the purpose of calculating reliable change estimates. A table of confidence intervals for test-retest measurement error is provided to help the clinician determine if patients have reliably improved or deteriorated on follow-up testing.

Journal Article↗

PubMed1994

Subtypes of psychosocial adjustment to breast cancer.

By means of cluster analytic techniques, four subtypes of psychosocial adjustment were identified in a sample of 122 breast cancer patients who completed the Psychosocial Adjustment to Illness Scale. Internal consistency and internal validity of the derived typology were suggested by the finding that two different hierarchical agglomerative clustering methods (average linkage between groups, Ward's) produced similar solutions. Three of the derived subtypes reported normal affect levels but different patterns of relative strengths and dysfunctions, while the fourth subtype appeared to be highly distressed and globally maladjusted. External validation was demonstrated by differentiating the subtypes on variables of negative affect, avoidance coping, and fighting spirit. The clinical and heuristic implications of these findings are discussed. The findings highlight the need for comprehensive assessment of psychosocial functioning of cancer patients. They demonstrate that even non-emotionally distressed patients can have very different profiles of adjustment and may benefit from correspondingly individually tailored psychosocial interventions.

Adaptation, Psychological↗

PubMed2005

Cross-cultural adaptation of the Diabetes Management Self-Efficacy Scale for patients with type 2 diabetes mellitus: scale development.

BACKGROUND: As a profession, nurses are particularly concerned with cross-cultural influences that affect the health practices of populations. Although the international literature describes questionnaires and specific scales in health and disease behaviours, adequate Turkish-language instruments are scarce. Therefore, suitable Turkish-language instruments need to be developed or adapted for the Turkish population. OBJECTIVES: Study aim was to adapt a Dutch/English version of the diabetes management self-efficacy (SE) scale for use with a Turkish population and evaluate its psychometric properties. DESIGN: Methodological research design. SETTINGS: Attendants of an outpatient clinic of a university hospital in Turkey. PARTICIPANTS: A convenience sample of 110 patients with type 2 diabetes mellitus (DM). METHODS: Translation and back-translation of the original English instrument and content validation through a expert panel were the first two steps of the study. Third step was the psychometric testing of the adapted instrument by establishing internal consistency (Cronbach's alpha), stability (test-retest reliability), and construct validity (factor analysis). RESULTS: Content validity procedure resulted in a final scale that consisted of 20 items. Internal consistency of the total scale was coefficient alpha=0.88, and test-retest reliability with a 4-week time interval was r=0.91 (p<0.001). Factor analysis yielded three factors related to diet, exercise and medical treatment. Two relevant items of the scale, weight control and blood sugar control, however, had low reliability and validity scores. CONCLUSIONS: Although acceptable levels of reliability and validity of the Turkish version of the diabetes management SE scale for people with type 2 DM were reached, cultural factors appeared to play a role in the applicability of some items of the scale.

Analysis of Variance↗

PubMed1999

Using conjoint analysis to take account of patient preferences and go beyond health outcomes: an application to in vitro fertilisation.

There has been an assumption in the health economics literature that health outcomes are all that need to be considered when attempting to measure the benefits from health care interventions. This is most evident in the development of the quality adjusted life year (QALY) approach to benefit assessment. This paper challenges this view and considers the technique of conjoint analysis (CA) as a methodology for both taking account of patient preferences and considering attributes beyond health outcomes. The technique is applied to in vitro fertilisation. CA is shown to be sensitive to considering health outcomes, nonhealth outcomes and process attributes. It is also shown to be internally consistent and internally valid. The paper demonstrates the application of CA to estimating willingness to pay indirectly. It is argued that benefit assessment within health economics should extend beyond health outcomes and future research should investigate more thoroughly the potential application of CA in this area. However, methodological issues need addressing before the instrument becomes an established evaluative instrument.

Choice Behavior↗

PubMed1991

The Drinking Problems Index: a measure to assess alcohol-related problems among older adults.

Research on problem drinking among older adults has been hampered by the lack of specialized instruments to assess drinking problems. In this paper, we examine the psychometric properties of a 17-item measure specifically designed to assess drinking problems in this population. The Drinking Problems Index (DPI) exhibits excellent psychometric properties, with an internal consistency reliability estimate of .94, a cross-temporal correlation over a 1-year interval of .66, and cross-sectional correlations with alcohol consumption at two points a year apart of .37 and .42. In addition, the construct validity of the DPI is supported by significant concurrent correlations indicating that persons who have more drinking-related problems experience more depression, have less self-confidence, and participate in fewer social activities. Consistent with the high internal consistency reliability estimate, a factor analysis confirmed that the measure is largely unifactorial. Overall, the findings suggest that the DPI is a reliable and valid instrument for assessing problems associated with drinking in surveys of older persons.

Activities of Daily Living↗

PubMed2001

The royal free interview for spiritual and religious beliefs: development and validation of a self-report version.

BACKGROUND: Spiritual beliefs are rarely considered in psychological or medical publications. We recently published the psychometric properties of an interview designed to measure religious and spiritual belief. In this study, we aimed to develop this instrument further as a self-report questionnaire and to make it more comprehensive by including measurement of spiritual experiences in addition to faith or intellectual assent. METHODS: Based on extensive discussion with colleagues, advice from users of the interview and comments from respondents, a self-report format was designed. We then evaluated the final format of the questionnaire in terms of (1) patterns of response and demographic predictors of beliefs; (2) test-retest reliability and internal consistency; (3) criterion and internal validity; and (4) the nature of spiritual experiences and their relationship to beliefs and strength of beliefs. RESULTS: Two hundred and ninety-seven people took part in the validity and reliability tests of the questionnaire. Criterion validity, predictive validity, internal consistency and test-retest reliability were acceptably high. The instrument consistently differentiated between people with high and low spiritual beliefs. CONCLUSIONS: This instrument is brief and simple to complete. We would recommend that measures of religious and/or spiritual belief like this be more widely applied in health services research as they evaluate aspects of people's lives that go somewhat further than health status or quality of life.

Adult↗

PubMed1998

Factorial validation of a widely disseminated educational framework for evaluating clinical teachers.

PURPOSE: To examine an instrument for evaluating clinical teaching using factor analysis and to refine the validated instrument to a practical length. METHOD: Factor analysis on a split sample of 1,581 student evaluations rating 178 teachers. The instrument was based on the seven-category Stanford Faculty Development Program's (SFDP's) clinical teaching framework and contained 58 Likert-scaled items, with at least seven items per category plus five items measuring "teacher's knowledge." Standard methodology for survey item reduction was used to remove items with low or complex factor loadings and iteratively remove items with low item-scale correlation. Results were replicated on the second sample. RESULTS: The seven original categories emerged and items originally categorized under "knowledge" statistically combined with "promoting self-directed learning." Over 73% of the variance was explained. Item reduction resulted in 25 items with overall internal consistency over .97 and internal consistency of constructs ranging from .82 to .95. CONCLUSIONS: Factor analysis of student ratings validated the seven-category SFDP framework. An abbreviated instrument to measure the seven categories is described. Results suggest that students may not systematically distinguish between their teachers' knowledge and their teachers' ability to promote self-directed learning, an important finding for both administrators and faculty development programs.

Adult↗

PubMed2006

Development of the client-centred care questionnaire.

AIM: This paper reports the development and testing of the Client-Centred Care Questionnaire, aimed at evaluating the client-centredness of professional home nursing care from a client perspective. BACKGROUND: Client-centred care has become an important theme in health care. To evaluate the client-centredness of care and services from a client's perspective, there is a need for measurement instruments. METHOD: The questionnaire was developed on the basis of a qualitative study into client perspectives on home nursing care. Items were formulated that closely followed the aspects clients mentioned as central to client-centred home care. A pilot study was conducted with a sample of 107 clients in three home care organizations in 2003 and 2004. These clients had chronic diseases and were expected to receive care for at least another 6 months. The questionnaire comprises 15 items. FINDINGS: Principal components analysis and internal consistency analysis show strong internal consistency of the items. All items had strong factor loadings on one dimension, and Cronbach's alpha was 0.94. Clients tended to be most critical about their say in the practical arrangements and organization of care: which person came, how often and when? Clients of the three organizations differed in their perceptions of client-centredness, which may indicate that the questionnaire is capable of differentiating between respondents. CONCLUSION: The results of this pilot study are promising. The validity of the questionnaire needs further testing.

Aged↗

PubMed2001

Disease specific quality of life instruments in multiple sclerosis: validation of the Hamburg Quality of Life Questionnaire in Multiple Sclerosis (HAQUAMS).

Quality of life (QoL) is discussed as an additional outcome measure in multiple sclerosis (MS). However, few questionnaires assessing disease specific QoL in MS have been published. On the basis of the literature and interviews with clinicians and MS patients, we have developed a disease specific QoL instrument and validated it in a broad range of patients with MS. In this study, a heterogeneous sample of n = 237 MS patients completed the newly developed Hamburg Quality of Life Questionnaire in Multiple Sclerosis (HAQUAMS, in German language) and a battery of already validated questionnaires. They further underwent neurological scoring and objective tests. By these means, we investigated its validity, appropriateness, internal consistency, and retest reliability. Internal consistency and retest coefficients were high and satisfied psychometric standards. Convergent and discriminant validity was supported by direction, magnitude and pattern of correlations with other health measures. HAQUAMS subscales and its total score distinguished between patient groups of varied disease severity, cognitive impairment, and affective symptomatology. No floor or ceiling effects were found in either of the HAQUAMS subscales. The HAQUAMS is a reliable, valid and appropriate instrument for QoL assessment in multiple sclerosis. Data of responsiveness are currently being obtained.

Adult↗

PubMed1990

A theory of phenomenal geometry and its applications.

The geometry of perceived space (phenomenal geometry) is specified in terms of three basic factors: the perception of direction, the perception of distance or depth, and the perception of the observer's own position or motion. The apparent spatial locations of stimulus points resulting from these three factors thereupon determine the derived perceptions of size, orientation, shape, and motion. Phenomenal geometry is expected to apply to both veridical and illusory perceptions. It is applied here to explain a number of representative illusions, including the illusory rotation of an inverted mask (Gregory, 1970), a trapezoidal window (Ames, 1952), and any single or multiple point stimuli in which errors in one or more of the three basic factors are present. It is concluded from phenomenal geometry that the size-distance and motion-distance invariance hypotheses are special cases of the head motion paradigm, and that proposed explanations in terms of compensation, expectation, or logical processes often are unnecessary for predicting responses to single or multiple stimuli involving head or stimulus motion. Two hypotheses are identified in applying phenomenal geometry. It is assumed that the perceptual localization of stimulus points determines the same derived perceptions, regardless of the source of perceptual information supporting the localizations. This assumption of cue equivalence or cue substitution provides considerable parsimony to the geometry. Also, it is assumed that the perceptions specified by the geometry are internally consistent. Departures from this internal consistency, such as those which occur in the size-distance paradox, are considered to often reflect the intrusion of nonperceptual (cognitive) processes into the responses. Some theoretical implications of this analysis of phenomenal geometry are discussed.

Attention↗

PubMed2003

Psychometric properties of the Consumer Assessment of Health Plans Study (CAHPS) 2.0 adult core survey.

OBJECTIVE: To estimate the reliability and validity of survey measures used to evaluate health plans and providers from the consumer's perspective. DATA SOURCES: Members (166,074) of 306 U.S. health plans obtained from the National CAHPS Benchmarking Database 2.0, a voluntary effort in which sponsors of CAHPS surveys contribute data to a common repository. STUDY DESIGN: Members of privately insured health plans serving public and private employers across the United States were surveyed by mail and telephone. Interitem correlations and correlations of items with the composite scores were estimated. Plan-level and internal consistency reliability are estimated. Multivariate associations of composite measures with global ratings are also examined to assess construct validity. Confirmatory factor analysis is used to examine the factor structure of the measure. FINDINGS: Plan-level reliability of all CAHPS 2.0 reporting composites is high with the given sample sizes. Fewer than 170 responses per plan would achieve plan-level reliability of .70 for the five composites. Two of the composites display high internal consistency (Cronbach's alpha > or = .75), while responses to items in the other three composites were not as internally consistent (Cronbach's alpha from .58 to .62). A five-factor model representing the CAHPS 2.0 composites fits the data better than alternative two- and three-factor models. CONCLUSION: Two of the five CAHPS 2.0 reporting composites have high internal consistency and plan-level reliability. The other three summary measures were reliable at the plan level and approach acceptable levels of internal consistency. Some of the items that form the CAHPS 2.0 adult core survey, such as the measure of waiting times in the doctor's office, could be improved. The five-dimension model of consumer assessments best fits the data among the privately insured; therefore, consumer reports using CAHPS surveys should provide feedback using five composites.

Benchmarking↗

PubMed1999

Quality of life impact of urge incontinence in older persons: a new measure and conceptual structure.

OBJECTIVE: To develop a condition-specific measure for assessing the impact of urge urinary incontinence (UI) on the quality of life (QoL) of older persons. DESIGN: A 32-item Urge Impact Scale (URIS) was drafted using content area data from focus groups composed of urge incontinent older persons. Pilot testing in 21 urge incontinent persons (mean age 67.7 years) resulted in the elimination of eight items by internal consistency, skew, and patient response criteria. The resulting scale (URIS-24) was tested for reliability (internal consistency and test-retest correlation) and construct validity (correlation with UI severity from voiding records) in a separate group of 27 urge incontinent persons (89% women, mean age 72 years). Factor analysis of URIS-24 data from the combined 48 persons was used to explore the conceptual structure underlying urge UI-related QoL. SETTING: University-affiliated community-based practice and tertiary hospital. PARTICIPANTS: Community-dwelling women and men, older than age 60 and with urge incontinence at least twice weekly, recruited from newspaper, newsletter, and radio advertisements. RESULTS: Cronbach's alpha for URIS-32 was 0.84, and for URIS-24 it was 0.94. When administered (mean +/- standard deviation) 9.2 +/- 5.1 days apart, URIS-24 had good test-retest reliability for total scores (interclass coefficient = .88, concordance coefficient = .88), and individual item scores at time 2 were within 1 point (on a 5-category Likert scale) of time 1 answers for 89% of responses. URIS-24 scores had modest but nearly significant correlation with the number of UI episodes (r = -0.39, P = .05). Factor analysis revealed a three component structure corresponding to psychological burden, perception of personal control, and self concept. CONCLUSIONS: The URIS-24 is an internally-consistent, highly reproducible tool for the assessment of the QoL impact of urge UI on older persons. It can be used to evaluate QoL impact by specific items as well as by overall score. Compared with other UI-specific QoL measures, the URIS-24 had similar or superior internal consistency, test-retest reliability, and validity, but it is the first measure designed and tested specifically for older persons with urge UI. These results also highlight the multifactorial structure of urge UI-related QoL and the importance of its psychological dimensions.

Aged↗

PubMed2005

Responsiveness: a reinvention of the wheel?

BACKGROUND: Since the mid eighties, responsiveness is considered to be a separate property of health status questionnaires distinct from reliability and validity. The aim of the study was to assess the strength of the relationship between internal consistency reliability, referring to an instrument's sensitivity to differences in health status among subjects at one point in time, and responsiveness referring to sensitivity to health status changes over time. METHODS: We used three different datasets comprising the scores of patients on the Barthel, the SIP and the GO-QoL instruments at two points in time. The internal consistency was reduced stepwise by removing the item that contributed most to a scale's reliability. We calculated the responsiveness expressed by the Standardized Response Mean (SRM) on each set of remaining items. The strength of the relationship between the thus obtained internal consistency coefficients and SRMs was quantified by Spearman rank correlation coefficients. RESULTS: Strong to perfect correlations (0.90-1.00) was found between internal consistency coefficients and SRMs for all instruments indicating, that the two can be used interchangeably. CONCLUSION: The results contradict the conviction that responsiveness is a separate psychometric property. The internal consistency coefficient adequately reflects an instrument's potential sensitivity to changes over time.

Activities of Daily Living↗

PubMed2005

Development and psychometric tests of the Chinese-version Low Vision Quality of Life Questionnaire.

BACKGROUND/AIMS: To develop and assess the psychometric validity of a Chinese language Vision Health related quality-of-life (VRQoL) measurement instrument for the Chinese visually impaired. METHODS: The Low Vision Quality of Life Questionnaire (LVQOL) was translated and adapted into the Chinese-version Low Vision Quality of Life Questionnaire (CLVQOL). The CLVQOL was completed by 100 randomly selected people with low vision (primary group) and 100 people with normal vision (control group). Ninety-four participants from the primary group completed the CLVQOL a second time 2 weeks later (test-retest group). The internal consistency reliability, test-retest reliability, item-internal consistency, item-discrimination validity, construct validity and discriminatory power of the CLVQOL were calculated. RESULTS: The review committee agreed that the CLVQOL replicated the meaning of the LVQOL and was sensitive to cultural differences. The Cronbach's alpha coefficient and the split-half coefficient for the four scales and total CLVQOL scales were 0.75-0.97. The test-retest reliability as estimated by the intraclass correlations coefficient was 0.69-0.95. Item-internal consistency was > 0.4 and item-discrimination validity was generally < 0.40. The Varimax rotation factor analysis of the CLVQOL identified four principal factors. the quality-of-life rating of four subscales and the total score of the CLVQOL of the primary group were lower than those of the Control group, both in hospital-based subjects and community-based subjects. CONCLUSION: The CLVQOL Chinese is a culturally specific vision-related quality-of-life measure instrument. It satisfies conventional psychometric criteria, discriminates visually healthy populations from low vision patients and may be valuable in screening the local community as well as for use in clinical practice or research.

Aged↗

PubMed2005

[Development and evaluation of psychometric tests of the Chinese-version of low vision quality of life questionnaire].

OBJECTIVE: To develop and evaluate a Chinese language vision health related quality-of-life (VRQoL) questionnaire. METHODS: The low vision quality of life questionnaire (LVQOL) was translated and adapted into the Chinese-version low vision quality of life questionnaire (CLVQOL). The systematic protocols were set as 3 forward translations, 2 committee reviews and 1 back-ward translation. The CLVQOL was performed in 100 randomly selected people with low vision (primary group) and 100 people with normal vision (control group). Ninety-four participants from the primary group completed the CLVQOL and repeated 2 weeks later (test-retest group). The results were compared with patient demographics and the internal consistency reliability, test-retest reliability, item-internal consistency, item-discrimination validity, construct validity and discrimination validity of the CLVQOL were calculated. RESULTS: The review committee agreed that the CLVQOL replicated the meaning of the LVQOL and was sensitive to cultural adaptations. The Cronbach alpha coefficient and the split-half coefficient for the four scales and total CLVQOL scales were 0.75 to 0.97. The test-retest reliability as estimated by intraclass correlation coefficient was 0.69 to 0.95. Item-internal consistency was > 0.4 and item-discrimination validity was generally < 0.40. The varimax rotation factor analysis of the CLVQOL identified four principal factors. All of the scores of four subscales and the total score of CLVQOL of the primary group were lower than those of the control group, both in patients and local residents. CLVQOL scores were highly correlated with visual acuity. CONCLUSIONS: The CLVQOL is a culturally specific VRQOL measure instrument. CLVQOL can satisfy conventional psychometric criteria, can discriminate visually healthy populations from low vision patients and is valuable in the clinical practice and in the screening of the community populations.

Adult↗