| 1. |
- Hellström, Amanda, et al.
(författare)
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A classical test theory evaluation of the Sleep Condition Indicator accounting for the ordinal nature of item response data
- 2019
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Ingår i: PLOS ONE. - : Public Library of Science. - 1932-6203. ; 14:3, s. 1-13
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Tidskriftsartikel (refereegranskat)abstract
- Background Insomnia symptoms are common among young adults and affect about 5% to 26% of 19 to 34-year-olds. In addition, insomnia is associated with poor mental health and may affect daily performance. In research, as well as in clinical practice, sleep questionnaires are used to screen for and diagnose insomnia. However, most questionnaires are not developed according to current DSM-5 diagnostic criteria. An exception is the recently developed Sleep Condition Indicator (SCI), an eight-item scale screening for insomnia. Aim The aim of this study was to perform a Classical Test Theory (CTT) based psychometric evaluation of the SCI in a sample of Swedish university students, by taking the ordinal nature of item level data into account. Methods The SCI was translated into Swedish and distributed online to undergraduate students at three Swedish universities, within programs of health, psychology, science or economy. Of 3673 invited students, 634 (mean age 26.9 years; SD = 7.4) completed the questionnaire that, in addition to the SCI, comprised other scales on sleep, stress, lifestyle and students' study environment. Data were analyzed according to CTT investigating data completeness, item homogeneity and unidimensionality. Results Polychoric based explorative factor analysis suggested unidimensionality of the SCI, and internal consistency was good (Cronbach's alpha, 0.91; ordinal alpha, 0.94). SCI scores correlated with the Insomnia Severity Index (-0.88) as well as with sleep quality (-0.85) and perceived stress (-0.50), supporting external construct validity. Conclusions These observations support the integrity of the of the SCI. The SCI demonstrates sound CTT-based psychometric properties, supporting its use as an insomnia screening tool.
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| 2. |
- de Roos, Paul, et al.
(författare)
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A Consensus Set of Outcomes for Parkinson's Disease from the International Consortium for Health Outcomes Measurement
- 2017
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Ingår i: Journal of Parkinson's Disease. - : IOS Press. - 1877-7171 .- 1877-718X. ; 7:3, s. 533-543
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Parkinson's disease (PD) is a progressive neurodegenerative condition that is expected to double in prevalence due to demographic shifts. Value-based healthcare is a proposed strategy to improve outcomes and decrease costs. To move towards an actual value-based health care system, condition-specific outcomes that are meaningful to patients are essential.OBJECTIVE: Propose a global consensus standard set of outcome measures for PD.METHODS: Established methods for outcome measure development were applied, as outlined and used previously by the International Consortium for Health Outcomes Measurement (ICHOM). An international group, representing both patients and experts from the fields of neurology, psychiatry, nursing, and existing outcome measurement efforts, was convened. The group participated in six teleconferences over a six-month period, reviewed existing data and practices, and ultimately proposed a standard set of measures by which patients should be tracked, and how often data should be collected.RESULTS: The standard set applies to all cases of idiopathic PD, and includes assessments of motor and non-motor symptoms, ability to work, PD-related health status, and hospital admissions. Baseline demographic and clinical variables are included to enable case mix adjustment.CONCLUSIONS: The Standard Set is now ready for use and pilot testing in the clinical setting. Ultimately, we believe that using the set of outcomes proposed here will allow clinicians and scientists across the world to document, report, and compare PD-related outcomes in a standardized fashion. Such international benchmarks will improve our understanding of the disease course and allow for identification of 'best practices', ultimately leading to better informed treatment decisions.
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| 3. |
- Hagell, Peter, et al.
(författare)
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Measuring fatigue in Parkinsons disease: A psychometric study of two brief generic fatigue questionnaires
- 2006
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Ingår i: Journal of Pain and Symptom Management. - : Elsevier BV. - 0885-3924 .- 1873-6513. ; 32:5, s. 420-432
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Tidskriftsartikel (refereegranskat)abstract
- This study evaluated and compared the measurement properties of the 13-item Functional Assessment of Chronic Illness Therapy-Fatigue Scale (FACIT-F) and the 9-item Fatigue Severity Scale (FSS) in 118 consecutive Parkinsons disease (PD) patients, using traditional and Rasch measurement methodologies. Both questionnaires exhibited excellent data quality and reliability (coefficient alpha greater than= 0.9), and acceptable rating scale functionality, and both discriminated between fatigued and nonfatigued patients. factor and Rasch analyses provided general support for unidimensionality of both FACIT-F and FSS, although they do not appear to measure identical aspects of fatigue. No signs of differential item functioning (DIF) were found for the FACIT-F, whereas potential age DIF, was detected for two FSS items. These results support the measurement validity of both questionnaires in PD, although the FACIT-F displayed better measurement precision and modest psychometric advantages over the FSS. Availability of psychometrically sound fatigue measures that are applicable across disorders provides a sound basis for advancing the understanding of this common and distressing complaint.
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| 4. |
- Sjödahl Hammarlund, Catharina, et al.
(författare)
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Measuring outcomes in Parkinson's disease: a multi-perspective concept mapping study.
- 2012
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Ingår i: Quality of Life Research. - : Springer Science and Business Media LLC. - 1573-2649 .- 0962-9343. ; 21:Aug 26, s. 453-463
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To identify and develop a conceptual map of prioritized areas and to determine their relative importance for outcome measurement in clinical Parkinson's disease (PD) trials, from the perspectives of health care professionals and people with PD. METHOD: We used concept mapping, a qualitative/quantitative method consisting of three steps: item generation through focus groups (n = 27; 12 people with PD, 12 health care professionals, 3 researchers), item sorting and rating (n = 38; 19 people with PD, 19 health care professionals), and data analysis (multidimensional scaling, cluster analysis). RESULTS: Ninety-nine items and eight clusters were generated. Clusters representing Participation; Mobility and motor functioning; Cognitive and executive functioning; and Emotions were the most homogenous. Statements within clusters representing Energy and abilities; Autonomic dysfunctions; Sensory, speech and swallowing problems; and Neuropsychiatric symptoms also related to statements outside their respective clusters. Clusters rated most important were Participation and Mobility and motor functioning, and the highest rated items were quality of life, walking ability, and sleeping problems. CONCLUSION: By the use of concept mapping, a multi-perspective conceptual map of prioritized aspects for the outcome measurement in PD was defined. These findings provide an initial conceptual basis toward improved outcome measurement priorities in clinical PD trials.
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| 5. |
- Norlin, Jenny M., et al.
(författare)
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Clinical Impression of Severity Index for Parkinson's Disease and Its Association to Health-Related Quality of Life
- 2022
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Ingår i: Movement Disorders Clinical Practice. - : John Wiley and Sons Ltd. - 2330-1619.
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Tidskriftsartikel (refereegranskat)abstract
- Background: Clinical Impression of Severity Index for Parkinson's Disease (CISI-PD) is a simple tool that can easily be used in clinical practice. Few studies have investigated the relationship between health-related quality of life and the CISI-PD. Objective : To analyze the association of CISI-PD scores with those of generic (EQ-5D-5L) and Parkinson's disease (PD) disease-specific (Parkinson's Disease Questionnaire–8 [PDQ-8]) health-related quality of life assessments. Methods : Persons with idiopathic PD in the Swedish Parkinson's Disease registry with simultaneous registrations of CISI-PD and EQ-5D-5L and/or PDQ-8 were included. Correlations with EQ-5D dimensions were analyzed. The relationships between the CISI-PD, EQ-5D-5L, and PDQ-8 were estimated by linear mixed models with random intercept. Results : In the Swedish Parkinson's Disease registry, 3511 registrations, among 2168 persons, fulfilled the inclusion criteria. The dimensions self-care, mobility, and usual activities correlated moderately with the CISI-PD (rs = 0.60, rs = 0.54, rs = 0.57). Weak correlations were found for anxiety/depression and pain/discomfort (rs = 0.39, rs = 0.29) (P values < 0.001). The fitted model included the CISI-PD, age, sex, and time since diagnosis. The CISI-PD had a statistically significant impact on the EQ-5D and PDQ-8 (P values < 0.001). Conclusions : The CISI-PD provides a moderate correlation with the EQ-5D and could possibly be useful as a basis for defining health states in future health economic models and serving as outcomes in managed entry agreements. Nonetheless, the limitation of capturing nonmotor symptoms of the disease remains a shortcoming of clinical instruments, including the CISI-PD.
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| 6. |
- Jonasson, Stina B., et al.
(författare)
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Psychometric evaluation of the Parkinson’s disease Activities of Daily Living Scale
- 2017
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Ingår i: Parkinson's Disease. - : Hindawi Limited. - 2090-8083 .- 2042-0080.
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To evaluate a set of psychometric properties (i.e., data completeness, targeting andexternal construct validity) of the Parkinson’s disease Activities of Daily Living Scale (PADLS) in people with Parkinson’s disease (PD). Specific attention was paid to the association between PADLS and PD severity, according to the Hoehn & Yahr (H&Y) staging. Methods: The sample included 251 persons with PD (mean age 70 [SD 9] years). The data collection comprised a self-administered postal survey, structured interviews and clinical assessments at home visits. Results: Data completeness was 99.6% and the mean PADLS score was 2.1. Floor and ceiling effects were 22% and 2%, respectively. PADLS scores were more strongly associated (rs>0.5) with perceived functional independence, dependence in ADL, walking difficulties and self- rated PD severity than with variables such as PD duration and cognitive function (rs<0.5).PADLS scores differed across H&Y stages (Kruskal-Wallis test, p<0.001). Those in H&Y stages IV-V had more ADL disability than those in stage III (Mann-Whitney U-test, p<0.001), whereas there were no significant differences between the other stages. Conclusion: The PADLS revealed excellent data completeness, acceptable targeting and external construct validity. It seems to be well suited as a rough estimate of ADL disability inpeople with PD.
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| 7. |
- Jakobsson, Ulf, et al.
(författare)
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Construct validity of the SF-12 in three different samples
- 2012
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Ingår i: Journal of Evaluation in Clinical Practice. - : Wiley-Blackwell Publishing Ltd. - 1356-1294 .- 1365-2753. ; 18:3, s. 560-566
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Tidskriftsartikel (refereegranskat)abstract
- Rationale, aims and objectives Studies have challenged the validity and underlying measurement model of the physical and mental component summary scores of the 36-item Short-Form Health Survey in, for example the elderly and people with neurological disorders. However, it is unclear to what extent these observations translate to physical and mental component summary scores derived from the 12-item short form (SF-12) of the 36-item Short-Form Health Survey. This study evaluated the construct validity of the SF-12 in elderly people and people with Parkinson's disease (PD) and stroke. Methods SF-12 data from a general elderly (aged 75+) population (n = 4278), people with PD (n = 159) and stroke survivors (n = 89) were analysed regarding data quality, reliability (coefficient alpha) and internal construct validity. The latter was assessed through item-total correlations, exploratory and confirmatory factor analyses. Results Completeness of data was high (93–98.8%) and reliability was acceptable (0.78–0.85). Item-total correlations argued against the suggested items-to-summary scores structure in all three samples. Exploratory factor analyses failed to support a two-dimensional item structure among elderly and stroke survivors, and cross-loadings of items were seen in all three samples. Confirmatory factor analyses showed lack of fit between empirical data and the proposed items-to-summary measures structure in all samples. Conclusions These observations challenge the validity and interpretability of SF-12 scores among the elderly, people with PD and stroke survivors. The standard orthogonally weighted SF-12 scoring algorithm is cautioned against. Instead, when the assumed two-dimensional structure is supported in the data, oblique scoring algorithms appear preferable. Failure to consider basic scoring assumptions may yield misleading results.
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| 8. |
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| 9. |
- Lindholm, Beata, et al.
(författare)
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Clinical usefulness of retropulsion tests in persons with mild to moderate parkinson’s disease
- 2021
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Ingår i: International Journal of Environmental Research and Public Health. - : MDPI Multidisciplinary Digital Publishing Institute. - 1661-7827 .- 1660-4601. ; 18:23, s. 1-10
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Tidskriftsartikel (refereegranskat)abstract
- People with Parkinson’s disease (PwPD) have an increased risk for falls and near falls. They have particular difficulties with maintaining balance against an external perturbation, and several retropulsion tests exist. The Unified PD Rating Scale item 30 (UPDRS30) is the most common, involving an expected shoulder pull. Others recommend using an unexpected shoulder pull, e.g., the Nutt Retropulsion Test (NRT). We aimed to evaluate the clinical usefulness of these tests for detecting future fallers. By using two different golden standards related to self-reported prospective falls and near falls over 6 months following two different time points with 3.5 years between, we estimated sensitivity/specificity, Youden index, predictive values, and likelihood ratios for each test. The different time points yielded a different prevalence of falls and near falls, as well as different predictive values. When comparing the performance of the NRT and UPDRS30 for detecting future fallers, we found that the NRT consistentlyperformed better than UPDRS30. However, neither test exhibited optimal performance in terms of predictive values and associated likelihood ratios. Our findings speak against using either of these tests as a single assessment for this purpose and support previous recommendations of using a multifactorial approach when targeting balance problems in PwPD.
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| 10. |
- Hagell, Peter
(författare)
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Assessment of Graft Effects and Function in Cell Replacement Therapy for Parkinson's Disease
- 2002
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This explorative study aimed to apply, develop, and evaluate assessment methods at various levels in cell replacement therapy for Parkinson’s disease (PD). Observed motor effects in five grafted patients support that timed motor tasks and clinical ratings of parkinsonism are able to monitor motor function, but their psychometric properties need further attention. Using positron emission tomography in a unilaterally grafted PD patient, dopamine receptor binding of [11C]-raclopride was found upregulated in the non-grafted, but normal in the grafted putamen. Binding reduction was normal in the grafted putamen, but not in other striatal areas, following amphetamine administration. This supports that graft-derived dopamine release can be measured in vivo in PD. The Clinical Dyskinesia Rating Scale (CDRS) yielded reliable hyperkinesia ratings, whereas dystonia ratings were reliable within but not between raters. In grafted patients the CDRS showed that grafts can increase dyskinesias, without associated motor improvement and unrelated to the degree of dopaminergic reinnervation. Observations support the value of the CDRS, while reliability problems call for improvements. Application of the generic health status questionnaire NHP in grafted patients demonstrated effects beyond motor function, indicating the value of such questionnaires. Psychometric evaluations of the NHP and the PD-specific PDQ-39 showed ambiguities with both, emphasizing the need for further refinements and evaluations, and illustrating the importance of systematic evaluations of outcome measures. Although most methods used here require further attention before they can be considered optimal, this study illustrates the value and importance of multi-level assessments of cell replacement therapies in PD.
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