The psychometric properties of the Dutch version of the Telephone Interview Cognitive Status (TICS)

The Telephone Interview Cognitive Status (TICS) is an instrument to screen for dementia in older persons by telephone. Although the psychometric properties of the TICS have been studied in various countries, the quality of the Dutch version of the TICS was yet unknown. This paper presents the Dutch version of the TICS and reports on its reliability and validity among 51 patients of Maastricht University Hospital, The Netherlands. The Pearson and intra-class correlations for test-retest reliability were 0.93 and 0.92, respectively. The Pearson and intra-class correlations for inter-rater reliability were 0.91 and 0.90, respectively. Sensitivity and specificity were studied in relation to the Mini Mental State Examination (MMSE, cut-off point 23/ 24) and the diagnosis of dementia as assessed according to DSM-IV criteria. When using the TICS cut-off point of 26/27, the coefficients for sensitivity and specificity were at least 0.80. The percentages ROC under the curve were 90% and 93% with the MMSE and the diagnosis dementia as criterion, respectively. We conclude that the Dutch version of the TICS is an acceptable instrument for screening for dementia in older persons, particularly when face-to-face contact is not possible.     

Visual event-related potentials to moving stimuli: normative data

Visual cognitive responses (P300) to moving stimuli were tested in 36 subjects with the aim to find the normal range of P300 parameters. Concomitantly, the circadian intra-individual variability of the P300 was studied in a subgroup of 6 subjects. Visual stimuli consisted of either coherent (frequent stimulus) or non-coherent motion (random stimulus). The oddball paradigm was applied for recording cognitive responses. P300 to rare stimuli had an average latency of 447.3 +/- 46.6 ms and amplitude of 12.9 +/- 6.0 microV. The average reaction time was in the range from 322 to 611 ms and there was no correlation between the reaction time and P300 latency. We did not find any significant circadian changes of the P300 parameters in the 6 subjects tested four times during the same day. Cognitive (event-related) responses (P300) displayed distinctly greater inter-individual variability (S.D. of 50 ms) when compared with pattern-reversal and motion-onset VEPs (S.D. of 6.0 ms and 14 ms, respectively). For this reason, the clinical use of P300 elicited by this kind of visual stimuli seems to be rather restricted and the evaluation of its intra-individual changes is preferable.     

The assessment of fear of falling with the Falls Efficacy Scale-International (FES-I). Development and psychometric properties in Dutch elderly

Fear of falling is common in older persons. Different methods have been developed to assess fear of falling. The most well-know measure is the 10-item Falls Efficacy Scale (FES). However, the FES items (a) focus on low functioning older persons and particularly on in-home activities, (b) do not comprise social activities, and (c) were developed from a US perspective so that translation in European languages is hampered. To solve these issues, the 16-item Falls Efficacy Scale-International (FES-I) was recently developed within the Prevention of Falls Network Europe (ProFaNE). In this article, the Dutch version of the FES-I is presented and the psychometric properties in 213 Dutch persons aged 70 years of age and over are described. The FES-I showed to be unidimensional and internally consistent; the Cronbach alpha coefficient was 0.96. The 4 week test-retest intra-class correlation coefficient was 0.82. The associations of the FES-I sumscores with age, gender, falls history and overall fear of falling was as expected, indicating construct validity. In addition, the FES-I discriminated in the same extent as the original 10-item FES scale. We conclude that the FES-I showed acceptable reliability and construct validity and may be useful in cross-national research. Future studies should focus on the sensitivity to change of FES-I.     

Neuropsychiatric symptoms of dementia: psychometric aspects of the Dutch Neuropsychiatric Inventory (NPI)

Behavioral and psychological symptoms are highly prevalent in dementia. The Neuropsychiatric Inventory was constructed to measure these symptoms. Data from three studies are presented concerning psychometric aspects of the NPI Dutch version. The NPI was compared to the Revised Memory and Behavioral Problems Checklist (RMBPC) and the Mini Mental State Examination (MMSE). In the three selected patient samples prevalence of behavioral or psychological symptoms was as high as 90%. Interrater agreement (n = 19) was very high (kappa > .90). Factor analysis (n = 199) supports NPI construct validity. The NPI items correlated reasonably high (R = .35 - .60) with the relevant RMBPC subscales (n = 24). Although some NPI items did, the NPI total score was not significantly related to the MMSE. The NPI Dutch version can be scored objectively and it is a valid rating scale for measuring a wide range of behavioral and psychological symptoms of dementia.     

Analysis of standing up and sitting down in humans: definitions and normative data presentation

A formal definition of human standing up and sitting down movements based on sagittal plane goniometric and force plate data from 20 normal subjects is presented. This definition is comparable to the established gait cycle diagram, and consists of defined characteristic events and relative time intervals between them. The characteristic events are selected primarily on changes in ground reaction forces. The terminology proposed may be valuable for introducing more formalized and standardized reporting of both qualitative and quantitative studies in both normals and in patients. This presentation is directed toward the process of defining generally acceptable standards for human standing up and sitting down movements.     

The Revised Fibromyalgia Impact Questionnaire (FIQR): validation and psychometric properties

Introduction  

The Fibromyalgia Impact Questionnaire (FIQ) is a commonly used instrument in the evaluation of fibromyalgia (FM) patients. Over the last 18 years, since the publication of the original FIQ, several deficiencies have become apparent and the cumbersome scoring algorithm has been a barrier to widespread clinical use. The aim of this paper is to describe and validate a revised version of the FIQ: the FIQR.     

Limnological data of an isolated Dutch broad

Summary Water quality research was started in the province of Friesland, The Netherlands, in order to set the ecological water quality standards. One of the waters under study is the broad of the Boornbergumer Petten. This water, as well as the supplying ditch, was investigated with regard to physico-chemical factors, macro-invertebrates and macrophyte vegetation. Supplementary the broad was sampled on phytoplankton. Preliminary results as well as older limnological data are presented. Macrophytes are the dominating primary producers. Worth mentioning is the extensive vegetation ofScirpus lacustris ssp.lacustris f.fluitans and of someChara species. The Boornbergumer Petten can be regarded as a usable and appropriate reference water for peatdiggings and broads. By means of limnological data of also other waters regional water quality standards will be postulated in the near future. Prepurification of the inflowing water by a marsh vegetation is considered necessary to prevent eutrophication of the broad and may act as a precursor of the appearance of theChara vegetation. Ceasing the inflow of polderwater would lead to drying up of the broad, because of deep draining the surrounding grassland areas.     

Letter: Preliminary crystallographic data for Escherichia coli beta-lactamase

The β-lactamase (penicillinase) from Escherichia coli W3310 has been crystallized from 25% saturated ammonium sulfate solution at pH 6.9. An X-ray examination of the monoclinic crystals shows the space group is C2, with unit cell dimensions $\text{a = 47.2}\text{A}\text{?}$, $\text{b = 76.9}\text{A}\text{?}$, $\text{c = 73.3}\text{A}\text{?}$ and β = 98.6°. With Z = 4 and the molecular weight = 22,000 (Melling &; Scott, 1972), the ų/dalton ratio is 2.98. The crystals are suitable for structure analysis to at least 2.4 Å resolution.     

Letter: Preliminary crystallographic data for spinach superoxide dismutase

Superoxide dismutase from spinach leaves was salted out with ammonium sulphate. The resulting crystals were monoclinic, space group C2, with unit cell dimensions $\text{a = 166.2}\text{A}\text{?}\text{, b = 46.1}\text{A}\text{?}\text{, c = 85.6}\text{A}\text{?}\text{and}\text{β = 99.3 °}$. Considerations of cell volume and protein molecular weight indicated two molecules of superoxide dismutase in the asymmetric unit.     

Letter: crystallographic data fro lysoxyme from bacteriophage T4

The lysozyme of bacteriophage T4 has been crystallized in a form suitable for X-ray diffraction analysis. The space group is P3₁21 or enantiomorph, and the cell dimensions are $\text{a = b = 61.1}\text{A}\text{?}$, $\text{c = 96.3}\text{A}\text{?}$.     

Letter: Crystallographic data of an L-arabinose-binding protein from Escherichia coli

Single crystals of an l-arabinose-binding protein from Escherichia coli B/r suitable for a high-resolution structural analysis have been obtained. An X-ray examination of the orthorhombic crystals shows the space group is P2₁2₁2₁, with unit cell dimensions: $\text{a = 55.3}\text{A}\text{?}\text{, b = 71.4}\text{A}\text{?}\text{and}\text{c = 77.5}\text{A}\text{?}$. The asymmetric unit contains one protein molecule with a molecular weight of 38,000.     

Letter: X-ray data for four crystalline forms of serum albumin

Cell dimensions, space groups and crystal densities are reported for a monoclinic form of human serum albumin (a = 126.5, b = 39.2, c = 135.2Å, β = 93.3 °, C2, Z = 4), tetragonal human serum albumin (a = 84.0, c = 276Å, P4₁2₁2, Z = 8), a mercury dimer of human serum albumin (a = 155, b = 83, c = 122Å, P2₁2₁2₁, Z = 4) and a hexagonal form of equine serum albumin (a = 96.6, c = 144.5Å, P6₁, Z = 6).     

Derivation of normative data for the COPD assessment test (CAT)

Background

The tradition classification of the severity of COPD, based on spirometry, fails to encompass the heterogeneity of the disease. The COPD assessment test (CAT), a multi-dimensional, patient-filled questionnaire, assesses the overall health status of patients, and is recommended as part of the assessment of individuals with COPD. However, information regarding the range of values for the test in a non-COPD population (normative values) is limited, and consequently, knowledge regarding the optimal cut-off, and the minimum clinically important difference (MCID) for the test remain largely empirical.

Methods

CanCOLD is a population-based multi-center cohort study conducted across Canada, the methodology of which is based on the international BOLD initiative. The study includes subjects with COPD, at-risk individuals who smoke, and healthy control subjects. CAT questionnaires were administered at baseline to all subjects. Among non-COPD subjects, normative values for the CAT questionnaire, and psychometric properties of the test were characterized. Predictors of high CAT scores were identified using multivariable logistic regression.

Results

Of the 525 non-COPD subjects enrolled, 500 were included in the analysis. Mean FEV₁/FVC ratio among the 500 included subjects was 0.77 (SD 0.49); the mean predicted FEV₁ was 99.38% (SD 16.88%). The overall mean CAT score was 6 (SD 5.09); scores were higher among females (6.43, SD 5.59), and subjects over 80 years of age (mean 7.58, SD 6.82). Cronbach alpha for the CAT was 0.79, suggesting a high internal consistency for the test. A score of 16 was the 95th percentile for the population, and 27 subjects (5.4%) were found to have a CAT score > =16. Current smoking (aOR 3.41, 95% CI 1.05, 11.02), subject-reported physician-diagnosed asthma (aOR 7.59, 95% CI 2.71, 21.25) and musculoskeletal disease (aOR 4.09, 95% CI 1.72, 9.71) were found to be significantly associated with a score ≥16.

Conclusions

The characterization of CAT scores in the general population will be useful for norm-based comparisons. Longitudinal follow-up of these subjects will help in the optimization of cut-offs for the test.     

The Thai version of the PSS-10: An Investigation of its psychometric properties

Background  

Among the stress instruments that measure the degree to which life events are perceived as stressful, the Perceived Stress Scale (PSS) is widely used. The goal of this study was to examine the psychometric properties of a Thai version of the PSS-10 (T-PSS-10) with a clinical and non-clinical sample. Internal consistency, test-retest reliability, concurrent validity, and the factorial structure of the scale were tested.