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Objective: To develop a self-report measure for assessment of the stage of change in patients with osteoarthritis, in order to identify patients who would benefit from a self-management programme. Methods: According to the 'stages of change' model a questionnaire was developed with three groups of items corresponding to the precontemplation stage (Pre), the contemplation (Cont) and the action (Act) stage. Internal consistency and factor structure of this questionnaire were investigated by assessing Cronbach's alphas and by performing factor analysis. Subjects and setting: The questionnaire was offered to 273 patients who entered a randomized clinical trial on self-management in a general health care setting. Results: Factor analysis revealed that most items corresponded to the a priori described groups, while some items were not loading on the presumed factor. In each subgroup some items were deleted, resulting in a 15-item questionnaire. After this item reduction Cronbach's alphas were 0.72 (Pre), 0.76 (Cont) and 0.79 (Act) and all factor loadings were satisfactory (above 0.35). Classification revealed some differences between parts of the total group, for example in the proportion of patients in the preparation stage (recruited by general practitioner = 33.6%; advertisement = 49.2%). Conclusions: The Stages of Change Questionnaire in Osteoarthritis, a 15-item questionnaire to assess the 'stage of change' of a patient with osteoarthritis showed good internal consistency and adequate factor structure. These findings warrant further studies on validity and applicability in a clinical context. © 2005 Edward Arnold (Publishers) Ltd.

Health-related quality of life (HRQoL), conceptualized as patients' own evaluations of their health status, is an important criterion in evaluating health and health care and in the treatment of individual patients. Until now, few systematic attempts have been made to develop instruments to assess the HRQoL of children using such a conceptualization. This article describes the conceptualization and results of a study aiming to develop such an instrument for children aged 6-15 years using their parents as a proxy. The feasibility and psychometric performance of the instrument were evaluated in a study of 77 patients of the paediatric out-patient clinic of Leiden University Hospital. For each of the a priori-defined domains, a parent form scale could be constructed with satisfactory reliability and moderate correlations with the other scales. Only some of the parents indicating health status problems also signalled negative reactions to these problems. This is, in our view, a strong argument for the distinction between health status and quality of life (QoL). The correlation coefficients between the parent form and a children's questionnaire were low. Overall, the psychometric performance of the TACQOL parent form looks promising, which suggests that this instrument - with some modifications - can indeed be used to assess group differences in HRQoL in children. The results, however, should be replicated in larger samples, currently under study. The relation between parents' proxy reports on the HRQoL of their children and children's self-reports needs further investigation.

As part of a large-scale epidemiological study, occupational isocyanate exposure was assessed in spray-painting environments. The aim was to assess which compounds contribute to isocyanate exposure in car body repair shops and industrial painting companies, and to identify tasks with high risk of isocyanate exposure. Mainly personal task-based samples (n = 566) were collected from 24 car body repair shops and five industrial painting companies using impingers with DBA in toluene. Samples were analysed by LC-MS for isocyanate monomers, oligomers and products of thermal degradation. From the 23 analysed compounds, 20 were detected. Exploratory factor analysis resulted in a HDI, TDI and MDI factor with the thermal degradation products divided over the TDI and MDI factors. The HDI factor mainly consisted of HDI oligomers and was dominant in frequency and exposure levels in both industries. Spray painting of PU lacquers resulted in the highest exposures for the HDI factor (<LOD-2643 μg/m3 NCO), with no significant difference between the industries. Exposure variability during PU spray painting was large with a variability over time of WWS2 = 9.1 compared with between-worker variability of bwS2 = 1.6. Lower level exposure to the HDI factor was found during other painting-related tasks and even tasks without direct exposure to paint. Exposure to the TDI factor was found more regularly in car body repair shops than in industrial painting companies. Exposure levels were low (<LOD-5 μg/m3 NCO) compared with the HDI factor and no clear contrast in levels between the tasks was observed. Exposure to the MDI factor was found incidentally during spraying and welding in car body repair shops (<LOD-0.5 μg/m3 NCO). The results indicate that paint is the most important source and major contributor of isocyanate exposure in both industries with highest exposures during PU spraying. However, since respiratory protection is less extensively used during other tasks, lower level exposure during these other tasks may significantly contribute to the internal dose. © 2005 British Occupational Hygiene Society.

Objectives: To determine which exposure metrics are sufficient to characterize 'peak' inhalation exposure to organic solvents (OS) during spraying operations. Methods: Personal exposure measurements (n = 27; duration 5-159 min) were collected during application of paints, primers, resins and glues in 15 companies. A MiniRAE Photolonization Detector measured OS concentrations every second. These readings were adjusted for OS composition, which was determined by charcoal tubes. A peak was defined as a period during which exposure exceeded the time-weighted average (TWA) exposure. Five second and 1 and 15 min moving average times were considered in defining a peak. The number of peaks per hour, the duration of a peak, the maximum concentration within a peak, the average concentration within a peak, the ratio between maximum and average concentration within a peak and the average time between two peaks were recorded for each sample. Data were analyzed using factor analysis on 13 variables for the 27 samples: TWA concentration of the task and the six peak characteristics based on the 5 s and 1 min moving averaging time. Results: There were three statistically independent sources of correlation among metrics of peak exposure, explaining 87% of the multiple correlation. The first factor reflected the intensity of peak exposure; it was also associated with the TWA. The second and third factors were related to measures of variability (in frequency and intensity) and duration of peaks, respectively. Conclusions: We present a method for describing peak profiles for inhalation exposure in terms of various distinguishable and independent parameters. Pending development of toxicologically justified peak exposure metrics, such investigations can be of value in identifying exposure metrics for which non-confounded risk estimates can be obtained in epidemiological studies.

Objectives: The aim of this study is to assess the structural and cross-cultural validity of the KIDSCREEN-27 questionnaire. Methods: The 27-item version of the KIDSCREEN instrument was derived from a longer 52-item version and was administered to young people aged 8-18 years in 13 European countries in a cross-sectional survey. Structural and cross-cultural validity were tested using multitrait multi-item analysis, exploratory and confirmatory factor analysis, and Rasch analyses. Zumbo's logistic regression method was applied to assess differential item functioning (DIF) across countries. Reliability was assessed using Cronbach's alpha. Results: Responses were obtained from n = 22,827 respondents (response rate 68.9%). For the combined sample from all countries, exploratory factor analysis with procrustean rotations revealed a five-factor structure which explained 56.9% of the variance. Confirmatory factor analysis indicated an acceptable model fit (RMSEA = 0.068, CFI = 0.960). The unidimensionality of all dimensions was confirmed (INFIT: 0.81-1.15). Differential item functioning (DIF) results across the 13 countries showed that 5 items presented uniform DIF whereas 10 displayed non-uniform DIF. Reliability was acceptable (Cronbach's α = 0.78-0.84 for individual dimensions). Conclusions: There was substantial evidence for the cross-cultural equivalence of the KIDSCREEN-27 across the countries studied and the factor structure was highly replicable in individual countries. Further research is needed to correct scores based on DIF results. The KIDSCREEN-27 is a new short and promising tool for use in clinical and epidemiological studies. © 2007 Springer Science+Business Media B.V.

Objectives - This paper examines the relationship between work stressors and the following health indicators: psychosomatic complaints, health behavior, and musculoskeletal problems. Methods - Secondary analyses were performed on data from the National Work and Living Condition Survey, which provides a representative sample of the working population in The Netherlands. The survey was made in 1977, 1983, and 1986 by The Netherlands Central Bureau of Statistics. By means of factor analysis the following three risk dimensions were identified in the survey: work pace, intellectual discretion, and physical stressors. Results - High work pace, low intellectual discretion, and physical stressors were associated with increased health complaints (both psychosomatic and musculoskeletal) and musculoskeletal disorders after adjustment for gender, age, education, and sports participation. Low intellectual discretion, but not high work pace, was associated with poor general health and health behavior indicative of poor health. Physical stressors were associated with general health as well, but not with health behavior, except for reported absenteeism. Conclusions - Psychosocial stressors are not only associated with psychosomatic complaints and health indicators, but also with musculoskeletal problems, both acute and chronic. Especially the relation between intellectual discretion and musculoskeletal problems can be partly attributed to physical load. Even after adjustment for physical stressors and moderating personal characteristics, the relationships between the psychosocial stressors and musculoskeletal problems remained significant and comparable in strength to the relationship between psychosocial stressors and several other health outcomes, such as psychosomatic complaints. This work is licensed under a Creative Commons Attribution 4.0 International License.

The association between diet and cancer, predominantly investigated univariately, has often been inconsistent, possibly because of the large number of candidate risk factors and their high intercorrelations. Analysis of dietary patterns is expected to give more insight than analysis of single nutrients or foods. This study aimed to develop and apply a common methodological approach to determine dietary patterns in four cohort studies originating in Finland, the Netherlands, Sweden and Italy. Food items on each of the food frequency questionnaires were aggregated into 51 food groups, defined on the basis of their position in the diet pattern and possible relevance to cancer etiology. Exploratory factor analysis was used to analyze dietary patterns. Using a standardized approach, 3-5 stable dietary patterns were identified, explaining 20-29% of total variance in consumption of the food groups. Two dietary patterns, which explained most of the variance, were consistent across the studies. The first pattern was characterized by high consumption of (salad) vegetables, the second by high consumption of pork, processed meat and potatoes, In addition, a few specifically national food patterns were identified. Sensitivity analyses showed that the identified patterns were robust for number of factors extracted, distribution of input variables and energy adjustment. Our findings suggest that some important eating patterns are shared by the four populations under study, whereas other eating patterns are population specific.

Background: An analysis of dietary patterns or combinations of foods may provide insight regarding the influence of diet on the risk of colon and rectal cancer. Objective: A primary aim of the Dietary Patterns and Cancer (DIETSCAN) Project was to develop and apply a common methodologic approach to study dietary patterns and cancer in 4 European cohorts: the Alpha-Tocopherol Beta-Carotene Cancer Prevention Study (Finland-ATBC), the Netherlands Cohort Study (NLCS) on Diet and Cancer, the Swedish Mammography Cohort (SMC), and the Ormoni e Dieta nella Eziologia dei Tumori (Italy-ORDET). Three cohorts (ATBC, NLCS, and SMC) provided data on colon and rectal cancer for the present study. Design: The cohorts were established between 1985 and 1992; follow-up data were obtained from national cancer registries. The participants completed validated semiquantitative food-frequency questionnaires at baseline. Results: Exploratory factor analysis, conducted within each cohort, identified 3-5 stable dietary patterns. Two dietary patterns - Vegetables and Pork, Processed Meats, Potatoes (PPP) - were common across all cohorts. After adjustment for potential confounders, PPP was associated with an increased risk of colon cancer in the SMC women (quintile4multivariate relative risk: 1.62; 95% CI: 1.12,2.34; P for trend = 0.01). PPP was also associated with an increased risk of rectal cancer in the ATBC men (quintile 4multivariate relative risk: 2.21; 95% CI: 1.07, 4.57; P for trend = 0.05). Neither pattern was associated with the risk of colon or rectal cancer in the NLCS women and men. Conclusion: Although certain dietary patterns may be consistent across European countries, associations between these dietary patterns and the risk of colon and rectal cancer are not conclusive. © 2004 American Society for Clinical Nutrition.