Work-related fatigue among medical personnel in Taiwan.

BACKGROUND/PURPOSE: Work-related fatigue among medical personnel is a major concern for patient safety, however heavy on-call duty is common in many hospitals. The purpose of this study was to investigate the prevalence of self-reported work-related fatigue and its associated factors. METHODS: A cross-sectional survey of 1833 participants was conducted in two hospitals in Taipei City, Taiwan, using a self-administered questionnaire. Participants reported their demographic characteristics, health-related behavior, health status and symptoms, and work-related fatigue during the past 3 months. RESULTS: The prevalence of work-related fatigue among the 1833 participants was 30.9%. Younger participants (20-29 years old) were more likely to report work-related fatigue than older participants (40-65 years old) [adjusted odds ratio (aOR) = 1.55, 95% confidence interval (CI) = 1.18-2.01]. Physicians, nurses, and medical technicians were more likely to report work-related fatigue symptoms than administrative personnel (aOR = 2.30, 95% CI = 1.57-2.79; aOR = 2.83, 95% CI = 1.87-3.99; and aOR = 2.01, 95% CI = 1.12-3.06, respectively). Those who drank coffee more than five times a week were more likely to report work-related fatigue than those who did not drink coffee at all (aOR = 2.53, 95% CI = 1.25-1.93). Participants with poor and very poor self-reported health were more likely to report work-related fatigue (aOR = 1.80, 95% CI = 1.26-2.38) than those who reported that their health was fair, good, or very good. CONCLUSION: We identified factors associated with work-related fatigue among hospital workers in Taipei City. These findings can be applied toward on-the-job training and the development of preventive measures for occupational safety in general hospitals.

Estimates of relative risks for cancers in a population after prolonged low-dose-rate radiation exposure: a follow-up assessment from 1983 to 2005.

Radiation effects on cancer risks in a cohort of Taiwanese residents who received protracted low-dose-rate gamma-radiation exposures from (60)Co-contaminated reinforcing steel used to build their apartments were studied, and risks were compared to those in other radiation-exposed cohorts. Analyses were based on a more extended follow-up of the cohort population in which 117 cancer cases diagnosed between 1983 and 2005 among 6,242 people with an average excess cumulative exposure estimate of about 48 mGy. Cases were identified from Taiwan's National Cancer Registry. Radiation effects on cancer risk were estimated using proportional hazards models and were summarized in terms of the hazard ratio associated with a 100-mGy increase in dose (HR(100mGy)). A significant radiation risk was observed for leukemia excluding chronic lymphocytic leukemia (HR(100mGy) 1.19, 90% CI 1.01-1.31). Breast cancer exhibited a marginally significant dose response (HR(100mGy) 1.12, 90% CI 0.99-1.21). The results further strengthen the association between protracted low-dose radiation and cancer risks, especially for breast cancers and leukemia, in this unique cohort population.

Patient level cost of diabetes self-management education programmes: an international evaluation.

OBJECTIVES: The objective of this study was to examine the value of time-driven activity-based costing (TDABC) in understanding the process and costs of delivering diabetes self-management education (DSME) programmes in a multicountry comparative study. SETTING: Outpatient settings in five European countries (Austria, Denmark, Germany, Ireland, UK) and two countries outside Europe, Taiwan and Israel. PARTICIPANTS: Providers of DSME programmes across participating countries (N=16) including healthcare professionals, administrators and patients taking part in DSME programmes. PRIMARY AND SECONDARY MEASURES: Primary measure: time spent by providers in the delivery of DSME and resources consumed in order to compute programme costs. Secondary measures: self-report measures of behavioural self-management and diabetes disease/health-related outcomes. RESULTS: We found significant variation in costs and the processes of how DSME programmes are provided across and within countries. Variations in costs were driven by a combination of price variances, mix of personnel skill and efficiency variances. Higher cost programmes were not found to have achieved better relative outcomes. The findings highlight the value of TDABC in calculating a patient level cost and potential of the methodology to identify process improvements in guiding the optimal allocation of scarce resources in diabetes care, in particular for DSME that is often underfunded. CONCLUSIONS: This study is the first to measure programme costs using estimates of the actual resources used to educate patients about managing their medical condition and is the first study to map such costs to self-reported behavioural and disease outcomes. The results of this study will inform clinicians, managers and policy makers seeking to enhance the delivery of DSME programmes. The findings highlight the benefits of adopting a TDABC approach to understanding the drivers of the cost of DSME programmes in a multicountry study to reveal opportunities to bend the cost curve for DSME.

The effects of GSTM1 and GSTT1 polymorphisms on micronucleus frequencies in human lymphocytes in vivo.

The influence of genetic polymorphisms in GSTM1 and GSTT1 genes on micronucleus frequencies in human peripheral blood lymphocytes was assessed through a pooled analysis of data from seven laboratories that did biomonitoring studies using the in vivo cytokinesis-block micronucleus assay. A total of 301 nonoccupationally exposed individuals (207 males and 94 females) and 343 workers (237 males and 106 females) occupationally exposed to known or suspected genotoxic substances were analyzed by Poisson regression. The results of the pooled analysis indicate that the GSTT1 null subjects had lower micronucleus frequencies than their positive counterparts in the total population (frequency ratio, 0.55; 95% confidence interval, 0.33-0.89). The protective effect of this genotype is reversed with increasing age, with a frequency ratio of 1.33 (95% confidence interval, 1.06-1.68) in subjects aged 60 years. A significant overall increase in micronucleus frequency with age and gender (P < 0.001 and P = 0.024, respectively) was observed, females having higher micronucleus frequencies than males, when occupationally exposed (P = 0.002). Nonoccupationally exposed smokers had lower micronucleus frequencies than nonsmokers (P = 0.001), whereas no significant difference in micronucleus level was observed between smokers and nonsmokers in the occupationally exposed group (P = 0.79). This study confirms that pooled analyses, by increasing the statistical power, are adequate for assessing the involvement of genetic variants on genome stability and for resolving discrepancies among individual studies.

Intra- and inter-laboratory variation in the scoring of micronuclei and nucleoplasmic bridges in binucleated human lymphocytes. Results of an international slide-scoring exercise by the HUMN project.

One of the objectives of the HUman MicroNucleus (HUMN) project is to identify the methodological variables that have an important impact on micronucleus (MN) or micronucleated (MNed) cell frequencies measured in human lymphocytes using the cytokinesis-block micronucleus assay. In a previous study we had shown that the scoring criteria used were likely to be an important variable. To determine the extent of residual variation when laboratories scored cells from the same cultures using the same set of standard scoring criteria, an inter-laboratory slide-scoring exercise was performed among 34 laboratories from 21 countries with a total of 51 slide scorers involved. The results of this study show that even under these optimized conditions there is a great variation in the MN frequency or MNed cell frequency obtained by individual laboratories and scorers. All laboratories ranked correctly the MNed cell frequency in cells from cultures that were unirradiated, or exposed to 1 or 2Gy of gamma rays. The study also estimated that the intra-scorer median coefficient of variation for duplicate MNed cell frequency scores is 29% for unexposed cultures and 14 and 11% for cells exposed to 1 and 2Gy, respectively. These values can be used as a standard for quality or acceptability of data in future studies. Using a Poisson regression model it was estimated that radiation dose explained 67% of the variance, while staining method, cell sample, laboratory, and covariance explained 0.6, 0.3, 6.5, and 25.6% of the variance, respectively, leaving only 3.1% of the variance unexplained. As part of this exercise, nucleoplasmic bridges were also estimated by the laboratories; however, inexperience in the use of this biomarker of chromosome rearrangement was reflected in the much greater heterogeneity in the data and the unexplained variation estimated by the Poisson model. The results of these studies indicate clearly that even after standardizing culture and scoring conditions it will be necessary to calibrate scorers and laboratories if MN, MNed cell and nucleoplasmic bridge frequencies are to be reliably compared among laboratories and among populations.

Risk factors of depression after prolonged low-dose rate environmental radiation exposure.

PURPOSE: More than 10,000 Taiwanese people were exposed to excessive protracted low-dose rate radiation from contaminated reinforcement bars, which were installed in buildings before 1992. This study was conducted to assess the prevalence of depression amongst the exposed and identify related determinants now that more than two decades have passed since this population was informed of their exposure to radiation. MATERIALS AND METHODS: We used the Beck depression inventory (BDI)-1A questionnaire to survey 2143 eligible people during their annual physical examinations between March 2009 and December 2009. In total, 1621 people participated in the survey. We employed multivariate logistic regression models with generalized estimating equations method to identify the determinants of depression. RESULTS: The prevalence of depression (BDI-IA score ≥ 12) was 18.7%. Those who exhibited higher cumulative exposure [adjusted odds ratio (OR): 1.46, 95% confidence interval (CI): 1.02-2.07] and a previous history of depression (adjusted OR: 2.49, 95% CI: 1.36-4.58) were significantly associated with the risk of depression, whereas education level was inversely related to depression (adjusted OR: 0.71, 95% CI: 0.50-0.99). CONCLUSION: Long-term, low-dose rate radiation exposure early in life might cause subsequent psychological stress and an increased risk of depression decades later.

Shrinkage methods enhanced the accuracy of parameter estimation using Cox models with small number of events.

OBJECTIVE: When the number of events is small during Cox regression analysis, it is unclear what alternative analytical strategies can be used and when this type of alternative approach is needed. This study explores several analytical strategies in this situation. STUDY DESIGN AND SETTING: Simulations and sensitivity analyses were performed on data with numbers of events per predictive variable (EPVs) below 10 using a Cox model with a partial likelihood (PL), Firth's penalized likelihood, or the Bayesian approach. RESULTS: For scenarios involving binary predictors with an EPV of six or less, the simulations showed that the Firth and Bayesian approaches were more accurate than was PL. The performances of various approaches were similar when the EPV was greater than six in the binary predictor. Furthermore, the performances involving continuous predictors were similar, regardless of the EPV. The bias and precision of the parameter estimates using Bayesian analysis depended on the selection of priors. CONCLUSIONS: When the EPV is six or less, the results for categorical predictors tend to be too conservative. Firth's estimator may be a good alternative in this situation. Appropriate choices of priors when using Bayesian analysis should increase the accuracy of the parameter estimates, although this requires expertise.

Late effects on the health-related quality of life in a cohort population decades after environmental radiation exposure.

PURPOSE: To evaluate the late effects on the quality of life (QOL) of individual years after protracting low-dose radiation exposure. MATERIALS AND METHODS: We assessed 1,818 subjects using the World Health Organization Questionnaire on Quality of Life--Brief Version (WHOQOL-BREF) in several Health-Related Quality of Life (HRQoL) domains. After adjusting for demographic characteristics and comorbidities, we examined the HRQoL differences at various levels of exposure and ages at disclosure. We also evaluated the potential effect modification by gender. RESULTS: After adjusting for potential confounders, girls aged 12 years or younger at the disclosure of exposure had lower HRQoL scores in physical, psychological, and environmental domains compared to those with later age at disclosure. The differences in the HRQoL scores between different exposure subgroups were not significant in physical, psychological, and social relationship domains, and only appeared in the environmental domain. CONCLUSIONS: Being female and less than 12 years of age at disclosure were more significant predictors of HRQoL scores than the levels of radiation exposure among people exposed to protracted low-dose radiation. Further studies are needed to determine the psychological distresses, such as depression and anxiety, and their relationships in this case, especially for the most vulnerable young females.

Accuracy of short-term residential measurement in the prediction of 72-h exposure to power frequency magnetic field in households very close to high-tension transmission lines.

Between February and April 2003, a total of 80 single-dwelling households close (< 70 m) to high-tension (161 or 345 kV) power lines in a northern community of Taiwan received measurements of indoor extremely low-frequency (ELF) magnetic field for 72 h. Measurements were performed with EMDEX II meter at a sampling rate of every 300 s, yielding some 860 readings of ELF magnetic field for each household. In addition to the 72-h mean ELF magnetic field, we also calculated arithmetic means of the first 2, 6, 12, and 288 readings taken in each household to represent the information on spot, 30-min, 60-min, and 24-h exposures, respectively. The mean 72-h exposure to ELF magnetic field for the 80 study households was estimated at 0.80 micro-Tesla (microT) with a standard deviation (SD) of 1.13 microT. The mean for pot, 30-min, 60-min, and 24-h exposure was 0.88 (SD 1.38), 0.90 (SD 1.40), 0.9 (SD 1.17), and 0.83 (SD 1.17) microT, respectively. There were high agreements, indicated by a nearly perfect intra-class correlation coefficient, between 72-h mean exposure and those short-term exposure measures. Additionally, the sensitivity and specificity of various short-term exposures in the prediction of 72-h exposure greater than 0.4 microT were similar at values of 0.82-0.87 and 0.93-0.95, respectively. This study indicates that short-term measurements of indoor ELF magnetic field seem adequate to represent the mean 72-h exposure, but tended to overpredict 72-h exposure greater than 0.4 microT. Further investigation is needed to assess whether these findings can be replicated in households far away from high-tension power lines.

An increased micronucleus frequency in peripheral blood lymphocytes predicts the risk of cancer in humans.

The frequency of micronuclei (MN) in peripheral blood lymphocytes (PBL) is extensively used as a biomarker of chromosomal damage and genome stability in human populations. Much theoretical evidence has been accumulated supporting the causal role of MN induction in cancer development, although prospective cohort studies are needed to validate MN as a cancer risk biomarker. A total of 6718 subjects from of 10 countries, screened in 20 laboratories for MN frequency between 1980 and 2002 in ad hoc studies or routine cytogenetic surveillance, were selected from the database of the HUman MicroNucleus (HUMN) international collaborative project and followed up for cancer incidence or mortality. To standardize for the inter-laboratory variability subjects were classified according to the percentiles of MN distribution within each laboratory as low, medium or high frequency. A significant increase of all cancers incidence was found for subjects in the groups with medium (RR=1.84; 95% CI: 1.28-2.66) and high MN frequency (RR=1.53; 1.04-2.25). The same groups also showed a decreased cancer-free survival, i.e. P=0.001 and P=0.025, respectively. This association was present in all national cohorts and for all major cancer sites, especially urogenital (RR=2.80; 1.17-6.73) and gastro-intestinal cancers (RR=1.74; 1.01-4.71). The results from the present study provide preliminary evidence that MN frequency in PBL is a predictive biomarker of cancer risk within a population of healthy subjects. The current wide-spread use of the MN assay provides a valuable opportunity to apply this assay in the planning and validation of cancer surveillance and prevention programs.