Low Strain Group Research Articles

Relationships between biatrial substrate and recurrence after radiofrequency ablation in patients with persistent atrial fibrillation.

Global longitudinal strain (GLS) and atrial voltage are acknowledged markers for worse rhythm outcome after ablation of persistent atrial fibrillation (PeAF). The majority of research efforts have been directed towards the left atrium (LA), with relatively fewer studies focusing on the right atrium (RA). The aim of this study was to investigate the effect of the biatrial substrate on the outcome following radiofrequency catheter ablation (RFCA). All patients underwent two-dimensional speckle tracking echocardiography (2D-STE) and high-density mapping (HDM) on LA and RA in preoperative and postoperative stages of RFCA. Atrial substrate was assessed by GLS, average voltage, and low voltage zone (LVZ). This retrospective study enrolled 48 patients. With a follow-up of 385.98±161.78days, 22.92% (11/48) of all patients had AF recurrence and 63.64% in low strain group. Left atrial-low voltage zone (LA-LVZ) prior to RFCA was 67.52±15.27% and 54.21±20.07%, respectively, in the recurrence group and non-recurrence group. Multivariate regression analysis showed that preoperative LA-GLS (OR 0.047, 95%CI 0.002-0.941, p=.046) was independent predictors of AF recurrence. Biatrial average voltage in preoperative and postoperative stages were positively correlated (preoperative: r=0.563 p<.001; postoperative: r=0.464 p=.002). There was no significant difference in the proportion of RA in the recurrence group except the septum in preoperative and postoperative stages. Low LA-GLS and high LA-LVZ may be predictors of RFCA recurrence in PeAF patients. Biatrial average voltage were positively correlated in preoperative and postoperative stages.

The effects of job characteristics on physicians' orientation toward lifelong learning.

With the rapidly growing body of medical knowledge, physicians must engage in lifelong learning. Physicians' orientation toward lifelong learning is of crucial importance. This study aimed to explore the effects of job characteristics on physicians' lifelong learning. A multicenter study collecting data from physicians from three medical centers in Taiwan was performed. A total of 321 physicians were surveyed with the Chinese version of the Job Content Questionnaire (C-JCQ) and the revised Jefferson Scale of Physician Lifelong Learning (JeffSPLL) to assess their job characteristics (i.e., job demands, job control, social support) and orientation toward lifelong learning. Exploratory factor analysis was employed to validate both questionnaires. Hierarchical regression was utilized to explore the relationship of job characteristics and predictors with physicians' lifelong learning. The results revealed that job demands (β = 0.10), job control (β = 0.19), social support from supervisors (β = 0.16), the interaction of job demands × job control (β = - 0.11) and the interaction of job demands × social support from colleagues (β = 0.13) were significantly (p < .05, p < .001) related to lifelong learning. Moreover, physicians in the active group (high demand, high control) possessed a stronger orientation toward lifelong learning (mean = 3.57) than those in the low-strain group (mean = 3.42), high-strain group (mean = 3.39) and passive group (mean = 3.20). In conclusion, examining physicians' job demands, job control and social support helps us to understand their orientation toward lifelong learning and may provide insight to improve educational strategies.

Association of job strain with accelerometer-based sleep duration and timing of sleep among older employees.

Job strain has been associated with poor sleep quality and could lead to changes in duration and timing of sleep as well. This study examined the association of job strain with sleep duration, bedtimes and awakening times among public sector employees close to their retirement age. Differences in these sleep parameters between workdays and free days across job strain groups were examined. Duration and timing of sleep were measured repeatedly with accelerometers among 466 public sector employees in Finland (mean age 63years, 86% women), who contributed to 759measurements in total. Job demands (low/high) and control (low/high) measured by self-reports and job exposure matrix were used to identify low strain (low demand, high control), passive (low, low), active (high, high) and high strain (high, low) jobs. No differences in sleep duration were observed on workdays, whereas on free days those in the high strain group had longer sleep duration than those in the low strain and passive job groups. The high strain group also extended their sleep from workdays to free days more, the extension being on average 59min (95% CI 42min-75min) when adjusted for several sociodemographic, work and health factors. This extension of sleep duration resulted mostly from a greater delay of awakening times from workdays to free days. Psychosocial work factors, such as job strain, need to be considered when promoting sufficient sleep duration among older employees, as those with job strain may have a greater need for recovery and sleep.

Negative effects of high mechanical tensile strain stimulation on chondrocyte injury in vitro

The mechanism underlying the development of osteoarthritis induced by high tensile strain is unclear. In this study, the effects of different degrees of mechanical tensile strain stimulation on Sprague–Dawley rat chondrocytes were explored. Rat chondrocytes were subjected to mechanical tensile strain at different intensities and frequencies (control group, low tensile strain group, intermediate tensile strain group, and high tensile strain group) using a self-made in vitro tensile strain device. After applying mechanical tensile strain, chondrocytes were collected to detect the expression of collagen II, Aggrecan, matrix metalloproteinase 13 (MMP13), ADAMTS5, and uncoupling protein 2 (UCP2) by real-time quantitative PCR and western blotting as well as reactive oxygen species (ROS) by fluorescence probes. Mechanical tensile strain at different frequencies and intensities had different effects on the biological functions of chondrocytes. Compared with the control group, the expression levels of Col II and Aggrecan in the low and intermediate tensile strain groups increased significantly, while the expression of MMP13 and ADAMTS5 decreased. There were no significant differences between the low and intermediate tensile strain groups. Col II and Aggrecan levels were significantly lower in the high tensile strain group than in the control group, while MMP13 and ADAMTS5 levels were higher. There were no significant differences in ROS production between the low and intermediate tensile strain groups and the control group, but the high tensile strain group exhibited significantly increased ROS production. The expression of UCP2 was significantly lower in the high tensile strain group than in all other groups. These results showed that stimulation with different levels of mechanical tensile strain has different effects on chondrocytes. Repeated high tensile strain promoted the anabolic function of chondrocytes, increased ROS production, and decreased UCP2. These results provide a potential mechanism by which osteoarthritis is induced by high mechanical tensile strain.

Family Caregiver Strain and Likelihood of Heart Failure Patient Clinical Events: A Replication Study

Introduction Higher caregiver strain was identified as a predictor of lower patient clinical event-risk in a previous analysis of Italian heart failure (HF) patient-caregiver dyads. The purpose of this analysis was to determine whether this trade-off in patient and caregiver outcomes was culturally bound, or replicable in a North American sample. Hypothesis We hypothesized that, similar to the Italian study, higher strain in North American caregivers would predict lower patient event-risk. Methods This was a secondary analysis of data from a 3-arm (usual care, patient-family education, and family partnership intervention) randomized controlled trial to improve HF self-care. Data collection occurred pre-intervention and 4 and 8 months post-intervention. Caregiver strain was measured pre-intervention using the 15-item Bakas Caregiving Outcomes Survey (BCOS: range 15-105, higher scores indicate more positive outcomes related to caregiving), and tertiles were used to divide caregivers into low, moderate, or high strain for analysis. Generalized linear regression was used to examine caregiver strain as a predictor of the likelihood of having any event (HF hospitalization, HF emergency room visit, or all-cause mortality) over time, controlling for intervention group and recent HF hospitalization (previous 4 months). Results All patients (n=92) were NYHA Class II or III, with the majority being Class II (n=68, 73.9%). Patients and caregivers were in their mid-fifties on average (56.3±10.1 and 53.4±12.4 years, respectively) and racially diverse (n=58, 63.0% and n=59, 64.8% African American, respectively), with most patients being male (n=57, 62.0%) and most caregivers being female (n=75, 84.2%). The most common dyad type was spousal (n=40, 44.0%). Over the 8 months, 28 patients were hospitalized, 6 had an emergency room visit and 6 died. The average BCOS scores for the low, moderate, and high strain groups were 82.9±12.5 (range 66-105), 61.1±1.6 (range 60-65), and 52.1±7.4 (range 31-59), respectively. There was no difference in events by intervention group. High caregiver strain (as compared to low strain) was associated with 91.9% lower likelihood of the patient having an event over 8 months follow-up (OR=0.081, 95%CI=0.008-0.850, p=0.036). There was no significant difference in event-risk by moderate caregiver strain. Conclusions Similar to previous findings in an Italian cohort, higher caregiver strain predicted lower HF patient clinical event-risk in this North American sample. Patient event-risk reductions may come with a cost for the family caregiver - a cost that has known sequelae (morbidity, mortality) and must be assessed and addressed.

Salivary cortisol and alpha-amylase: Is there consistency between psychosocial stress test and burdensome work shifts?

ABSTRACTThis study examined the consistency of salivary cortisol and alpha-amylase (sAA) total daily secretion between laboratory and field circumstances. The 95 participants were shift working female health care professionals with high (n = 53) or low (n = 42) psychosocial stress (job strain) measured by the Job Content Questionnaire (JCQ). The Trier Social Stress Test including a 5-min free speech and a mental arithmetic task was conducted with four, and field measurements with three daily saliva samples of cortisol and sAA during circadian rhythm and inter-shift recovery controlled morning shift, night shift, and a day off. The associations of salivary cortisol and sAA area under the curve with respect to ground (AUCg) and area under the curve with respect to increase (AUCi) between laboratory and field were tested using OLS (Ordinary Least Squares) regression. The sAA AUCg output in the laboratory was correlated with the output during all field measurement days and similarly among high and low job strain groups (p < 0.001). SAA AUCi and salivary cortisol AUCg and AUCi were not correlated between laboratory and field measurement, neither in the whole sample nor among the low or high job strain group. In conclusion, a laboratory measure of sAA AUCg output is promising in predicting stress-related output during burdensome work shifts and leisure time, whereas sAA AUCi or salivary cortisol seem not to have this potential.

Noninvasive characterization of carotid plaque strain

ObjectiveCurrent risk stratification of internal carotid artery plaques based on diameter-reducing percentage stenosis may be unreliable because ischemic stroke results from plaque disruption with atheroembolization. Biomechanical forces acting on the plaque may render it vulnerable to rupture. The feasibility of ultrasound-based quantification of plaque displacement and strain induced by hemodynamic forces and their relationship to high-risk plaques have not been determined. We studied the feasibility and reliability of carotid plaque strain measurement from clinical B-mode ultrasound images and the relationship of strain to high-risk plaque morphology. MethodsWe analyzed carotid ultrasound B-mode cine loops obtained in patients with asymptomatic ≥50% stenosis during routine clinical scanning. Optical flow methods were used to quantify plaque motion and shear strain during the cardiac cycle. The magnitude (maximum absolute shear strain rate [MASSR]) and variability (entropy of shear strain rate [ESSR] and variance of shear strain rate [VSSR]) of strain were combined into a composite shear strain index (SSI), which was assessed for interscan repeatability and correlated with plaque echolucency. ResultsNineteen patients (mean age, 70 years) constituting 36 plaques underwent imaging; 37% of patients (n = 7) showed high strain (SSI ≥0.5; MASSR, 2.2; ESSR, 39.7; VSSR, 0.03) in their plaques; the remaining clustered into a low-strain group (SSI <0.5; MASSR, 0.58; ESSR, 21.2; VSSR, 0.002). The area of echolucent morphology was greater in high-strain plaques vs low-strain plaques (28% vs 17%; P = .018). Strain measurements showed low variability on Bland-Altman plots with cluster assignment agreement of 76% on repeated scanning. Two patients developed a stroke during 2 years of follow-up; both demonstrated high SSI (≥0.5) at baseline. ConclusionsCarotid plaque strain is reliably computed from routine B-mode imaging using clinical ultrasound machines. High plaque strain correlates with known high-risk echolucent morphology. Strain measurement can complement identification of patients at high risk for plaque disruption and stroke.

Reciprocal relationships between psychosocial work characteristics and sleep problems: A two-wave study

ABSTRACTSleep problems are common and impair the health and productivity of employees. Work characteristics constitute one possible cause of sleep problems, and sleeping poorly might influence wellbeing and performance at work. This study examines the reciprocal associations between sleep problems and psychosocial work characteristics. The participants were 1744 full-time employed individuals (56% women; mean age 38 years in 2007) from the Young Finns study who responded to questionnaires on work characteristics (conceptualised by the demand–control model and effort–reward imbalance model) and sleep problems (Jenkins Sleep Scale) in 2007 and 2012. Cross-lagged structural equation models are used to examine the associations. The results show that low control and low rewards at baseline predicted sleep problems. Baseline sleep problems predicted higher effort, higher effort–reward imbalance, and lower reward. Sleep problems also predicted lower odds for belonging to the low (rather than high) job strain group and active jobs group. The association between work characteristics and sleep problems appears to be reciprocal, with a stressful work environment increasing sleep problems, and sleep problems influencing future work characteristics. The results emphasise the importance of interventions aimed at both enhancing sleep quality and reducing psychosocial risks at work.

Circumferential Strain Can Be Used to Detect Lipopolysaccharide-Induced Myocardial Dysfunction and Predict the Mortality of Severe Sepsis in Mice

BackgroundSepsis-induced myocardial dysfunction is a common and severe complication of septic shock. However, conventional echocardiography often fails to reveal myocardial depression in severe sepsis. Recently, strain measurements based on speckle tracking echocardiography (STE) have been used to evaluate cardiac function.AimsTo investigate the role of STE in detecting lipopolysaccharide (LPS)-induced cardiac dysfunction, M-mode and 2-D echocardiography were used in LPS-treated mice.MethodsThe mice were treated with a 10mg/kg (n = 10), 20mg/kg (n = 10) or 25mg/kg LPS (n = 30) to induce cardiac dysfunction. Subsequently, the ejection fraction (EF) and fractional shortening (FS) were measured with standard M-mode tracings, whereas the circumferential (Scirc) and radial strain (Srad) were measured with STE. Serum biochemical and cardiac histopathological examinations were performed to assess sepsis-induced myocardial injury.Results20mg/kg LPS resulted in more deterioration, myocardial damage and cardiac contractile dysfunction based on serum biochemical and histological examinations. The mice that were subjected to 20mg/kg LPS exhibited reduced Scirc but no reduction in Srad, whereas on conventional echocardiography, the ejection fraction (EF) and fractional shortening (FS) were similar in the 10mg/kg and 20mg/kg groups. Moreover, Scirc was positively correlated with body temperature in the mice at 20 h after LPS injection (r = 0.746, p = 0.001), but no significant correlation was observed between Srad and body temperature (r = 0.356, p = 0.123). Moreover, the mice with high Scirc (-5.9% to -10.4%) exhibited reduced mortality following the administration of 25mg/kg LPS (p = 0.03) compared with the low-strain group (-2% to -5.9%).ConclusionsTaken together, our findings indicate that circumferential strain is a specific and reliable indicator for evaluating LPS-induced cardiac dysfunction in mice.

The association between job strain and coronary heart disease: A meta-analysis of prospective cohort studies

Background. Studies about work stress and the risk of coronary heart disease (CHD) have yielded inconsistent results. This meta-analysis aimed to investigate the association between job strain and the risk of CHD.Methods. We searched PubMed and Embase databases for studies reporting data on job strain and the risk of CHD. Studies were included if they reported multiple-adjusted relative risk (RR) with 95% confidence interval (CI) with respect to CHD from job strain.Results. Fourteen prospective cohort studies comprising 232,767 participants were included. The risk of CHD was increased in high-strain (RR 1.26; 95% CI 1.12–1.41) and passive jobs (RR 1.14; 95% CI 1.02–1.29) but not in active jobs (RR 1.09; 95% CI 0.97–1.22), when compared with low-strain group. The increased risk of CHD in high-strain and passive jobs was mainly driven by studies with a follow-up duration of ≥ 10 years. Neither the low-control (RR 1.06; 95% CI 0.93–1.19) nor high-demand (RR 1.13; 95% CI 0.97–1.32) dimension was independently associated with the risk of CHD.Conclusions. Individuals with high-strain and passive jobs were more likely to experience a CHD event. Intervention programs incorporating individual and organizational levels are crucial for reducing job strain and the risk of CHD.

Effect of maternal job strain during pregnancy on infant neurodevelopment by gender at 6 and 12months: Mothers and Children's Environmental Health (MOCEH) study.

ObjectivesLimited evidence is available regarding the association between prenatal job strain and infant neurodevelopment. Most studies used stress indicators other than job strain to explain the relationship between prenatal maternal stress and child development. The objective of this study was to investigate the association between maternal job strain during pregnancy and neurodevelopment in infancy.MethodsMothers and Children’s Environmental Health (MOCEH) study, an on-going prospective birth cohort study, has been conducted in South Korea since 2006. Job strain during pregnancy was measured using Korean version of Job Content Questionnaire (JCQ). Infant neurodevelopment was assessed using Korean Bayley Scale of Infant Development II (K-BSID-II) at 6 and 12 months of age. A total of 343 mother-child pairs that completed JCQ and K-BSID-II more than once were included. Mental Developmental Index (MDI) and Psychomotor Developmental Index (PDI) defined in the K-BSID-II were used as outcome variables.ResultsCompared to infants from mothers with low job strain, significant (p < 0.05) decreases in PDI were found in infants from mothers with active and passive job at 6 months of age. After stratification by infant sex, boys in the high strain group had a lower MDI score than boys in the low job strain group at 12 months. On the other hand, girls in the high strain and active groups had higher MDI scores than girls in the low job strain group at 12 months. PDI at 12 months also showed different results by sex. Boys in the high strain and passive job groups had lower PDI scores than boys in the low job strain group. However, such difference was not observed in girls.ConclusionsThe findings of this study suggest that prenatal job strain affects infant neurodevelopment in a gender-dependent manner.

Covariation in the human masticatory apparatus.

Many studies have described shape variation of the modern human cranium in relation to subsistence; however, patterns of covariation within the masticatory apparatus (MA) remain largely unexplored. The patterns and intensity of shape covariation, and how this is related to diet, are essential for understanding the evolution of functional masticatory adaptations of the human cranium. Within a worldwide sample (n = 255) of 15 populations with different modes of subsistence, we use partial least squares analysis to study the relationships between three components of the MA: upper dental arch, masseter muscle, and temporalis muscle attachments. We show that the shape of the masseter muscle and the shape of the temporalis muscle clearly covary with one another, but that the shape of the dental arch seems to be rather independent of the masticatory muscles. On the contrary, when relative positioning, orientation, and size of the masticatory components is included in the analysis, the dental arch shows the highest covariation with the other cranial parts, indicating that these additional factors are more important than just shape with regard to covariation within the MA. Covariation patterns among these cranial regions differ mainly between hunting-fishing and gathering-agriculture groups, possibly relating to greater masticatory strains resulting from a large meat component in the diet. High-strain groups show stronger covariation between upper dental arch and masticatory muscle shape when compared with low-strain groups. These results help to provide a clearer understanding of constraints and interlinkage of shape variation within the human MA and allow for more realistic modeling and predictions in future biomechanical studies.

Association Between Exposure to Work Stressors and Cognitive Performance

To examine the association between work stress and cognitive performance. Cognitive performance of a total of 99 women (mean age = 47.3 years) working in hospital wards at either the top or bottom quartiles of job strain was assessed using validated tests that measured learning, short-term memory, and speed of memory retrieval. The high job strain group (n = 43) had lower performance than the low job strain group (n = 56) in learning (P = 0.025), short-term memory (P = 0.027), and speed of memory retrieval (P = 0.003). After controlling for education level, only the difference in speed of memory retrieval remained statistically significant (P = 0.010). The association found between job strain and speed of memory retrieval might be one important factor explaining the effect of stress on work performance.

Effects of Psychosocial Strain on Back Symptoms in Tehran General Hospital Nursing Personnel

Nursing is a stressful and highly demanding job. The aim of this study was to investigate the association between psychosocial job strain and the prevalence of back symptoms in nursing personnel using the demand-control model. In a cross-sectional study, 545 nursing professionals answered to a self-administered questionnaire on demography, job content, and lower and upper back symptoms (LBS and UBS, respectively). Based on their answers, the participants were grouped as follows: low strain, high strain, active job, and passive job. The groups were compared in regard to the prevalence of LBS and UBS (totalling 58.5% and 47.9%, respectively) over the past 12 months. We found no association between job control and back symptoms, but participants with high psychosocial job demands showed greater risk of LBS (OR=1.57 and p=0.014) and UBS (OR=1.73 and p=0.005) than those with low job demands. LBS in the low strain, high strain, and active job groups was more prevalent than in the passive group (OR=1.64, OR=2.49 and OR=1.90, respectively; p≤0.05). In addition, the high strain group showed greater prevalence of UBS than the passive group (OR=1.82 and p=0.019). Our study suggests that psychosocial job strain, high psychosocial demands in particular, may be associated with greater prevalence of back symptoms in nursing personnel. Our findings may help to design preventive measures that would lower the prevalence of musculoskeletal disorders in this profession.

Acute reductions in mechanical wall strain precede the formation of intimal hyperplasia in a murine model of arterial occlusive disease

Intimal hyperplasia (IH) continues to plague the durability of vascular interventions. Employing a validated murine model, ultrasound biomicroscopy, and speckle-tracking algorithms, we tested the hypothesis that reduced cyclic arterial wall strain results in accentuated arterial wall IH. A 9-0 suture was tied around the left mouse (n= 10) common carotid artery and a 35-gauge (outer diameter= 0.14mm) blunt mandrel. We previously showed that mandrel removal results in a ∼78% reduction in diameter and ∼85% reduction in flow, with subsequent delayed induction of IH by day 28. Preoperative, postoperative day-4 (before measurable IH), and postoperative day-27 circumferential wall strains were measured in locations 1, 2, and 3mm proximal to the stenosis and in the same locations on the contralateral (nonstenosed) carotid. At postoperative day 28, arteries were perfusion fixed and arterial wall morphology was assessed microscopically in the same regions. Strains were the same in all locations preoperatively. Wall strain was decreased in all regions proximal to the stenosis by day 4 (0.26± 0.01 to 0.11± 0.02; P< .001), while strains remained unchanged for the contralateral artery (P= .45). No statistical regional differences in mean strain or IH were noted at any time point for the experimental or contralateral artery. Based on the median, regions were divided into those with low strain (≤0.1) and high strain (>0.1). Average preoperative strains in both groups were the same (0.27± 0.09 and 0.27± 0.08). All segments in the low-strain group (n= 13) demonstrated significant IH formation by day 28, while only 31% of the high strain group demonstrated any detectable IH at day 28. (Mean low-strain intimal thickness= 32± 20μm, high strain= 8.0± 16μm; P< .01). Changes in cross-sectional area at diastole drove the reduction in strain in the low-strain group, increasing significantly from preoperatively to day 4 (P= .04), while lumen cross-section at systole remained unchanged (P= .46). Cross-sectional area at diastole and systole in the high-strain group remained unchanged from preoperatively to day 4 (P= .67). Early reduction in arterial wall strain is associated with subsequent development of hemodynamically induced IH.

Association of job strain with working hours, shift-dependent perceived workload, sleepiness and recovery

We explored the relationship of job strain with working hours, shift-dependent perceived workload, sleepiness and recovery. Nurses/nursing assistants (n = 95) were recruited from wards that belonged to either the top (high-strain group, HJS) or the bottom (low-strain group, LJS) job strain quartiles of a Job Content Questionnaire survey of employees in five health care districts and four cities in Finland. Three-week field measurements during naturally occurring shift schedules and a subset of pre-selected shift arrangements consisted of the Karolinska Sleepiness Scale, perceived workload and recovery. The HJS group (n = 42) had more single days off and quick returns than the LJS group (n = 53, p < 0.01), and both mental workload and physical workload were rated as higher (p < 0.01). During naturally occurring shift arrangements, severe sleepiness was more common in the HJS group only in quick returns (p = 0.04) and the HJS group recovered on average more poorly from work after all shifts (p = 0.01) and morning shifts (p = 0.02). During pre-selected shift arrangements, the differences between the groups were only minor. In conclusion, job strain-related differences in sleepiness and recovery were mostly attributable to differences in shift arrangements.

Job Strain, Sleep and Alertness in Shift Working Health Care Professionals —A Field Study

We explored the associations of job strain with sleep and alertness of shift working female nurses and nursing assistants. Participants (n=95) were recruited from the Finnish Public Sector Study, from hospital wards that belonged to the top or bottom quartiles on job strain. Participants' own job strain was at least as high in high-strain group or low in low-strain group as the ward's average. The study included three-week measurements with sleep diary and actigraphy. Psychomotor Vigilance Test (PVT) was performed during one pre-selected morning and night shift and a day off. Sleep efficiency before morning shifts was lower in the high-strain than low-strain group (p=0.03). Low-strain group took more often (72 vs. 45%; p<0.01) and longer naps (62 vs. 35 min; p=0.01) before the first night shift than high-strain group. Difficulties initiating sleep were more common in high-strain group, especially after evening shifts (p<0.01). High-strain group had more often at least one lapse in PVT during the night shift (p=0.02). Average sleep duration (06:49 h) and efficiency (89%) did not differ between these groups. In conclusion, high job strain is associated with difficulties initiating sleep and reduced psychomotor vigilance in night shifts. Shift working contributed to impaired sleep in both high and low job strain group. Individual and organization-based actions are needed to promote sufficient sleep in shift working nurses, especially with high job strain.

The Effect of Job Strain on Psychological Morbidity and Quality of Life in Military Hospital Nurses in Taiwan: A Follow-up Study

This study investigated changes in job strain in female nurses serving in a military hospital system being restructured and the effect of these changes on psychological morbidity and quality of life (QOL). Questionnaire surveys were sent twice to 618 nurses working in three military hospitals in southern Taiwan at the beginning and at follow up a half year later. A Job Content Questionnaire was used to divide subjects into high and low strain groups. The General Health Questionnaire and the WHO QOL Questionnaire were used to assess psychological morbidity and QOL. Four hundred eighteen nurses completed the study. Initially, the high strain group had a greater prevalence of psychological morbidity and lower QOL than the low strain group. At follow up, high strain group did not have a greater prevalence of psychological morbidity, though significant differences in QOL remained. Job control and social support directly affected the QOL (B=0.42, p<0.001; B=0.41, p=0.038, respectively) and the psychological demand affected directly on psychological morbidity (B=0.12, p<0.001). Job control and psychological demand are different aspects in job strain to impact the psychological morbidity and QOL in nurses working in military hospitals in Taiwan.

직장인의 직무스트레스가 구강건조감에 미치는 영향

Objectives : The purpose of this study was to examine the effect between job stress in jobholders and xerostomia. Methods : 250 jobholders living in Jecheon city were the subjects of this questionnaire. The questionnaire was made up of three contents and 37 items: general characteristic(13), job stress(14), degree & behavior of xerostomia(10). The data were analyzed by two-sample t-test, one-way ANOVA to examine the subjects general characteristics, job stress and degree of xerostomia and were analyzed by Chi-square test to examine the subjects general characteristics, job stress and behavior of xerostomia. Results : Only 215 jobholders were evaluated due to inadequate responses. The results were as follow. 1. As general characteristic of jobholder, male(83.7%) were more than women(16.3%), 30~39 year-old(47%) in age variable, university graduation(63.7%) in the last educational background variable, 2~3 million won(31.2%) in the month average income variable, 1~5 year(33.5%) in tour of duty variable, non-smoker(47.9%) in smoking variable were most. Married(58.6%) were more than unmarried(39.5%). Alcoholic(69.8%) were more than non-alcoholic(30.2%). 2. As classification of job stress, high strain group was 28.4%, active group was 26%, low strain group was 24.2%, passive group was 21.4%. 3. Analysis of effect between general characteristic and degree & behavior of xerostomia showed smoker were statistical significantly higher than non-smoker on 'dry eat', 'Am-sal', 'Night awake', 'Slip-liq'and 'Gumcandy'(p<0.05) and showed alcoholic were statistical significantly higher than non-alcoholic on 'Dry PM', 'Night awake, <TEX>$H_2O$</TEX>-bed'(p<0.05). 4. Analysis of effect between job stress and degree & behavior of xerostomia showed hight strain group were statistical significantly higher than low strain group on 'Dry PM', 'Dry-day', 'Am-sal', 'Eff-life'and 'Night awake'(p<0.05). Conclusions : As high strain group were higher than other groups on degree & behavior of xerostomia, stress would be factor that have an effect on xerostomia. Thus consider and management of stress is necessary for diagnosis and treatment of xerostomia.

Job strain among Malaysian office workers of a multinational company

Information on job strain exposure among Malaysian workers in multinational companies is limited. To investigate the prevalence and factors associated with high job strain among office workers of a multinational company in Malaysia. A cross-sectional study was conducted in November 2007 among 470 eligible workers. Respondents self-administered the Job Content Questionnaire downloaded from the company's intranet. A median-split procedure was applied to create four groups according to the Job Demand-Control Model: active, passive, high and low job strain. Logistic regression models were used to investigate the associations between socio-demographic, occupational and psychosocial factors and high job strain. A total of 356 questionnaires were received (response rate 76%). Twenty-one per cent of respondents were in the high job strain group, 35% were in the passive group, whereas 26% and 17% of workers were in the low strain and active groups, respectively. After controlling for confounders, three factors were found to be associated with high job strain: male workers (adjusted OR 1.94, 95% CI 1.04-3.64), working >48 h per week (adjusted OR 2.51, 95% CI 1.44-4.39) and job insecurity (adjusted OR 1.14, 95% CI 1.02-1.27). One protective factor for high job strain was the scale 'created skill', which is part of skill discretion (adjusted OR 0.70, 95% CI 0.57-0.86). About one in five workers in this study experience high job strain. Work improvement measures include reducing long working hours and job insecurity and giving workers the opportunity to learn, use creativity and develop abilities.