Effects of moderate-to-high intensity resistance training in patients with chronic heart failure.

CONTEXT: Resistance training may be beneficial for patients with chronic heart failure (CHF). OBJECTIVE: To systematically review the methodological quality of, and summarise the effects of, moderate-to-high intensity resistance training in CHF. DATA SOURCES: Medline/PubMed, Science Citation Index Expanded, SSCI and A&HCI. STUDY SELECTION: English language (non-)randomised controlled trials. DATA EXTRACTION: A predesigned data extraction form was used to obtain data on trial design and relevant results. Methodological quality of the identified trials were scored using the Delphi list. RESULTS: Most of the 10 trials identified had moderate-to-severe methodological limitations. Effects of resistance training (alone or in combination with endurance training) are inconclusive for outcomes like exercise capacity and disease-specific quality of life. CONCLUSIONS: Even though moderate-to-high intensity resistance training does not seem be harmful for patients with CHF, the current peer-reviewed evidence seems inadequate to generally recommend incorporation of resistance training into exercise-based rehabilitation programmes for patients with CHF.

Fatigue as a predictor of sickness absence: results from the Maastricht cohort study on fatigue at work.

OBJECTIVES: To investigate whether there is a relationship between fatigue and sickness absence. Two additional hypotheses were based on the theoretical distinction between involuntary, health related absence and voluntary, attitudinal absence. In the literature, the former term is usually used to describe long term sickness absence, the latter relates to short term sickness absence. In line with this, the first additional hypothesis was that higher fatigue would correspond with a higher risk of long term, primarily health related absence. The second additional hypothesis was that higher fatigue would correspond with a higher risk of short term, primarily motivational absence. METHODS: A multidimensional fatigue measure, as well as potential sociodemographic and work related confounders were assessed in the baseline questionnaire of the Maastricht cohort study on fatigue at work. Sickness absence was objectively assessed on the basis of organisational absence records and measured over the six months immediately following the baseline questionnaire. In the first, general hypothesis the effect of fatigue on time-to-onset of first sickness absence spell during follow up was investigated. For this purpose, a survival analysis was performed. The effect of fatigue on long term sickness absence was tested by a logistic regression analysis. The effect of fatigue on short term sickness absence was investigated by performing a survival analysis with time-to-onset of first short absence spell as an outcome. RESULTS: It was found that higher fatigue decreased the time-to-onset of the first sickness absence spell. Additional analyses showed that fatigue was related to long term as well as to short term sickness absence. The effect of fatigue on the first mentioned outcome was stronger than the effect on the latter outcome. Potential confounders only weakened the effect of fatigue on long term absence. CONCLUSIONS: Fatigue was associated with short term but particularly with long term sickness absence. The relation between fatigue and future sickness absence holds when controlling for work related and sociodemographic confounders. Fatigue as measured with the Checklist Individual Strength can be used as a screening instrument to assess the likelihood of sickness absence in the short term.

A comparative study of work characteristics and reactions between general and mental health nurses: a multi-sample analysis.

AIM OF THE STUDY: The first aim of this study was to examine differences in work characteristics (autonomy, social support and workload) and work reactions (emotional exhaustion and job involvement) between general and mental health nurses. The second aim was to validate whether a specific pattern of relationships between work characteristics and reactions was the same for mental health and general nurses. BACKGROUND: Nurses are generally being considered as an above risk group regarding work stress. However, health care is a diverse sector and literature suggests important differences regarding the work of different categories of nursing, such as general and mental health nurses. In addition, little empirical evidence exists about these differences. In order to improve their work situation, more insight is needed regarding differences and similarities in the work of general and mental health nurses. The demand-control-support (DCS) model was used as a research framework. We hypothesized that autonomy, job involvement, and emotional exhaustion are higher in mental health nursing, whereas social support is expected to be lower. Next, in line with the propositions of this model and several recent studies, we hypothesized that emotional exhaustion is primarily predicted by workload and social support, whereas job involvement is primarily predicted by autonomy. In addition, we investigated whether this pattern of relationships was similar in both groups. DESIGN/METHODS: Questionnaires were distributed to nurses working in a general and a psychiatric hospital in the Netherlands. We used MANOVA and MSA (by means of LISREL) to analyse the data. RESULTS AND CONCLUSIONS: Regarding the differences in work characteristics and work reactions between mental health and general nurses, our hypotheses were confirmed, except for social support and job involvement. Autonomy and emotional exhaustion were higher among mental health nurses, whereas their job involvement proved to be significantly lower. Emotional exhaustion was primarily predicted by workload and lack of social support. Contrary to our expectations, the relationship between autonomy and job involvement was not significant in both samples. Finally, we found that the proposed pattern of relationships appeared to be invariant across the two samples.

Burnout and engagement at work as a function of demands and control.

OBJECTIVES: The present study was designed to test the demand-control model using indicators of both health impairment and active learning or motivation. METHODS: A total of 381 insurance company employees participated in the study. Discriminant analysis was used to examine the relationship between job demands and job control on one hand and health impairment and active learning on the other. RESULTS: The amount of demands and control could be predicted on the basis of employees' perceived health impairment (exhaustion and health complaints) and active learning (engagement and commitment). Each of the four combinations of demand and control differentially affected the perception of strain or active learning. Job demands were the most clearly related to health impairment, whereas job control was the most clearly associated with active learning. CONCLUSIONS: These findings partly contradict the demand-control model, especially with respect to the validity of the interaction between demand and control. Job demands and job control seem to initiate two essentially independent processes, and this occurrence is consistent with the recently proposed job demands-resources model.

Interval versus continuous training in patients with severe COPD: a randomized clinical trial.

Limited information is available regarding the physiological responses to different types of exercise training in patients with severe chronic obstructive pulmonary disease (COPD). The aim of this study was two fold: firstly, to investigate the physiological response to training at 60% of achieved peak load in patients with severe COPD; and secondly to study the effects of interval (I) versus continuous (C) training in these patients. Twenty-one patients with COPD (mean+/-SD forced expiratory volume in one second: 37+/-15% of predicted, normoxaemic at rest) were evaluated at baseline and after 8 weeks' training. Patients were randomly allocated to either I or C training. The training was performed on a cycle ergometer, 5 days a week, 30 min daily. The total work load was the same for both training programmes. C training resulted in a significant increase in oxygen consumption (V'O2) (17%, p<0.05) and a decrease in minute ventilation (V'E)/V'O2 (p<0.01) and V'E/carbon dioxide production (V'CO2) (p<0.05) at peak exercise capacity, while no changes in these measures were observed after interval training. During submaximal exercise a significant decrease was observed in lactic acid production, being most pronounced in the C-trained group (-31%, p<0.01 versus -20%, p<0.05). Only in the I-trained group did a significant increase in peak work load (17%, p<0.05) and a decrease in leg pain (p<0.05) occur. Training did not result in a significant improvement in lung function, but maximal inspiratory mouth pressure increased in both groups by 10% (C: p<0.05) and 23% (I: p<0.01). The present study shows a different physiological response pattern to interval or continuous training in chronic obstruction pulmonary disease, which might be a reflection of specific training effects in either oxidative or glycolytic muscle metabolic pathways. Further work is required to determine the role of the different exercise programmes and the particular category of patients for whom this might be beneficial.

Specific determinants of intrinsic work motivation, burnout and turnover intentions: a study among nurses.

This study of 156 Dutch general hospital nurses tested a theoretically derived model of specific relationships between work stressors and stress reactions. The model proposes four central domains of the work situation, namely work content, working conditions, social and labour relations, and conditions of employment. In addition, the model proposes three important stress reactions, namely a diminished intrinsic work motivation, occupational burnout and an inclination to leave the job. More specifically, it was hypothesized that (i) intrinsic work motivation is primarily determined by work content variables, (ii) burnout is primarily determined by both work load and limited social support, and (iii) propensity to leave is primarily determined by conditions of employment. All these relationships were simultaneously tested using a structural equations modelling technique. The results of a series of LISREL analyses indicate that the postulated model fits well to the data. The present study used conceptually integrated measures that cover the area of work stress and stress reactions, and provides directions for interventions aimed at preventing or reducing specific negative outcomes of work-related stress in general hospitals.

A test of Leiter's process model of burnout.

This study among Dutch nurses (N = 156) tested Leiter's 1993 process model of burnout. The LISREL results of this study partially support Leiter's model. It appeared that emotional exhaustion was primarily related with the demand variable work overload while depersonalization was, to a lesser degree, associated with the resource variable coworker support. Personal accomplishment was significantly related with coping and emotional exhaustion was associated with depersonalization. However, Leiter's model did not fit to the data in all respects. Modifications indices provided by LISREL 8 suggested to relax the relationship between: (1) coping and depersonalization and (2) social support and emotional exhaustion. Because these relationships were supported by both theory and existing empirical evidence, they were successively added to the model. Eventually, the model improved considerably and all selected criteria were met. Several relationships in the final model, however, were nonsignificant (e.g., the relationship between personal accomplishment and autonomy and participation, respectively).

Analysis of the metabolic and ventilatory response to self-paced 12-minute treadmill walking in patients with severe chronic obstructive pulmonary disease.

BACKGROUND: The 12-minute walking test is frequently used to measure exercise capacity in patients with severe chronic obstructive pulmonary disease. However, the physiological response to this test has been the subject of limited investigation. METHODS: In this study, the metabolic and ventilatory consequences of a self-paced 12-minute treadmill walking test (WT) were measured in 17 patients with severe chronic obstructive pulmonary disease (FEV1: 40 +/- 9%) and evaluated using the physiological response to symptom-limited cycle ergometry (CE). During exercise testing, heart rate, transcutaneous oxygen saturation, and lactate concentration were measured, and oxygen consumption, carbon dioxide production, tidal volume, and breathing frequency were recorded breath by breath. RESULTS: After 4 minutes walking, the peak oxygen consumption (VO2) was already 99 +/- 11% of last-minute walking VO2. Walking speed was chosen within 2 minutes and remained stable throughout the test. The WT and CE showed similar (end-) test results for all measurements, except for a higher carbon dioxide production, venous lactate concentration, and respiratory quotient after CE. However, lactate concentration was also significantly increased after WT. Severe and prolonged desaturation was shown during walking in most patients. CONCLUSIONS: The physiological stress evoked during the WT is close to the stress developed at an incremental symptom-limited test and the relatively high metabolic and ventilatory stress is sustained from at least 4 to 12 minutes during the WT. This study has shown that anaerobic metabolism not only occurs during incremental cycle ergometry, but also during the WT.

Metabolic and ventilatory response pattern to arm elevation in patients with COPD and healthy age-matched subjects.

Many patients with chronic obstructive pulmonary disease (COPD) experience problems in those activities of daily living which involve so-called unsupported arm elevations (AE). In this study, possible differences in the metabolic and ventilatory response pattern to three types of arm elevation were compared between 13 COPD patients (forced expiratory volume in one second (FEV1) (mean (SD)) 38 (13)% of predicted) and 13 age-matched healthy subjects. Each subject consecutively performed three types of arm elevation for 2 min, with 3 min rest periods in between. Breath-by-breath metabolic and ventilatory parameters and heart rate (HR) were registered during a 3 min baseline period and throughout the measurement period. Adjusted for significantly greater baseline test results in COPD patients, it was found that AE (arm elevation including recovery) tended to be more demanding with respect to metabolic and ventilatory response for patients with COPD than for the age-matched healthy subjects. Arm elevation resulted in an increase in oxygen consumption (V'O2) (COPD 12%; healthy 6%), carbon dioxide elimination V'CO2 (COPD 15%; healthy 10%), minute ventilation V'E (COPD 13%; healthy 7%) and heart rate (COPD 2%; healthy 5%). A pronounced difference was found in the pattern of metabolic and ventilatory response to arm elevation, i.e. there was an earlier but sluggish V'O2 onset in COPD patients, whereas the healthy subjects demonstrated a sudden peak approximately 30 s after arm elevations. Mutual comparison of the three different types of arm elevation demonstrated a comparable response pattern. Knowledge of the specific response to arm elevations in COPD patients seems essential for interpretation of arm elevation tests in upper extremity rehabilitation programmes.