Dorte Kronborg

Effect of a multimodal high intensity exercise intervention in cancer patients undergoing chemotherapy: randomised controlled trial

Objective To assess the effect of a multimodal group exercise intervention, as an adjunct to conventional care, on fatigue, physical capacity, general wellbeing, physical activity, and quality of life in patients with cancer who were undergoing adjuvant chemotherapy or treatment for advanced disease. Design Randomised controlled trial. Setting Two university hospitals in Copenhagen, Denmark. Participants 269 patients with cancer; 73 men, 196 women, mean age 47 years (range 20-65) representing 21 diagnoses. Main exclusion criteria were brain or bone metastases. 235 patients completed follow-up. Intervention Supervised exercise comprising high intensity cardiovascular and resistance training, relaxation and body awareness training, massage, nine hours weekly for six weeks in addition to conventional care, compared with conventional care. Main outcome measures European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30), Medical Outcomes Study Short Form (MOS SF-36), Leisure Time Physical Activity Questionnaire, muscular strength (one repetition maximum), maximum oxygen consumption (Vo2max). Statistical methods The general linear model was used for continuous outcome while analysis of associates between categorical outcomes was performed as analysis of marginal homogeneity in contingency tables. Results Adjusted for baseline score, disease, and demographic covariates, the intervention group showed an estimated improvement at six weeks for the primary outcome, fatigue, of −6.6 points (95% confidence interval −12.3 to −0.9, P=0.02; effect size=0.33, 0.04 to 0.61). Significant effects were seen on vitality (effect size 0.55, 95% CI 0.27 to 0.82), physical functioning (0.37, 0.09 to 0.65), role physical (0.37, 0.10 to 0.64), role emotional (0.32, 0.05 to 0.59), and mental health (0.28, 0.02 to 0.56) scores. Improvement was noted in physical capacity: estimated mean difference between groups for maximum oxygen consumption was 0.16 l/min (95% CI 0.1 to 0.2, P<0.0001) and for muscular strength (leg press) was 29.7 kg (23.4 to 34.9, P<0.0001). No significant effect was seen on global health status/quality of life. Conclusion A supervised multimodal exercise intervention including high and low intensity components was feasible and could safely be used in patients with various cancers who were receiving adjuvant chemotherapy or treatment for advanced disease. The intervention reduced fatigue and improved vitality, aerobic capacity, muscular strength, and physical and functional activity, and emotional wellbeing, but not quality of life. Trial registration Current Controlled trials ISRCTN05322922.

Foreign Ownership and Long-term Survival

Does foreign ownership enhance or decrease a firm’s chances of survival? Over the 100 year period 1895-2001 this paper compares the survival of foreign subsidiaries in Denmark to a control sample matched by industry and firm size. We find that foreign-owned companies have higher survival probability. On average exit risk for domestic companies is 2.3 times higher than for foreign companies. First movers like Siemens, Philips, Kodak, Ford, GM or Goodyear have been active in the country for almost a century. Relative foreign survival increases with company age. However, the foreign survival advantage appears to be eroded by globalization, it decreases over time and disappears at the end of the century.

Railway Reforms: Do They Influence Operating Efficiency?

This paper considers railway operations in 23 European countries during 1995-2001, where a series of reform initiatives were launched by the European Commission, and analyses whether these reform initiatives improved the operating efficiency of the railways. Efficiency is measured using Multi-directional Efficiency Analysis, which enables investigation of how railway reforms affect the inefficiencies of specific cost drivers. The main findings are that the reform initiatives generally improve operating efficiency but potentially differently for different cost drivers. Specifically, the paper provides clear empirical evidence that accounting separation is important for improving operating efficiency for both material and staff costs, whereas other reforms only influenced one of these factor.

Measuring Inefficiency Via Potential Improvements

In a recent paper Bogetoft and Hougaard (1999) suggest the use of a new potential improvements approach to efficiency evaluation which has the advantage of separating the issue of benchmark selection from the issue of efficiency measurement. In the present paper the potential improvements inefficiency index is reexamined and a DEA-like approach for its determination is suggested. The approach is called Multi-directional Efficiency Analysis (MEA). An empirical example on Danish dairy farms is used for illustrative purposes and comparisons with various versions of DEA.

Respiratory Illnesses in Children and Air Pollution in Copenhagen

The relationship between air pollution and the daily number of contacts (i.e., telephone calls and home visits) with or at Copenhagen Emergency Medical Service for children with and without respiratory illnesses was studied during a 91-d period (i.e., January 14, 1991, to April 14, 1991). A total of 12,132 contacts occurred. Diagnoses, which were recorded on the invoices for 5,307 contacts, revealed that 3,974 contacts were the result of respiratory illnesses. Regression analysis was used to investigate the short-term relationship between pollutants (i.e., carbon monoxide, nitric oxide, nitrogen dioxide, NOx, sulfur dioxide, ozone, and black smoke), measured at monitoring stations, and both the number of all contacts for children and the number of contacts for children with respiratory illnesses. Temperature and systematic effects that were the result of holidays and weekends were controlled for, after which only nitric oxide and NOx were associated significantly with the number of contacts for children who had respiratory illnesses. Nitric oxide and NOx, as indicators of traffic pollution, appeared, at low levels, to slightly exacerbate respiratory illnesses among children.

Prepro-vasoactive intestinal polypeptide-derived peptide sequences in cerebral blood vessels of rats: on the functional anatomy of metabolic autoregulation.

This study describes the distribution of peptide sequences derived from the prepro-vasoactive intestinal polypeptide (preproVIP) molecule in perivascular nerves of rat brain arteries and arterioles. The peptides were identified by immunohistochemistry using highly specific antibodies. Five peptide sequences (preproVIP 60–76, peptide histidine isoleucine (PHI), preproVIP 111–122, VIP, and preproVIP 156–170) were identified in the perivascular nerves throughout the arterial cerebral circulation. The density of the immunoreactive fibers was highest in the nerves of the larger extracerebral arteries, declining in smaller branching arteries. All peptide sequences were identified in the nerves of small pial arterioles overlying the cortical convexity, whereas capillaries and veins contained no immunoreactive material. Dendritic processes of neocortical neurons immunoreactive for VIP and PHI could be followed towards the brain surface where the processes penetrated into the pial layer, often close to the pial vasculature. Some of the processes were also observed to enter the Virchow-Robin space, close to the arterioles. It is possible that cortical nerve cells containing VIP and PHI release the peptides in the perivascular space during periods of activity and thereby contribute to local vasodilatation associated with changes of neuronal function.

Migraine with Aura, Cerebral Ischemia, Spreading Depression, and Compton Scatter

Patients suffering from attacks of migraine with aura (MA) display reduced regional cerebral blood flow (rCBF) during the first hours of the attack,1 followed by a reactive hyperemia.2 It is an open question whether the reduced rCBF causes cerebral ischemia, or whether rCBF and in turn the brains O2 and glucose supply is sufficient to preserve normal energy metabolism and in consequence neuronal function.

Do efficiency scores depend on input mix? A statistical test and empirical illustration

In this paper we examine the possibility of using the standard Kruskal-Wallis (KW) rank test in order to evaluate whether the distribution of efficiency scores resulting from Data Envelopment Analysis (DEA) is independent of the input (or output) mix of the observations. Since the DEA frontier is estimated, many standard assumptions for evaluating the KW test statistic are violated. Therefore, we propose to explore its statistical properties by the use of simulation studies. The simulations are performed conditional on the observed input mixes. The method, unlike existing approaches in the literature, is also applicable when comparing distributions of efficiency scores in more than two groups and does not rely on bootstrapping of, or questionable distributional assumptions about, the efficiency scores. The approach is illustrated using an empirical case of demolition projects. Since the assumption of mix independence is rejected the implication is that it, for example, is impossible to determine whether machine intensive project are more or less efficient than labor intensive projects.

A Method for Comparison of Efficiency Scores: A Case Study of Danish Dairy Farms

This paper suggests the use of a particular parametric test when comparing the efficiency scores resulting from efficiency analysis. As an illustrative case Data Envelopment Analysis (DEA) is run on a set of Danish dairy farm data. Assuming that the efficiency scores resulting from DEA are right censored log-normally distributed, the influence of potential external factors affecting the efficiency can be investigated. It is found that efficiency increases with size and more surprisingly, that farms with jersey cows tend to be more efficient than non-jersey farms.

Introducing and modeling inefficiency contributions

Whilst Data Envelopment Analysis (DEA) is the most commonly used non-parametric benchmarking approach, the interpretation and application of DEA results can be limited by the fact that radial improvement potentials are identified across variables. In contrast, Multi-directional Efficiency Analysis (MEA) facilitates analysis of the nature and structure of the inefficiencies estimated relative to variable-specific improvement potentials. This paper introduces a novel method for utilizing the additional information available in MEA. The distinguishing feature of our proposed method is that it enables analysis of differences in inefficiency patterns between subgroups. Identifying differences, in terms of which variables the inefficiency is mainly located on, can provide management or regulators with important insights. The patterns within the inefficiencies are represented by so-called inefficiency contributions, which are defined as the relative contributions from specific variables to the overall levels of inefficiencies. A statistical model for distinguishing the inefficiency contributions between subgroups is proposed and the method is illustrated on a data set on Chinese banks.