Beyond FEV1 in COPD: a review of patient-reported outcomes and their measurement

Abstract: Patients with chronic obstructive pulmonary disease (COPD) present with a variety of symptoms and pathological consequences. Although primarily viewed as a respiratory disease, COPD has both pulmonary and extrapulmonary effects, which have an impact on many aspects of physical, emotional, and mental well-being. Traditional assessment of COPD relies heavily on measuring lung function, specifically forced expiratory volume in 1 second (FEV1). However, the evidence suggests that FEV1 is a relatively poor correlate of symptoms such as breathlessness and the impact of COPD on daily life. Furthermore, many consequences of the disease, including anxiety and depression and the ability to perform daily activities, can only be described and reported reliably by the patient. Thus, in order to provide a comprehensive view of the effects of interventions in clinical trials, it is essential that spirometry is accompanied by assessments using patient-reported outcome (PRO) instruments. We provide an overview of patient-reported outcome concepts in COPD, such as breathlessness, physical functioning, and health status, and evaluate the tools used for measuring these concepts. Particular attention is given to the newly developed instruments emerging in response to recent regulatory guidelines for the development and use of PROs in clinical trials. We conclude that although data from the development and validation of these new PRO instruments are emerging, to build the body of evidence that supports the use of a new instrument takes many years. Furthermore, new instruments do not necessarily have better discriminative or evaluative properties than older instruments. The development of new PRO tools, however, is crucial, not only to ensure that key COPD concepts are being reliably measured but also that the relevant treatment effects are being captured in clinical trials. In turn, this will help us to understand better the patient's experience of the disease

The effect of cultural orientation and leadership style on self- versus other-oriented organizational citizenship behavior in Turkey and the Netherlands

This paper investigated the effects of a paternalistic and empowering leadership style on organizational citizenship behaviour (OCB) in an experimental design using 100 Turkish and 100 Dutch students who held part-time jobs. Confirming our expectations, a paternalistic leadership style had a more positive effect on job dedication and organizational support in Turkey than in the Netherlands. Contradicting our expectations, an empowering leadership style did not have a more positive effect on any of the OCB dimensions in the Netherlands than it did in Turkey. However, in the Netherlands an empowering leadership style had a stronger effect on interpersonal facilitation, job dedication, and organizational support than a paternalistic leadership style. Paternalistic and empowering leadership styles both had positive effects on OCB dimensions in Turkey. As expected, collectivism moderated the relationship between paternalistic leadership style and other oriented OCB (i.e., interpersonal facilitation). Specifically, people who had more collectivistic tendencies were more positively influenced by a paternalistic leader than people who had low collectivistic tendencies in both countries. However, individualism did not have any moderating effects on the relationship between empowering leadership style and self-oriented OCB (i.e., job dedication). Our findings are relevant for understanding the effects of leadership styles and cultural orientations on self- versus other-oriented OCB in Turkey and the Netherlands

Bulk and Surface Nucleation Processes in Ag2S Conductance Switches

We studied metallic Ag formation inside and on the surface of Ag2S thin films, induced by the electric field created with a STM tip. Two clear regimes were observed: cluster formation on the surface at low bias voltages, and full conductance switching at higher bias voltages (V > 70mV). The bias voltage at which this transition is observed is in agreement with the known threshold voltage for conductance switching at room temperature. We propose a model for the cluster formation at low bias voltage. Scaling of the measured data with the proposed model indicates that the process takes place near steady state, but depends on the STM tip geometry. The growth of the clusters is confirmed by tip retraction measurements and topography scans. This study provides improved understanding of the physical mechanisms that drive conductance switching in solid electrolyte memristive devices.Comment: In press for PR

Controlled formation of metallic nanowires via Au nanoparticle ac trapping

Applying ac voltages, we trapped gold nanoparticles between microfabricated electrodes under well-defined conditions. We demonstrate that the nanoparticles can be controllably fused together to form homogeneous gold nanowires with pre-defined diameters and conductance values. Whereas electromigration is known to form a gap when a dc voltage is applied, this ac technique achieves the opposite, thereby completing the toolkit for the fabrication of nanoscale junctions.Comment: Nanotechnology 18, 235202 (2007

Fracture diagnostics, unnecessary travel and treatment: a comparative study before and after the introduction of teleradiology in a remote general practice

Background Teleradiology entails attainment of x-rays in one location, transfer over some distance and assessment at another location for diagnosis or consultation. This study documents fracture diagnostics, unnecessary trips to the hospital, treatment and number of x-rays for the years 2006 and 2009, before and after the introduction of teleradiology in a general practice on the island of Ameland in the north of the Netherlands. Methods In a retrospective, descriptive, observational before and after study of the introduction of x-ray facilities in an island-based general practice, we compared the number of accurately diagnosed fractures, unnecessary trips, treatments and number of x-rays taken in 2006 when only a hospital x-ray facility was available 5 hours away with those in 2009 after an x-ray facility became available at a local general practice. All patients visiting a general practice on the island of Ameland in 2006 and 2009 with trauma and clinical suspicion of a fracture, dislocation or sprain were included in the study. The initial clinical diagnoses, including those based on the outcomes of x-rays, were compared for the two years and also whether the patients were treated at home or in hospital. Results A total of 316 and 490 patients with trauma visited a general practice in 2006 and 2009, respectively. Of these patients, 66 and 116 were found to have fractures or dislocations in the two years, respectively. In 2006, 83 x-rays were ordered; in 2009, this was 284. In 2006, 9 fractures were missed; in 2009, this was only 2. In 2006, 15 patients with fractures or dislocations were treated at the general practice; in 2009, this had increased to 77. Conclusion Since the introduction of teleradiology the number of missed fractures in patients visiting the general practice with trauma and the number of the unnecessary trips to a hospital are reduced. In addition more patients with fractures and dislocations can be treated in the general practice as opposed to the hospital

Relationship between guideline treatment and health-related quality of life in asthma

The aim of this study was to compare the health-related quality of life (HRQL) of asthma patients treated according to the 1997 National Institute of Health (NIH) international asthma guideline and that of asthmatics receiving non-guideline treatment. The suitability of 146 asthmatics' medication regimes was determined according to the 1997 NIH asthma guideline. Quality of life was assessed on a seven-point scale using the Asthma Quality of Life questionnaire. Just over half of the patients were not currently using the treatment considered necessary for controlling their asthma. Patients treated according to the guideline (n=72) had a significantly higher overall HRQL than patients with non-guideline treatment (5.7 versus 5.3). The differences were also significant for the subscales measuring symptoms and environmental exposure, but not for activities or emotional function. An association between non-guideline treatment and a poorer health-related quality of life in asthma patients treated in general practice was observed. This study supports the role of evidence-based guidelines in daily practice. Further studies are needed to determine if guideline treatment is responsible for the increase in health-related quality of life observed in this work