Gradual versus continuous increase of load in ergometric tests: are the results comparable?

Standard exercise testing (ET) comprises progressive exercise provocation with cardiovascular monitoring. Exercise tolerance is estimated by workload. Cardiopulmonary exercise testing (CPX) is a non-invasive measurement of ventilatory gas exchange which provides more accurate quantifications of cardiorespiratory fitness (CRF). Workload is usually increased stepwise in ET and continuously (ramp) in CPX. Our aim was to examine the comparability of the results. Thirty two healthy volunteers (17 females/15 males, age 26.8±6.1 years, BMI 24.5±3.0) underwent exercise testing on a bicycle ergometer up to maximum physical exhaustion; under ramp protocol (CPX) and 2-7 days later with a stepwise increase of workload (ET). We compared the physical work capacity under both methods at maximum workload, at heart rate of 150 and 170 beats/min (PWC150 and PWC170), and the exercise duration. We found that there were no statistically significant differences in the maximum heart rate (CPX: 177.1±11.7/min vs. ET: 178.5±11.2/min) or maximal workload (CPX: 219.8±50.6 vs. ET: 209.4±42.5). PWC150 and PWC150/kg were higher with CPX than those with ET (156.6±51 vs. 146.4±42.3, p<0.001 and 2.1±0.5 vs. 1.9±0.4, respectively, p<0.001). Exercise duration was almost equal (12.1 vs. 11.3 min). We conclude that overall physical performance was higher with CPX. Since the results are similar, we recommend the CPX: wattage and other parameters in performance assessment are to be determined directly, interpolations are obsolete.

[Do advers health effects of chrysotile and amphibole asbestos differ?]. / Gibt es Unterschiede in den gesundheitsschädlichen Wirkungen von Chrysotil- und Amphibol-Asbest?

Due to the current query whether the predominantly used chrysotile (white) asbestos comprises health risks we performed a literature search including in vitro and animal experiments as well as epidemiological studies.As shown by epidemiological studies chrysotile causes less pleural fibrosis and mesotheliomas when compared with other asbestos types. However, its otherwise inflammatory, toxic, carcinogenic, and fibrosis-inducing effects correspond to those of other occupationally relevant asbestos types. This is based on clinical, animal as well as on in-vitro findings. This means that denying a causal relationship, e. g. in a case with lung fibrosis (= asbestosis) or lung cancer with an asbestos load of 25 fiber-years in the absence of identification of a significant concentration of asbestos fibers or asbestos bodies in the lung (see so-called "hit and run" phenomenon), contradicts the medical-scientific knowledge.

[Do primary care physicians acting as gatekeepers really improve health outcomes and decrease costs? A systematic review of the concept gatekeeping]. / Macht der Hausarzt als Lotse die Gesundheitsversorgung wirklich besser und billiger? Ein systematischer Review zum Konzept Gatekeeping.

AIM: The aim of this systematic review was to analyse the effects of gatekeeping where primary care physicians (PCP) control access to specialist care. METHODS: Literature search in Medline, EMBASE, Cochrane Library, and a hand search were carried out. INCLUSION CRITERIA: (1) intervention: gatekeeping by PCP compared to free access to specialist care; (2) outcomes: health outcomes, health related quality of life, quality of care, utilization of care, costs, satisfaction of patients and providers; (3) design: RCT, quasi-random. CT, CBA, cohort and case control studies, ITS. Data extraction and assessment was done by two independent reviewers according to Cochrane EPOC-Group and USTFCPS. RESULTS: 24 included studies (1989-2007) were as follows: 1 RCT, 2 quasi-randomised CT, 3 prospective, and 12 retrospective cohort studies, 4 CBA, and 2 ITS. 67% of the studies analysed data from the USA, the remaining from CH, UK, DK and NL. Studies had relevant limitations concerning the quality of execution and publication. Overall 13 of 24 studies reported a positive and two a negative effect of gatekeeping compared to open access models; nine showed no differences. The results varied according to outcome parameters. CONCLUSIONS: International evidence on effects of gatekeeping is limited by the low internal validity of studies and applicability to other contexts. It suggests that gatekeeping by PCP decreases utilization of specialist care and health care costs. Based on very few studies health outcomes and patient quality of life in gatekeeping models might be comparable with those in open access models. Evidence is inconsistent or not available concerning the quality of care, patient or provider satisfaction.

What do community-based dengue control programmes achieve? A systematic review of published evaluations.

Owing to increased epidemic activity and difficulties in controlling the insect vector, dengue has become a major public health problem in many parts of the tropics. The objective of this review is to analyse evidence regarding the achievements of community-based dengue control programmes. Medline, EMBASE, WHOLIS and the Cochrane Database of Systematic Reviews were searched (all to March 2005) to identify potentially relevant articles using keywords such as 'Aedes', 'dengue', 'breeding habits', 'housing' and 'community intervention'. According to the evaluation criteria recommended by the Cochrane Effective Practice and Organisation of Care Review Group, only studies that met the inclusion criteria of randomised controlled trials (RCT), controlled clinical trials (CCT), controlled before and after trials (CBA) or interrupted time series (ITS) were included. Eleven of 1091 studies met the inclusion criteria. Of these, two were RCTs, six were CBAs and three were ITS. The selected studies varied widely with respect to target groups, intervention procedures and outcome measurements. Six studies combined community participation programmes with dengue control tools. Methodological weaknesses were found in all studies: only two papers reported confidence intervals (95% CI); five studies reported P-values; two studies recognised the importance of water container productivity as a measure for vector density; in no study was cluster randomisation attempted; and in no study were costs and sustainability assessed. Evidence that community-based dengue control programmes alone and in combination with other control activities can enhance the effectiveness of dengue control programmes is weak.

Defining the "Health Benefit Basket" in nine European countries. Evidence from the European Union Health BASKET Project.

This article identifies and analyses a framework for "health baskets," the taxonomy of benefit catalogues for curative services, and the criteria for the in- or exclusion of benefits in nine EU member states (Denmark, England, France, Germany, Hungary, Italy, The Netherlands, Poland and Spain). Focusing on services of curative care, it is found that the explicitness of benefit catalogues varies largely between the countries. In the absence of explicitly defined benefit catalogues, in- and outpatient remuneration schemes have the character of benefit catalogues. The criteria for the in- or exclusion into benefit catalogues are often not transparent and (cost-)effectiveness is applied only for certain sectors. An EU-wide harmonization of benefit baskets does not seem realistic in the short or medium term as the variation in criteria and the taxonomies of benefit catalogues are large but not insurmountable. There may be scope for a European core basket.

[When is expensive pharmacotherapy good value for the money?]. / Wann ist eine teure Arzneimitteltherapie preiswert?

Expensive drugs are good value for money if they are effective and safe, and if they have a better cost-effectiveness ratio than the standard therapy. In this article, an overview of commonly used methods, sources and functions of health economic evaluation is presented and illustrated using clinical examples to facilitate interpretation of the health economic information.