Determination of the anaerobic threshold in the pre-operative assessment clinic: inter-observer measurement error.

The variability between observers in the interpretation of cardiopulmonary exercise tests may impact upon clinical decision making and affect the risk stratification and peri-operative management of a patient. The purpose of this study was to quantify the inter-reader variability in the determination of the anaerobic threshold (V-slope method). A series of 21 cardiopulmonary exercise tests from patients attending a surgical pre-operative assessment clinic were read independently by nine experienced clinicians regularly involved in clinical decision making. The grand mean for the anaerobic threshold was 10.5 ml O(2).kg body mass(-1).min(-1). The technical error of measurement was 8.1% (circa 0.9 ml.kg(-1).min(-1); 90% confidence interval, 7.4-8.9%). The mean absolute difference between readers was 4.5% with a typical random error of 6.5% (6.0-7.2%). We conclude that the inter-observer variability for experienced clinicians determining the anaerobic threshold from cardiopulmonary exercise tests is acceptable.

Globalization, diet, and health: an example from Tonga.

The increased flow of goods, people, and ideas associated with globalization have contributed to an increase in noncommunicable diseases in much of the world. One response has been to encourage lifestyle changes with educational programmes, thus controlling the lifestyle-related disease. Key assumptions with this approach are that people's food preferences are linked to their consumption patterns, and that consumption patterns can be transformed through educational initiatives. To investigate these assumptions, and policies that derive from it, we undertook a broad-based survey of food-related issues in the Kingdom of Tonga using a questionnaire. Data on the relationships between food preferences, perception of nutritional value, and frequency of consumption were gathered for both traditional and imported foods. The results show that the consumption of health-compromising imported foods was unrelated either to food preferences or to perceptions of nutritional value, and suggests that diet-related diseases may not be amenable to interventions based on education campaigns. Given recent initiatives towards trade liberalization and the creation of the World Trade Organization, tariffs or import bans may not serve as alternative measures to control consumption. This presents significant challenges to health policy-makers serving economically marginal populations and suggests that some population health concerns cannot be adequately addressed without awareness of the effects of global trade.

Empirically supported ethical research practice: the costs and benefits of research from the participants' view.

Researchers and institutional review boards are routinely called upon to evaluate the cost-benefit status of proposed research protocols that involve human participants. Often these assessments are based on subjective judgments in the absence of empirical data. This reliance on subjective judgments is of particular concern for studies involving clinical samples where unfounded assumptions may adversely affect research progress or clinical outcomes. The Reactions to Research Participation Questionnaire (RRPQ) was designed to address this shortcoming and to help promote ethical decision making about research practice. The present study describes development of the RRPQ and presents a series of exploratory and confirmatory analyses investigating its structure. Based on these findings, a revised version of the instrument and suggestions for future research are presented. This approach provides a foundation for scientifically informed protection of human subjects.

The radial artery as a bypass graft.

The radial artery is being reintroduced into clinical practice to increase the number of arterial grafts for patients undergoing coronary artery bypass surgery. The radial artery is readily available from one or both forearms and removal is safe in patients who have a normal collateral circulation to the hand. Harvesting the radial artery with the adjacent veins using a minimal touch technique and vasodilators will prevent vasospasm and possibly early occlusion. A concern is that subclinical atheroma is present in many patients. The radial artery can be used as a single graft, anastomosed in a "Y" fashion with the internal mammary artery, or used as a sequential graft. The early mortality and complications are low. There are potential cost savings because the need for an incision in the leg is avoided, so that patients may be discharged early. The early results of radial artery grafting are encouraging. Further follow-up is required to determine the late patency and effects on survival of using the radial artery graft.

Understanding the provision of postretirement health care and pension benefits: which firm characteristics are most explanatory?

This article investigates the impact of firm work force characteristics, human resource practices, and external environmental attributes upon the likelihood that a company provides postretirement income and health care benefits. Using data from a national stratified random sample of 953 companies with 20 or more employees, logistic regression models were estimated to explore the impact of these three sets of variables on benefit provision. Results indicate that work force characteristics and human resources practices contribute considerably to the likelihood that these benefits are provided and that the impact of some of the more global characteristics, such as industry, diminishes in a fuller predictive model.

Coughing frequency in patients with persistent cough: assessment using a 24 hour ambulatory recorder.

Cough is an important symptom of many respiratory disorders. We determined the frequency and diurnal variation of cough in normal subjects and in patients with asthma or with persistent cough of unknown cause. We used a portable, solid-state, multiple-channel recorder to record cough sounds over a 24 h period. The audio-signal was recorded from a unidirectional microphone strapped over the chest wall, and electromyographic (EMG) signals from the lower respiratory muscles were simultaneously registered with surface electrodes. The recorded digital data were examined on an IBM-compatible computer, and the typical signals induced by cough (as assessed by voluntary or experimentally-induced cough) were counted. In 12 normal subjects, only 0-16 coughs were recorded over 24 h. In 21 stable asthmatics with a history of chronic cough ("asthma") the median number was 282 (ranges: 45-1,577), and in 14 patients with the predominant symptom of daily dry coughs ("chronic coughers") the median number was 794 (64-3,639). In both groups of patients, there was a diurnal variation of coughs, such that the least numbers occurred between 2 and 5 a.m. (< 3% of total). In the asthma group, there was no significant correlation between forced expiratory volume in one second (FEV1) (% predicted) or diurnal variation of peak expiratory flow and cough frequency. In the chronic coughers, there was a significant correlation between daytime cough numbers and daytime cough symptoms scores but not for the night-time values. Our data show that cough frequency is not determined by the severity of asthma in relatively stable asthmatics on inhaled steroids, and is reduced during sleep in both asthmatics and chronic cough patients. This portable cough recorder may be useful in the assessment of drug therapy for chronic cough.

A clinical assessment of fluorescence polarisation changes in lymphocytes stimulated by phytohaemagglutinin (PHA) in malignant and benign diseases.

The modified double-zone SCM technique, developed in these laboratories as an in vitro test for cancer, is based on the differential response to PHA of lymphocytes harvested from two regions of a Ficoll-Triosil gradient. Lymphocyte responses are measured by changes in intracellular fluorescein fluorescence polarisation. We report its continued clinical evaluation in patients hospitalised with malignant and non-malignant diseases, including a blind trial of 78 patients with disorders of the gastrointestinal tract, breast and lung. Overall "false' negative and "false' positive rates from 336 blood samples were 1.8 and 3.3% respectively.