A Bayesian approach to stochastic cost-effectiveness analysis

The aim of this paper is to discuss the use of Bayesian methods in cost-effectiveness analysis (CEA) and the common ground between Bayesian and traditional frequentist approaches. A further aim is to explore the use of the net benefit statistic and its advantages over the incremental cost-effectiveness ratio (ICER) statistic. In particular, the use of cost-effectiveness acceptability curves is examined as a device for presenting the implications of uncertainty in a CEA to decision makers. Although it is argued that the interpretation of such curves as the probability that an intervention is cost-effective given the data requires a Bayesian approach, this should generate no misgivings for the frequentist. Furthermore, cost-effectiveness acceptability curves estimated using the net benefit statistic are exactly equivalent to those estimated from an appropriate analysis of ICERs on the cost-effectiveness plane. The principles examined in this paper are illustrated by application to the cost-effectiveness of blood pressure control in the U.K. Prospective Diabetes Study (UKPDS 40). Due to a lack of good-quality prior information on the cost and effectiveness of blood pressure control in diabetes, a Bayesian analysis assuming an uninformative prior is argued to be most appropriate. This generates exactly the same cost-effectiveness results as a standard frequentist analysis

Laboratory Procedure for Measuring the Effectiveness of Dust Control Palliatives

Creation of fugitive dust on unpaved roads results in the loss of up to 25 mm (one inch) of surface aggregate annually (FHWA, 1998). On these roads, shearing forces created by vehicles dislodge the fine aggregate fraction (silt and clay) that binds the coarse aggregate. Turbulent airflow created by vehicles loft these fine particles in plumes of fugitive dust that impact health, safety, and quality of life. The loss of these particles results in raveling of the road surface, culminating in large annual losses of surface aggregate. Chemical dust control (palliatives) is an attractive option. However, there are currently no accepted field or laboratory performance testing procedures for chemical road dust palliatives. The lack of a method to predict palliative performance forces engineers and road managers into a trial-and-error methodology or reliance on personal judgment and supplier claims to determine what will work best on their unpaved road or runway surfaces. The overall objective of this research was to finalize the development of a laboratory test procedure for evaluating different dust control formulations and application rates required to effectively control the airborne suspension of dust particles in the size range (aerodynamic diameter) of 10 μm or less.Pacific Northwest Transportation Consortiu

Effectiveness of blood pressure control in a small community

The aim of this study was to examine the degree of control of blood pressure with respect to individuals on anti-hypertensive drug therapy attending a Health Centre for repeat prescription. Despite their being on anti-hypertensive drug therapy, only 35% of the individuals were found to be normotensive, 27% were in the borderline range whereas 38% were found to be hypertensive. The relatively high prevalence of poorly controlled patients suffering from high blood pressure is partly a reflection of the degree of non-compliance by patients to prescribed drug regimens although this is difficult to either qualify or quantify. Education of the patient vis-à-vis his medical condition and its treatment is of great importance as is regular monitoring and effective control of raised blood pressure by the family physician.peer-reviewe

PROBABILISTIC COST EFFECTIVENESS IN AGRICULTURAL NONPOINT POLLUTION CONTROL

Conceptual weaknesses in the use of costs of average abatement as a measure of the cost effectiveness of agricultural nonpoint pollution control are examined. A probabilistic alternative is developed. The focus is on methods for evaluating whole-farm pollution control plans rather than individual practices. As a consequence, the analysis is presented in a chance-constrained activity analysis framework because activity procedures are a practical and well developed device for screening farm planes. Reliability of control is shown to be as important as reduction targets in designing farm plans for pollution control. Furthermore, broad-axe prescriptions of technology in the form of Best Management Practices may perform poorly with respect to cost effectiveness.Environmental Economics and Policy,

An in-flight simulation of lateral control nonlinearities

An in-flight simulation program was conducted to explore, in a generalized way, the influence of spoiler-type roll-control nonlinearities on handling qualities. The roll responses studied typically featured a dead zone or very small effectiveness for small control inputs, a very high effectiveness for mid-range deflections, and low effectiveness again for large inputs. A linear force gradient with no detectable breakout force was provided. Given otherwise good handling characteristics, it was found that moderate nonlinearities of the types tested might yield acceptable roll control, but the best level of handling qualities is obtained with linear, aileron-like control

Competition, non-financial measures and the effectiveness of management control system

This paper reports the results of an empirical study examining the relationship between the emphasis on non-financial measures and two other variables; the intensity of competition and the effectiveness of a management control system, in a manufacturing company. Two important issues focused in the study are: does competition compel managers to utilize more non-financial measures in decision making and is the emphasis given to non-financial measures worthwhile? Data from 105 manufacturing companies throughout Malaysia were analyzed using correlation and regression analysis. The results of both analyses indicate that the emphasis given to non-financial measures in decision making has a positive correlation with the effectiveness of a management control system and secondly, the intensity of competition faced by an organization is positively correlated with the emphasis on non-financial indicators. Descriptive analysis was also performed to evaluate the distribution of emphasis on non-financial measures by the age, location, ownership, size of an organization and its industry