Analysis of participation in the federally mandated coal workers' health surveillance program

The Federal Coal Mine Health and Safety Act of 1969 required that periodic chest radiographs be offered to underground coal miners to protect the miners from the development of Coal Workers' Pneumoconiosis (CWP) and progression of the disease to progressive massive fibrosis (PMF). These examinations are administered by the National Institute for Occupational Safety and Health (NIOSH) through the Coal Workers' Health Surveillance Program (CWHSP). The mine operator is required to provide each miner with the opportunity to have the chest radiograph at no cost to the miner.^ Three rounds of examinations have been conducted since 1969 and the fourth is underway. The decrease in participation over rounds is of great concern if the incidence and progression of CWP are to be understood and controlled.^ This study developed rates of participation for each of 558 West Virginia underground coal mines who submitted or had NIOSH assigned plans for making chest radiographs available during the third round, July 1978 through December 1980. These rates were analyzed in relation to desired levels of participation and to reinforcing, predisposing and enabling factors presumed to affect rates of participation in disease prevention and surveillance programs.^ Two reinforcing factors, size of mine and inclusion of the mine in the National Coal Study (NCS) epidemiology research program, and the enabling factor, use of an on-site radiograph facility, demonstrated highly significant relationships to participation rates.^ The major findings of the study were: (1) Participation in the CWHSP is even lower than previously estimated; (2) CWHSP program evaluation is not systematic and program data base is not complete and comprehensive; and (3) NIOSH program policy is not clear and administration of the CWHSP is fragmented and lacks adequate fiscal and personnel resources. ^

Determinants of participation in worksite health risk appraisal (HRA) programs

The purpose of this study was to apply the Behavioral Model of Health Services Utilization to examine an existing worksite HRA program to identify and examine the roles of determinants of participation in HRA programs. The program consisted of three activities: questionnaire, physical examination, and group interpretation sessions. All of the 1821 employees were eligible for the program; 523 (29%) participated in at least one activity. Results from bivariate analyses suggest that being female, being white, having fewer dependents, and having higher medical claims for the past year were positively associated with participation. Results of logistic regression suggest that Age, Sex, Race, Marital, Number of Dependents, Job Title, Months with the Company, and a log transformed value of Employee's Total Medical Claims were all significant determinants of participation. Applications of the logistic regression models, other factors that should be investigated in future studies, and the limitations of the study were discussed. ^

Organizational perspectives on the management and evaluation of large -scale multicenter controlled clinical trials: An exploratory study of participation in the beta -blocker heart attack trial

A review of literature related to appointment-keeping served as the basis for the development of an organizational paradigm for the study of appointment-keeping in the Beta-blocker Heart Attack Trial (BHAT). Features of the organizational environment, demographic characteristics of BHAT enrollees, organizational structure and processes and previous organizational performance variables were measured so as to provide exploratory information relating to the appointment-keeping behavior of 3,837 participants enrolled at thirty-two Clinical Centers. Results suggest that the social context of individual behavior is an important consideration for the understanding of patient compliance. In particular, the degree to which previous organizational performance--as measured by obtaining recruitment goals--and the ability to utilize resources had particularly strong bivariate associations with appointment-keeping. Implications for future theory development, research and practical implications were provided as was a suggestion for the development of multidisciplinary research efforts conducted within the context of Centers for the study and application of adherence behaviors. ^

Evaluation of the attack rates and level of damages by the fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae), affecting corn-crops in the northeast of Argentina

The fall armyworm (FAW) is the most important threat to corn crops in Argentina, and there exists very little up-to-date information on its actual pest status because the available literature was published more than 20 years ago. Therefore, field surveys were carried out in the northeast of Argentina, in order to establish the attack rates and injury levels of the pest in relation to the crop phenology. The study was carried out at two localities: Colonia Benítez, an agricultural region, and Tapenagá, a cattle-raising area. At each site two 1-ha plots were sown either with a Bt-corn expressing Cry 1F protein or with an untransformed corn germplasm. Optimal and late sowing was assayed and FAW larval abundance, relative age composition, attack rates and level of damage to corn were recorded. At the moment of the field experiments, Bt-corn was not affected by FAW larvae. However, untransformed germplasms were severely affected by FAW larvae, with an average of attacked plants of 18% or more. In contrast to data obtained 30 years ago, higher values of FAW density were registered. Levels of damage to corn plants were higher after the V4 stage. It was found that the sowing date affected the infestation levels and early seeding avoided high armyworm densities that develop later in the season; in northern Argentina, this was only relevant in agricultural areas.

Neutrality in the choice of number of firms or level of fixed costs in calibrating an Armington-Krugman-Melitz encompassing module for applied general equilibrium models

This paper shows how an Armington-Krugman-Melitz encompassing module based on Dixon and Rimmer (2012) can be calibrated, and clarifies the choice of initial levels for two kinds of number of firms, or parameter values for two kinds of fixed costs, that enter a Melitz-type specification can be set freely to any preferred value, just as the cases we derive quantities from given value data assuming some of the initial prices to be unity. In consequence, only one kind of additional information, which is on the shape parameter related to productivity, just is required in order to incorporate Melitz-type monopolistic competition and heterogeneous firms into a standard applied general equilibrium model. To be a Krugman-type, nothing is needed. This enables model builders in applied economics to fully enjoy the featured properties of the theoretical models invented by Krugman (1980) and Melitz (2003) in practical policy simulations at low cost.