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Biomedical subjects

P Harber

Publications and source records attributed to P Harber.

At least 19 recordsLinked to original sources

Longitudinal analyses of chest radiographs from the European Carbon Black Respiratory Morbidity Study.

High levels of exposure to carbon black have been linked with an increased prevalence of chest radiograph abnormalities. However, it is unclear to what extent current levels of exposure in the carbon black manufacturing industry are associated with new cases of and progression in small opacities. Longitudinal analyses were carried out on data from workers in the European carbon black manufacturing industry who provided three full-size chest radiographs sequentially between 1987-1995. All chest radiographs were independently read by three experienced readers according to the International Labour Organisation (ILO) classification. After exclusion of participants with previous lung diseases or injuries, females, unreadable chest radiographs and from factories with a low participation rate, data from 675 workers were available for the longitudinal analyses. An association was observed between cumulative carbon black exposure and new cases of chest radiograph abnormalities (ILO category > or = 1/0) and progression in small opacities. These associations were mainly related to changes in chest radiographs from workers at one factory. A large percentage of workers with chest radiograph abnormalities reversed to normal chest films; however, after adjusting for other factors, this was not associated with levels of exposure to carbon black dust. In conclusion, the results show that exposure to carbon black is associated with increased risk of chest radiographic abnormalities, which may be reversible after reduction or cessation of exposure.

Administration, Inhalation↗

Time and knowledge barriers to recognizing occupational disease.

Traditionally, inadequate training has been considered the major barrier to recognition of occupational disease. A survey of 136 practitioners was conducted to determine which barriers were actually considered most relevant. The sample included three subgroups: primary care, occupational medicine-oriented, and Mexican. Four aggregate indices were derived: Knowledge, Time, Unpleasant aspects, and Importance. Inadequate Time was as important as inadequate Knowledge, whereas perceived lack of Importance and Unpleasant aspects were less relevant. Patterns among the subgroups were generally comparable. This study implies that training more occupational medicine specialists in increasing recognition is not sufficient unless specific strategies to overcome time constraints are also implemented. For example, emphasizing a "complete occupational history" may be counterproductive. Limiting histories to selected patients; use of focused, brief histories; and, perhaps, computer-based methods are needed.

Attitude of Health Personnel↗

Frequency of occupational health concerns in general clinics.

Studies have suggested that occupational disease and injury are under-recognized by clinicians. To estimate the frequency of occupational factors in disease and injury, 108 patients in a general (not occupational) health care facility were interviewed about the frequency and types of workplace-health interactions. Thirty-nine percent reported possible causation by work, and 66% reported a possible increase in symptoms by work, even if not caused by work. Twenty-seven percent reported changing jobs and/or tasks because of work-health interactions. The majority of men and women reported that worksite changes could improve their functional ability at work. This study therefore indicates that (1) occupational health concerns are common in primary care clinics, even if not addressed by clinicians; (2) the definition of occupational health concerns should be broadened to include disease caused by work, disease symptoms worsened by work, and the need for occupational accommodation even if the disease itself is not caused by work; and (3) inquiring about patient concerns about workplace-health interactions can provide clinicians with significant opportunities for primary, secondary, and tertiary prevention.

Accidents, Occupational↗

Intelligent database generated occupational questionnaire system.

Obtaining an adequate occupational history requires special expertise to "ask the right questions" that are relevant to a particular patient's specific health conditions and potential exposures. This article describes a way to systematically accomplish this by means of a computer system that can overcome limited availability of necessary clinical occupational health expertise. The Intelligent Questionnaire system is a computer-based system for generating case-specific questionnaires about the influence of work on respiratory disease. Intelligent Questionnaire includes three databases: Questions, Responses, and Calls (clues to identify questions). The Questionnaire also arranges questions in a logical manner and provides a customized data entry screen for each subject. This approach provides primary practitioners with expertise on a case-by-case basis. It also facilitates occupational health surveillance because it allows acquiring detailed case-specific information in a systematic fashion. A computer-based system can facilitate obtaining occupational histories with high specificity and consistency without depending on general availability of a human occupational health clinical expertise.

Artificial Intelligence↗

Decision model for optimizing respirator protection.

Respirators are widely used for protection against inhaled toxins. The emphasis of research and implementation effort has evolved through several stages: the respirator device itself, use situation, respirator program factors under employer control, individual worker factors not under employer control, and occupational health systems. For this study, a computer-simulation decision assistance model was developed to assess the impact of various factors on the number of workers receiving adequate protection. Factors include the respirator protection factor, identification of sites needing respirator protection, selection of proper device, availability when needed, frequency of ever use, regularity of use among users, and variability in personal susceptibility or other factors. This analysis demonstrates that for both moderate-risk and high-risk (i.e., IDLH, immediately dangerous to life and health) exposures under current circumstances, the actual protection afforded depends upon the optimization of program factors and detection of atypical outlier persons and worksites. Therefore, programs and research must focus on these areas. Occupational medicine specialists should help optimize these areas and, in addition, use each case of respiratory protection failure as an index case to improve the overall programs.

Computer Simulation↗

Hypersensitivity pneumonitis from Pezizia domiciliana. A case of El Niño lung.

A previously healthy woman developed severe dyspnea and was found to have restrictive lung disease and evidence of alveolitis. Open lung biopsy revealed extrinsic allergic alveolitis (hypersensitivity pneumonitis). The etiology was not initially apparent, but a home inspection showed an unusual mushroom growing in the patient's basement. Air sampling and serum precipitins against the fungal antigens confirmed that Pezizia domiciliana was the cause of the patient's hypersensitivity pneumonitis. This is the first described case of hypersensitivity pneumonitis cause by P. domiciliana. We speculate that unprecedented rainfall and flooding of the patient's basement as a result of El Niño rains produced ideal factors for the growth of this fungus.

Alveolitis, Extrinsic Allergic↗

Radiographic and spirometric findings in diatomaceous earth workers.

Diatomaceous earth is a noncrystalline form of silica; in processing, calcining leads to formation of cristobalite, a form of crystalline silica. Four hundred ninety-two currently employed diatomaceous earth workers in a large mine and processing facility had chest radiographs performed and interpreted by the International Labour Office (ILO) system. Two hundred sixty-seven subjects underwent spirometry testing. Exposure indices for total dust (largely diatomaceous earth) and cristobalite were reconstructed for each individual based upon personnel records. Analysis demonstrated the following prevalences of radiographic findings: 5% had ILO scores > or = 1/0, and 25% had scores of 0/1 or higher. Regression analyses showed that there was a relationship between both total cristobalite exposure and total dust (largely diatomaceous earth) exposure and the ILO score. Radiographic patterns are not typical of those of classic silicosis. Linear regression analyses for forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and FEV1/FVC ratio did not demonstrate a relationship between cumulative exposure and lung function. Such analyses were performed using all subjects and stratified by smoking status. There were differences in spirometric data according to radiographic ILO category, but the results were inconsistent and did not permit determining if physiologic changes are associated with radiographic change or if this is due to confounding. Overall, the study suggests that diatomaceous earth pneumoconiosis (radiographically defined) is an entity distinct from silicosis. Recent exposure levels may produce radiographic abnormalities but do not lead to demonstrable physiologic effect. The prevalence of the disorder has diminished markedly in response to modern dust control measures. Ongoing medical surveillance is recommended in workers with potential exposure to significant quantity of material.

Adult↗

Community environmental health concerns and the nursing process. Four environmental health nursing care plans.

1. Many clients have concerns about environmental exposures. 2. Nursing care plans can be adapted to guide practice related to environmental health issues including physiologic, behavioral, emotional concerns, and educational needs. 3. Experience and education in counseling, along with sensitivity to client needs and beliefs, make nurses particularly valuable members of the environmental health team.

Community Health Nursing↗

Study of respirator effect on nasal-oral flow partition.

Factors affecting worker tolerance of respiratory personal protective devices are inadequately understood. This study evaluates whether respirator-type loads affected the switch from nasal to oral breathing. Eleven healthy subjects were studied under progressive exercise conditions, using a respirator full-face mask with inspiratory resistance (I), pressure breathing (P) (10 cm H2O end-expiratory pressure), or no load (N). A rapid-response thermistor was used to determine whether flow was predominantly oral or nasal. Both P and I increased the percentage of time that breathing was predominantly oral. The effect was most pronounced at higher exercise levels. The percentage of mouth breathing appeared to be closely related to the expiratory time. This study suggests that nasal-oral flow partitioning should be considered as a possible determinant of respirator tolerance.

Adult↗

Environmental health response clinics. A survey of program options.

Environmental Health Response Clinics are established in response to concerns about community exposures to hazardous situations (chemical, biological, radiological). They are developed in response to a demand for "clinical services" and operate outside the usual health care financing and delivery mechanisms. Prompted by their experience in California, the authors formed a focus group to identify possible goals and services. A mail survey of occupational-environmental health professionals was then conducted to evaluate the feasibility and priority of representative goals. The analysis suggests that services should focus on the specific hazard of concern and that communication and education are essential components. The tendency to "do a general physical examination" should be eschewed. Ratings for priority and feasibility were disparate for several possible goals. In some instances, a "hands-on examination" may not be the best use of resources. Environmental health professionals may serve by direct clinical service or by advising community-based practitioners. Providing routine clinical services alone cannot meet the expectations for an environmental health response clinic.

California↗

Chest radiography in Portland cement workers.

To investigate the prevalence of pneumoconiosis in Portland cement workers, a controlled cross-sectional survey was conducted. Chest radiographs of approximately 2640 Portland cement workers showed prevalence rates of about 1% for rounded and for irregular small opacities and about 2% for pleural abnormalities. After age and smoking adjustment, the overall prevalences were still significantly elevated over controls, but when examined separately by smoking status, the significant increases were confined to smokers. Although statistically significant, the prevalences were only elevated about 1% in cement workers, compared with controls. A statistically significant relationship with exposure was found for pleural abnormalities but not for rounded or irregular small opacities. Thus a weak association exists between pulmonary radiographic abnormalities and employment in US Portland cement plants, and there appears to be a dose-response relationship between exposure and pleural abnormalities.

Adult↗

An "atomic" approach to dis/ability assessment.

Disability assessment is a complex process that requires consideration of both work demands and clinical conditions. It is commonly practiced in two very distinct fashions. First, poorly specified processes are used to reach decisions about highly specific situations; second, broad generalizations are often applied, which may be poorly applicable to specific situations. A new approach allows the integration of these two methods. The "atomic" approach has two phases: "disaggregation" into the smallest possible meaningful knowledge units (atoms) and then "reintegration" (reassembly). Individual information units may be applicable to a wide variety of different situations, providing an efficient system. The atomic approach includes two tracks that merge to produce the dis/ability assessment: Clinical track (diagnosis-->confirmation test; diagnosis-->impact assessment test-->test result-->physiologic/anatomic limitation; and the job demand track (job-->task-->sub task-->functional work demand index-->empiric data). The approach describe offers advantages of rationality, empiric and face validity, and efficiency. The logic is fully explicable, and most information units (atoms) can be used in many ways to cover new situations. It is applicable to both individual case situations and to large-scale system development.

Disability Evaluation↗

Medical causation analysis heuristics.

Medical causation analysis determines whether or not a specific patient's illness is the result of a work site or an environmental exposure. In the past, this has been conducted implicitly with little analysis of the process per se. Our review suggests that there are several distinct heuristics that may be utilized; these include probability-based models, application of group-based data (epidemiology) to individuals, Bayesian analysis, a priori assumptions about which conclusions are better, and others. Some methods consider only work causes, whereas others explicitly consider alternative explanations. There are considerable differences among the methods in process, outcome, and fundamental assumptions. Formal assessment of the medical causation analysis process can provide insight and may ultimately lead to its standardization and improvement.

Causality↗

An expert system based preventive medicine examination adviser.

Periodic preventive medicine examinations generally rely on a standardized approach. In addition, they are often performed by physicians with only limited training in preventive medicine. Evaluation of a corporate-based program led to the prototype development of an artificial intelligence (AI)-based expert system to collect information from employees and make very specific recommendations for primary practitioners. Unique features include the customizing of questions for each subject and the selection of information to be acquired, both based on answers to previous questions. Recommendations are highly person specific and fall into four categories: laboratory testing, primary physician testing, counseling, and referral. The AI approach allows for easy updating of recommendations in order to meet changes in local preventive resources and national recommendations.

Artificial Intelligence↗

Role of chest physicians in detection and treatment of occupational and environmental respiratory disease. A practice survey.

A survey of American College of Chest Physicians (ACCP) members was conducted to determine their degree of involvement in the diagnosis and prevention of occupational and environmental respiratory disease (OERD). Although the response rate was relatively low, the results are likely to be representative. Calculations based on the data estimate that in the prior year, chest physicians on the average saw 15 patients with OERD caused by work, 13 worsened by work, and 28 affected by the home environment. Asthma appears to be a more common occupational or environmental concern than pulmonary fibrosis. Chest physicians clearly perceived a need for more education in OERD. The survey also demonstrated that although many chest physicians perform routine industrial surveillance testing, it is often done without using standardized methods. Furthermore, chest physicians are actively involved with medical/legal aspects of OERD. Overall, the survey documents the role of chest physicians in the area of OERD and emphasizes significant educational needs.

Adult↗

Personal history, training, and worksite as predictors of back pain of nurses.

Back pain among nurses is a common problem. Prior studies of this problem have been based on cross-sectional or retrospective data. This 18-month prospective study involving nurses newly graduated from nursing school investigated personal, worksite, and training factors associated with future risk of back pain. Each nurse underwent a preliminary interview and periodic follow-ups to identify those with back injuries. Contingency tables and logistic regression analyses demonstrated that prior significant back pain episodes (evidenced by previous job changes because of back pain, frequent medication use, etc.) were associated with increased future risk. Training at nursing school or on the job did not have a protective effect. This pilot study therefore suggests factors useful in placement and counseling of new nurses and indicates the need for further implementation of mechanical lift assist device use.

Accidents, Occupational↗