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Biomedical subjects

A C Chovil

Publications and source records attributed to A C Chovil.

9 recordsLinked to original sources
PubMed1989

Ultrasonic measurement of lumbar canal diameter: a screening tool for low back disorders?

Preventive screening measures for low back pain are limited. Despite considerable evidence that anatomic narrowing of the lumbar spinal canal is a risk factor for specific back problems, difficulty in measuring the canal without unacceptable radiation exposure, cost, or discomfort has limited the assessment of its clinical significance. Using ultrasound to measure the lumbar canal is relatively easy to do, and provides accurate values. In this paper we review the reports on this use of ultrasound, including our own experience in a case control study, and discuss the potential use of ultrasonic measurement as a screening tool to identify narrow lumbar canals.

Back Pain↗
PubMed1988

Ultrasound lumbar canal measurement in hospital employees with back pain.

The oblique parasagittal diameter of the lumbar spinal canal at the L5-S1 level was measured in 49 employees of the Wm Jennings Bryan Dorn Veterans' Hospital using real time ultrasound in a case-control study. Individuals with a canal diameter of less than 14 mm represented the lowest 10th percentile in this population and being in the narrowest 10th percentile constituted a risk factor for time missed from work because of low back pain (odds ratio 10.7). Whereas numbers in this pilot study are small, results are consistent with earlier ultrasound studies done in the United Kingdom and with other research showing increased morbidity from low back pain in individuals with small lumbar canals. Ultrasound has advantages over other modalities for measuring the size of the lumbar canal and may be useful as a preplacement screening examination in industry.

Adult↗
PubMed1987

Calculating expected deaths: a comparison of two methods.

A comparison is presented between the traditional "person-years" and more recently described "prospective model" methods for calculating mortality expectations. Problems arising from the fact that expectations under the person-years method are calculated on the basis that a null hypothesis is true, which results in artificial figures that, at least theoretically, are meaningless if the hypothesis is rejected, are discussed. Data are presented from two studies in which expectations have been calculated both ways, showing important differences between the two methods with an exaggeration of the expectation when the study group has an above normal mortality experience. It is suggested that the person-years methodology should be replaced by that of the prospective model.

Actuarial Analysis↗
PubMed1982

Identifying the cause of ischemic heart disease/myocardial infarction syndrome: a new approach.

Risk factor identification in the coronary heart disease/ myocardial infarction syndrome has failed to account for the epidemic pattern of increase in this century with recent decline. It is hypothesized that the true cause remains unidentified and that innovative application of traditional epidemiologic techniques, to correlate the identifiable peaks in different regions with possible agents, may prove successful.

Coronary Disease↗
PubMed1981

Occupational cancer: experience in Ontario.

This paper reviews the experience of the Workmen's Compensation Board of Ontario in identifying cases of cancer that could be attributed to occupational hazards. Worker's claims for compensation are allowed if there is reasonable medical evidence that their cancer was caused by exposure to risk factors associated with their occupation. Details of the types of cancer associated with specific carcinogens or fields of employment are discussed. About 50% of the cases were related to exposure in particular industrial operations that functioned for relatively brief periods. The number of deaths from cancer identified as being caused by occupational factors is compared with the total for cancer from all causes in Ontario during the period 1971 through 1975. Although all workers eligible for compensation may not have been identified, the data suggest that less than 1% of cancer is presently caused by occupational factors.

Aniline Compounds↗
PubMed1979

Occupational lung cancer and smoking: a review in the light of current theories of carcinogenesis.

This paper considers modern theories of carcinogenesis as they apply to the induction of lung cancer by tobacco smoking and occupational exposure to carcinogens. Some of the known and postulated factors affecting carcinogenesis are discussed, with particular reference to syncarcinogenesis and thresholds. Factors affecting the intensity of smoking exposure are reviewed, and the generally accepted occupational lung carcinogens are listed. Relative risks for the various carcinogens according to smoking status (where known) are presented. The carcinogens are considered individually, and known or postulated interactions with smoking are discussed. It is concluded that the effects of lung carcinogens can be explained on the basis of current theories that support a rational definition of priorities for the prevention of occupational lung cancer.

Arsenic↗
PubMedDate not supplied

Occupational health services in South Carolina manufacturing plants: results of a survey.

A mailed survey of occupational health and safety practices in industrial manufacturing plants with more than 50 employees was carried out in South Carolina, with a response rate of 60 percent. The responding plants represented 73 percent of the total workforce in the industries. Data were analyzed in relation to the types of industry as delineated by the Standard Industrial Code. Eighty-three percent of the responding plants (a percentage that represented more than 92 percent of the total workforce in the industries) had some arrangements for the medical or nursing care of employees. For the study, occupational health services were defined at three levels: basic (mandatory), secondary (beneficial to management), and tertiary (health promotion-preventive medicine). The basic services provided by most of the industries surveyed appeared to be adequate. Secondary services were well developed except in the apparel and lumber industries. Tertiary services, in terms of five selected preventive programs, were moderately developed only in the paper, petroleum, and chemical industries. Only alcohol abuse control programs were commonly offered in the other types of industry. The size of the workforce in a plant partly dictated the level of occupational health services it offered but did not always account for all inter-industry variation.

Health Promotion↗