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Biomedical subjects

L M Irwig

Publications and source records attributed to L M Irwig.

At least 55 records · Page 3Linked to original sources
PubMed1986

Excess mortality from stomach cancer, lung cancer, and asbestosis and/or mesothelioma in crocidolite mining districts in South Africa.

To determine whether exposure to crocidolite is associated with excess mortality, the authors calculated standardized mortality ratios based on deaths in South African crocidolite mining districts from 1968 to 1980 for selected causes of death. Contiguous districts were used as controls. To take account of background geographic variability, they divided the control districts into groups of population size similar to those of the crocidolite mining districts. Standardized mortality ratios in crocidolite mining districts were elevated for asbestosis and/or mesothelioma, and cancer of the lung and stomach. These findings could not be explained by background geographic variability in mortality and are likely to be due to exposure to South African crocidolite during mining and milling or to environmental contamination. The increased standardized mortality ratios for stomach cancer are of particular interest, since excess deaths have not previously been shown in individuals exposed to crocidolite alone.

Adolescent↗
PubMed1986

Protein-energy malnutrition: the role of nutrition education in rehabilitation.

A randomized trial was carried out to test the effectiveness of nutrition education as a rehabilitation measure for childhood protein-energy malnutrition. The intervention comprised a series of home-based nutrition counselling sessions for the mothers/caretakers of 65 children (hospital outpatients) aged 7-36 months, who were suffering from mild to moderate protein-energy malnutrition. Both the intervention and control groups of children and their caretakers were assessed over a 12-month period: the children on admission and at 3-monthly intervals for weight-for-age, weight-for-height, height-for-age, triceps skinfold-for-age and clinical features; the caretakers on admission and at the final follow-up for nutrition knowledge. Although the nutrition knowledge score of the caretakers in the intervention group improved significantly, no significant differences developed between the two groups of children regarding any of the nutritional status measures assessed. Thus, nutrition education per se was not found to be a major factor in promoting recovery from malnutrition. Nevertheless, both groups of children showed highly significant improvements in all age-adjusted anthropometric assessments except height-for-age.

Age Factors↗
PubMed1985

Clinical competence of paediatric primary health care nurses in Soweto.

Primary health care (PHC) nurses provide care at polyclinics in Soweto. Our study assessed nurse competence in the clinical detection of important respiratory signs in 337 consecutive paediatric patients with respiratory complaints. The patients were then independently re-examined by two paediatricians, one of whom was arbitrarily chosen as a 'standard doctor'. The standard doctor found 95 patients with important respiratory signs; nurses detected the same signs in 45 and the other doctor in 44 patients. Therefore nurses detected important signs as well as could be expected, considering the inter-observer variation between doctors. The nurses did, however, significantly overdiagnose one condition, follicular tonsillitis. Our results suggest that the Soweto paediatric PHC nurses detect clinical signs with as much accuracy as doctors. This study adds to the available evidence that adequately trained and supervised nurse practitioners can provide high-quality health care.

Clinical Competence↗
PubMed1985

Relative observer accuracy for dichotomized variables.

We suggest that the relative accuracy of several observers of a disease manifestation can be assessed by comparing the strength of association between their observations and a known cause of that disease. In principle, the observer whose findings are most strongly associated with the causal variable has the least error. In practice many observations appear binary ("normal" or "abnormal") when the underlying distribution of the variable they measure is continuous. For this case of a dichotomized variable, several observers may find different prevalences of abnormality in the same sample either because their accuracy differs or because they use different thresholds above which they regard abnormality as present. A comparison of how strongly their observations are associated with a causal variable using statistical methods for binary observations may lead to incorrect conclusions about the relative accuracy of the observers. We suggest and evaluate a method, based on the biserial correlation coefficient, for comparing the relative accuracy of several observers who may differ in the thresholds they use.

Asbestosis↗
PubMed1984

Childhood mortality rates, infant feeding and use of health services in rural Transkei.

Childhood mortality rates in rural Transkei were calculated using data obtained from a sample survey of about 5 000 women who were questioned about the outcome of their pregnancies. There was almost a 1 in 5 risk of children dying before the age of 5 years. The greatest risk was in the 1st year; the infant mortality rate was 130/1 000. About 75% of infant deaths occurred in the postneonatal period. We suggest that many postneonatal deaths are probably caused by diarrhoea and could be prevented by community-based oral rehydration programmes. About 75% of the children were breast-fed beyond the age of 1 year; however, 66% of them were also given other milk before they were 4 months old. Over 80% of women attended an antenatal clinic at least once, although only about 33% of the babies were delivered by the health services. Health services had been attended by 85% of children over 3 months old. The survey methods used were found suitable for ascertaining childhood mortality rates in rural areas of southern Africa. They should be applied more extensively to provide information for planning health services.

Black or African American↗
PubMed1984

Tuberculosis management in Soweto.

Despite the availability of highly effective therapy, tuberculosis (TB) remains a major problem in South Africa, even in urban centres such as Soweto which is relatively well provided with health services. We therefore assessed two aspects of TB management in Soweto: (i) the proportion of known tuberculous patients adequately treated; (ii) whether case finding through investigation of home contacts of notified patients was effective. In 1978 patients with TB were required to take chemotherapy for at least a year. Only 28% of newly notified patients attended the clinics frequently enough and/or were hospitalized long enough to obtain 80% or more of the treatment they required during that first year. A major part of this problem of non-compliance was infrequent attendance; these patients received therapy of an adequate duration, but at an inadequate dosage. At least 17% of patients over 10 years of age had tubercle bacilli in their sputa on microscopy more than 4 months after therapy was started. About two-thirds of known home contacts were investigated by the health services in accordance with their stated policy, and 5% of contacts were subsequently notified. Home-contact tracing therefore seems worthwhile.

Adolescent↗
PubMed1983

Pointers to preventing hyperglycaemic emergencies in Soweto.

Sixty people with hyperglycaemia were admitted to Baragwanath Hospital as emergency patients during an 8-week study period in 1981, and one-quarter of them died in hospital. Many of these hyperglycaemic emergencies could have been prevented; 88% of the patients were known diabetics, one-third of whom required only oral hypoglycaemic agents for diabetic control. Sixty-one per cent of the patients had concomitant diseases, primarily infections. Earlier treatment might well have prevented deterioration of diabetic control, yet only 6% of the patients had attended the health services in the previous week in spite of recognizing that they were becoming progressively more ill. These patients were at high risk of subsequent admission, one-third of those discharged being readmitted within 3 months. Attendance compliance during a 3-month follow-up period was poor, and the discharged patients lacked the skills and knowledge necessary to maintain adequate diabetic control. One-quarter of those on insulin could not measure their dose correctly, most could not adequately test their urine and did not know what action to take if they had worsening symptoms of hyperglycaemia or developed intercurrent illness. Hyperglycaemic emergency admissions could be reduced by improving ambulatory diabetic services, thus saving costs of hospital care. Recommendations for improving the hospital service include maintaining a register of patients who have had hyperglycaemic emergencies and special care to ensure that they acquire the necessary knowledge and skills. Other methods of improving compliance regarding attendance and medication should be applied. These recommendations need to be implemented and their efficacy evaluated.

Adolescent↗
PubMed1982

Primary health care nurse training in Kwazulu. An evaluation of diagnostic flow charts versus a conventional training method.

Diagnostic flow charts have been adapted for the training of primary health care (PHC) nurses in a rural area of South Africa. We designed a randomized controlled trial to assess whether nurses' clinical competence differed if they were trained using flow charts or using conventional patient-centered teaching. Although clinical competence improved during the training programme, this improvement did not differ significantly according to which of the two training methods was used. The nurses in this trial had considerable earlier experience and some training in primary care. Before the trial they had a high level of clinical competence and may already have developed their own diagnostic strategies. We therefore cannot make inferences from our study about whether or not flow charts will be a valuable addition in PHC. Flow charts need to be adapted to take into account where, by whom, and for what purpose they will be used. They must then be tested to ensure that they only rarely result in incorrect diagnosis and treatment. A decision on the use of flow charts in the training of PHC nurses should be based on further educational trials and long-term follow-up of trained health workers. Nurses should participate in educational trials at the start of their careers in PHC. The additional value of flow charts in the auditing of competence and assessment of educational needs should also be explored.

Ambulatory Care Facilities↗
PubMed1982

Hypertension management and patient compliance at a Soweto polyclinic.

The aim of our study was to assess the quality of hypertension detection and management at the Senaoane polyclinic for Black patients in Soweto and to determine the degree of patient compliance with antihypertensive drug treatment. We reviewed the records of 2,200 consecutive new patients who were 15 years of age or older. The blood pressures of 84% of the patients were measured at their first visit to the polyclinic. Of the patients seen initially by primary health care nurses, 98% were managed correctly according to the blood pressure management protocol that these nurses had been trained to use. Of 55 patients started on antihypertensive drug treatment at their first visit to the polyclinic, 31% did not visit the polyclinic again during the next year. Only 15 patients (27%) were compliant, i.e. they attended often enough during the following year to allow them to receive 80% or more of the necessary drugs. These 15 patients had substantial reductions in their diastolic blood pressures (mean reduction 21 mmHg). We regard poor compliance as the major factor preventing the polyclinic from reducing morbidity and mortality in hypertensives. Strategies for improving compliance need to be developed and evaluated for different poor compliance groups. These groups can be defined according to the severity of the hypertension and the pattern of poor compliance ("early drop-outs' v. "irregular attenders').

Adolescent↗
PubMed1981

Infant care and feeding in an urban black population.

Health education programmes aimed at improving infant feeding must be developed from data on current practices and growth. Infants born in Pimville, Soweto, were traced when they were 6 weeks old and again at 6 months and their mothers and child-minders were interviewed. Length of tay in the area, breastfeeding and weaning intention and practice, age standard of education, understanding of Boston growth charts, and infant growth data were investigated. It is suggested that more specific health education programmes need to be developed and that community-based health workers need to be selected and trained to assist and support mothers in learning better feeding practices.

Adolescent↗
PubMed1981

Serum lipid, uric acid and glucose levels in urban black males doing manual or clerical work.

Serum lipid, uric acid and glucose levels were measured in four groups of Black male factory workers 1 hour after an oral glucose load. These groups comprised non-obese manual, obese manual, non-obese clerical and obese clerical workers. Obese men had significantly higher serum uric acid, total cholesterol and triglyceride levels and lower high=density lipoprotein (HDL) cholesterol levels than non-obese men. Serum glucose and low-density lipoprotein (LDL) cholesterol values were also higher in obese than in non-obese men, but the differences were not significant. Clerical workers had higher levels than manual workers for most of the biochemical variables measured, but only in the case of uric acid was the difference significant. Possible reasons for the fact that the effect of occupation on the variables was slight are briefly discussed.

Adult↗
PubMed1979

Hypertension in urban Black outpatients. Who gets treated and for how long?

Two-thirds of all Black patients who attended the Medical Outpatient Department of the Johannesburg General Hospital for the first time during May 1975 had recorded diastolic blood pressures of 90 mmHg or above. Almost one-third of all patients were treated for hypertension. About half of the patients with diastolic blood pressures between 90 and 119 mmHg were started on treatment, a decision which was predicted by diastolic blood pressure, recorded symptoms and systolic blood pressure, but not by age. Four of the 50 patients with diastolic blood pressures of 120 mmHg or above were not treated. Less than one-third of all patients started on anti-hypertensive treatment were still returning for treatment at the end of 1 year. There was no difference in initial diastolic blood pressure between those patients who did and those who did not return for treatment. Hospital policies are required for standardizing initial decision-making and long-term treatment of hypertension. Strategies to improve compliance by altering health care delivery and changing patient behaviour must be developed and evaluated.

Adolescent↗
PubMed1979

Risk of asbestosis in crocidolite and amosite mines in South Africa.

X-rays of all while and mixed-race men employed in crocidolite and amosite mines and mills were read independently by three experienced readers according to the ILO U/C classification. Abnormality was regarded as present if reported by two or more readers. Parenchymal abnormality, defined as the presence of small irregular opacities of profusion 1/0 or greater, was found in 7.3% of the workers. Pleural thickening was found in 4.5% of the workers, costophrenic angle obliteration in 3.2%, and pleural calcification in 1.7%. The prevalences of both pleural and parenchymal abnormality were strongly related to the duration of exposure to asbestos at work. The overall prevalence of abnormality increase from 4.0% in men with exposure for 1 year or less to 47.9% in men with more than 15 years of exposure. After taking into account the effects of age and duration of asbestos exposure, the prevalence of pleural abnormality was not predicted by fiber concentration. However, white men working with amosite tended to develop a higher prevalence of pleural abnormality than did those working with crocidolite. Compared to whites, men of mixed race, who only work with crocidolite, had a high prevalence of pleural abnormality in each exposure duration category. In contrast to pleural abnormality, the prevalence of parenchymal abnormality, after taking into account the effects of age and duration of exposure, was significantly predicted by fiber concentration but not by race or asbestos type. Our results suggest that parenchymal abnormality in workers in South African asbestos mines could be largely prevented by reducing exposure to fibers visible under the light microscope. However, this may not be the case for pleural abnormality.

Adult↗
PubMed1979

The influence of availability of free school milk on the height of children in England and Scotland.

The effect is investigated of availability of free school milk on height gain in one year of six- and seven-year-old primary schoolchildren in England and Scotland, using data collected annually from 1972 to 1976. The height gain of children for whom milk was available for the whole year of observation was compared with that of children who had no milk. Out of 16 sex-country-year-specific analyses for children from manual social classes only, 13 showed no significant evidence of greater height gain in children who had milk. Comparison of children from Social Classes IV and V (semi-skilled and unskilled) showed no greater increase in height for those who had milk, nor was there a difference in height gain between manual social class children according to the number of glasses of milk they drank a day at home or at school. We concluded that, given the standard of living at the time of the survey, the drinking of free school milk did not increase the growth rate of six- and seven-year-old children.

Animals↗
PubMed1979

Lung function in sisal ropemakers.

Lung function was measured by spirometry in 66 workers in a sisal ropemaking factory, and in their matched controls. The major atmospheric contaminant was the lubricant (or a component part thereof) used to soften the fibre. The concentration of airborne matter was generally less than 1 mug m--3. There was no difference in lung function between the two groups before the start of the working shift, that is, the mixture of softening lubricant and sisal caused no long-term effects. Although there was no change in lung function over the working shift in the group making sisal rope, the control group did show a significant increase in lung function over the same period. This suggests that an effect attributable to the lubricant and sisal dust did exist. In previous studies little mention has been made of the softeners used in the processing of sisal fibre. These additives may exert a significant effect on ventilatory capacity and may act in conjunction with sisal dust.

Adult↗