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Biomedical subjects

D Yach

Publications and source records attributed to D Yach.

At least 91 records · Page 5Linked to original sources
PubMed1991

Environmental determinants of acute respiratory symptoms and diarrhoea in young coloured children living in urban and peri-urban areas of South Africa.

The impact of environmental risk factors associated with housing was examined in relation to diarrhoeal disease and acute respiratory symptoms in South African coloured children. A multistage cluster sample representative of all coloured people living in the major urban and peri-urban areas of South Africa was used for the study. Interviews were conducted with respondents from 1,227 households. Overall, 8.5% children under 5 years were reported to have had diarrhoea, while 29% had experienced coughing and breathing problems in a 2-week recall period. Individual risk factors identified using the odds ratios (ORs) for diarrhoea included not having an inside tap or a flush toilet in the homes (both yielded an OR of 3.3), not owning a refuse receptacle (OR = 2.5), not being connected to an electricity supply (OR = 2.5), low household income (OR = 1.8), more than 2 people per room (OR = 2.0) and less than Standard 5 maternal education (OR = 1.6). Absence of an inside toilet, not having a refuse receptacle and overcrowding all remained as independent risk factors after logistic regression analyses. Multiple logistic regression analyses revealed that not having a refuse receptacle and the absence of electricity for heating purposes were independently associated with respiratory symptoms. The overall preventive potentials for respiratory symptoms were significantly less than those for diarrhoea. Improving physical access to essential environmental health services in urban areas and improvements in the educational status of women are urgently needed if childhood infections are to be prevented.

Black or African American↗
PubMed1991

Epidemiology of non-fatal injuries due to external causes in Johannesburg-Soweto. Part I. Methodology and materials.

In this, the first of two articles examining the epidemiology of non-fatal trauma in Johannesburg-Soweto, we define case inclusion criteria, and discuss the methodology and materials used in this low-cost, hospital-based survey. The survey was conducted between 8 June 1989 and 24 August 1990. Sampling of both inpatient trauma cases and those seen in casualty departments took place in 6 state and 5 private hospitals located within or nearby the Johannesburg magisterial district. Demographic details about each patient, as well as information concerning spatial and temporal details of the incident, involvement of alcohol or drugs, diagnosis, severity of injury, and placement after casualty treatment, were collected by interviewing each patient. Data concerning the age, sex and racial composition of the background population were assembled from a number of sources. After discussing the internal limitations of this methodology, it is concluded that its findings may be of limited use for improving secondary interventions, but are of definite value for trauma prevention programmes.

Adolescent↗
PubMed1991

Epidemiology of non-fatal injuries due to external causes in Johannesburg-Soweto. Part II. Incidence and determinants.

A total of 3,535 trauma cases were enumerated in Johannesburg-Soweto between 1989 and 1990 in the course of 271 hospital ward rounds and 43 casualty watches. The overall trauma incidence was 2,886 new cases per annum per 100,000 population, rising to 19,872 for coloured males aged 20 - 24 years and to 8,761 for black males aged 20 - 24 years. Overall the male/female ratio was 2.9 rising to 6 or more in adolescence (15 - 19) for blacks and coloureds. There were some 156 new resident cases of trauma daily; half these were victims of interpersonal violence, and coloureds constituted 22% of this group, although forming only 8% of the denominator population. With regards to cause, most trauma among blacks and coloureds arose from interpersonal violence and significantly less from transport accidents. Among blacks injured in transport accidents (the majority of which involved motor vehicles) most were pedestrians, whereas most whites injured in such accidents were occupants of vehicles. For all groups trauma was most likely to be incurred 'in the street' although for white and coloured women the home was most dangerous. The implications of these and related findings for treatment and prevention and briefly reviewed.

Adolescent↗
PubMed1991

Evaluation of a peri-urban community health worker project in the western Cape.

The South African Christian Leadership Assembly (SACLA) Health Project is a non-governmental organisation that runs a community health worker (CHW) programme in 4 peri-urban townships of Cape Town. A cross-sectional descriptive community survey was conducted in April 1990 to evaluate coverage and health education on oral rehydration solution (ORS) and to plan future preventive, promotive and development programmes. Research concepts and methods were made accessible to the CHWs through a training process designed to facilitate participation in every stage of the research. A multi-stage cluster sampling scheme was used, and the CHWs interviewed 822 residents. Coverage indicators showed that over 80% of all respondents had previously known about or consulted the CHW. The most common community problems related to water, filth and refuse, toilets, housing, unemployment and lack of community facilities. The most common health problems were generalised aches and pains, chest problems, skin problems, worms, and diarrhoea. An index developed to measure knowledge of ORS showed very few respondents had 'complete knowledge'. The community's expectations of the CHW included health education, attending to sanitation problems, providing a clean environment, organising community facilities, and helping with employment.

Community Health Services↗
PubMed1991

Birth to ten: child health in South Africa in the 1990s. Rationale and methods of a birth cohort study.

Birth to Ten is a longitudinal birth cohort study which began in April 1990 in the Johannesburg/Soweto area of Transvaal, South Africa. In this paper, the reason for the initiation of the study and its location in the current sociopolitical context is discussed. The health status of South Africa children in terms of infant mortality, morbidity (notifiable diseases) and nutritional status is described and mention is made of measures of psychological health and the importance of environmental pollution on health. The existing health service infrastructure in the study area is described and the fragmentation of health services between races, between preventive and curative services and on a geographical basis is highlighted. The study objectives, design, population, inclusion and exclusion criteria, methods of measurement and logistics are described.

Child↗
PubMed1990

Measles vaccination coverage and its determinants in a rapidly growing peri-urban area.

A study was undertaken to ascertain the vaccination coverage of children aged 12-23 months living in Khayelitsha, a peri-urban township outside Cape Town, and to identify factors associated with measles vaccination coverage. A stratified proportional cluster sampling technique was used to select 46 clusters of 10 children each. Three strata were defined according to area of residence. The vaccination status of each child was determined from the preschool card. Usable information was obtained for 432 children; in 75.4% of cases the respondent was the child's mother, and 69.4% of children possessed a preschool card. Measles vaccination coverage was 63.5% (95% confidence interval 58-67%). Three factors had a significant association with incomplete measles vaccination: less than 6 months' residence in the area (odds ratio (OR) 3.1), having been born outside Cape Town (OR 2.5), and home delivery (OR 2.0). The mothers' level of education and children's age were not associated with measles vaccination status. Children in the New Shanty area were identified as a high-risk group. Carers of children in the New Shanty area were the least likely to know of the need for measles vaccination and to be visited by a community health worker. Greater efforts are required to identify high-risk children and areas.

Black or African American↗
PubMed1990

Meta-analysis in epidemiology.

Meta-analysis is the structured and systematic qualitative and quantitative integration of the results of several independent studies (i.e. the epidemiology of results). As in any epidemiological study, a meta-analysis needs to start with clearly stated aims and objectives. Attention needs to be paid to selection bias in selecting the study population (all publications on the topic). An initial qualitative assessment (conducted blinded to results) categorises projects on the basis of their methods, as unacceptable (dropped from later analysis) and acceptable or good. Further analysis could be conducted by stratifying or weighting independent studies according to preset quality criteria. The quantitative assessment involves deriving a pooled measure of outcome (usually the relative or attributable risk). Tests for heterogeneity are required before pooling. By pooling the results from many settings using different methods, the ability to generalise them in terms of their public health relevance is increased.

Meta-Analysis as Topic↗
PubMed1990

Village health-workers and GOBI-FFF. An evaluation of a rural programme.

Growth monitoring, oral rehydration, breast-feeding and immunisation--female education, family spacing and food supplementation (GOBI-FFF) are a selective package of World Health Organisation primary health care strategies recommended by UNICEF. Changes over a 1-year period in the implementation of the components of GOBI-FFF were investigated in a rural village in Ciskei to detect any changes associated with a newly modified village health-worker (VHW) programme. A baseline survey was conducted before the introduction of a modified VHW programme and a second survey took place a year later. The principles of GOBI-FFF were already familiar to and have since been increasingly practised by the community and health personnel. Breast-feeding is widespread, most carers know how to make oral rehydration solution and most children have a 'Road to Health' card and are being weighed regularly. However, malnutrition remains a major problem and the food supplementation programme is operating poorly. The high coverage of the community by the village health-workers and the clinic suggest that these two channels should be used more intensively to strengthen the GOBI-FFF programme in the area.

Breast Feeding↗
PubMed1990

Tuberculosis in commerce and industry in a Western Cape suburb, South Africa, 1987.

A postal questionnaire of 557 industries in a defined area of the Western Cape, South Africa, aimed to determine the incidence of pulmonary tuberculosis (TB) in 1987 as well as the provision of health services. A 65% response rate was obtained. A random sample of non-respondents did not differ from respondents with respect to factory size or sector. The overall incidence rate for 1987 was 472 per 100,000 workers (95% confidence interval 386-558). Tuberculosis rates of Africans and "coloureds" were substantially higher than those of Asians and whites. There was considerable variation in the rates by employment sector. We found highest rates of TB in the textile and iron and steel industries and the lowest rates are reported among the printing and paper industry, in trade and commerce, and in the transport sectors. It is likely that the differences in the rates by sector reflect the different social class composition of their work force. TB incidence rates also varied by factory size, with the highest rates being reported in the smallest factories. The implications of the study are that the current policy of not screening workers in industry on a routine basis for TB needs to be urgently reviewed. The provision of health services, shown to vary according to factory size, was found to be inadequate in the smaller factories. Alternative methods of providing such care to workers need to be implemented.

Adult↗
PubMed1990

Urbanisation and health: methodological difficulties in undertaking epidemiological research in developing countries.

Rapid urbanisation has historically resulted in complex societal changes which have had both beneficial and adverse effects on the health of communities. Recently, it has been recognised that the urban poor in developing countries are at greatest risk for several adverse health effects. The epidemiologist has a key role to play in planning to meet current and future health needs of urban communities. Epidemiological research needs to focus on understanding the relationship between the changes that occur with urbanisation and their impact on health, in order to identify those at greatest risk, to identify the important risk factors that are amenable to intervention, and to evaluate the effectiveness of interventions aimed at improving the health of urban communities. This paper addresses several methodological difficulties in conducting epidemiological research on urbanisation and health in developing countries, with particular reference to Southern Africa. These relate to the definition of urban areas and residence thereof, the comparability across areas of exposure and outcome information, the identification of intra-urban variability, selection bias in cross-sectional studies, associating outcomes with specific urban exposures in analytic studies, and determining appropriate interventions and means of evaluation. Ways of overcoming these difficulties are suggested. Epidemiologists need to address these issues in order to make a valuable contribution to the improvement of health in urban communities.

Bias↗
PubMed1990

Drop-out and newcomer bias in a community cardiovascular follow-up study.

Bias resulting from a loss of baseline subjects at follow-up (drop-out), and newcomer bias resulting from subjects entering the study at the follow-up stage, were investigated in a three-community coronary risk factor follow-up study. The study consisted of a cross-sectional baseline study on 7188 participants aged 15 to 64 years, a four-year intervention period and a follow-up cross-sectional study in the same communities on 6283 participants aged 19 to 68 years. The overall non-response rate of 45% in men and 42% in women varied from 30 to 79% in the various age and sex groups, with the biggest drop-out rate occurring in the youngest age group of 15 to 24 years. At baseline drop-outs were more likely to have lower educational qualifications than those who participated in both the baseline and follow-up studies (stayers) and included significantly more smokers than non-smokers. Coronary risk factors of newcomers were not different from that of the stayers at follow-up except for slightly, but not significantly, higher smoking rates in newcomers. These findings suggest that drop-out and newcomer bias need to be assessed and its effect studied before final evaluation of data in community follow-up studies.

Adolescent↗