ABSTRACT
In a hospital-based case-control study, 316 lung cancer cases and 536 controls were interviewed for their occupational, smoking, passive smoking, cancer in the family and residential histories as well as social economic status, by trained interviewers, using a standardized questionnaire. Cases and controls were matched by hospital, sex and age. The study was carried out between 1st July 1990 and 31st January 1991 in 14 hospitals in the Metropolitan Region of S. Paulo, the most highly industrialized and urbanized region in Brazil. Score criteria were developed for the ordering of the individuals of the study by occupational exposure to know carcinogens to the lung, in order to evaluate this exposure during the occupational life of each person. The criteria accumulated information on exposure to carcinogens as regards type, sector of work and time in each employment. The unconditional logistic regression analysis showed an odds ratio of 1.97 (95% IC: 1.52 to 2.55) for the highest exposure group. This result showed that workers linked to the production sectors of several industries have about twice the risk of developing lung cancer as workers involved in non-industrial activities.
Subject(s)
Industry , Lung Neoplasms/etiology , Occupational Exposure , Adult , Aged , Brazil , Case-Control Studies , Female , Humans , Logistic Models , Lung Neoplasms/epidemiology , Lung Neoplasms/genetics , Male , Middle Aged , Multivariate Analysis , Odds Ratio , Risk FactorsABSTRACT
Several case-control studies evaluating the effectiveness of BCG vaccine in the last decade have presented contradictory results like previous prospective studies. Methodological differences could explain some of the case-control study results. This study explores the possibility that contradictory results could be imputed to the choice of different series of controls. Three controls were compared for each case of tuberculous meningitis: neighbourhood, hospital and household. BCG effectiveness estimates were 86.8%, 92.0% and 29.5%, respectively. The data indicated an interaction between BCG vaccine status and tuberculous focus. This could have influenced the lower effectiveness estimates found when cases were compared with household controls. The paper discusses aspects related to case-control studies applied to evaluate BCG effectiveness such as: incubation period and sufficient time since vaccination to allow development of an immune response; the presence of a tuberculous focus among the groups of cases and controls and the interaction between focus and BCG vaccination; recall bias; and optimum selection of controls in case-control studies in the context of infectious diseases.
Subject(s)
BCG Vaccine , Tuberculosis, Meningeal/prevention & control , Bias , Brazil , Case-Control Studies , Child, Preschool , Evaluation Studies as Topic , Female , Humans , Infant , Infant, Newborn , Male , Regression AnalysisABSTRACT
A sampling project applied in a survey for estimating the vaccination coverage in Araraquara County, S. Paulo State (Brazil), in 1983, is described. A target population of children aged 12-13 months was divided into the strata: children living in private dwellings (i.e. single-family houses) and those living in collective dwelling places (orphanage, asylum). R.H. Henderson and T. Sundaresan's method, proposed by the World Health Organization (WHO) for use by the Expanded Programme on Immunization (EPI) was applied to the first stratum. This method consists of the random selection of 30 partial areas with a degree of probability proportional to the respective partial populations in each area chosen; a starting point ("household") is selected at random within each selected area; the selection of 7 children within each area begins with the first household and continues according to fixed rules. The sample of the first stratum was taken from areas in both urban and rural zones. In the urban zone, after the selection of the area and before the selection of the starting point, an intermediate stage, which consist in the selection of a block with probability proportional to its estimated population, was introduced. A sample was selected form the second stratum with the same sampling fraction used in the first stratum. The ratio-estimate is proposed as the estimator of the vaccination coverage rate and the formula for the calculation of the standard error is presented.
Subject(s)
Immunization Schedule , Vaccination , Brazil , Evaluation Studies as Topic , Humans , Infant , Sampling Studies , Statistics as TopicABSTRACT
O objetivo das equipes volantes de Saúde é dar atendimento a populaçäo da zona rural do Município de Säo Paulo. A equipe volante é constituída por um médico, um auxiliar de enfermagem, um atendente de enfermagem e um motorista, sendo o transporte da mesma efetuado por veículo tipo furgäo que leva também vacinas, medicamentos, suplemento alimentar, material e prontuários necessários ao atendimento. Os locais de atendimento säo fixos, indicados e cedidos pela comunidade, obedecendo a uma frequência semanal de 1 até 3 vezes por semana, de acordo com a demanda. Esse projeto foi implantado em dezembro de 1980 e vem sendo avaliado continuamente