ABSTRACT
@#New case is a basic concept in epidemiology and often serves as the numerator for the indexes of the frequency of disease in a population． However，the exact definition of new case is still un- clear． Based on the natural history of disease combined with the concept of event-state，this article rede- fines case-related concepts and compares them with traditional concepts． The study found that the so- called new cases in traditional epidemiological studies are actually the cases firstly discovered，including newly discovered cases and identifiable newly incident cases ( disease initiation) ． In the real world，new cases are often difficult to measure，and together with the continuous process of disease development and iceberg phenomenon，those may affect the accuracy of disease frequency measurement and causal infer- ence． A correct understanding of the meaning of case-related concepts，the meanings they reflect，and the differences between them help to rationally interpret the results of epidemiological research．
ABSTRACT
OBJECTIVE: To screen the optimal fitting model for the change trend of the number of new cases of occupational diseases in Guangdong Province by using linear and nonlinear regression models. Method The number of new cases of occupational diseases in Guangdong Province from 2003 to 2017 was used as the dependent variable(■) and the year(time) as the independent variable(x).Eleven mathematical models including linear regression, cubic function, quadratic function, composite function, growth function, exponential function, logistic function, power function, logarithmic function, S-type function and inverse function were used to fit the data, and the best-fit model was selected to describe and verify the change of new occupational diseases. RESULTS: Among the 11 mathematical models, the determination coefficient of fit results of cubic curve regression model was the highest(0.94, P<0.01), and the fit effect was the best. The fitting curve was ■. The cubic curve regression model was used to fit the number of new cases of occupational diseases in Guangdong Province from 2003 to 2019. The results showed that the measured value of new cases in all those years, except 2011, was within 95% confidence interval of the fitting value. The median(25 th, 75 th percentile) of absolute relative deviation between the fitting value and the actual value was 8.9%(4.3%, 14.7%). CONCLUSION: The regression model based on cubic curve can better fit the incidence of occupational diseases and can be used to describe the occurence of occupational diseases.
ABSTRACT
Este trabalho teve como objetivo detectar os casos novos de hanseníase do período de 1998 a 2005 no município de Prudentópolis, PR. Assim como, verificar a faixa etária e a forma clínica predominante entre os casos de hanseníase. Os dados foram obtidos através das fichas clínico-epidemiológicas de casos com diagnóstico definitivo de hanseníase notificado no Sistema de Informação sobre Agravos de Notificação, de 1998 a 2005. Neste período, foram relatados 222 casos de hanseníase, dos quais 63 por cento apresentavam a forma multibacilar, com predominância da forma clínica virchowiana, indicando um processo de intensa transmissão da doença. Dos casos de hanseníase, 35 por cento dos pacientes se encontravam na faixa economicamente ativa, 31 a 45 anos. Esses indicadores apontam para uma elevada circulação do bacilo na comunidade, já que um fator de risco para infecção pelo bacilo Mycobacterium Leprae é o contato com pacientes com a forma multibacilar, sem tratamento, embora nas duas últimas décadas, tenha havido redução drástica da prevalência da hanseníase pela implementação da poliquimioterapia e outras medidas preventivas.
The aim of this study was to evaluate the detection of new cases of leprosy in Prudentópolis, State of Paraná, from 1998 to 2005. Additionally, we investigated the age group and predominant clinical form of leprosy cases. Data were obtained from clinical-epidemiological records of confirmed leprosy cases that were notified in the Information System for Notifiable Diseases, between 1998 and 2005. Over this period, 222 leprosy cases were notified, of which 63 percent presented the multibacillary form, with predominance of the Virchow clinical form, thus indicating a process of intense disease transmission. Among these leprosy cases, 35 percent of the patients were at an economically active age (31 to 45 years old). These indicators showed that there was a high level of bacillus circulation in the community, considering that one risk factor for infection by the bacillus Mycobacterium leprae is contact with untreated individuals who have the multibacillary form. This is despite the drastic reduction in leprosy prevalence over the last two decades, through the implementation of polychemotherapy and other preventive measures.