Aspectos da mortalidade atribuível ao tabaco: revisão sistemática

O artigo teve por objetivo analisar as metodologias publicadas e empregadas no cálculo da mortalidade atribuível ao fumo. Foram pesquisadas as bases de dados eletrônicas MEDLINE, LILACS entre 1990 e 2006. Foram encontrados 186 estudos que apresentaram a mensuração de mortalidade a partir do cálculo da fração atribuível ao fumo. Desses, foram selecionados 41 artigos. Os estudos realizados nos Estados Unidos e Canadá apresentaram metodologia uniformizada e taxas de mortalidade entre 18%-23%; 25%-29% no sexo masculino e 14%-17% no feminino. As variações metodológicas podem justificar as diferenças da mortalidade entre os estudos e nas estimativas para as principais doenças tabaco-relacionadas.The objective of the article was to assess methodologies published and applied in calculating mortality attributable to smoking. A review of the literature was made for the period 1990 to 2006, in the electronic databases MEDLINE and LILACS. A total of 186 studies were found, which measured mortality based on calculating the smoking-attributable risk. Of these, a total of 41 were selected. The studies that were carried out in the United States and Canada presented a more standard methodology and reported smoking attributable mortality to be 18%-23%, with male mortality being 25%-29% and female mortality 14%-17%. The variations can be attributed to methodological differences and to different estimates of the main tobacco-related illnesses

Assessing regional differences in contraceptive discontinuation, failure and switching in Brazil

<p>Abstract</p> <p>Background</p> <p>Contraceptive prevalence is relatively high in Brazil (55% among women of reproductive age). However, reversible methods account for less than half of the method mix and widespread differences persist across regions and social groups. This draws attention to the need for monitoring family planning service-related outcomes that might be linked with quality of care. The present study examines the factors associated with method discontinuation, failure and switching among current contraceptive users, with a focus on sub-national assessment.</p> <p>Methods</p> <p>Data for the analysis are drawn from the Brazil Demographic and Health Survey, notably the calendar module of reproductive events. Multilevel discrete-time competing risks hazard models are used to estimate the random- and fixed-effects on the probability of a woman making a specific transition after a given duration of contraceptive use.</p> <p>Results</p> <p>Contraceptive continuation was found to be highest for the contraceptive pill, the most popular reversible method. Probabilities of abandonment while in need of family planning and of switching to another method were highest for injections. Failure, abandonment and switching were each higher among users in the Northeast region compared to the more prosperous Southeast and South.</p> <p>Conclusion</p> <p>Findings point to seemingly important disparities in the availability and quality of family planning and reproductive health care services across regions of the country. Expanding access to a range of contraceptive methods, improving knowledge among health agents of contraceptive technologies and increasing medical supervision of contraceptive practice may be considered key to expanding quality reproductive health care services for all.</p

Assessing the effects of multiple infections and long latency in the dynamics of tuberculosis

In order to achieve a better understanding of multiple infections and long latency in the dynamics of Mycobacterium tuberculosis infection, we analyze a simple model. Since backward bifurcation is well documented in the literature with respect to the model we are considering, our aim is to illustrate this behavior in terms of the range of variations of the model's parameters. We show that backward bifurcation disappears (and forward bifurcation occurs) if: (a) the latent period is shortened below a critical value; and (b) the rates of super-infection and re-infection are decreased. This result shows that among immunosuppressed individuals, super-infection and/or changes in the latent period could act to facilitate the onset of tuberculosis. When we decrease the incubation period below the critical value, we obtain the curve of the incidence of tuberculosis following forward bifurcation; however, this curve envelops that obtained from the backward bifurcation diagram

Blood lead, cadmium and mercury among children from urban, industrial and rural areas of Fez Boulemane Region (Morocco): Relevant factors and early renal effects

Objectives: To describe blood lead (Pb-B), cadmium (Cd-B) and mercury (Hg-B) levels in children living in urban, industrial and rural areas in Fez city (north of Morocco) and to identify the determinants and some renal effects of exposure. Material and Methods: The study was conducted from June 2007 to January 2008 in 209 school children (113 girls, 96 boys), aged 6-12 years, from urban, industrial and rural areas in Fez city. Interview and questionnaires data were obtained. Blood and urinary samples were analyzed. Results: The mean of blood lead levels (Pb-B) in our population was 55.53 μg/l (range: 7.5-231.1 μg/l). Children from the urban area had higher blood lead levels (BLLs) mean (82.36 μg/l) than children from industrial and rural areas (48.23 and 35.99 μg/l, respectively); with no significant difference between boys and girls. BLLs were associated with traffic intensity, passive smoking and infancy in the urban area. The mean of blood cadmium levels (BCLs) was 0.22 μg/l (range: 0.06-0.68 μg/l), with no difference between various areas. Rural boys had higher BCLs mean than rural girls, but no gender influence was noticed in the other areas. BCLs were associated with the number of cigarettes smoked at children's homes. The blood mercury levels (BMLs) mean was 0.49 μg/l (range: 0.01-5.31 μg/l). The BMLs mean was higher in urban and industrial areas than in the rural area with no gender-related difference. BMLs were associated with amalgam fillings and infancy in the urban area. About 8% of the children had BLLs ≥ 100 μg/l particularly in the urban area, microalbuminuria and a decrease in height were noticed in girls from the inner city of Fez and that can be related to high BLLs (89.45 μg/l). Conclusions: There is a need to control and regulate potential sources of contamination by these trace elements in children; particularly for lead