916 resultados para Time-trends
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This study explores whether the introduction of selectively trained radiographers reporting Accident and Emergency (A&E) X-ray examinations or the appendicular skeleton affected the availability of reports for A&E and General Practitioner (GP) examinations at it typical district general hospital. This was achieved by analysing monthly data on A&E and GP examinations for 1993 1997 using structural time-series models. Parameters to capture stochastic seasonal effects and stochastic time trends were included ill the models. The main outcome measures were changes in the number, proportion and timeliness of A&E and GP examinations reported. Radiographer reporting X-ray examinations requested by A&E was associated with it 12% (p = 0.050) increase in the number of A&E examinations reported and it 37% (p
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Background: Falciparum malaria is the most deadly among the four main types of human malaria. Although great success has been achieved since the launch of the National Malaria Control Programme in 1955, malaria remains a serious public health problem in China. This paper aimed to analyse the geographic distribution, demographic patterns and time trends of falciparum malaria in China. Methods: The annual numbers of falciparum malaria cases during 1992–2003 and the individual case reports of each clinical falciparum malaria during 2004–2005 were extracted from communicable disease information systems in China Center for Diseases Control and Prevention. The annual number of cases and the annual incidence were mapped by matching them to corresponding province- and county-level administrative units in a geographic information system. The distribution of falciparum malaria by age, gender and origin of infection was analysed. Time-series analysis was conducted to investigate the relationship between the falciparum malaria in the endemic provinces and the imported falciparum malaria in non-endemic provinces. Results: Falciparum malaria was endemic in two provinces of China during 2004–05. Imported malaria was reported in 26 non-endemic provinces. Annual incidence of falciparum malaria was mapped at county level in the two endemic provinces of China: Yunnan and Hainan. The sex ratio (male vs. female) for the number of cases in Yunnan was 1.6 in the children of 0–15 years and it reached 5.7 in the adults over 15 years of age. The number of malaria cases in Yunnan was positively correlated with the imported malaria of concurrent months in the non-endemic provinces. Conclusion: The endemic area of falciparum malaria in China has remained restricted to two provinces, Yunnan and Hainan. Stable transmission occurs in the bordering region of Yunnan and the hilly-forested south of Hainan. The age and gender distribution in the endemic area is characterized by the predominance of adult men cases. Imported falciparum malaria in the non-endemic area of China, affected mainly by the malaria transmission in Yunnan, has increased both spatially and temporally. Specific intervention measures targeted at the mobile population groups are warranted.
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From human biomonitoring data that are increasingly collected in the United States, Australia, and in other countries from large-scale field studies, we obtain snap-shots of concentration levels of various persistent organic pollutants (POPs) within a cross section of the population at different times. Not only can we observe the trends within this population with time, but we can also gain information going beyond the obvious time trends. By combining the biomonitoring data with pharmacokinetic modeling, we can re-construct the time-variant exposure to individual POPs, determine their intrinsic elimination half-lives in the human body, and predict future levels of POPs in the population. Different approaches have been employed to extract information from human biomonitoring data. Pharmacokinetic (PK) models were combined with longitudinal data1, with single2 or multiple3 average concentrations of a cross-sectional data (CSD), or finally with multiple CSD with or without empirical exposure data4. In the latter study, for the first time, the authors based their modeling outputs on two sets of CSD and empirical exposure data, which made it possible that their model outputs were further constrained due to the extensive body of empirical measurements. Here we use a PK model to analyze recent levels of PBDE concentrations measured in the Australian population. In this study, we are able to base our model results on four sets5-7 of CSD; we focus on two PBDE congeners that have been shown3,5,8-9 to differ in intake rates and half-lives with BDE-47 being associated with high intake rates and a short half-life and BDE-153 with lower intake rates and a longer half-life. By fitting the model to PBDE levels measured in different age groups in different years, we determine the level of intake of BDE-47 and BDE-153, as well as the half-lives of these two chemicals in the Australian population.
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Background: Extreme heat is a leading weather-related cause of illness and death in many locations across the globe, including subtropical Australia. The possibility of increasingly frequent and severe heat waves warrants continued efforts to reduce this health burden, which could be accomplished by targeting intervention measures toward the most vulnerable communities. Objectives: We sought to quantify spatial variability in heat-related morbidity in Brisbane, Australia, to highlight regions of the city with the greatest risk. We also aimed to find area-level social and environmental determinants of high risk within Brisbane. Methods: We used a series of hierarchical Bayesian models to examine city-wide and intracity associations between temperature and morbidity using a 2007–2011 time series of geographically referenced hospital admissions data. The models accounted for long-term time trends, seasonality, and day of week and holiday effects. Results: On average, a 10°C increase in daily maximum temperature during the summer was associated with a 7.2% increase in hospital admissions (95% CI: 4.7, 9.8%) on the following day. Positive statistically significant relationships between admissions and temperature were found for 16 of the city’s 158 areas; negative relationships were found for 5 areas. High-risk areas were associated with a lack of high income earners and higher population density. Conclusions: Geographically targeted public health strategies for extreme heat may be effective in Brisbane, because morbidity risk was found to be spatially variable. Emergency responders, health officials, and city planners could focus on short- and long-term intervention measures that reach communities in the city with lower incomes and higher population densities, including reduction of urban heat island effects.
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Background: The incidence of sexually transmitted infections (STIs) in most EU states has gradually increased and the rate of newly diagnosed HIV cases has doubled since 1999. STIs differ in their clinical features, prognosis and transmission dynamics, though they do share a common factor in their mode of transmission −that is, human behaviour. The evolvement of STI epidemiology involves a joint action of biological, epidemiological and societal factors. Of the more immediate factors, besides timely diagnosis and appropriate treatment, STI incidence is influenced by population patterns of sexual risk behaviour, particularly the number of sexual partners and the frequency of unprotected intercourse. Assessment of sexual behaviour, its sociodemographic determinants and time-trends are important in understanding the distribution and dynamic of STI epidemiology. Additionally, in the light of the basic structural determinants, such as increased level of migration, changes in gender dynamics and impacts from globalization, with its increasing alignment of values and beliefs, can reveal future challenges related to STI epidemiology. STI case surveillance together with surveillance on sexual behaviour can guide the identification of preventive strategies, assess their effectiveness and predict emerging trends. The objective of this study was to provide base line data on sexual risk behaviour, self-reported STIs and their patterns by sociodemographic factors as well as associations of sexual risk behaviour with substance use among young men in Finland and Estonia. In Finland national population based data on adult men s sexual behaviour is limited. The findings are discussed in the context of STI epidemiology as well as their possible implications for public health policies and prevention strategies. Materials and Methods: Data from three different cross-sectional population-based surveys conducted in Finland and Estonia, during 1998 2005, were used. Sexual behaviour- and health-related questions were incorporated in two surveys in Finland; the Health 2000, a large scale general health survey, focussed on young adults, and the Military health behavioural survey on military conscripts participating in the mandatory military training. Through research collaboration with Estonia, similar questions to the Finnish surveys were introduced to the second Estonian HIV/AIDS survey, which was targeted at young adults. All surveys applied mail-returned, anonymous, self-administered questionnaires with multiple choice formatted answers. Results: In Finland, differences in sexual behaviour between young men and women were minor. An age-stratified analysis revealed that the sex-related difference observed in the youngest age group (18 19 years) levelled off in the age group 20 24 and almost disappeared among those aged 25 29. Marital status was the most important sociodemographic correlate for sexual behaviour for both sexes, singles reporting higher numbers of lifetime-partners and condom use. This effect was stronger for women than for men. However, of those who had sex with casual partners, 15% were married or co-habiting, with no difference between male and female respondents. According to the Military health behavioural survey, young men s sexual risk behaviour in Finland did not markedly change over a period of time between 1998 and 2005. Approximately 30−40% of young men had had multiple sex partners (more than five) in their lifetime, over 20% reported having had multiple sex partners (at least three) over the past year and 50% did not use a condom in their last sexual intercourse. Some 10% of men reported accumulation of risk factors, i.e. having had both, multiple sex partners and not used a condom in their last intercourse, over the past year of the survey. When differences and similarities were viewed within Finland and Estonia, a clear sociodemographic patterning of sexual risk behaviour and self-reported STIs was found in Finland, but a somewhat less consistent trend in Estonia. Generally, both, alcohol and drug use were strong correlates for sexual risk behaviour and self-reported STIs in Finland and Estonia, having a greater effect on engagement with multiple sex partners rather than unprotected intercourse or self-reported STIs. In Finland alcohol use, relative to drug use, was a stronger predictor of sexual risk behaviour and self-reported STIs, while in Estonia drug use predicted sexual risk behaviour and self-reported STIs stronger than alcohol use. Conclusions: The study results point to the importance for prevention of sexual risk behaviour, particularly strategies that integrate sexual risk with alcohol and drug use risks. The results point to the need to focus further research on sexual behaviour and STIs among young people; on tracking trends among general population as well as applying in-depth research to identify and learn from vulnerable and high-risk population groups for STIs who are exposed to a combination of risk factors.
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Apesar da cidade do Rio de Janeiro ser uma das mais importantes metrópoles brasileiras são muito pouco conhecidos os efeitos da exposição aos poluentes atmosféricos na saúde da população carioca. Este trabalho foi idealizado para suprir uma parte desta carência. Os poluentes investigados foram PM10, SO2, NO2, CO e O3 e os desfechos envolveram os atendimentos pediátricos de emergência por sintomas respiratórios em três unidades públicas de saúde de Jacarepaguá, entre abril de 2002 e março de 2003. As variáveis de confusão foram a tendência temporal, sazonalidade, temperatura, umidade relativa do ar, precipitação de chuva e infecções respiratórias. Também foram ajustados os efeitos do calendário, isto é, determinados dias do ano que apresentaram comportamentos anormais como feriados e finais de semana. Houve inúmeras falhas no monitoramento de todos os poluentes e devido ao reduzido volume de dados, optou-se por não incluir o SO2 nas análises. Uma vez que os determinantes e as conseqüências clínicas das exposições aos poluentes atmosféricos são bastante distintos nas vias aérias superiores e nas vias aéreas inferiores, um dos estudos verificou a associação dos poluentes do ar com transtornos nestes dois segmentos. Embora de pequena magnitude, somente o O3 apresentou resultado positivo e estatisticamente significativo, tanto com todos os atendimentos de emergência por queixas respiratórias como com os atendimentos motivados por sintomas nas vias aéreas inferiores. O efeito foi no mesmo dia da exposição (lag 0). No outro estudo, investigou-se a associação dos poluentes do ar com os atendimentos de emergência por sintomas de obstrução brônquica. Neste caso, as crianças foram categorizadads em três faixas etárias. Somente as crianças com idades menores que 2 anos tiveram um resultado positivo e estatisticamente significativo, de expressiva magnitude com PM10. Semelhante efeito foi visto com o O3, embora com significado estatístico limítrofe (p<0,06). Também neste estudo o efeito ocorreu no mesmo dia da exposição. Apesar das falhas no monitoramento, nos dois estudos, os parâmetros da poluição ambiental estiveram associados ao aumento do número de atendimentos pediátricos de emergência por motivos respiratórios em Jacarepaguá. Durante o período de estudos, os níveis de todos os poluentes monitorados permaneceram abaixo dos limites recomendados.
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Este é um estudo ecológico misto onde o perfil de distribuição de chuvas e das variações térmicas foi relacionado à variação sazonal das taxas de incidência de leishmaniose visceral em vinte municípios brasileiros de transmissão intensa da doença, no período de 2001 a 2008. O objetivo foi identificar similaridades e diferenças entre os municípios estudados quanto à tendência temporal e sazonalidade da doença e à possível relação entre variações climáticas e a distribuição sazonal da doença. Os dados de incidência de leishmaniose visceral foram obtidos do Sistema de Informação de Agravos de Notificação (Sinan), os dados demográficos foram obtidos do Departamento de Informática do Sistema Único de Saúde (DATASUS), os dados pluviométricos e de temperatura foram obtidos do Sistema de Monitoramento Agrometeorológico do Ministério da Agricultura (AGRITEMPO). Os resultados são apresentados graficamente e mostram que a distribuição sazonal da incidência e períodos prováveis de transmissão são diferentes em vários municípios e acompanham as diferenças climáticas, sugerindo que as intervenções que visem diminuir a incidência devem ser pontuais, obedecendo às características de cada município.
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Esta tese tem como foco os efeitos da desigualdade de renda na saúde bucal e as tendências em desigualdades socioeconômicas em saúde bucal. Qualquer injustiça social, pelo caráter moral é digna de estudo, porém nem toda desigualdade de renda é socialmente injusta. Ela se torna injusta quando as pessoas com menos recursos são aquelas que permitem que as desigualdades econômicas afetem direitos humanos, como o direito a um nível de vida que assegure ao indivíduo e a sua família uma vida saudável. As desigualdades de renda foram estudadas em duas vertentes:a) efeitos contextuais da desigualdade de renda na saúde bucal ; b) tendências na diferença de saúde bucal entre pessoas com maior e menor renda. A primeira parte contém quatro artigos originais que estudaram a associação e os mecanismos contextuais p elos quais a desigualdade de renda afeta a saúde bucal. Para isso, foram utilizados dados do inquérito em saúde bucal SBBrasil de 2002. Os resultados mostraram que: a) a associação entre desigualdade de renda e saúde bucal é mais forte em relação à cárie dental do que outras doenças bucais (e.g. doenças periodontais e maloclusões); b)seus efeitos estão mais fortemente associados à doenças bucais de menor latência; c) os efeitos associados à cárie dental afetam pobres e ricos igualmente; e d) a ausência de políticas públicas parece ser a melhor explicação para os efeitos da excessiva desigualdade de renda no Brasil. Ainda em relação às políticas públicas, foi encontrados que os ricos beneficiam-se mais de políticas públicas municipais do que os pobres. A segunda parte desta tese contém dois artigos originais que descrevem as tendências em saúde bucal e o uso dos serviços odontológicos em grupos de maior e menor renda, no Brasil e na Suécia. Para essas análises, foram usados dados dos inquéritos em saúde bucal no Brasil dos anos de 1986 e 2002, e para Suécia foram obtidos dados do "Swedish Level of Living Survey" para 1968, 1974, 1981, 1991 e 2000. As tendências relacionadas à prevalência de edentulismo mostraram que houve uma redução das desigualdade em percentuais absolutos nos dois países, porém, no Brasil houve um aumento das diferenças quando o desfecho foi a prevalência de nenhum dente perdido. As reduções das disparidades em edentulimo estiveram associadas à presença de uma diferença inicial significativa ,já o aumento das desigualdade na prevalência de nenhum dente perdido esteve relacionado a uma pequena desigualdade no início da coleta de dados. Em relação às desigualdades de uso dos serviços, ressalta-se que o grupo mais pobre permanece utilizando menos os serviços odontológicos em ambos os países e as diferenças continuam significantes através dos tempos. Entretanto, tanto no Brasil como na Suécia, essas diferenças reduziram levemente nas coortes jovens em função do declínio no percentual de pessoas mais ricas que visitam o dentista. Nossos dados permitem concluir que as desigualdades, em saúde bucal, mesmo em países altamente igualitários, como a Suécia.
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Background: Considerable variation in the prevalence of childhood asthma and its symptoms (wheezing) has been observed in previous studies and there is evidence that the prevalence has been increasing over time. Methods: We have systematically reviewed the reported prevalence and time trends of wheezing symptoms among children, worldwide and within the same country over time. All studies comprising more than 1000 persons and meeting certain other quality criteria published over a 16-year period, between January 1990 and December 2005, are reported and a comparison of ISAAC (International Study of Asthma and Allergies in Childhood) and non-ISAAC studies is made, in part as a way of expanding the power to examine time trends (the older studies tend to be non-ISAAC), but also to examine possible methodological differences between ISAAC and non-ISAAC questions. Results: A wide range of current prevalence of wheeze was observed between and within countries over time. The UK had the highest recorded prevalence of 32.2% in children aged 13–14 in 1994–5 and Ethiopia had the lowest prevalence, 1.7% in children aged 10–19 in 1996. All studies in Australia and the UK were compared using multiple logistic regression. ISAAC phase I and III studies reported significantly higher prevalence of current wheeze (OR = 1.638) compared with non-ISAAC studies, after adjusting for various other factors (country, survey year, age of child, parental vs child response to the survey). Australia showed a significantly higher prevalence of current wheezing (OR = 1.343) compared with the UK, there was a significant increase in the prevalence odds ratio per survey year (2.5% per year), a significant decrease per age of child (0.7% per year), and a significantly higher response in current wheezing if the response was self-completed by the child (OR = 1.290). These factors, when explored separately for ISAAC and non-ISAAC studies, showed very different results. In ISAAC studies, or non-ISAAC studies using ISAAC questions, there was a significant decrease in current wheezing prevalence over time (2.5% per year). In non-ISAAC studies, which tend to cover an earlier period, there was a significant increase (2.6% per year) in current wheezing prevalence over time. This is very likely to be a result of prevalence of wheezing increasing from the 1970s up to the early 1990s, but decreasing since then. Conclusion: The UK has the highest recorded prevalence of wheezing and Ethiopia the lowest. Prevalence of wheezing in Australia and the UK has increased from the 1970s up to the early 1990s, but decreased since then and ISAAC studies report significantly higher prevalences than non-ISAAC studies.
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Objective
To examine age and gender specific trends in coronary heart disease (CHD) and stroke mortality in two neighbouring countries, the Republic of Ireland (ROI) and Northern Ireland (NI). Design Epidemiological study of time trends in CHD and stroke mortality.
Setting/patients
The populations of the ROI and NI, 1985–2010.
Interventions
None.
Main outcome measures
Directly age standardised CHD and stroke mortality rates were calculated and analysed using joinpoint regression to identify years where the slope of the linear trend changed significantly. This was performed separately for specific age groups (25–54, 55–64, 65–74 and 75–84 years) and by gender. Annual percentage change (APC) and 95% CIs are presented.
Results
There was a striking similarity between the two countries, with percentage change between 1985 and 1989 and between 2006 and 2010 of 67% and 69% in
CHD mortality, and 64% and 62% in stroke mortality for the ROI and NI, respectively. However, joinpoint analysis identified differences in the pace of change between the two countries. There was an accelerated pace of decline (negative APC) in mortality for both CHD and stroke in both countries from the mid-1990s (APC ROI −8% (95% CI −9.5 to 6.5) and NI −6.6% (−6.9 to −6.3)), but the accelerated decrease started later for CHD mortality in the ROI. In recent years, a levelling off in CHD mortality was observed in the 25–54 year age group in NI and in stroke mortality for men and women in the ROI.
Conclusions
While differences in the pace of change in mortality were observed at different time points, similar, substantial decreases in CHD and stroke mortality were achieved between 1985 and 1989 and between 2006 and 2010 in the ROI and NI despite important differences in health service structures. There is evidence of a levelling in mortality rates in some groups in recent years.
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Background: More effective treatments have become available for haematological malignancies from the early 2000s, but few large-scale population-based studies have investigated their effect on survival. Using EUROCARE data, and HAEMACARE morphological groupings, we aimed to estimate time trends in population-based survival for 11 lymphoid and myeloid malignancies in 20 European countries, by region and age. Methods: In this retrospective observational study, we included patients (aged 15 years and older) diagnosed with haematological malignancies, diagnosed up to Dec 31, 2007, and followed up to Dec 31, 2008. We used data from the 30 cancer registries (across 20 countries) that provided continuous incidence and good quality data from 1992 to 2007. We used a hybrid approach to estimate age-standardised and age-specific 5-year relative survival, for each malignancy, overall and for five regions (UK, and northern, central, southern, and eastern Europe), and four 3-year periods (1997–99, 2000–02, 2003–05, 2006–08). For each malignancy, we also estimated the relative excess risk of death during the 5 years after diagnosis, by period, age, and region. Findings: We analysed 560 444 cases. From 1997–99 to 2006–08 survival increased for most malignancies: the largest increases were for diffuse large B-cell lymphoma (42·0% [95% CI 40·7–43·4] to 55·4% [54·6–56·2], p<0·0001), follicular lymphoma (58·9% [57·3–60·6] to 74·3% [72·9–75·5], p<0·0001), chronic myeloid leukaemia (32·3% [30·6–33·9] to 54·4% [52·5–56·2], p<0·0001), and acute promyelocytic leukaemia (50·1% [43·7–56·2] to 61·9% [57·0–66·4], p=0·0038, estimate not age-standardised). Other survival increases were seen for Hodgkin's lymphoma (75·1% [74·1–76·0] to 79·3% [78·4–80·1], p<0·0001), chronic lymphocytic leukaemia/small lymphocytic lymphoma (66·1% [65·1–67·1] to 69·0% [68·1–69·8], p<0·0001), multiple myeloma/plasmacytoma (29·8% [29·0–30·6] to 39·6% [38·8–40·3], p<0·0001), precursor lymphoblastic leukaemia/lymphoma (29·8% [27·7–32·0] to 41·1% [39·0–43·1], p<0·0001), acute myeloid leukaemia (excluding acute promyelocytic leukaemia, 12·6% [11·9–13·3] to 14·8% [14·2–15·4], p<0·0001), and other myeloproliferative neoplasms (excluding chronic myeloid leukaemia, 70·3% [68·7–71·8] to 74·9% [73·8–75·9], p<0·0001). Survival increased slightly in southern Europe, more in the UK, and conspicuously in northern, central, and eastern Europe. However, eastern European survival was lower than that for other regions. Survival decreased with advancing age, and increased with time only slightly in patients aged 75 years or older, although a 10% increase in survival occurred in elderly patients with follicular lymphoma, diffuse large B-cell lymphoma, and chronic myeloid leukaemia. Interpretation: These trends are encouraging. Widespread use of new and more effective treatment probably explains much of the increased survival. However, the persistent differences in survival across Europe suggest variations in the quality of care and availability of the new treatments. High-resolution studies that collect data about stage at diagnosis and treatments for representative samples of cases could provide further evidence of treatment effectiveness and explain geographic variations in survival.
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BACKGROUND: Head and neck (H&N) cancers are a heterogeneous group of malignancies, affecting various sites, with different prognoses. The aims of this study are to analyse survival for patients with H&N cancers in relation to tumour location, to assess the change in survival between European countries, and to investigate whether survival improved over time.
METHODS: We analysed about 250,000 H&N cancer cases from 86 cancer registries (CRs). Relative survival (RS) was estimated by sex, age, country and stage. We described survival time trends over 1999-2007, using the period approach. Model based survival estimates of relative excess risks (RERs) of death were also provided by country, after adjusting for sex, age and sub-site.
RESULTS: Five-year RS was the poorest for hypopharynx (25%) and the highest for larynx (59%). Outcome was significantly better in female than in male patients. In Europe, age-standardised 5-year survival remained stable from 1999-2001 to 2005-2007 for laryngeal cancer, while it increased for all the other H&N cancers. Five-year age-standardised RS was low in Eastern countries, 47% for larynx and 28% for all the other H&N cancers combined, and high in Ireland and the United Kingdom (UK), and Northern Europe (62% and 46%). Adjustment for sub-site narrowed the difference between countries. Fifty-four percent of patients was diagnosed at advanced stage (regional or metastatic). Five-year RS for localised cases ranged between 42% (hypopharynx) and 74% (larynx).
CONCLUSIONS: This study shows survival progresses during the study period. However, slightly more than half of patients were diagnosed with regional or metastatic disease at diagnosis. Early diagnosis and timely start of treatment are crucial to reduce the European gap to further improve H&N cancers outcome.
Survival of patients with skin melanoma in Europe increases further: Results of the EUROCARE-5 study
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Background In Europe skin melanoma (SM) survival has increased over time. The aims were to evaluate recent trends and differences between countries and regions of Europe.
Methods Relative survival (RS) estimates and geographical comparisons were based on 241,485 patients aged 15 years and over with a diagnosis of invasive SM in Europe (2000-2007). Survival time trends during 1999-2007 were estimated using the period approach, for 213,101 patients. Age, gender, sub-sites and morphology subgroups were considered.
Results In European patients, estimated 5-year RS was 83% (95% confidence interval, CI 83-84%). The highest values were found for patients resident in Northern (88%; 87-88%) and Central (88%; 87-88%) Europe, followed by Ireland and United Kingdom (UK) (86%; 85-86%) and Southern Europe (83%; 82-83%). The lowest survival was in Eastern Europe (74%; 74-75%). Within regions the intercountry absolute difference in percentage points of RS varied from 4% (North) to 34% (East). RS decreased markedly with patients' age and was higher in women than men. Differences according to SM morphology and skin sub-sites also emerged. Survival has slightly increased from 1999 to 2007, with a small improvement in Northern and the most pronounced improvement in Eastern Europe.
Discussion SM survival is high and still increasing in European patients. The gap between Northern and Southern and especially Eastern European countries, although still present, diminished over time. Differences in stage distribution at diagnosis may explain most of the geographical differences. However, part of the improvement in survival may be attributed to overdiagnosis from early diagnosis practices.
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RESUMO: A estrutura demográfica portuguesa é marcada por baixas taxas de natalidade e mortalidade, onde a população idosa representa uma fatia cada vez mais representativa, fruto de uma maior longevidade. A incidência do cancro, na sua generalidade, é maior precisamente nessa classe etária. A par de outras doenças igualmente lesivas (e.g. cardiovasculares, degenerativas) cuja incidência aumenta com a idade, o cancro merece relevo. Estudos epidemiológicos apresentam o cancro como líder mundial na mortalidade. Em países desenvolvidos, o seu peso representa 25% do número total de óbitos, percentagem essa que mais que duplica noutros países. A obesidade, a baixa ingestão de frutas e vegetais, o sedentarismo, o consumo de tabaco e a ingestão de álcool, configuram-se como cinco dos fatores de risco presentes em 30% das mortes diagnosticadas por cancro. A nível mundial e, em particular no Sul de Portugal, os cancros do estômago, recto e cólon apresentam elevadas taxas de incidência e de mortalidade. Do ponto de vista estritamente económico, o cancro é a doença que mais recursos consome enquanto que do ponto de vista físico e psicológico é uma doença que não limita o seu raio de ação ao doente. O cancro é, portanto, uma doença sempre atual e cada vez mais presente, pois reflete os hábitos e o ambiente de uma sociedade, não obstante as características intrínsecas a cada indivíduo. A adoção de metodologia estatística aplicada à modelação de dados oncológicos é, sobretudo, valiosa e pertinente quando a informação é oriunda de Registos de Cancro de Base Populacional (RCBP). A pertinência é justificada pelo fato destes registos permitirem aferir numa população específica, o risco desta sofrer e/ou vir a sofrer de uma dada neoplasia. O peso que as neoplasias do estômago, cólon e recto assumem foi um dos elementos que motivou o presente estudo que tem por objetivo analisar tendências, projeções, sobrevivências relativas e a distribuição espacial destas neoplasias. Foram considerados neste estudo todos os casos diagnosticados no período 1998-2006, pelo RCBP da região sul de Portugal (ROR-Sul). O estudo descritivo inicial das taxas de incidência e da tendência em cada uma das referidas neoplasias teve como base uma única variável temporal - o ano de diagnóstico - também designada por período. Todavia, uma metodologia que contemple apenas uma única variável temporal é limitativa. No cancro, para além do período, a idade à data do diagnóstico e a coorte de nascimento, são variáveis temporais que poderão prestar um contributo adicional na caracterização das taxas de incidência. A relevância assumida por estas variáveis temporais justificou a sua inclusão numaclasse de modelos designada por modelos Idade-Período-Coorte (Age-Period-Cohort models - APC), utilizada na modelação das taxas de incidência para as neoplasias em estudo. Os referidos modelos permitem ultrapassar o problema de relações não lineares e/ou de mudanças súbitas na tendência linear das taxas. Nos modelos APC foram consideradas a abordagem clássica e a abordagem com recurso a funções suavizadoras. A modelação das taxas foi estratificada por sexo. Foram ainda estudados os respectivos submodelos (apenas com uma ou duas variáveis temporais). Conhecido o comportamento das taxas de incidência, uma questão subsequente prende-se com a sua projeção em períodos futuros. Porém, o efeito de mudanças estruturais na população, ao qual Portugal não é alheio, altera substancialmente o número esperado de casos futuros com cancro. Estimativas da incidência de cancro a nível mundial obtidas a partir de projeções demográficas apontam para um aumento de 25% dos casos de cancro nas próximas duas décadas. Embora a projeção da incidência esteja associada a alguma incerteza, as projeções auxiliam no planeamento de políticas de saúde para a afetação de recursos e permitem a avaliação de cenários e de intervenções que tenham como objetivo a redução do impacto do cancro. O desconhecimento de projeções da taxa de incidência destas neoplasias na área abrangida pelo ROR-Sul, levou à utilização de modelos de projeção que diferem entre si quanto à sua estrutura, linearidade (ou não) dos seus coeficientes e comportamento das taxas na série histórica de dados (e.g. crescente, decrescente ou estável). Os referidos modelos pautaram-se por duas abordagens: (i)modelos lineares no que concerne ao tempo e (ii) extrapolação de efeitos temporais identificados pelos modelos APC para períodos futuros. Foi feita a projeção das taxas de incidência para os anos de 2007 a 2010 tendo em conta o género, idade e neoplasia. É ainda apresentada uma estimativa do impacto económico destas neoplasias no período de projeção. Uma questão pertinente e habitual no contexto clínico e a que o presente estudo pretende dar resposta, reside em saber qual a contribuição da neoplasia em si para a sobrevivência do doente. Nesse sentido, a mortalidade por causa específica é habitualmente utilizada para estimar a mortalidade atribuível apenas ao cancro em estudo. Porém, existem muitas situações em que a causa de morte é desconhecida e, mesmo que esta informação esteja disponível através dos certificados de óbito, não é fácil distinguir os casos em que a principal causa de morte é devida ao cancro. A sobrevivência relativa surge como uma medida objetiva que não necessita do conhecimento da causa específica da morte para o seu cálculo e dar-nos-á uma estimativa da probabilidade de sobrevivência caso o cancro em análise, num cenário hipotético, seja a única causa de morte. Desconhecida a principal causa de morte nos casos diagnosticados com cancro no registo ROR-Sul, foi determinada a sobrevivência relativa para cada uma das neoplasias em estudo, para um período de follow-up de 5 anos, tendo em conta o sexo, a idade e cada uma das regiões que constituem o registo. Foi adotada uma análise por período e as abordagens convencional e por modelos. No epílogo deste estudo, é analisada a influência da variabilidade espaço-temporal nas taxas de incidência. O longo período de latência das doenças oncológicas, a dificuldade em identificar mudanças súbitas no comportamento das taxas, populações com dimensão e riscos reduzidos, são alguns dos elementos que dificultam a análise da variação temporal das taxas. Nalguns casos, estas variações podem ser reflexo de flutuações aleatórias. O efeito da componente temporal aferida pelos modelos APC dá-nos um retrato incompleto da incidência do cancro. A etiologia desta doença, quando conhecida, está associada com alguma frequência a fatores de risco tais como condições socioeconómicas, hábitos alimentares e estilo de vida, atividade profissional, localização geográfica e componente genética. O “contributo”, dos fatores de risco é, por vezes, determinante e não deve ser ignorado. Surge, assim, a necessidade em complementar o estudo temporal das taxas com uma abordagem de cariz espacial. Assim, procurar-se-á aferir se as variações nas taxas de incidência observadas entre os concelhos inseridos na área do registo ROR-Sul poderiam ser explicadas quer pela variabilidade temporal e geográfica quer por fatores socioeconómicos ou, ainda, pelos desiguais estilos de vida. Foram utilizados os Modelos Bayesianos Hierárquicos Espaço-Temporais com o objetivo de identificar tendências espaço-temporais nas taxas de incidência bem como quantificar alguns fatores de risco ajustados à influência simultânea da região e do tempo. Os resultados obtidos pela implementação de todas estas metodologias considera-se ser uma mais valia para o conhecimento destas neoplasias em Portugal.------------ABSTRACT: mortality rates, with the elderly being an increasingly representative sector of the population, mainly due to greater longevity. The incidence of cancer, in general, is greater precisely in that age group. Alongside with other equally damaging diseases (e.g. cardiovascular,degenerative), whose incidence rates increases with age, cancer is of special note. In epidemiological studies, cancer is the global leader in mortality. In developed countries its weight represents 25% of the total number of deaths, with this percentage being doubled in other countries. Obesity, a reduce consumption of fruit and vegetables, physical inactivity, smoking and alcohol consumption, are the five risk factors present in 30% of deaths due to cancer. Globally, and in particular in the South of Portugal, the stomach, rectum and colon cancer have high incidence and mortality rates. From a strictly economic perspective, cancer is the disease that consumes more resources, while from a physical and psychological point of view, it is a disease that is not limited to the patient. Cancer is therefore na up to date disease and one of increased importance, since it reflects the habits and the environment of a society, regardless the intrinsic characteristics of each individual. The adoption of statistical methodology applied to cancer data modelling is especially valuable and relevant when the information comes from population-based cancer registries (PBCR). In such cases, these registries allow for the assessment of the risk and the suffering associated to a given neoplasm in a specific population. The weight that stomach, colon and rectum cancers assume in Portugal was one of the motivations of the present study, that focus on analyzing trends, projections, relative survival and spatial distribution of these neoplasms. The data considered in this study, are all cases diagnosed between 1998 and 2006, by the PBCR of Portugal, ROR-Sul.Only year of diagnosis, also called period, was the only time variable considered in the initial descriptive analysis of the incidence rates and trends for each of the three neoplasms considered. However, a methodology that only considers one single time variable will probably fall short on the conclusions that could be drawn from the data under study. In cancer, apart from the variable period, the age at diagnosis and the birth cohort are also temporal variables and may provide an additional contribution to the characterization of the incidence. The relevance assumed by these temporal variables justified its inclusion in a class of models called Age-Period-Cohort models (APC). This class of models was used for the analysis of the incidence rates of the three cancers under study. APC models allow to model nonlinearity and/or sudden changes in linear relationships of rate trends. Two approaches of APC models were considered: the classical and the one using smoothing functions. The models were stratified by gender and, when justified, further studies explored other sub-models where only one or two temporal variables were considered. After the analysis of the incidence rates, a subsequent goal is related to their projections in future periods. Although the effect of structural changes in the population, of which Portugal is not oblivious, may substantially change the expected number of future cancer cases, the results of these projections could help planning health policies with the proper allocation of resources, allowing for the evaluation of scenarios and interventions that aim to reduce the impact of cancer in a population. Worth noting that cancer incidence worldwide obtained from demographic projections point out to an increase of 25% of cancer cases in the next two decades. The lack of projections of incidence rates of the three cancers under study in the area covered by ROR-Sul, led us to use a variety of forecasting models that differ in the nature and structure. For example, linearity or nonlinearity in their coefficients and the trend of the incidence rates in historical data series (e.g. increasing, decreasing or stable).The models followed two approaches: (i) linear models regarding time and (ii) extrapolation of temporal effects identified by the APC models for future periods. The study provide incidence rates projections and the numbers of newly diagnosed cases for the year, 2007 to 2010, taking into account gender, age and the type of cancer. In addition, an estimate of the economic impact of these neoplasms is presented for the projection period considered. This research also try to address a relevant and common clinical question in these type of studies, regarding the contribution of the type of cancer to the patient survival. In such studies, the primary cause of death is commonly used to estimate the mortality specifically due to the cancer. However, there are many situations in which the cause of death is unknown, or, even if this information is available through the death certificates, it is not easy to distinguish the cases where the primary cause of death is the cancer. With this in mind, the relative survival is an alternative measure that does not need the knowledge of the specific cause of death to be calculated. This estimate will represent the survival probability in the hypothetical scenario of a certain cancer be the only cause of death. For the patients with unknown cause of death that were diagnosed with cancer in the ROR-Sul, the relative survival was calculated for each of the cancers under study, for a follow-up period of 5 years, considering gender, age and each one of the regions that are part the registry. A period analysis was undertaken, considering both the conventional and the model approaches. In final part of this study, we analyzed the influence of space-time variability in the incidence rates. The long latency period of oncologic diseases, the difficulty in identifying subtle changes in the rates behavior, populations of reduced size and low risk are some of the elements that can be a challenge in the analysis of temporal variations in rates, that, in some cases, can reflect simple random fluctuations. The effect of the temporal component measured by the APC models gives an incomplete picture of the cancer incidence. The etiology of this disease, when known, is frequently associated to risk factors such as socioeconomic conditions, eating habits and lifestyle, occupation, geographic location and genetic component. The "contribution"of such risk factors is sometimes decisive in the evolution of the disease and should not be ignored. Therefore, there was the need to consider an additional approach in this study, one of spatial nature, addressing the fact that changes in incidence rates observed in the ROR-Sul area, could be explained either by temporal and geographical variability or by unequal socio-economic or lifestyle factors. Thus, Bayesian hierarchical space-time models were used with the purpose of identifying space-time trends in incidence rates together with the the analysis of the effect of the risk factors considered in the study. The results obtained and the implementation of all these methodologies are considered to be an added value to the knowledge of these neoplasms in Portugal.
Resumo:
Au cours du siècle dernier, nous avons pu observer une diminution remarquable de la mortalité dans toutes les régions du monde, en particulier dans les pays développés. Cette chute a été caractérisée par des modifications importantes quant à la répartition des décès selon l'âge, ces derniers ne se produisant plus principalement durant les premiers âges de la vie mais plutôt au-delà de l'âge de 65 ans. Notre étude s'intéresse spécifiquement au suivi fin et détaillé des changements survenus dans la distribution des âges au décès chez les personnes âgées. Pour ce faire, nous proposons une nouvelle méthode de lissage non paramétrique souple qui repose sur l'utilisation des P-splines et qui mène à une expression précise de la mortalité, telle que décrite par les données observées. Les résultats de nos analyses sont présentés sous forme d'articles scientifiques, qui s'appuient sur les données de la Human Mortality Database, la Base de données sur la longévité canadienne et le Registre de la population du Québec ancien reconnues pour leur fiabilité. Les conclusions du premier article suggèrent que certains pays à faible mortalité auraient récemment franchi l'ère de la compression de la mortalité aux grands âges, ère durant laquelle les décès au sein des personnes âgées tendent à se concentrer dans un intervalle d'âge progressivement plus court. En effet, depuis le début des années 1990 au Japon, l'âge modal au décès continue d'augmenter alors que le niveau d'hétérogénéité des durées de vie au-delà de cet âge demeure inchangé. Nous assistons ainsi à un déplacement de l'ensemble des durées de vie adultes vers des âges plus élevés, sans réduction parallèle de la dispersion de la mortalité aux grands âges. En France et au Canada, les femmes affichent aussi de tels développements depuis le début des années 2000, mais le scénario de compression de la mortalité aux grands âges est toujours en cours chez les hommes. Aux États-Unis, les résultats de la dernière décennie s'avèrent inquiétants car pour plusieurs années consécutives, l'âge modal au décès, soit la durée de vie la plus commune des adultes, a diminué de manière importante chez les deux sexes. Le second article s'inscrit dans une perspective géographique plus fine et révèle que les disparités provinciales en matière de mortalité adulte au Canada entre 1930 et 2007, bien décrites à l'aide de surfaces de mortalité lissées, sont importantes et méritent d'être suivies de près. Plus spécifiquement, sur la base des trajectoires temporelles de l'âge modal au décès et de l'écart type des âges au décès situés au-delà du mode, les différentiels de mortalité aux grands âges entre provinces ont à peine diminué durant cette période, et cela, malgré la baisse notable de la mortalité dans toutes les provinces depuis le début du XXe siècle. Également, nous constatons que ce sont précisément les femmes issues de provinces de l'Ouest et du centre du pays qui semblent avoir franchi l'ère de la compression de la mortalité aux grands âges au Canada. Dans le cadre du troisième et dernier article de cette thèse, nous étudions la longévité des adultes au XVIIIe siècle et apportons un nouvel éclairage sur la durée de vie la plus commune des adultes à cette époque. À la lumière de nos résultats, l'âge le plus commun au décès parmi les adultes canadiens-français a augmenté entre 1740-1754 et 1785-1799 au Québec ancien. En effet, l'âge modal au décès est passé d'environ 73 ans à près de 76 ans chez les femmes et d'environ 70 ans à 74 ans chez les hommes. Les conditions de vie particulières de la population canadienne-française à cette époque pourraient expliquer cet accroissement.