Differential trends in myocardial infarction mortality over 1975-2010 in France according to gender: An age-period-cohort analysis.

BACKGROUND: A dramatic reduction in mortality from myocardial infarction (MI) has been observed in France as in other western countries. The dynamics of this decline are likely to have differed according to age and sex. Our study sought to clarify the contributions of age, period and birth-cohort effects on post-MI mortality in France between 1975 and 2010 and to identify gender-specific trends. METHODS: Trends were analysed using an age-period-cohort (APC) model. MI mortality data were selected using the International Classification of Diseases (ICD) (8, 9 and 10th revision) codes from the French national mortality databases. RESULTS: Age-standardised MI mortality rates decreased by 70% from 1975 to 2010 in both sexes. Linear trend (drift) accounted for the majority of this decline and appeared very similar between genders. However, we found that increased MI mortality with advancing age was more pronounced in women than men beyond the age of 50. We also observed a slowdown in the decline among cohorts born after 1945, particularly in women. CONCLUSIONS: MI mortality showed a dramatic downward trend for the last 35years in France. The linear decline was modulated by cohort effects, whereas no major period effect was identified. This study also showed noticeable differential age and cohorts' effects between genders, especially the no longer decline in MI mortality for women born after World War II. This highlights the need for specific preventive measures to target this population in the future.

[Record linkage of hospital discharge data and first health certificates: a test in the Val d'Oise]. / Chaînage d'enregistrements de séjours PMSI aux premiers certificats de santé: un test dans le Val d'Oise.

BACKGROUND: Our objective was to test the feasibility of an indirect linkage of data on births from health certificates (HC) with hospital discharge (HD) data. METHODS: The linkage was carried out for live births between April 1st and June 30th, 2011 in six of the nine maternity units in the district of Val d'Oise. The HC and HD had 3284 and 3550 births registered during this period, respectively. Linkage was conducted using variables available in both sources: number of fetuses, baby's birth date, gender, maternity unit of birth, maternal age, municipality of residence, gestational age and birth-weight. Two linkage methods were tested: a deterministic and a semi-deterministic method and a probabilistic approach. The latter method calculates a probability estimate for the strength of the relationship between two linked observations related to the discriminatory power and the error rate of the matched variables. For cases that were linked despite discordance on some of the matching variables, random samples of observations were checked against both HC and HD records to compute rates of false matches. RESULTS: The deterministic and semi-deterministic method linked 92.5% and 85.6% of observations in the HC and HD, respectively. The probabilistic method achieved a linkage rate of 99.6% for HC and 92.7% for HD. Cases only linked by the probabilistic method were more often preterm and had low birth-weight. Cases matched using the probabilistic method only had an error rate of 0.4% with 95% CI [0.2-0.6%]. CONCLUSION: Common items in the HC and HD make it possible to achieve a high rate of linkage. The probabilistic method links more births and, in particular, those at higher risk, and error rates were low.

[Health risk assessment of traffic-related air pollution near busy roads]. / Exposition à la pollution atmosphérique de proximité liée au trafic : quelles méthodes pour quels risques sanitaires ?

BACKGROUND: Although ambient urban air pollution has well-established health effects, epidemiology faces many difficulties in estimating the risks due to exposure to traffic pollutants near busy roads. This review aims to summarize how exposure to traffic-related air pollution near busy roads is assessed in epidemiological studies and main findings regarding health effects. METHOD: After presenting the specificity of emissions due to traffic road, this review identifies the key methods and main results found in epidemiologic studies seeking to measure the influence of exposure to nearby traffic on health published over the past decade. RESULTS: The characterization and measurement of population exposure to traffic pollution faces many difficulties. Thus, epidemiological studies have used two broad categories of surrogates to assess exposure: direct measures of traffic itself such as distance of the residence to the nearest road and traffic volume and modeled concentrations of pollutant surrogates. Studies that implemented these methods showed that people living near heavy traffic road or exposed to near-road air pollution tend to report more health outcomes. DISCUSSION: Traffic-related air pollution near busy roads is the subject of increasing attention, and tends to be better characterized. However, its health impacts remain difficult to grasp, especially because of the vast diversity of approaches used in epidemiological studies. Greater consistency in the protocols would be desirable to provide better understanding of the health issue of traffic in urban areas and thus to better implement policies to protect those most at risk.

Can a second wave of new variant of the CJD be discarded in absence of observation of clinical non Met-Met cases?

BACKGROUND: Presently, all patients with clinical variant Creutzfeldt-Jakob disease in the United Kingdom have been Met-Met at codon 129 of the PrP gene. There is much worry about the possibility of a second wave of the epidemic in the 60% of the United Kingdom population which are not Met-Met. METHODS: A mathematical model of a putative United Kingdom variant Creutzfeldt-Jakob disease epidemic that could occur in non Met-Met is derived. The risk of infection is assumed to parallel the Met-Met risk which has been previously modelled. The reason for the present absence of clinical non Met-Met cases is assumed to be a longer incubation period in these subjects than in others. The incubation period is assumed to be lognormally distributed. The means and coefficients of variation compatible with the present absence of clinical cases are systematically searched. RESULTS: We show that the present absence of clinical cases of variant Creutzfeldt-Jakob disease in the Met-Val or Val-Val population can be compatible with a second wave only if the mean incubation period is more than 25 years. The best estimates of the size of the second wave are always below 250. A fraction of these cases however will never be observed, as they will die from other causes before the onset of the new variant. CONCLUSION: The mean incubation period values compatible with the absence of non Met-Met clinical cases that we found are not implausible, and the possibility of a second wave cannot yet be ruled out. However, should this second wave occur, it would be below 250 in the worst hypothesis.