[Les retraités au Canada : portrait comparatif selon le statut d'immigrant].

La retraite au Canada a fait l'objet de plusieurs recherches, mais peu d'études ont comparé le passage de la vie active à la retraite des natifs et des immigrants ainsi que leurs caractéristiques une fois à la retraite, une lacune importante compte tenu de l'augmentation de la part des immigrants parmi les futures cohortes canadiennes de retraités. Cette étude descriptive vise à pallier cette lacune à l'aide des données de l'Enquête sociale générale de 2016. Les résultats montrent, entre autres, que les femmes et les hommes natifs ont plus de chances de prendre leur retraite que les immigrants, quel que soit le groupe d'âge étudié, et que l'âge moyen à la retraite des femmes et hommes immigrants est de deux ans supérieur à celui des natifs. Cette étude suggère que le statut d'immigrant implique une transition vers la retraite différente de celle vécue par les natifs ; différence qui devrait être considérée dans la structure du système de revenus de retraite.

Staged Mastopexy Before Nipple-Sparing Mastectomy: Improving Safety and Appearance in Implant-Based and Autologous Breast Reconstruction.

BACKGROUND: Breast reconstruction following nipple sparing mastectomy in patients with large or ptotic breasts remains challenging because of the risk of ischemic complications and the difficulty in managing the redundant skin envelope. Staged mastopexy or breast reduction before the mastectomy/reconstruction has been shown to decrease the risk of complications and improve clinical outcomes. METHODS: A retrospective analysis was conducted of patients with a genetic predisposition to breast cancer who underwent staged breast reduction/mastopexy before nipple sparing mastectomy and reconstruction in our institution. In patients with in situ disease or invasive cancer, the first stage consisted of lumpectomy and oncoplastic reduction/mastopexy. Breast reconstruction at the second stage was performed with free abdominal flaps or breast implants and acellular dermal matrix. Data regarding the ischemic complications were recorded. RESULTS: In total, 47 patients (84 breasts) underwent this staged approach. All patients had a genetic predisposition to breast cancer. The time interval between the two stages was 11.5 months (range, 1.3 to 23.6 months). Twelve breasts (14.3 percent) were reconstructed with free abdominal flaps, 6 (7.1 percent) with tissue expanders and 66 (78.6 percent) with permanent subpectoral implants and acellular dermal matrix. There was one postoperative superficial nipple areolar complex epidermolysis (1.2 percent), and two partial mastectomy skin flap necrosis (2.4 percent). The mean follow-up time after completion of reconstruction was 8.3 months. CONCLUSION: Mastopexy or breast reduction before nipple sparing mastectomy and reconstruction is a safe procedure with a low risk of ischemic complications.

BREAST-Q Patient-reported Outcomes in Different Types of Breast Reconstruction after Fat Grafting.

Breast reconstruction after mastectomy improves patient quality of life. Independently of the type of reconstruction, ancillary procedures are sometimes necessary to improve results. Fat grafting to the breast is a safe procedure with excellent results. We report patient-reported outcomes using the BREAST-Q questionnaire after autologous fat grafting in different types of reconstructed breasts. Methods: We performed a single-center, prospective, comparative study that compared patient-reported outcomes using the BREAST-Q in patients after different types of breast reconstruction (autologous, alloplastic, or after breast conserving) who subsequently had fat grafting. Results: In total, 254 patients were eligible for the study, but only 54 (68 breasts) completed all the stages needed for inclusion. Patient demographic and breast characteristics are described. Median age was 52 years. The mean body mass index was 26.1 ± 3.9. The mean postoperative period at the administration of BREAST-Q questionnaires was 17.6 months. The mean preoperative BREAST-Q was 59.92 ± 17.37, and the mean postoperative score was 74.84 ± 12.48 (P < 0.0001). There was no significant difference when divided by the type of reconstruction. Conclusion: Fat grafting is an ancillary procedure that improves the outcomes in breast reconstruction independently of the reconstruction type and heightens patient satisfaction, and it should be considered an integral part of any reconstruction algorithm.

Locally advanced breast cancer arising in the axilla.

Locally advanced breast cancer arising from ectopic axillary breast tissue is an unusual presentation of this malignancy. The work-up and treatment approach pose some unique challenges. We present the case of a 37-year-old female presenting with a left axillary lesion with skin involvement. Radiological studies and biopsy demonstrated an underlying axillary mass compatible with a triple-positive invasive ductal carcinoma of the breast. Following neoadjuvant therapy, the patient underwent nipple-sparing mastectomy with wide local excision of the involved axillary skin and axillary lymph node dissection. Ectopic locally advanced breast cancer can be treated similarly to its orthotopic counterpart, favoring a neoadjuvant therapy approach followed by surgical excision. Special considerations include the local anatomy of the tumor, the extent of surgery and reconstructive options.

Age-Specific Incidence of Influenza A Responds to Change in Virus Subtype Dominance.

When H3N2 replaced H1N1 as the dominant influenza A subtype during the 2018-2019 season, the pattern of age-specific incidence shifted due to the lingering effects of antigenic imprinting. The characteristic shape that imprinting leaves on influenza susceptibility could foster important advances in understanding and predicting the epidemiology of influenza.

Correction to: Determinants of Influenza Mortality Trends: Age-Period-Cohort Analysis of Influenza Mortality in the United States, 1959-2016.

First, we use Lexis surfaces based on Serfling models to highlight influenza mortality patterns as well as to identify lingering effects of early-life exposure to specific influenza virus subtypes (e.g., H1N1, H3N2).

Determinants of Influenza Mortality Trends: Age-Period-Cohort Analysis of Influenza Mortality in the United States, 1959-2016.

This study examines the roles of age, period, and cohort in influenza mortality trends over the years 1959-2016 in the United States. First, we use Lexis surfaces based on Serfling models to highlight influenza mortality patterns as well as to identify lingering effects of early-life exposure to specific influenza virus subtypes (e.g., H1N1, H3N2). Second, we use age-period-cohort (APC) methods to explore APC linear trends and identify changes in the slope of these trends (contrasts). Our analyses reveal a series of breakpoints where the magnitude and direction of birth cohort trends significantly change, mostly corresponding to years in which important antigenic drifts or shifts took place (i.e., 1947, 1957, 1968, and 1978). Whereas child, youth, and adult influenza mortality appear to be influenced by a combination of cohort- and period-specific factors, reflecting the interaction between the antigenic experience of the population and the evolution of the influenza virus itself, mortality patterns of the elderly appear to be molded by broader cohort factors. The latter would reflect the processes of physiological capital improvement in successive birth cohorts through secular changes in early-life conditions. Antigenic imprinting, cohort morbidity phenotype, and other mechanisms that can generate the observed cohort effects, including the baby boom, are discussed.

Using Geographic Distance as a Potential Proxy for Help in the Assessment of the Grandmother Hypothesis.

Life-history theory predicts that selection could favor the decoupling of somatic and reproductive senescence if post-reproductive lifespan (PRLS) provides additional indirect fitness benefits [1, 2]. The grandmother hypothesis proposes that prolonged PRLS evolved because post-reproductive grandmothers gain inclusive fitness benefits by helping their daughters and grandchildren [3, 4]. Because most historical human data do not report direct evidence of help, we hypothesized that geographic distance between individuals may be inversely related to their capacity to help. Using an exceptionally detailed dataset of pre-industrial French settlers in the St. Lawrence Valley during the 17th and 18th centuries, we assessed the potential for grandmothers to improve their inclusive fitness by helping their descendants, and we evaluated how this effect varied with geographic distance, ranging between 0 and 325 km, while accounting for potential familial genetic and environmental effects [5-9]. Grandmothers (F0) who were alive allowed their daughters (F1) to increase their number of offspring (F2) born by 2.1 and to increase their number of offspring surviving to 15 years of age by 1.1 compared to when grandmothers were dead. However, the age at first reproduction was not influenced by the life status (alive or dead) of grandmothers. As geographic distance increased, the number of offspring born and lifetime reproductive success decreased, while the age at first reproduction increased, despite the grandmother being alive in these analyses. Our study suggests that geographic proximity has the potential to modulate inclusive fitness, supporting the grandmother hypothesis, and to contribute to our understanding of the evolution of PRLS.

Epidemic cycles and environmental pressure in colonial Quebec.

OBJECTIVES: Research on historical populations in Europe finds that infectious disease epidemics appear to induce predictable cycles in age-specific mortality. We know little, however, about whether such cycles also occurred in less dense founder populations of North America. We used high-quality data on the Quebecois population from 1680 to 1798 to examine the extent to which age-specific mortality showed predictable epidemic cycles. We further examined whether environmental pressures-temperature, lack of precipitation, or crop failure-may have set the stage for the emergence of epidemics. METHODS: We applied autoregressive, integrated, moving average time series methods to annual counts of period mortality for the following age groups: < 1 year, 1 to < 5 years, 5 to < 15 years, 15 to < 50 years, and 50 years and above. These methods controlled for other patterns (e.g., trend) before empirically identifying cycles. RESULTS: Results indicate a strong seven-year cycle in mortality among infants and children under seven years of age. Warm temperatures (across Quebec overall) and relatively dry years (in Eastern Quebec) also predicted an increased risk of mortality in infancy and childhood, although these environmental variables appear to act independently of the epidemic cycle pattern. DISCUSSION: Findings indicate a strong seven-year epidemic cycle in historical Quebec which afflicted naïve birth cohorts not previously exposed to the prior epidemic. We contend that smallpox epidemics likely contributed to this cycle. The seven-year cycle occurred only in the latter half of the test period (post 1740) with increasing size of the colony and population concentration in urban areas.

Outcomes of Selective Reduction of DCDA Twins Complicated by PV-PROM Compared with Expectant Management: A Case Series and Review of the Literature.

OBJECTIVE: To report the outcomes of selective reduction (SR) in dichorionic twins complicated by pre-viable, premature rupture of membranes (PV-PROM). METHODS: Retrospective case series. Ultrasound database was searched for cases of dichorionic twin pregnancy with PV-PROM, either managed conservatively or with SR. Chart reviews were done for these cases. Simple descriptive statistics were used where appropriate. RESULTS: Twenty-two cases of expectantly managed dichorionic twins complicated by PV-PROM with delivery information were available for analysis. Mean GA at PV-PROM was 20.6 weeks, mean GA of delivery was 27.6 weeks, and the mean latency was 39.6 days. There were five cases of SR following PV-PROM in dichorionic twin pregnancies. Mean GA of PV-PROM was 17.0 weeks. Average time from PV-PROM to procedure was 2.5 weeks. Mean GA of delivery of the surviving fetus was 32.6 weeks (P = 0.20) with mean latency of 108 days (P = 0.06). Twelve additional cases have been published and are summarized along with our five cases. CONCLUSION: There was a trend towards an increase in latency interval between cases of PV-PROM managed by SR and expectant management in our institution. When combined with the existing literature data, there may be an improvement in latency.

Pandemic Paradox: Early Life H2N2 Pandemic Influenza Infection Enhanced Susceptibility to Death during the 2009 H1N1 Pandemic.

Recent outbreaks of H5, H7, and H9 influenza A viruses in humans have served as a vivid reminder of the potentially devastating effects that a novel pandemic could exert on the modern world. Those who have survived infections with influenza viruses in the past have been protected from subsequent antigenically similar pandemics through adaptive immunity. For example, during the 2009 H1N1 "swine flu" pandemic, those exposed to H1N1 viruses that circulated between 1918 and the 1940s were at a decreased risk for mortality as a result of their previous immunity. It is also generally thought that past exposures to antigenically dissimilar strains of influenza virus may also be beneficial due to cross-reactive cellular immunity. However, cohorts born during prior heterosubtypic pandemics have previously experienced elevated risk of death relative to surrounding cohorts of the same population. Indeed, individuals born during the 1890 H3Nx pandemic experienced the highest levels of excess mortality during the 1918 "Spanish flu." Applying Serfling models to monthly mortality and influenza circulation data between October 1997 and July 2014 in the United States and Mexico, we show corresponding peaks in excess mortality during the 2009 H1N1 "swine flu" pandemic and during the resurgent 2013-2014 H1N1 outbreak for those born at the time of the 1957 H2N2 "Asian flu" pandemic. We suggest that the phenomenon observed in 1918 is not unique and points to exposure to pandemic influenza early in life as a risk factor for mortality during subsequent heterosubtypic pandemics.IMPORTANCE The relatively low mortality experienced by older individuals during the 2009 H1N1 influenza virus pandemic has been well documented. However, reported situations in which previous influenza virus exposures have enhanced susceptibility are rare and poorly understood. One such instance occurred in 1918-when those born during the heterosubtypic 1890 H3Nx influenza virus pandemic experienced the highest levels of excess mortality. Here, we demonstrate that this phenomenon was not unique to the 1918 H1N1 pandemic but that it also occurred during the contemporary 2009 H1N1 pandemic and 2013-2014 H1N1-dominated season for those born during the heterosubtypic 1957 H2N2 "Asian flu" pandemic. These data highlight the heretofore underappreciated phenomenon that, in certain instances, prior exposure to pandemic influenza virus strains can enhance susceptibility during subsequent pandemics. These results have important implications for pandemic risk assessment and should inform laboratory studies aimed at uncovering the mechanism responsible for this effect.

Mother's curse neutralizes natural selection against a human genetic disease over three centuries.

According to evolutionary theory, mitochondria could be poisoned gifts that mothers transmit to their sons. This is because mutations harmful to males are expected to accumulate in the mitochondrial genome, the so-called 'mother's curse'. However, the contribution of the mother's curse to the mutation load in nature remains largely unknown and hard to predict, because compensatory mechanisms could impede the spread of deleterious mitochondria. Here we provide evidence for the mother's curse in action over 290 years in a human population. We studied a mutation causing Leber's hereditary optical neuropathy, a disease with male-biased prevalence and which has long been suspected to be maintained in populations by the mother's curse. Male carriers showed a low fitness relative to non-carriers and to females, mostly explained by their high rate of infant mortality. Despite poor male fitness, selection analysis predicted a slight (albeit non-significant) increase in frequency, which sharply contrasts with the 35.5% per-generation decrease predicted if mitochondrial DNA transmission had been through males instead of females. Our results are therefore even suggestive of positive selection through the female line that may exacerbate effects of the mother's curse. This study supports a contribution of the mother's curse to the reduction of male lifespan, uncovering a large fitness effect associated with a single mitochondrial variant.

No. 262-Prenatal Screening for and Diagnosis of Aneuploidy in Twin Pregnancies.

OBJECTIVE: To provide a Canadian consensus document with recommendations on prenatal screening for and diagnosis of fetal aneuploidy (e.g., Down syndrome and trisomy 18) in twin pregnancies. OPTIONS: The process of prenatal screening and diagnosis in twin pregnancies is complex. This document reviews the options available to pregnant women and the challenges specific to screening and diagnosis in a twin pregnancy. OUTCOMES: Clinicians will be better informed about the accuracy of different screening options in twin pregnancies and about techniques of invasive prenatal diagnosis in twins. EVIDENCE: PubMed and Cochrane Database were searched for relevant English and French language articles published between 1985 and 2010, using appropriate controlled vocabulary and key words (aneuploidy, Down syndrome, trisomy, prenatal screening, genetic health risk, genetic health surveillance, prenatal diagnosis, twin gestation). Results were restricted to systematic reviews, randomized controlled trials, and relevant observational studies. Searches were updated on a regular basis and incorporated in the guideline to August 2010. Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology assessment-related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies. The previous Society of Obstetricians and Gynaecologists of Canada guidelines regarding prenatal screening were also reviewed in developing this clinical practice guideline. VALUES: The quality of evidence was rated using the criteria described in the Report of the Canadian Task Force on Preventive Health Care (Table 1). BENEFITS, HARMS, AND COSTS: There is a need for specific guidelines for prenatal screening and diagnosis in twins. These guidelines should assist health care providers in the approach to this aspect of prenatal care of women with twin pregnancies. SUMMARY STATEMENTS: RECOMMENDATIONS.

Socio-economic status and fertility decline: Insights from historical transitions in Europe and North America.

The timings of historical fertility transitions in different regions are well understood by demographers, but much less is known regarding their specific features and causes. In the study reported in this paper, we used longitudinal micro-level data for five local populations in Europe and North America to analyse the relationship between socio-economic status and fertility during the fertility transition. Using comparable analytical models and class schemes for each population, we examined the changing socio-economic differences in marital fertility and related these to common theories on fertility behaviour. Our results do not provide support for the hypothesis of universally high fertility among the upper classes in pre-transitional society, but do support the idea that the upper classes acted as forerunners by reducing their fertility before other groups. Farmers and unskilled workers were the latest to start limiting their fertility. Apart from these similarities, patterns of class differences in fertility varied significantly between populations.

Are immigrants healthier than native-born Canadians? A systematic review of the healthy immigrant effect in Canada.

OBJECTIVES: Immigrants are typically healthier than the native-born population in the receiving country and also tend to be healthier than non-migrants in the countries of origin. This foreign-born health advantage has been referred to as the healthy immigrant effect (HIE). We examined evidence for the HIE in Canada. DESIGN: We employed a systematic search of the literature on immigration and health and identified 78 eligible studies. We used a narrative method to synthesize the HIE across different stages of the life-course and different health outcomes within each stage. We also examined the empirical evidence for positive selection and duration effects - two common explanations of migrants' health advantage and deterioration, respectively. RESULTS: We find that the HIE appears to be strongest during adulthood but less so during childhood/adolescence and late life. A foreign-born health advantage is also more robust for mortality but less so for morbidity. The HIE is also stronger for more recent immigrants but further research is needed to determine the critical threshold for when migrants' advantage disappears. Positive selection as an explanation for the HIE remains underdeveloped. CONCLUSIONS: There is an absence of a uniform foreign-born health advantage across different life-course stages and health outcomes in Canada. Nonetheless, it remains the case that the HIE characterizes the majority of contemporary migrants since Canada's foreign-born population consists mostly of core working age adults.

North American Fetal Therapy Network: intervention vs expectant management for stage I twin-twin transfusion syndrome.

BACKGROUND: Stage I twin-twin transfusion syndrome presents a management dilemma. Intervention may lead to procedure-related complications while expectant management risks deterioration. Insufficient data exist to inform decision-making. OBJECTIVE: The aim of this retrospective observational study was to describe the natural history of stage I twin-twin transfusion syndrome, to assess for predictors of disease behavior, and to compare pregnancy outcomes after intervention at stage I vs expectant management. STUDY DESIGN: Ten North American Fetal Therapy Network centers submitted well-documented cases of stage I twin-twin transfusion syndrome for analysis. Cases were retrospectively divided into 3 management strategies: those managed expectantly, those who underwent amnioreduction at stage I, and those who underwent laser therapy at stage I. Outcomes were categorized as no survivors, 1 survivor, 2 survivors, or at least 1 survivor to live birth, and good (twin live birth ≥30.0 weeks), mixed (single fetal demise or delivery between 26.0-29.9 weeks), and poor (double fetal demise or delivery <26.0 weeks) pregnancy outcomes. Outcomes were analyzed by initial management strategy. RESULTS: A total of 124 cases of stage I twin-twin transfusion syndrome were studied. In all, 49 (40%) cases were managed expectantly while 30 (24%) underwent amnioreduction and 45 (36%) underwent laser therapy at stage I. The overall fetal mortality rate was 20.2% (50 of 248 fetuses). Of those managed expectantly, 11 patients regressed (22%), 4 remained stage I (8%), 29 advanced in stage (60%), and 5 experienced spontaneous previable preterm birth (10%) during observation. The mean number of days from diagnosis of stage I to a change in status (progression, regression, loss, or delivery) was 11.1 (SD 14.3) days. Intervention by amniocentesis or laser therapy was associated with a lower risk of fetal loss (P = .01) than expectant management. The unadjusted odds of poor outcome were 0.33 (95% confidence interval, 0.09-01.20), for amnioreduction and 0.26 (95% confidence interval, 0.09-0.77) for laser therapy vs expectant management. Adjusting for nulliparity, recipient maximum vertical pocket, gestational age at diagnosis, and placenta location had negligible effect. Both amnioreduction and laser therapy at stage I decreased the likelihood of no survivors (odds ratio, 0.11; 95% confidence interval, 0.02-0.68 and odds ratio, 0.07; 95% confidence interval, 0.01-0.37, respectively). Only laser therapy, however, was protective against poor outcome in our data (odds ratio, 0.29; 95% confidence interval, 0.07-1.30 for amnioreduction vs odds ratio, 0.12, 95% confidence interval, 0.03-0.44 for laser), although the estimate for amnioreduction suggests a protective effect. CONCLUSION: Stage I twin-twin transfusion syndrome was associated with substantial fetal mortality. Spontaneous resolution was observed, although the majority of expectantly managed cases progressed. Progression was associated with a worse prognosis. Both amnioreduction and laser therapy decreased the chance of no survivors, and laser was particularly protective against poor outcome independent of multiple factors. Further studies are justified to corroborate these findings and to further define risk stratification and surveillance strategies for stage I disease.