Life Table Approach Research Articles

The Length of Working Life in Spain: Levels, Recent Trends, and the Impact of the Financial Crisis

While there has been considerable debate about extending the length of working life, relatively little is known about this issue. We use data from the Spanish Continuous Working Life Sample for 2004–2013 to calculate period working life tables, which in turn allows us to assess the impact of the financial crisis on working life expectancy in Spain. Before the recession hit, working life expectancy in Spain was around 38 years for males and 33 years for females. The recession had a tremendous impact on the Spanish labor market, but the effects differed considerably by gender and occupational category. Men working in skilled non-manual jobs were less affected, while men working in unskilled manual jobs lost close to 14 years of working life expectancy. Women were less affected than men. With working life expectancy decreasing, the average proportion of lifetime spent in unemployment and outside the labor market increased markedly, whereas the average number of years spent in retirement changed only a little. When we decompose losses in working life expectancy by age group, we find that economic fluctuations affect both older and younger workers. This result suggests that policies that focus on retirement ages only are incomplete. We also compare our findings to the results obtained by Sullivans method, which is based on prevalence rates rather than the incidence-based working life table approach. We find that the use of Sullivans approach does not accurately reflect the levels of and the trends in working life expectancy.

Analysis of Nuptiality Data through Life Table Approach

Analysis of Nuptiality Data through Life Table Approach

Worklife expectancy in a cohort of Danish employees aged 55\u201365\xa0years - comparing a multi-state Cox proportional hazard approach with conventional multi-state life tables

BackgroundWork life expectancy (WLE) expresses the expected time a person will remain in the labor market until he or she retires. This paper compares a life table approach to estimating WLE to an approach based on multi-state proportional hazards models. The two methods are used to estimate WLE in Danish members and non-members of an early retirement pensioning (ERP) scheme according to levels of health.MethodsIn 2008, data on self-rated health (SRH) was collected from 5212 employees 55–65 years of age. Data on previous and subsequent long-term sickness absence, unemployment, returning to work, and disability pension was collected from national registers. WLE was estimated from multi-state life tables and through multi-state models.ResultsResults from the multi-state model approach agreed with the life table approach but provided narrower confidence intervals for small groups. The shortest WLE was seen for employees with poor SRH and ERP membership while the longest WLE was seen for those with good SRH and no ERP membership. Employees aged 55–56 years with poor SRH but no ERP membership had shorter WLE than employees with good SRH and ERP membership. Relative WLE reversed for the two groups after age 57.At age 55, employees with poor SRH could be expected to spend approximately 12 months on long-term sick leave and 9–10 months unemployed before they retired – regardless of ERP membership. ERP members with poor SRH could be expected to spend 4.6 years working, while non-members could be expected to spend 7.1 years working.ConclusionWLE estimated through multi-state models provided an effective way to summarize complex data on labor market affiliation. WLE differed noticeably between members and non-members of the ERP scheme. It has been hypothesized that while ERP membership would prompt some employees to retire earlier than they would have done otherwise, this effect would be partly offset by reduced time spent on long-term sick leave or unemployment. Our data showed no indication of such an effect, but this could be due to residual confounding and self-selection of people with poor health into the ERP scheme.

Heart rate variability and lifetime risk of cardiovascular disease: the Atherosclerosis Risk in Communities Study

PurposeThe purpose of this study was to estimate the heart rate variability (HRV)–related lifetime cardiovascular disease (CVD) risk. MethodsWe followed 9744 participants without baseline CVD and used a life-table approach to estimate lifetime CVD risk (coronary heart disease, heart failure, and stroke) from 45 through 85 years according to several HRV measures (the SD of RR intervals [SDNN], the root mean square of successive differences of successive RR intervals, the mean of all normal RR intervals [meanNN], low-frequency [LF] and high-frequency [HF] power, and the LF/HF ratio). ResultsDuring 192,110 person-years of follow-up, we documented 2856 CVD events. Cox regression analyses with the false discovery rate method correction showed independent associations of SDNN, meanNN, LF, and LF/HF in women with CVD. Lifetime CVD risks in the lowest compared with the highest tertile were significantly increased in men for LF/HF (51.3% [95% confidence interval, 47.3–54.7] vs. 43.9% [40.1–47.2]), and in women for SDNN (39.4% [36.0–43.0] vs. 29.9% [26.3–33.0]), meanNN (39.3% [35.7–42.7] vs. 28.9% [25.7–31.7]), LF (39.4% [35.9–43.0] vs. 30.0% [26.2–33.2]), and LF/HF (37.6% [33.9–40.9] vs. 30.0% [26.8–32.7]). ConclusionsGreater HRV was modestly associated with lower lifetime CVD risk.

Physical Activity and Lifetime Risk of Cardiovascular Disease and Cancer.

Although the World Health Organization has recommended moderate- to vigorous-intensity physical activity (MVPA) to prevent cardiovascular disease (CVD) and some cancers, there are no estimates of lifetime risk of these noncommunicable diseases according to PA levels. We aimed to estimate the lifetime risk of CVD and cancers according to PA levels. We followed 5807 men and 7252 women in the United States, 45-64 yr old, initially free of CVD and cancer from 1987 through 2012, and used a life table approach to estimate lifetime risks of CVD (coronary heart disease, heart failure, and stroke) and total cancer according to PA levels: poor (0 min·wk of MVPA), intermediate (1-74 min·wk of VPA or 1-149 min·wk of MVPA), or recommended (≥75 min·wk of VPA or ≥150 min·wk of MVPA). During the 246,886 person-years of follow-up, we documented 4065 CVD and 3509 cancer events and 2062 non-CVD and 2326 noncancer deaths. In men, the lifetime risks of CVD from 45 through 85 yr were 52.7% (95% confidence interval = 49.4-55.5) for poor PA and 45.7% (42.7-48.3) for recommended PA. In women, the respective lifetime risks of CVD were 42.4% (39.5-44.9) and 30.5% (27.5-33.1). Lifetime risks of total cancer were 40.1% (36.9-42.7) for poor PA and 42.6% (39.7-45.2) for recommended activity in men and 31.4% (28.7-33.8) and 30.4% (27.7-32.9), respectively, in women. Compared with a poor PA level, the PA recommended by the World Health Organization was associated with lower lifetime risk of CVD, but not total cancer, in both men and women.

Association of Educational Attainment With Lifetime Risk of Cardiovascular Disease

Estimates of lifetime risk may help raise awareness of the extent to which educational inequalities are associated with risk of cardiovascular disease (CVD). To estimate lifetime risks of CVD according to categories of educational attainment. Participants were followed from 1987 through December 31, 2013. All CVD events (coronary heart disease, heart failure, and stroke) were confirmed by physician review and International Classification of Diseases codes. A total of 13 948 whites and African Americans who were 45 to 64 years old and free of CVD at baseline were included from 4 US communities (Washington County, Maryland; Forsyth County, North Carolina; Jackson, Mississippi; and suburbs of Minneapolis, Minnesota). The data analysis was performed from June 7 to August 31, 2016. Educational attainment. We used a life table approach to estimate lifetime risks of CVD from age 45 through 85 years according to educational attainment. We adjusted for competing risks of death from underlying causes other than CVD. The sample of 13 948 participants was 56% female and 27% African American. During 269 210 person-years of follow-up, we documented 4512 CVD events and 2401 non-CVD deaths. Educational attainment displayed an inverse dose-response relation with cumulative risk of CVD, which became evident in middle age, with the most striking gap between those not completing vs completing high school. In men, lifetime risks of CVD were 59.0% (95% CI, 54.0%-64.1%) for grade school, 52.5% (95% CI, 47.7%-56.8%) for high school education without graduation, 50.9% (95% CI, 47.3%-53.9%) for high school graduation, 47.2% (95% CI, 41.5%-52.5%) for vocational school, 46.4% (95% CI, 42.8%-49.6%) for college with or without graduation, and 42.2% (95% CI, 36.6%-47.0%) for graduate/professional school; in women, 50.8% (95% CI, 45.7%-55.8%), 49.3% (95% CI, 45.1%-53.1%), 36.3% (95% CI, 33.4%-39.1%), 32.2% (95% CI, 26.0%-37.3%), 32.8% (95% CI, 29.1%-35.9%), and 28.0% (95% CI, 21.9%-33.3%), respectively. Educational attainment was inversely associated with CVD even within categories of family income, income change, occupation, or parental educational level. More than 1 in 2 individuals with less than high school education had a lifetime CVD event. Educational attainment was inversely associated with the lifetime risk of CVD, regardless of other important socioeconomic characteristics. Our findings emphasize the need for further efforts to reduce CVD inequalities related to educational disparities.

Chasing the American Dream: Understanding What Shapes Our FortunesMark RobertRank, Thomas A.Hirschl and Kirk A.Foster. Oxford, 2014.

Chasing American Dream: Understanding What Shapes Our Fortunes Mark Robert Rank, Thomas A. Hirschl and Kirk A. Foster. Oxford, 2014.Income and wealth inequality have been a central focus of American political discourse for last forty years. Of particular concern has been how increasing inequality erodes working- and middle-class Americans' ability to attain the American of providing a comfortable lifestyle for one's family through rewards of labor. The last forty years' political and economic scholarship focuses on increasing difficulty of attaining this dream; almost no work addresses what American Dream actually means to workingand middle-class Americans. Mark Robert Rank, Thomas A. Hirschl, and Kirk A. Foster's Chasing American Dream: Understanding What Shapes Our Fortunes moves beyond this tradition, using a multidimensional approach to examine what Americans think Dream is, as well as to explore viability of attaining this Dream through traditional pathways. By utilizing individual interviews, focus groups, and a lifetable approach that employs data from Panel Study of Income Dynamics (PSID), Census Bureau, Bureau of Labor Statistics, and Pew Center for Research, Rank et al. provide a somewhat different lens for interpreting and assessing current and future status of American (7).The authors break their study into three sections: identifying core components of, assessing pathways to, and exploring meanings of American Dream. Each section utilizes multidimensional approach, providing personal experiences and focus group discussions, as well as longitudinal quantitative data measuring economic risks and rewards across generations. The first section points to what Americans most commonly identify as crucial components of Dream. Most crucial is freedom to pursue one's passions or interests (28). Economic security is requisite for this pursuit and, indeed, ranks as second-most crucial component-more important, for many Americans, even than mobility (39). For most Americans, security is not attaining riches but is having resources and tools to live a comfortable and rewarding life: a decent paying job with benefits, accumulated savings and assets, ability to provide for one's children, home ownership, and possibility of retiring comfortably (49). Three quarters of Americans, however, think that attaining these two components have become more difficult, a reality Rank et al. attest to through data showing fewer decent-paying jobs, lower average wages, fewer benefits, and more part-time work relative to full-time opportunities. American workers have been living up to their end of bargain, producing more despite working less; Corporate America, however, has not lived up to its end (39). Despite this, third component is supreme optimism in ability to attain Dream in one's children's lifetimes, if not in one's own.The second section looks at changing landscape of opportunities for attaining Dream, with an eye specifically toward market for jobs paying enough to support a family. This section provides a wealth of useful data and interpretations of labor markets. There is a mismatch between number who need this type of job and supply, which results in increased polarization of jobs, further fostering inequality (71). …

Fitness and inheritance of metaflumizone resistance in Plutella xylostella

The diamondback moth, Plutella xylostella (L.) has developed resistance to many types of insecticides in the field. To study inheritance and fitness cost of metaflumizone resistance, a susceptible strain of diamondback moth was continuously selected with metaflumizone during 37 generations under laboratory conditions. The resistance to metaflumizone was at a high level (resistance ratios from 250.37 to 1450.47-fold). We investigated a metaflumizone resistance strain (G27) and a susceptible strain of P. xylostella, using the age-stage, two-sex life table approach. Compared to the susceptible strain, egg duration, the developmental time of the first and second instar larvae, pupae duration, adult preoviposition period (APOP), total preoviposition period (TPOP), egg hatchability, the survival rate of second instar larva and the mean generation time (T) were significantly differences in the resistant strain. The resistant strain had a relative fitness of 0.78. The inheritance of metaflumizone resistance was also studied by crossing the metaflumizone resistant and susceptible populations. Results revealed an autosomal and incompletely recessive mode of inheritance for metaflumizone resistance in the resistant population of P. xylostella. The present study provided useful information for planning potential management strategies to delay development of metaflumizone resistance in P. xylostella.

A Life Table Approach to Estimating Disproportionate Minority Contact in the Juvenile Justice System

Disproportionate minority contact (DMC) in the U.S. juvenile justice system persists despite substantial efforts to reduce it. The juvenile justice system is comprised of a series of interconnected stages, yet few studies to-date use methods to measure DMC that take the cascading nature of the decision-making process into account. Our study addresses this gap by applying life table analysis to identify the cumulative nature of DMC across multiple stages of the juvenile justice system using data from 2008 to 2010 in Georgia that include white, black, and Hispanic/Latino youth. We then compare these state-level results to life tables from a national sample of black youth and a subnational sample of Hispanic/Latino youth. Our findings show that arrest/referral accounts for the greatest proportion of total system-wide DMC for black youth, but most of the total DMC for Hispanic/Latino youth results from later stages.

Abstract P329: Educational Attainment and Lifetime Risk of Cardiovascular Disease: the Atherosclerosis Risk in Communities Study

Background: Estimates of lifetime risk may help raise awareness of the extent to which educational inequalities affect risk of cardiovascular disease (CVD). To date, no study has reported the lifetime risk of CVD according to categories of educational attainment. Objectives: To estimate the lifetime risk of CVD from 45 through 85 years according to educational attainment. Methods: We followed 13,948 whites and African Americans initially free of CVD from 1,987 through 2,013, and used a life table approach to estimate lifetime risks of life-threatening CVD events (coronary heart disease, heart failure and stroke) according to educational attainment (grade school, high school without graduation, high school graduation, vocational school, college with or without graduation, and graduate/professional school). We adjusted for competing risks of death from underlying causes other than CVD. Results: During the 269,210 person-years of follow-up, we documented 4,512 CVD events, and 2,401 non-CVD deaths. Educational attainment displayed an inverse dose-response relation with cumulative risk of CVD, which became evident in middle-age, with the most striking gap between those not completing versus completing high school. Lifetime risk estimates of CVD from age 45 years though 85 years were 55.0% (95% confidence interval, 51.4-58.6) for grade school, 50.5% (47.3-53.3) for high school education without graduation, 41.7% (39.5-43.8) for high school graduation, 39.7% (35.5-43.4) for vocational school, 39.2% (36.4-41.4) for college with or without graduation, and 36.1% (31.9-39.7) for graduate/professional school. For both men and women, and whites as well as African Americans, those who did not graduate from high school had a sizably higher lifetime CVD risk. There was a similar pattern for cumulative CVD risk to 65 years. Lower family income and parental educational attainment were also associated with greater lifetime CVD risk, but individuals with more than a high school education had a lower lifetime risk than those with less educational attainment, regardless of their income or parental educational attainment. Conclusions: Educational attainment was inversely associated with the lifetime risk of CVD, and cumulative risk differences were already evident during middle-age, suggesting that greater educational attainment might promote lower lifetime risk of CVD.

Response of Chrysoperla nipponensis (Okamoto) (Neuroptera: Chrysopidae) Under Long and Short Photoperiods.

Photoperiod is an important factor influencing many biological processes including population dynamics of many insect species in temperate zones. To determine the population response of Chrysoperla nipponensis under altered conditions (high temperature and short photoperiod) and to test whether the short photoperiod was suitable for artificial storage, the life table data of C. nipponensis were collected at 25 °C under a long photoperiod, 15:9 h (L:D), and a short photoperiod, 9:15 h (L:D) and analyzed using the age-stage, two-sex life table approach. We found that C. nipponensis developed faster under the long photoperiod than under the short photoperiod. The shorter developmental time, higher fecundity, and higher proportion of females found during the long photoperiod resulted in higher intrinsic and net reproductive rates, but a shorter mean generation time and life expectancy compared to those reared during the short photoperiod. Individuals reared under the short photoperiod also had a high reproductive value. Population projection demonstrated that C. nipponensis reared at the long photoperiod would complete four generations in 150 d, while reared under the short photoperiod would just be entering the second generation. Our results demonstrated that the different fitness values obtained for C. nipponensis individuals by varying photoperiod lengths, were readily distinguishable when using the age-stage, two-sex life table. High winter temperatures would be detrimental to a diapausing population, and diapause induced by the short photoperiod would be beneficial to the storage of natural enemies.

Natural history of breast cancer: a systematic review of worldwide randomized controlled trials of mammography screening

Objective: To parameterize the 1-year transition probabilities between different health status of the natural history of breast cancer based on the data of randomized controlled trial of X-ray mammography screening worldwide. Methods: Based on the breast cancer screening randomized controlled trials defined by a mammography screening review from the Cochrane 2013 and the International Agency for Research on Cancer, a systematic review was initiated in PubMed by searching names of the key investigators of the trials, combined with the diseases, screening intervention and outcome indicators. If applicable, all the original cumulative incidence rates were converted into one-year transition rate, using the life-table approach considering time length of follow-up. Results: A total of 23 reports from 9 RCTs were included. The data on transition rate between the healthy status to precancerous lesions was absent. The 1-year transition rate from health to carcinoma in situ was 17.78 to 50.21 per 100 000 persons in the intervention group and 9.16 to 26.84 per 100 000 persons in the control group. Correspondingly, the 1-year transition rate from health to breast cancer (including carcinoma in situ and invasive cancer) were estimated as 143.75 to 316.97 per 100 000 persons in the intervention group, and 141.45 to 288.84 per 100 000 persons in the control group. Furthermore, the transition rate from the healthy status to invasive breast cancer was 159.79 to 264.60 per 100 000 persons in intervention group and 170.12 to 255.33 per 100 000 persons in control group. The transition rate from carcinoma in situ to invasive breast cancer varied among different pathological types. Conclusions: The most common natural history states of reported by the included trials involved the full healthy status, carcinoma in situ and invasive breast cancer. The findings of transition rates between different health statuses will be informative for future model development of natural history studies of breast cancer. Information in relation to breast precancerous lesions still limited and needs to be further addressed.

Treating Prey With Glyphosate Does Not Alter the Demographic Parameters and Predation of the Harmonia axyridis (Coleoptera: Coccinellidae).

Glyphosate is an herbicide that is used worldwide with potential environmental risks to nontarget organisms. We applied an age-stage, two-sex life table approach to assess the sublethal effects of short-term oral exposure to a glyphosate-based herbicide on the life table parameters and biocontrol potential of Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae). Aphids (Metopolophium dirhodum (Walker) (Sternorrhyncha: Aphididae)) treated with herbicide (an isopropylamine-salt of glyphosate) at low recommended, maximum recommended, and double the maximum recommended concentration for agricultural situations, and untreated controls were offered to the fourth instar of H. axyridis for 24 h. Development, consumption, and fecundity were measured daily until death. We detected minor differences in the hatching rate and mean generation time, whereas the longevity, fecundity, net reproductive rate, intrinsic rate of increase, finite rate of increase, and consumption were unaffected across treatments. We conclude that biocontrol potential of H. axyridis was not affected by acute oral intoxication by a glyphosate-based herbicide during the larval stage for 24 h under the study design.

Treatment by glyphosate-based herbicide alters life history parameters of the rose-grain aphid Metopolophium dirhodum.

Glyphosate is the number one herbicide in the world. We investigated the sub-lethal effects of this herbicide on the aphid Metopolophium dirhodum (Walker), using an age-stage, two-sex life table approach. Three concentrations of the herbicide (low - 33.5, medium - 66.9 and high - 133.8 mmol dm−3 of active ingredient) and distilled water as the control were used. The LC50 of the IPA salt of glyphosate on M. dirhodum was equivalent to 174.9 mmol dm−3 of the active ingredient (CI95: 153.0, 199.0). The population parameters were significantly negatively affected by herbicide application, and this negative effect was progressive with the increasing concentration of the herbicide. A difference of two orders of magnitude existed in the predicted population development of M. dirhodum between the high concentration of the herbicide and the control. This is the first study that comprehensively documents such a negative effect on the population of an herbivorous insect.

Estimating the number of quit attempts it takes to quit smoking successfully in a longitudinal cohort of smokers

ObjectivesThe number of quit attempts it takes a smoker to quit successfully is a commonly reported figure among smoking cessation programmes, but previous estimates have been based on lifetime recall...

Body Mass Transitions Through Childhood and Early Adolescence: A Multistate Life Table Approach.

The growing prevalence of overweight and obesity among children is well documented, but prevalence estimates offer little insight into rates of transition to higher or lower body mass index (BMI; weight (kg)/height (m)(2)) categories. We estimated the expected numbers of years children would live as normal weight, overweight, and obese by race/ethnicity and sex, given rates of transition across BMI status levels. We used multistate life table methods and transition rates estimated from prospective cohort data (2007-2013) for Denver, Colorado, public schoolchildren aged 3-15 years. At age 3 years, normal-weight children could expect to live 11.1 of the following 13 years with normal weight status, and obese children could expect to live 9.8 years with obese status. At age 3 years, overweight children could expect to live 4.5 of the following 13 years with normal weight status, 5.1 years with overweight status, and 3.4 years with obese status. Whites and Asians lived more years at lower BMI status levels than did blacks or Hispanics; sex differences varied by race/ethnicity. Children who were normal weight or obese at age 3 years were relatively unlikely to move into a different BMI category by age 15 years. Overweight children are relatively likely to transition to normal weight or obese status.

Abstract B21: BRCA mutation status is not associated with better long-term survival from epithelial ovarian cancer.

Abstract Background: Previous studies have described better survival for women with epithelial ovarian cancer and an inherited BRCA1 or BRCA2 mutation compared to those without a mutation. Most of these studies had short follow-up periods. It is of importance to clarify the disease-specific mortality outcomes of BRCA mutation carriers using data from an unselected population with long follow-up. The overall goal of the current study was to evaluate the long-term mortality outcomes based on BRCA mutation status among women diagnosed with epithelial ovarian cancer. Methods: Women with unselected epithelial ovarian cancer diagnosed in Ontario, Canada from 1995-1999 and 2002-2004 included in the current study. Tumor histology was based on review of pathology records while clinical and treatment information was obtained from individual medical records. Survival status was determined by linkage to the Ontario Cancer Registry which provides information on date and cause of death. We also estimated the annual mortality for members of the cohort based on a life-table approach for each one-year period after the date of diagnosis until 12 years after diagnosis. Results: Of the 1,421 women with a diagnosis of invasive epithelial ovarian cancer, 109 (7.7%) had a BRCA1 mutation and 68 (4.8%) had a BRCA2 mutation while 1,244 (87.5%) were non-carriers. The mean age at diagnosis (in years) was 57.7 for non-carriers, 50.9 for BRCA1 mutation carriers and 57.4 for BRCA2 mutation carriers. Seventy-three percent of BRCA1 mutation carriers, 78% of BRCA2 mutation carriers and 52% of non-carriers were diagnosed with a serous tumor. The two-year survival rates were 78% for non-carriers, 85% for BRCA1 mutation carriers and 100% for BRCA2 mutation carriers. The five-year survival rates were 56% for non-carriers, 52% for BRCA1 mutation carriers and 61% for BRCA2 mutation carriers. The 12-year survival rates were 44% for non-carriers, 32% for BRCA1 mutation carriers and 28% for BRCA2 mutation carriers. At 12-years, the survival experience of BRCA mutation carriers was significantly worse than non-carriers (OR = 1.81; P < 0.0001). Among the women who died, the mean duration from diagnosis to death was 4.47 years for non-carriers, 4.78 years for BRCA1 mutation carriers and 5.13 years for BRCA2 mutation carriers. Conclusion: Findings from this study suggest a short-term survival advantage among women with a BRCA mutation but no impact on overall, long-term survival. This observation may reflect a better acute response of BRCA carriers to chemotherapy that is eventually diminished over time. Citation Format: Joanne Kotsopoulos, Isabel Fan, John McLaughlin, Barry Rosen, Taymaa May, Harvey Risch, Ping Sun, Steven Narod. BRCA mutation status is not associated with better long-term survival from epithelial ovarian cancer. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research: Exploiting Vulnerabilities; Oct 17-20, 2015; Orlando, FL. Philadelphia (PA): AACR; Clin Cancer Res 2016;22(2 Suppl):Abstract nr B21.

Improved estimation of intrinsic growth r(max) for long-lived species: integrating matrix models and allometry.

Intrinsic population growth rate (r(max)) is an important parameter for many ecological applications, such as population risk assessment and harvest management. However, r(max) can be a difficult parameter to estimate, particularly for long-lived species, for which appropriate life table data or abundance time series are typically not obtainable. We describe a method for improving estimates of r(max) for long-lived species by integrating life-history theory (allometric models) and population-specific demographic data (life table models). Broad allometric relationships, such as those between life history traits and body size, have long been recognized by ecologists. These relationships are useful for deriving theoretical expectations for r(max), but r(max) for real populations may vary from simple allometric estimators for "archetypical" species of a given taxa or body mass. Meanwhile, life table approaches can provide population-specific estimates of r(max) from empirical data, but these may have poor precision from imprecise and missing vital rate parameter estimates. Our method borrows strength from both approaches to provide estimates that are consistent with both life-history theory and population-specific empirical data, and are likely to be more robust than estimates provided by either method alone. Our method uses an' allometric constant: the product of r(max) and the associated generation time for a stable-age population growing at this rate. We conducted a meta-analysis to estimate the mean and variance of this allometric constant across well-studied populations from three vertebrate taxa (birds, mammals, and elasmobranchs) and found that the mean was approximately 1.0 for each taxon. We used these as informative Bayesian priors that determine how much to "shrink" imprecise vital rate estimates for a data-limited population toward the allometric expectation. The approach ultimately provides estimates of r(max) (and other vital rates) that reflect a balance of information from the individual studied population, theoretical expectation, and meta-analysis of other populations. We applied the method specifically to an archetypical petrel (representing the genus Procellaria) and to white sharks (Carcharodon carcharias) in the context of estimating sustainable-fishery bycatch limits.

A Multistate Life Table Approach to Understanding Return and Reentry Migration between Mexico and the United States During Later Life.

Empirical research describes retirement migration to Mexico as a viable option for some older Americans. However, far less research examines this phenomenon among Mexican immigrants in the United States. The literature that does address this topic treats international migration as a singular occurrence and does not examine the possibility of return and subsequent reentry between countries. This omission creates an important gap in our knowledge of international retirement migration considering the strong transnational ties that Mexican immigrants maintain to the home and destination countries. Using a multistate life table approach, this study examines the rate of return to Mexico and reentry back into the United States among Mexican males aged 50 and older with U.S. migration experience, as well as the number of years spent in both countries. Results show that the rate of reentry from Mexico into the United States declined from 3.33% at age 50-54 to less than 1% at age 70 and older (p-value<0.05). In contrast, the rate of return to Mexico from the United States increased from 3.19% at age 50 to 54 to 4.44%at age 65 to 69 and dropped to less than 2% at age 70 and older (p-value<0.05). While rates of return and reentry among this population are relatively low, they provide insight on the potential life course factors driving the migration patterns of a population of increasing size and relevance in the United States.

Adjustment of lifetime risks of space radiation-induced cancer by the healthy worker effect and cancer misclassification.

Background. The healthy worker effect (HWE) is a source of bias in occupational studies of mortality among workers caused by use of comparative disease rates based on public data, which include mortality of unhealthy members of the public who are screened out of the workplace. For the US astronaut corp, the HWE is assumed to be strong due to the rigorous medical selection and surveillance. This investigation focused on the effect of correcting for HWE on projected lifetime risk estimates for radiation-induced cancer mortality and incidence.Methods. We performed radiation-induced cancer risk assessment using Poisson regression of cancer mortality and incidence rates among Hiroshima and Nagasaki atomic bomb survivors. Regression coefficients were used for generating risk coefficients for the excess absolute, transfer, and excess relative models. Excess lifetime risks (ELR) for radiation exposure and baseline lifetime risks (BLR) were adjusted for the HWE using standardized mortality ratios (SMR) for aviators and nuclear workers who were occupationally exposed to ionizing radiation. We also adjusted lifetime risks by cancer mortality misclassification among atomic bomb survivors.Results. For all cancers combined (“Nonleukemia”), the effect of adjusting the all-cause hazard rate by the simulated quantiles of the all-cause SMR resulted in a mean difference (not percent difference) in ELR of 0.65% and mean difference of 4% for mortality BLR, and mean change of 6.2% in BLR for incidence. The effect of adjusting the excess (radiation-induced) cancer rate or baseline cancer hazard rate by simulated quantiles of cancer-specific SMRs resulted in a mean difference of in the all-cancer mortality ELR and mean difference of in the mortality BLR. Whereas for incidence, the effect of adjusting by cancer-specific SMRs resulted in a mean change of for the all-cancer BLR. Only cancer mortality risks were adjusted by simulated quantiles for misclassification, and results indicate a mean change of 1.1% for all-cancer mortality ELR, while the mean change in the all-cancer PC was approximately 4% for males and 6% for females.Conclusions. The typical life table approach for projecting lifetime risk of radiation-induced cancer mortality and incidence for astronauts and radiation workers can be improved by adjusting for HWE while simulating the uncertainty of input rates, input excess risk coefficients, and bias correction factors during multiple Monte Carlo realizations of the life table.