What shapes the continuum of reproductive isolation? Lessons from Heliconius butterflies.

The process by which species evolve can be illuminated by investigating barriers that limit gene flow between taxa. Recent radiations, such as Heliconius butterflies, offer the opportunity to compare isolation between pairs of taxa at different stages of ecological, geographical, and phylogenetic divergence. Here, we report a comparative analysis of existing and novel data in order to quantify the strength and direction of isolating barriers within a well-studied clade of Heliconius Our results highlight that increased divergence is associated with the accumulation of stronger and more numerous barriers to gene flow. Wing pattern is both under natural selection for Müllerian mimicry and involved in mate choice, and therefore underlies several isolating barriers. However, pairs which share a similar wing pattern also display strong reproductive isolation mediated by traits other than wing pattern. This suggests that, while wing pattern is a key factor for early stages of divergence, it may become facultative at later stages of divergence. Additional factors including habitat partitioning, hybrid sterility, and chemically mediated mate choice are associated with complete speciation. Therefore, although most previous work has emphasized the role of wing pattern, our comparative results highlight that speciation is a multi-dimensional process, whose completion is stabilized by many factors.

Divergence in brain composition during the early stages of ecological specialization in Heliconius butterflies.

During speciation across ecological gradients, diverging populations are exposed to contrasting sensory and spatial information that present new behavioural and perceptive challenges. These challenges may be met by heritable or environmentally induced changes in brain function which mediate behaviour. However, few studies have investigated patterns of neural divergence at the early stages of speciation, inhibiting our understanding of the relative importance of these processes. Here, we provide a novel case study. The incipient species pair, Heliconius erato and H. himera, are parapatric across an environmental and altitudinal gradient. Despite ongoing gene flow, these species have divergent ecological, behavioural and physiological traits. We demonstrate that these taxa also differ significantly in brain composition, in particular in the relative levels of investment in structures that process sensory information. These differences are not explained solely by environmentally-induced plasticity, but include heritable, nonallometric shifts in brain structure. We suggest these differences reflect divergence to meet the demands of contrasting sensory ecologies. This conclusion would support the hypothesis that the evolution of brain structure and function play an important role in facilitating the emergence of ecologically distinct species.

Differential effects of air conditioning type on residential endotoxin levels in a semi-arid climate.

Residential endotoxin exposure is associated with protective and pathogenic health outcomes. Evaporative coolers, an energy-efficient type of air conditioner used in dry climates, are a potential source of indoor endotoxins; however, this association is largely unstudied. We collected settled dust biannually from four locations in homes with evaporative coolers (n=18) and central air conditioners (n=22) in Utah County, Utah (USA), during winter (Jan-Apr) and summer (Aug-Sept), 2014. Dust samples (n=281) were analyzed by the Limulus amebocyte lysate test. Housing factors were measured by survey, and indoor temperature and relative humidity measures were collected during both seasons. Endotoxin concentrations (EU/mg) were significantly higher in homes with evaporative coolers from mattress and bedroom floor samples during both seasons. Endotoxin surface loads (EU/m2 ) were significantly higher in homes with evaporative coolers from mattress and bedroom floor samples during both seasons and in upholstered furniture during winter. For the nine significant season-by-location comparisons, EU/mg and EU/m2 were approximately three to six times greater in homes using evaporative coolers. A plausible explanation for these findings is that evaporative coolers serve as a reservoir and distribution system for Gram-negative bacteria or their cell wall components in homes.

Risk of Injury According to Attention Deficit Hyperactivity Disorder, Comorbid Mental Illness, and Medication Therapy.

INTRODUCTION: We identify the risk of selected types of injuries among patients with ADHD or ADHD and comorbid mental illness. We also assess whether selected medications used by patients with ADHD increase the risk of comorbid mental illness or influence the association between ADHD and injury. METHODS: A retrospective cohort study design was conducted using medical claims data from the Deseret Mutual Benefit Administrators (DMBA). ADHD diagnosis, injury, medication, and demographic data were extracted from claims files during 2001-2013. Rate ratios were adjusted for age, sex, and calendar year. RESULTS: Patients with ADHD were 7.9 (95% CI 7.6-8.2) times more likely to have psychosis, 5.5 (3.9-7.8) times more likely to have alcohol- or drug-induced psychosis, and 6.0 (5.9-6.2) times more likely to have neurotic or personality disorder. Therapy with amphetamine was positively associated with neurotic or personality disorder (rate ratio=1.08, 1.02-1.15); methylphenidate was negatively associated with neurotic or personality disorder (0.90, 0.84-0.97); and atomoxetine was positively associated with psychosis (1.33, 1.21-1.46), alcohol- or drug-induced psychosis (2.38, 1.04-5.43), and neurotic or personality disorder (2.38, 1.04-5.43). ADHD was associated with an increased risk of injury, with ADHD and comorbid mental illness having a stronger increased risk of injury. Psychostimulants ameliorated the increased risk of injury for patients with ADHD. CONCLUSION: Patients with ADHD have an increased risk of injury, significantly more so for those with ADHD and comorbid mental illness. Psychostimulants can lower the risk of injury among patients with ADHD.

The diversification of Heliconius butterflies: what have we learned in 150 years?

Research into Heliconius butterflies has made a significant contribution to evolutionary biology. Here, we review our understanding of the diversification of these butterflies, covering recent advances and a vast foundation of earlier work. Whereas no single group of organisms can be sufficient for understanding life's diversity, after years of intensive study, research into Heliconius has addressed a wide variety of evolutionary questions. We first discuss evidence for widespread gene flow between Heliconius species and what this reveals about the nature of species. We then address the evolution and diversity of warning patterns, both as the target of selection and with respect to their underlying genetic basis. The identification of major genes involved in mimetic shifts, and homology at these loci between distantly related taxa, has revealed a surprising predictability in the genetic basis of evolution. In the final sections, we consider the evolution of warning patterns, and Heliconius diversity more generally, within a broader context of ecological and sexual selection. We consider how different traits and modes of selection can interact and influence the evolution of reproductive isolation.

Ecological and genetic factors influencing the transition between host-use strategies in sympatric Heliconius butterflies.

Shifts in host-plant use by phytophagous insects have played a central role in their diversification. Evolving host-use strategies will reflect a trade-off between selection pressures. The ecological niche of herbivorous insects is partitioned along several dimensions, and if populations remain in contact, recombination will break down associations between relevant loci. As such, genetic architecture can profoundly affect the coordinated divergence of traits and subsequently the ability to exploit novel habitats. The closely related species Heliconius cydno and H. melpomene differ in mimetic colour pattern, habitat and host-plant use. We investigate the selection pressures and genetic basis underlying host-use differences in these two species. Host-plant surveys reveal that H. melpomene specializes on a single species of Passiflora. This is also true for the majority of other Heliconius species in secondary growth forest at our study site, as expected under a model of interspecific competition. In contrast, H. cydno, which uses closed-forest habitats where both Heliconius and Passiflora are less common, appears not to be restricted by competition and uses a broad selection of the available Passiflora. However, other selection pressures are likely involved, and field experiments reveal that early larval survival of both butterfly species is highest on Passiflora menispermifolia, but most markedly so for H. melpomene, the specialist on that host. Finally, we demonstrate an association between host-plant acceptance and colour pattern amongst interspecific hybrids, suggesting that major loci underlying these important ecological traits are physically linked in the genome. Together, our results reveal ecological and genetic associations between shifts in habitat, host use and mimetic colour pattern that have likely facilitated both speciation and coexistence.

Factors associated with attrition and success in a worksite wellness telephonic health coaching program.

OBJECTIVES: This study identifies factors associated with attrition and improvements in body mass index (BMI) in a telephonic health coaching program. METHODS: A cohort study design was used with 6,129 employees aged 21-88 years, enrolled in telephonic health coaching sometime during 2002 through 2008. RESULTS: Attrition through 3, 6 and 12 months of follow-up was 13%, 17% and 36%, respectively. Those currently making changes in physical activity or nutrition had the highest BMI (kg/m2), lowest levels of exercise and the poorest overall health at baseline. They were also most likely to continue with health coaching through 12 months. Those not ready to make changes at this time or having maintained an appropriate level of physical activity or nutrition for more than six months were least likely to continue with health coaching through 12 months. They also had the lowest BMI, highest levels of exercise and the best overall health. Among those continuing with health coaching through 12 months, the percent decrease in BMI between baseline and 12 months was: 1.5% for normal weight, 2.7% for overweight, 4.1% for class I & II obesity and 7.2% for class III obesity; 4.3% for high confidence to lose weight, 3.5% for medium confidence to lose weight and 3.1% for low confidence to lose weight; and 3.8% for very good or good general health, 4.5% for average general health and 6.8% for poor/very poor general health. CONCLUSIONS: Attrition in the telephonic health coaching program is greatest among those least in need of behavior change. Of those who continued in the program, the greatest decrease in BMI occurred in those in greatest need for behavior change. KEYWORDS: Behavior change, BMI, interactive health coaching, readiness to change, self-efficacy, weight.

Employee weight management through health coaching.

OBJECTIVE: This study will evaluate the effectiveness of an interactive health coaching intervention at lowering weight. METHODS: The study involved 5405 overweight or obese employees aged 18-85, who entered the program sometime during 2001-2008. RESULTS: Average body mass index (BMI) significantly decreased from 32.1 at baseline to 31.4 at 3 months, 31.0 at 6 months, and 30.6 at 12 months. Decreasing BMI was more pronounced in older age groups and among women, those using weight loss medication, those with higher BMI, and those with higher motivation and confidence to make behavior changes. When the effects of these variables on the decreasing trend in BMI were simultaneously estimated, only baseline classifications of BMI, health status, and confidence remained significant. Change in BMI through 12 months was -0.7% for those with normal weight, -2.0% for overweight, -3.6% for obese, and -7.1% for morbidly obese individuals at baseline. Among morbidly obese individuals, decrease in BMI through 12 months was -7.6% for those with "high" confidence to lose weight at baseline vs -4.4% for those with low confidence. Better health status at baseline was also related to more pronounced weight loss. CONCLUSION: Interactive health coaching significantly lowered BMI among participants through 3, 6, and 12 months of follow-up.

Sectors of the Russian economy that would benefit from reduced cigarette sales.

BACKGROUND: Cigarette companies argue that tobacco control measures will harm the Russian economy. Research in other countries has refuted this claim. OBJECTIVE: To identify how current and former smokers would (or did) spend their cigarette money if (or when) they quit smoking. METHODS: A nationwide face-to-face survey of 1599 participants aged 18 years and older in 128 cities was conducted in Russia during May 2008 by the Russian Levada Analytical Center. RESULTS: In all, 10% of respondents were former smokers and 33% were current smokers. Respondents indicated that they would spend their cigarette money on selected items if they quit. These items, from most to least common are groceries, recreation, housing, clothing, transportation, healthcare and savings. The ways that cigarette money would be spent in the absence of smoking significantly differed according to smoking status, gender, age, education, income, rural versus urban residency and geographic region. CONCLUSIONS: Tobacco control may benefit the Russian economy by producing healthier workers and because the money that would have been used for cigarettes would be shifted primarily to groceries, recreation, housing and clothing.

Perceived effectiveness of counselling patients about smoking among medical students in Amman, Jordan.

We identified the prevalence of smoking and perceived effectiveness of physicians counselling patients about smoking among 340 1st and 4th year medical students in Amman, Jordan. Smoking prevalence was 26% for males and 7% for females, similar to that of their peers in the general population. Smokers and male students were less likely to believe it is wrong for physicians to smoke in front of patients or that smoking policy or physician interaction with patients can influence smoking practices. Students believed that physicians can more effectively prevent smoking than influence patients to stop smoking. Student training on how to effectively counsel patients about smoking prevention and cessation is warranted.

The effects of an intensive lifestyle modification program on sleep and stress disorders.

BACKGROUND: To determine if a lifestyle change program can modify behavior to reduce sleep and stress disorders. METHODS: Analyses are based on 2,624 individuals aged 30 to 80 years from the Rockford, Illinois metropolitan area who completed a lifestyle evaluation at baseline and again after four weeks, following participation in a 40-hour educational course given over a four-week period. Participants receive instruction on the importance of making better lifestyle choices related to making long-term improvements in nutrition and physical activity and they learn ways to improve sleep and reduce stress in their lives. RESULTS: Significant percent decreases were observed in the number experiencing selected sleep or stress disorders from baseline to four weeks later for "sleeps restlessly" (-59%), "suffers from insomnia" (-64%), "feels under pressure" (-37%), "easily emotionally upset" (-52%), and "feels fearful or depressed" (-61%). Experiencing a selected sleep or stress disorder after four weeks among those who had the disorder at baseline was significantly more likely in those not physically active and/or not having lowered their BMI after four weeks. Changes in alcohol consumption and smoking did not significantly contribute to changes in the disorders. Those who failed to lower their coffee/tea use after four weeks were significantly more likely to have a sleep disorder and be easily emotionally upset. CONCLUSIONS: Changes in lifestyle behaviors after attending an educational program significantly reduced sleep and stress disorders in as little as four weeks, primarily explained by decreasing BMI and/or increasing exercise.

Cancer surveillance series: interpreting trends in prostate cancer--part II: Cause of death misclassification and the recent rise and fall in prostate cancer mortality.

BACKGROUND: The rise and fall of prostate cancer mortality correspond closely to the rise and fall of newly diagnosed cases. To understand this phenomenon, we explored the role that screening, treatment, iatrogenic (i.e., treatment-induced) deaths, and attribution bias (incorrect labeling of death from other causes as death from prostate cancer) have played in recent mortality trends. METHODS: Join point regression is utilized to assess the recent rise and fall in mortality and the relationship of total U.S. trends to those areas served by the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) Cancer Registry Program. Incidence-based mortality (IBM) is estimated with the use of prostate cancer data from the SEER Program to partition (from overall prostate cancer mortality trends) the contribution of cases diagnosed since the widespread use of prostate-specific antigen (PSA) testing starting in 1987. IBM is also used to examine the contribution of stage at diagnosis to the recent prostate cancer mortality trends. RESULTS: IBM for cases diagnosed since 1987 rose above the pre-1987 secular (i.e., background) trend, peaked in the early 1990s, and almost returned to the secular trend by 1994. This rise and fall of IBM track with the pool of prevalent cases diagnosed within the prior 2 years. IBM for cases diagnosed with metastatic disease fell starting in 1991, while IBM for those diagnosed with localized/regional disease was relatively flat. CONCLUSIONS: The rise and fall in prostate cancer mortality observed since the introduction of PSA testing in the general population are consistent with a hypothesis that a fixed percent of the rising and falling pool of recently diagnosed patients who die of other causes may be mislabeled as dying of prostate cancer. The decline in IBM for distant stage disease and flat IBM trends for localized/regional disease provide some evidence of improved prognosis for screen-detected cases, although alternative interpretations are possible.

Cancer surveillance series: interpreting trends in prostate cancer--part III: Quantifying the link between population prostate-specific antigen testing and recent declines in prostate cancer mortality.

BACKGROUND: The objective of this study was to investigate the circumstances under which dissemination of prostate-specific antigen (PSA) testing, beginning in 1988, could plausibly explain the declines in prostate cancer mortality observed from 1992 through 1994. METHODS: We developed a computer simulation model by use of information on population-based PSA testing patterns, cancer detection rates, average lead time (the time by which diagnosis is advanced by screening), and projected decreased risk of death associated with early diagnosis of prostate cancer through PSA testing. The model provides estimates of the number of deaths prevented by PSA testing for the 7-year period from 1988 through 1994 and projects what prostate cancer mortality for these years would have been in the absence of PSA testing. RESULTS: Results were generated by assuming a level of screening efficacy similar to that hypothesized for the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial. Under this assumption, the projected mortality in the absence of PSA testing continued the increasing trend observed before 1991 only when it was assumed that the mean lead time was 3 years or less. Projected mortality trends in the absence of PSA screening were not consistent with pre-1991 increasing trends for lead times of 5 years and 7 years. CONCLUSIONS: When screening is assumed to be at least as efficacious as hypothesized in the PLCO trial, it is unlikely that the entire decline in prostate cancer mortality can be explained by PSA testing based on current beliefs concerning lead time. Only very short lead times would produce a decline in mortality of the magnitude that has been observed.

Cancer surveillance series: interpreting trends in prostate cancer--part I: Evidence of the effects of screening in recent prostate cancer incidence, mortality, and survival rates.

BACKGROUND: The prostate-specific antigen test was approved by the U.S. Food and Drug Administration in 1986 to monitor the disease status in patients with prostate cancer and, in 1994, to aid in prostate cancer detection. However, after 1986, the test was performed on many men who had not been previously diagnosed with prostate cancer, apparently resulting in the diagnosis of a substantial number of early tumors. Our purpose is to provide insight into the effect of screening on prostate cancer rates. Detailed data are presented for whites because the size of the population allows for calculating statistically reliable rates; however, similar overall trends are seen for African-Americans and other races. METHODS: Prostate cancer incidence data from the National Cancer Institute's Surveillance, Epidemiology, and End Results Program and mortality data from the National Center for Health Statistics were analyzed. RESULTS/CONCLUSIONS: The following findings are consistent with a screening effect: 1) the recent decrease since 1991 in the incidence of distant stage disease, after not having been perturbed by screening; 2) the decline in the incidence of earlier stage disease beginning the following year (i.e., 1992); 3) the recent increases and decreases in prostate cancer incidence and mortality by age that appear to indicate a calendar period effect; and 4) trends in the incidence of distant stage disease by tumor grade and trends in the survival of patients with distant stage disease by calendar year that provide suggestive evidence of the tendency of screening to detect slower growing tumors. IMPLICATIONS: The decline in the incidence of distant stage disease holds the promise that testing for prostate-specific antigen may lead to a sustained decline in prostate cancer mortality. However, population data are complex, and it is difficult to confidently attribute relatively small changes in mortality to any one cause.

Breast cancer survival and treatment in health maintenance organization and fee-for-service settings.

BACKGROUND: Enrollment in health maintenance organizations (HMOs) has increased rapidly during the past 10 years, reflecting a growing emphasis on health care cost containment. To determine whether there is a difference in the treatment and outcome for female patients with breast cancer enrolled in HMOs versus a fee-for-service setting, we compared the 10-year survival and initial treatment of patients with breast cancer enrolled in both types of plans. METHODS: With the use of tumor registries covering the greater San Francisco-Oakland and Seattle-Puget Sound areas, respectively, we obtained information on the treatment and outcome for 13,358 female patients with breast cancer, aged 65 years and older, diagnosed between 1985 and 1992. We linked registry information with Medicare data and data from the two large HMOs included in the study. We compared the survival and treatment differences between HMO and fee-for-service care after adjusting for tumor stage, comorbidity, and sociodemographic characteristics. RESULTS: In San Francisco-Oakland, the 10-year adjusted risk ratio for breast cancer deaths among HMO patients compared with fee-for-service patients was 0.71 (95% confidence interval [CI] = 0.59-0.87) and was comparable for all deaths. In Seattle-Puget Sound, the risk ratio for breast cancer deaths was 1.01 (95% CI = 0.77-1.33) but somewhat lower for all deaths. Women enrolled in HMOs were more likely to receive breast-conserving surgery than women in fee-for-service (odds ratio = 1.55 in San Francisco-Oakland; 3.39 in Seattle). HMO enrollees undergoing breast-conserving surgery were also more likely to receive adjuvant radiotherapy (San Francisco-Oakland odds ratio = 2.49; Seattle odds ratio = 4.62). CONCLUSIONS: Long-term survival outcomes in the two prepaid group practice HMOs in this study were at least equal to, and possibly better than, outcomes in the fee-for-service system. In addition, the use of recommended therapy for early stage breast cancer was more frequent in the two HMOs.

Sit to stand transfer: performance in rising power, transfer time and sway by age and sex in senior athletes.

OBJECTIVE: To observe the differences in performance variables of the sit to stand transfer (as measured on the NeuroCom Balance Master) in a population of senior athletes. METHOD: A convenience sample of 173 subjects aged 50 years and older. Data were obtained from voluntary participation in a health fair offered at the annual Huntsman World Senior Games in St George, Utah, USA. All sit to stand tests were performed on the NeuroCom Balance Master. The measured parameters were weight transfer time (WTT), rising power (force exerted to rise), and centre of gravity sway (COG sway) during the rising phase. RESULTS: A significant difference was found between stratified age groups (50-64 and 65+ years) on rising power. There was also a sex difference in rising power. No significant differences were found in weight transfer time or COG sway. CONCLUSION: While rising power decreases with increasing age in senior athletes, WTT and COG sway remain similar regardless of age or sex. The maintenance of these other two variables (WTT and COG sway) may be attributable to physical activity and/or participation in sport.

The lifetime risk of developing prostate cancer in white and black men.

Two factors help explain increases in the lifetime risk of developing cancer: (a) decreasing overall mortality rates such that people are now living to older ages when cancer rates rise rapidly; and (b) increasing numbers of cancer cases discovered by new medical procedures, screening tests, and changes in the population risk factors. Prostate cancer lifetime risk estimates are particularly influenced by improved mortality rates and increased detection of asymptomatic disease. In this study, we report trends in lifetime risk estimates of developing prostate cancer in white and black men in the United States, from 1975 to 1993, and focus on the effects of changing mortality and screening. For the study period 1975-1977 to 1991-1993, the lifetime risk of developing invasive prostate cancer increased from 7.3 to 19.6% for whites and from 8.5 to 18.6% for blacks. When we recalculated these estimates using age-specific incidence trends from 1975 through 1989 (thereby controlling for the effect of prostate-specific antigen serum testing on prostate cancer incidence rates), the lifetime risk estimates in 1991-1993 fell to 13.8% for whites and 12.5% for blacks. When we made an additional assumption, basing lifetime risk estimates on higher 1975-1977 mortality rates, the lifetime risk estimates in 1991-1993 became 11.3% for whites and 11.8% for blacks. It is also shown that although mortality rates have improved for white and black men over the study period, they are much larger for blacks than whites in younger age groups, when the prevalence of prostate cancer is relatively low. As a result, fewer blacks survive to older ages when age-specific prostate cancer rates are large. It is of note that blacks have higher incidence rates for prostate cancer than do whites at every age-specific interval. Hence, increasing trends in lifetime risk of prostate cancer suggest, in large part, longer life expectancy and better detection methods.

Trends in tobacco smoking among adolescents in Lyon, France.

To provide information that may promote more effective cancer prevention, we identified factors associated with regular smoking among adolescents in Lyon, France. School grades where these factors began to influence regular smoking were also identified. Seven consecutive cross-sectional anonymous surveys were conducted in three public schools, beginning in grade 6ème (average age 11.5 years) in 1993 and ending in grade Terminale (average age 17.4 years) in 1999. All classes in each respective grade were surveyed, with 3650 completed questionnaires for all years combined. Prevalence of current regular smoking is presented according to school grade for 17 variables identified as significantly related to regular smoking in a multivariate logistic regression analysis. Important factors associated with regular smoking were identified as early as grade 6ème and included not viewing the taking care of one's health as important, not eating breakfast regularly, associating with groups where smoking occurs, having a best friend who smokes, and having a brother and/or sister who smokes. Not regularly reading was first associated with an increased risk of regular smoking in grade 5ème. Not living with both parents, alcohol drinking, episodes of drunkenness, illicit drug use, and sexual relationships were positively associated with regular smoking in the middle and later grades, when these questions were first asked. Not playing sports and not playing with computers were initially associated with an increased risk of regular smoking in grade 3ème.

Measuring the projected public health impact of lung cancer through lifetime and age-conditional risk estimates.

PURPOSE: Lifetime and age-conditional probability (risk) estimates of developing lung cancer in the United States are presented by age, race, and gender. Effects on the risk estimates of an aging population and changing tobacco use are identified. METHODS: Risk estimates were derived by applying cross-sectional, population-based incidence rates of malignant lung cancer and mortality rates from other causes to a hypothetical cohort. The cohort was aged through a double-decrement life table to determine the expected proportion of the population that would develop the disease across age intervals. Incidence and mortality data were obtained from the Surveillance, Epidemiology, and End Results (SEER) Program and the National Centers for Health Statistics, respectively. RESULTS: Among all cancers, risk estimates of developing lung cancer within 10 years, conditioned on being free of the disease at age 50, 60, or 70, ranked second to prostate cancer for men and second to breast cancer for women. For men, despite higher incidence rates of lung cancer for blacks than whites across most age groups, the risk of developing this disease over the life-span becomes similar, because white men are more likely to live to older ages where lung cancer is common. For women, lung cancer incidence rates are similar between Whites and Blacks, but an older age distribution among white women explains their greater lifetime risk of being diagnosed with the disease. Changes in the age distribution between the mid 1970s and the mid 1990s had little impact on the short-term risk estimates of developing lung cancer for younger ages but had a large influence on long-term risk estimates, particularly for the older age groups. CONCLUSIONS: Declining lung cancer among younger age groups may be attributed to declining tobacco use among the cohorts, but several more years may be required before the trends begin to fall in older age groups, particularly in women. In the meantime, an aging population is contributing to more people being diagnosed with lung cancer. Consequently, the projected risk of developing lung cancer will remain high for several years to come.

Prevalence corrected hysterectomy rates and probabilities in Utah.

PURPOSE: A life table method is used for correcting hysterectomy rates and probabilities for prevalent cases of hysterectomies in the population. Both corrected and conventional hysterectomy rates and probabilities are reported. METHODS: Hysterectomy prevalence estimates are derived from cross-sectional hysterectomy and mortality using a life table method. Analysis is based on the Utah Hospital Discharge Data Base and State death certificates. RESULTS: Hysterectomy rates are strongly influenced by age, reaching 150 per 10,000 for ages 45-49 years. The corresponding corrected hysterectomy rate is 196. Differences between the corrected and uncorrected cause-specific hysterectomy rates tend to be most pronounced at their peaks, particularly later in life where the prevalence of hysterectomy is greatest. Probability of hysterectomy approaches slightly above 35% over the life span, whereas the corrected hysterectomy probability approaches 43%. Probability of hysterectomy in the next 10 years is 12.9% for women aged 35 years and 11.7% for women aged 45 years. Corresponding corrected hysterectomy probabilities are 14.3 and 15.1. Higher prevalence of hysterectomy in later ages explains the reverse in magnitude of the rates when the correction is applied to the hysterectomy rates. CONCLUSIONS: Conventional hysterectomy rates are underestimated, particularly in older age groups. A prevalence correction of the rates and probabilities is necessary to fully understand the potential health related consequences and impact of this medical procedure in the population.