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Poisson Regression Models (poisson + regression_models)
Selected AbstractsA revisit on older adults suicides and Severe Acute Respiratory Syndrome (SARS) epidemic in Hong KongINTERNATIONAL JOURNAL OF GERIATRIC PSYCHIATRY, Issue 12 2008Y. T. Cheung Abstract Background The Severe Acute Respiratory Syndrome (SARS) outbreak in 2003 had an enormous impact on Hong Kong society and the suicide rate was also at its historical high, 18.6 per 100,000. The most significant increase was found among the older adults aged 65 or above. Methods Poisson Regression Models were used to examine impact of the SARS epidemic on older adults suicides in Hong Kong. A complete set of the suicide statistics for the period 1993,2004 from the Coroners' Court were made available for the analysis. Chi-square test was used to compare the profile of the older adult suicide cases in the pre-SARS, peri-SARS and post-SARS periods. Results It showed an excess of older adults suicides in April 2003, when compared to the month of April of the other years. A trough, instead of the usual summer peak, was observed in June, suggesting some of the older adults suicides might have been brought forward. On a year basis, the annual older adult's suicide rates in 2003 and 2004 were significantly higher than that in 2002, suggesting the suicide rate did not return to the level before the SARS epidemic. Based on the Coroners' suicide death records, overall severity of illness, level of dependency and worrying of having sickness among the older adult suicides were found to be significantly different in the pre-SARS, peri-SARS and post-SARS periods. Conclusion The SARS epidemic was associated with an increase in older adults' suicide rate in April 2003 and some suicide deaths in June 2003 might have been brought forward. Moreover, an increase in the annual older adults' suicide rate in 2003 was observed and the rate in 2004 did not return to the level of 2002. Loneliness and disconnectedness among the older adults in the community were likely to be associated with the excess older adults' suicides in 2003. Maintaining and enhancing mental well being of the public over the period of epidemic is as important as curbing the spread of the epidemic. Attention and effort should also be made to enhance the community's ability to manage fear and anxiety, especially in vulnerable groups over the period of epidemic to prevent tragic and unnecessary suicide deaths. Copyright © 2008 John Wiley & Sons, Ltd. [source] Elderly suicide and the 2003 SARS epidemic in Hong KongINTERNATIONAL JOURNAL OF GERIATRIC PSYCHIATRY, Issue 2 2006Sau Man Sandra Chan Abstract Background Hong Kong was struck by the community outbreak of Severe Acute Respiratory Syndrome (SARS) in 2003. In the same year, the elderly suicide rate in Hong Kong showed a sharp upturn from a previous downward trend. Methods Secondary analyses using Poisson Regression Models on the suicide statistics from the Census and Statistics Department of the Hong Kong Government were performed. Results In a Poisson Regression Model on the annual suicide rates in elders aged 65 and over in years 1986,2003, 2002 served as the reference year. Suicide rates in 1986,1997 were significantly higher than the reference year, with an Incident Rate Ratio (IRR) of 1.34 to 1.61. However, rates in 1998,2001 did not differ from the reference year significantly, representing stabilization of suicide rates for 4 years after 1997. The elderly suicide rate increased to 37.46/100,000 in 2003, with an IRR of 1.32 (p,=,0.0019) relative to 2002. Such trend is preserved when female elderly suicide rates in 1993,2003 were analyzed, while suicide rates in elderly men and younger age groups did not follow this pattern. Discussions Mechanistic factors such as breakdown of social network and limited access to health care might account for the findings. These factors could have potentiated biopsychosocial risk factors for suicide at individual levels, particularly in elderly. Female elders, by way of their previous readiness to utilize social and health services instituted in the past decade, are thus more susceptible to the effects of temporary suspension of these services during the SARS epidemic. Conclusions The SARS epidemic was associated with increased risk of completed suicide in female elders, but not in male elders or the population under 65 years of age. Copyright © 2006 John Wiley & Sons, Ltd. [source] Inflammatory bowel disease patients who leave hospital against medical advice: Predictors and temporal trendsINFLAMMATORY BOWEL DISEASES, Issue 6 2009Gilaad G. Kaplan MD Abstract Background: Leaving hospital against medical advice (AMA) may have consequences with respect to health-related outcomes; however, inflammatory bowel disease (IBD) patients have been inadequately studied. Thus, we determined the prevalence of self-discharge, assessed predictors of AMA status, and evaluated time trends. Methods: We analyzed the 1995,2005 Nationwide Inpatient Sample (NIS) to identify 93,678 discharges with a primary diagnosis of IBD admitted to the hospital emergently and did not undergo surgery. We described the proportion of IBD patients who left AMA. Predictors of AMA status were evaluated using a multivariate logistic regression model and temporal trend analyses were performed with Poisson regression models. Results: Between 1995 and 2005, 1.31% of IBD patients left hospitals AMA. Crohn's disease (CD) patients were more likely to leave AMA (adjusted odds ratio [aOR], 1.53; 95% confidence intervals [CI]: 1.30,1.79). Characteristics associated with leaving AMA included: ages 18,34 (aOR, 7.77, 95% CI: 4.34,13.89); male (aOR, 1.75; 95% CI: 1.55,1.99); Medicaid (aOR, 4.55; 95% CI: 3.81,5.43) compared to private insurance; African Americans (aOR, 1.34; 95% CI: 1.09,1.64) compared to white; substance abuse (aOR, 2.75; 95% CI: 2.14,3.54); and psychosis (aOR, 1.55; 95% CI: 1.13,2.14). The incidence rates of self-discharge for CD patients were stable (P > 0.05) between 1995 and 1999, while they significantly (P < 0.0001) increased after 1999. In contrast, AMA rates for UC patients remained stable during the study period. Conclusions: Approximately 1 in 76 IBD patients admitted emergently for medical management leave the hospital AMA. These were primarily disenfranchised patients who may lack adequate outpatient follow-up. (Inflamm Bowel Dis 2009) [source] Population dynamics of serologically identified coinfections with human papillomavirus types 11, 16, 18 and 31 in fertile-aged Finnish womenINTERNATIONAL JOURNAL OF CANCER, Issue 9 2009Marjo Kaasila Abstract Licensed human papillomavirus (HPV) vaccines are expected to prevent high-risk (hr) HPV-infections (most notably types 16 and 18). Whether HPV vaccination will change the distribution of hrHPVs at the population level is open, since competition between HPV types is not well understood. Two stratified random subcohorts (1983,1997 and 1995,2003) of 7,815 and 3,252 women with a minimum of 2 pregnancies (<32 years) were selected from the Finnish Maternity Cohort. Using ELISA based on virus-like particles (VLP), we determined antibodies to HPV11, 16, 18 and 31 in paired sera of the women and used Poisson regression models to estimate the risk of further infection with other HPV types in those positive for HPV16 or HPV18 at baseline. Baseline HPV16 seropositivity was associated with increased risk of later infections with HPV18 (3.1, 95% CI: 1.7, 5.6). HPV18 seropositivity was associated with increased risk of HPV16 (3.9, 95% CI: 2.5, 6.1). Our observations favor a coinfection rather than superinfection model for the different HPV types and are not suggestive for type-replacement following HPV vaccination. © 2009 UICC [source] Role of serum cytokines tumour necrosis factor- , and interleukin-6 in the association between body weight and periodontal infectionJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 2 2009Tuomas Saxlin Abstract Aim: To study the role of serum cytokines tumour necrosis factor , (TNF- ,) and interleukin 6 (IL-6) as potential mediators in the association between body weight and periodontal infection among an adult population. Material and Methods: This study was based on a subpopulation of the Health 2000 Health Examination Survey, which included dentate non-diabetic, non-rheumatic subjects, aged between 45 and 64 years, who had never smoked and whose serum levels of TNF- , and IL-6 were analysed and whose periodontal status was clinically determined (effective n=425). The number of teeth with periodontal pockets of 4 mm or more and the number of teeth with periodontal pockets of 6 mm or more were used as outcome variables. Relative risks and 95% confidence intervals were estimated using Poisson regression models. Results: Serum IL-6, but not TNF- , associated with teeth with deepened periodontal pockets. Multivariate models showed that IL-6, but not TNF- ,, could mediate the effect of body weight on periodontium. Conclusion: In this population of non-diabetic and non-rheumatic subjects, who had never smoked, serum IL-6 was associated with periodontal infection. The results suggest that serum IL-6 could be one mediating factor that connects body weight and periodontal infection. [source] A systematic review of the success of sinus floor elevation and survival of implants inserted in combination with sinus floor elevation Part II: Transalveolar techniqueJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 2008Wah Ching Tan Abstract Objectives: The objectives of this systematic review were to assess the survival rate of implants placed in sites with transalveolar sinus floor elevation. Material and Methods: An electronic search was conducted to identify prospective and retrospective cohort studies on transalveolar sinus floor elevation, with a mean follow-up time of at least 1 year after functional loading. Failure and complication rates were analyzed using random-effects Poisson regression models to obtain summary estimates/ year proportions. Results: The search provided 849 titles. Full-text analysis was performed for 176 articles, resulting in 19 studies that met the inclusion criteria. Meta-analysis of these studies indicated an estimated annual failure rate of 2.48% (95% confidence interval (95% CI): 1.37,4.49%) translating to an estimated survival rate of 92.8% (95% CI): 87.4,96.0%) for implants placed in transalveolarly augmented sinuses, after 3 years in function. Furthermore, subject-based analysis revealed an estimated annual failure of 3.71% (95% CI: 1.21,11.38%), translating to 10.5% (95% CI: 3.6,28.9%) of the subjects experiencing implant loss over 3 years. Conclusion: Survival rates of implants placed in transalveolar sinus floor augmentation sites are comparable to those in non-augmented sites. This technique is predictable with a low incidence of complications during and post-operatively. [source] Landmines and Local Community AdaptationJOURNAL OF CONTINGENCIES AND CRISIS MANAGEMENT, Issue 2 2002Aldo A. Benini Despite international mobilization for greater humanitarian mine action and despite considerable clearance achievements, the majority of mine-affected communities have not yet been involved in formal clearance activities. They adapt to the contamination largely by local means. The differing degree to which local adaptation is successful is now better understood as a result of the Global Landmine Survey, a multi-country survey project launched in the wake of the 1997 Ottawa treaty to ban anti-personnel mines. Socio-economic impact surveys have since been completed in several countries. In addition to landmines, the Global Landmine Survey records impacts also from unexploded ordnance (UXO). The ability to avoid mine incidents is used to measure adaptation success. We use a variant of Poisson regression models in order to identify community and contamination correlates of the number of recent landmine victims. We estimate separate models using data from the Yemen, Chad and Thailand surveys. We interpret them in a common framework that includes variables from three domains: Pressure on resources, intensity of past conflict and communities' institutional endowments. Statistically significant associations occur in all three domains and in all the three countries studied. Physical correlates are the most strongly associated, pointing to a lasting deadly legacy of violent conflict, but also significant learning effects over time are present. Despite different measurements of institutional endowments, in each country one factor signifying greater local development is correlated with reductions in victims, whereas factors commonly associated with the presence of government officials do not contribute to local capacity to diminish the landmine problem. Strong spatial effects are manifest in clusters of communities with recent victims. Two policy consequences emerge. Firstly, given humanitarian funding limits, trade-offs between clearing contaminated land and creating alternative employment away from that land need to be studied more deeply; the Global Landmine Survey will need to reach out to other bodies of knowledge in development. Secondly, communities with similar contamination types and levels often form local clusters that are smaller than the administrative districts of the government and encourage tailored planning approaches for mine action. These call for novel coalitions that bring advocacy and grassroots NGOs together with local governments, agricultural and forestry departments and professional mine clearance and awareness education agencies. [source] Model choice in time series studies of air pollution and mortalityJOURNAL OF THE ROYAL STATISTICAL SOCIETY: SERIES A (STATISTICS IN SOCIETY), Issue 2 2006Roger D. Peng Summary., Multicity time series studies of particulate matter and mortality and morbidity have provided evidence that daily variation in air pollution levels is associated with daily variation in mortality counts. These findings served as key epidemiological evidence for the recent review of the US national ambient air quality standards for particulate matter. As a result, methodological issues concerning time series analysis of the relationship between air pollution and health have attracted the attention of the scientific community and critics have raised concerns about the adequacy of current model formulations. Time series data on pollution and mortality are generally analysed by using log-linear, Poisson regression models for overdispersed counts with the daily number of deaths as outcome, the (possibly lagged) daily level of pollution as a linear predictor and smooth functions of weather variables and calendar time used to adjust for time-varying confounders. Investigators around the world have used different approaches to adjust for confounding, making it difficult to compare results across studies. To date, the statistical properties of these different approaches have not been comprehensively compared. To address these issues, we quantify and characterize model uncertainty and model choice in adjusting for seasonal and long-term trends in time series models of air pollution and mortality. First, we conduct a simulation study to compare and describe the properties of statistical methods that are commonly used for confounding adjustment. We generate data under several confounding scenarios and systematically compare the performance of the various methods with respect to the mean-squared error of the estimated air pollution coefficient. We find that the bias in the estimates generally decreases with more aggressive smoothing and that model selection methods which optimize prediction may not be suitable for obtaining an estimate with small bias. Second, we apply and compare the modelling approaches with the National Morbidity, Mortality, and Air Pollution Study database which comprises daily time series of several pollutants, weather variables and mortality counts covering the period 1987,2000 for the largest 100 cities in the USA. When applying these approaches to adjusting for seasonal and long-term trends we find that the Study's estimates for the national average effect of PM10 at lag 1 on mortality vary over approximately a twofold range, with 95% posterior intervals always excluding zero risk. [source] Agricultural tractor overturn deaths: Assessment of trends and risk factors,,AMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 7 2010John R. Myers MS Abstract Background Tractor overturn deaths have been recognized as a public health concern for decades. Studies have reported on the hazards associated with tractor overturns, but none have reported on trends in tractor overturn fatality rates in the United States (US). Methods Tractor overturn fatality data from the Bureau of Labor Statistics Census of Fatal Occupational Injuries were used in Poisson regression models to: identify risk factors associated with overturn fatalities; examine trends in tractor overturn fatality rates between 1992 and 2007; and assess trends in overturn fatality rates for specific risk factors. Results Characteristics found to be associated with tractor overturn fatality rates were age, type of farm, region, and the victim's relationship to the farm (P,<,0.0001). Older age groups, crop farms, farms in the Midwest and Northeast, and family workers all had higher fatal tractor overturn risks. Overall, tractor overturn fatality rates declined 28.5% between 1992 and 2007. Significant decreases in tractor overturn fatality rates were found for the Northeast and South regions, hired workers, crop farms, and in every age group except those less than 25 years of age. Conclusions Tractor overturn fatality rates decreased between 1992 and 2007. These decreases were not consistent between different categories of the agricultural workforce or regions of the US. Changes in tractor overturn fatality rates may be partially explained by increases in the prevalence of ROPS on farm tractors in the US. ROPS promotion programs are needed to reduce tractor overturn fatalities, especially among those subpopulations at highest risk. Am. J. Ind. Med. Published 2009 Wiley-Liss, Inc. [source] Breast Cancer Incidence in a Cohort of Women with Benign Breast Disease from a Multiethnic, Primary Health Care PopulationTHE BREAST JOURNAL, Issue 2 2007Maria J. Worsham PhD Abstract:, Women with benign breast diseases (BBD), particularly those with lesions classified as proliferative, have previously been reported to be at increased risk for subsequent development of breast cancer (BC). A cohort of 4970 women with biopsy-proven BBD, identified after histopathology review of BBD biopsies, was studied for determination of subsequent development of BC. We report on 4537 eligible women, 28% of whom are African-American, whose BBD mass was evaluable for pathologic assessment of breast tissue. Ascertainment of subsequent progression to BC from BBD was accomplished through examination of the tumor registries of the Henry Ford Health system, the Detroit SEER registry, and the State of Michigan cancer registry. Incidence rates (IR) are reported per 100,000 person years at risk (100 k pyr). Poisson regression models were used to evaluate the association of demographic and lesion characteristics with BC incidence, using person years at the time of BBD diagnosis as the offset variable. The estimated overall BC IR for this cohort is 452 (95% confidence interval [CI] = 394,519) per 100 k pyr. Incidence for women age 50 and older is 80% greater than for younger women (p = 0.007, IRR = 1.8, 95% CI = 1.36,2.36). Neither marital status (p = 0.91, IRR = 0.97, 95% CI = 0.73,1.29) nor race (p = 0.67, IRR = 0.9, 95% CI = 0.54,1.48) is associated with differences in BC IR. Compared with women having nonproliferative lesions, the risk for BC is greater for women with atypical ductal hyperplasia of (IRR = 5.0; 95%CI = 2.26,11.0; p < 0.001) and other proliferative lesions (IR = 1.7, 95% CI = 1.02,2.95; p = 0.04). BC risk for woman with atypical lesions is significantly higher than for women with proliferative lesions without atypia (IRR = 2.58, 95% CI = 1.35,4.90; p = 0.0039). Neither race nor marital status was a factor for BC incidence from BBD in this cohort. Age retained its importance as a predictor of risk. BBD lesion histopathology in the outcome categories of either proliferative without atypia or proliferative with atypia are significant risk factors for BC, even when adjusted for the influence of demographic characteristics. The risks associated with BBD histological classifications were not different across races. [source] Presence of a Community Health Center and Uninsured Emergency Department Visit Rates in Rural CountiesTHE JOURNAL OF RURAL HEALTH, Issue 1 2009FAAFP, FACPM, George Rust MD ABSTRACT:,Context: Community health centers (CHCs) provide essential access to a primary care medical home for the uninsured, especially in rural communities with no other primary care safety net. CHCs could potentially reduce uninsured emergency department (ED) visits in rural communities. Purpose: We compared uninsured ED visit rates between rural counties in Georgia that have a CHC clinic site and counties without a CHC presence. Methods: We analyzed data from 100% of ED visits occurring in 117 rural (non-metropolitan statistical area [MSA]) counties in Georgia from 2003 to 2005. The counties were classified as having a CHC presence if a federally funded (Section 330) CHC had a primary care delivery site in that county throughout the study period. The main outcome measure was uninsured ED visit rates among the uninsured (all-cause ED visits and visits for ambulatory care sensitive conditions). Poisson regression models were used to examine the relationship between ED rates and the presence of a CHC. To ensure that the effects were unique to the uninsured population, we ran similar analyses on insured ED visits. Findings: Counties without a CHC primary care clinic site had 33% higher rates of uninsured all-cause ED visits per 10,000 uninsured population compared with non-CHC counties (rate ratio [RR] 1.33, 95% confidence interval [CI] 1.11-1.59). Higher ED visit rates remained significant (RR 1.21, 95% CI 1.02-1.42) after adjustment for percentage of population below poverty level, percentage of black population, and number of hospitals. Uninsured ED visit rates were also higher for various categories of diagnoses, but remained statistically significant on multivariate analysis only for ambulatory care sensitive conditions (adjusted RR = 1.22, 95% CI 1.01-1.47). No such relationship was found for ED visit rates of insured patients (RR 1.06, 95% CI 0.92-1.22). Conclusions: The absence of a CHC is associated with a substantial excess in uninsured ED visits in rural counties, an excess not seen for ED visit rates among the insured. [source] Familial aggregation of amyotrophic lateral sclerosis,ANNALS OF NEUROLOGY, Issue 1 2009Fang Fang MD Objective To assess the relative risk for amyotrophic lateral sclerosis (ALS) in families of ALS patients. Methods We conducted a cohort study based on the Swedish Multi-Generation Register in 1961 to 2005. Among 6,671 probands (first ALS case in the family), 1,909 full siblings, 13,947 children, and 5,405 spouses were identified (exposed group). Other persons in the Multi-Generation Register, who were siblings, children, or spouses to persons without ALS, served as the reference group. Relative risks for ALS among the exposed group, compared with the reference group, were calculated from Poisson regression models. Concurrence of ALS within twins was assessed in 86,441 twin pairs registered in the Swedish Twin Register. Results Nine cases of ALS were noted among the siblings and 37 cases among the children of the probands, giving a 17-fold risk among the siblings (95% confidence interval, 8.1,30.4) and a 9-fold risk among the children (95% confidence interval, 6.2,12.0), compared with the reference group. Siblings and children had a greater excess risk if the proband was diagnosed at a younger age, and the excess risks decreased with increasing age at diagnosis of the proband (p < 0.001). Spouses had no significantly increased risk (p = 0.27). Two cases were identified among the cotwins of ALS probands, giving a relative risk of 32 (95% confidence interval, 5.2,102.6). Interpretation The siblings and children of ALS patients have an about 10-fold risk for ALS compared with the reference group. The excess risks vary with both age and kinship, indicating a major genetic role in familial ALS. Ann Neurol 2009;66:94,99 [source] Random-coefficients hidden-Markov Poisson regression models for inferring a competitor's promotion strategyAPPLIED STOCHASTIC MODELS IN BUSINESS AND INDUSTRY, Issue 4 2007Johannes Ledolter Abstract In this paper we consider the case of a drug manufacturer who has physician-level information on the prescription volume for its own brand and its competitor, has complete physician-level data on its own free-sampling plan, but has only sparse data on the competitor's promotion strategy. We investigate whether one is able to predict the competitor's promotion strategy from such limited data. We treat the competitor's promotion as a latent (unobservable) event, and propose a hidden Markov model (HMM) to describe its progression over time. Analysis of actual and simulated data shows that the HMM improves our ability to infer the missing promotion event if promotions are serially correlated. A simpler model assuming that the probability of transition from one sampling state to the other is independent of the current state is adequate if the serial correlation among promotions is weak. Copyright © 2007 John Wiley & Sons, Ltd. [source] Geographic distribution of autism in California: A retrospective birth cohort analysis,AUTISM RESEARCH, Issue 1 2010Karla C. Van Meter Abstract Prenatal environmental exposures are among the risk factors being explored for associations with autism. We applied a new procedure combining multiple scan cluster detection tests to identify geographically defined areas of increased autism incidence. This procedure can serve as a first hypothesis-generating step aimed at localized environmental exposures, but would not be useful for assessing widely distributed exposures, such as household products, nor for exposures from nonpoint sources, such as traffic. Geocoded mothers' residences on 2,453,717 California birth records, 1996,2000, were analyzed including 9,900 autism cases recorded in the California Department of Developmental Services (DDS) database through February 2006 which were matched to their corresponding birth records. We analyzed each of the 21 DDS Regional Center (RC) catchment areas separately because of the wide variation in diagnostic practices. Ten clusters of increased autism risk were identified in eight RC regions, and one Potential Cluster in each of two other RC regions. After determination of clusters, multiple mixed Poisson regression models were fit to assess differences in known demographic autism risk factors between the births within and outside areas of elevated autism incidence, independent of case status. Adjusted for other covariates, the majority of areas of autism clustering were characterized by high parental education, e.g. relative risks >4 for college-graduate vs. nonhigh-school graduate parents. This geographic association possibly occurs because RCs do not actively conduct case finding and parents with lower education are, for various reasons, less likely to successfully seek services. [source] Using Regression Models to Analyze Randomized Trials: Asymptotically Valid Hypothesis Tests Despite Incorrectly Specified ModelsBIOMETRICS, Issue 3 2009Michael Rosenblum Summary Regression models are often used to test for cause-effect relationships from data collected in randomized trials or experiments. This practice has deservedly come under heavy scrutiny, because commonly used models such as linear and logistic regression will often not capture the actual relationships between variables, and incorrectly specified models potentially lead to incorrect conclusions. In this article, we focus on hypothesis tests of whether the treatment given in a randomized trial has any effect on the mean of the primary outcome, within strata of baseline variables such as age, sex, and health status. Our primary concern is ensuring that such hypothesis tests have correct type I error for large samples. Our main result is that for a surprisingly large class of commonly used regression models, standard regression-based hypothesis tests (but using robust variance estimators) are guaranteed to have correct type I error for large samples, even when the models are incorrectly specified. To the best of our knowledge, this robustness of such model-based hypothesis tests to incorrectly specified models was previously unknown for Poisson regression models and for other commonly used models we consider. Our results have practical implications for understanding the reliability of commonly used, model-based tests for analyzing randomized trials. [source] Trends in stomach and pancreatic cancer incidence and mortality in England and Wales, 1951,2000BRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 9 2007D. Fitzsimmons Background: The aim of this study was to describe period and cohort effects in incidence and mortality of stomach and pancreatic cancer in England and Wales. Methods: National figures for mortality (1951,2000) and incidence (1971,2000) were analysed using log-linear Poisson regression models to obtain relative risks (RR) for period (year of incidence or death) and cohort (year of birth). Results: Stomach cancer shows a pronounced cohort effect in mortality with a decline in RR in men from 2·20 (1876) to 0·47 (1946) and a reduction from 2·79 to 0·41 for women. Mortality to incidence ratios are now less than 0·70. Pancreatic cancer mortality (men) RR rose from 0·91 (1951,1955) to a peak 1·11 (1976,1980) and then declined to 0·90 (1996,2000). Women showed a similar pattern. Cohort RR (men) increased to a peak of 1·14 in 1916 and declined to 1·01 in 1946, and continued to fall; the peak occurred slightly later in women. Mortality to incidence ratios were near 1 in the first 20 years, declining to 0·95 in the last 10 years. Conclusion: Stomach cancer incidence has fallen continuously from 19th century birth cohorts onwards. Incidence of pancreatic cancer has fallen in successive birth cohorts after 1920; peak period risk was 1976,1990. Age-standardized mortality and case mortality for pancreatic cancer are declining. Copyright © 2007 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd. [source] Fertility preservation in young women with epithelial ovarian cancerCANCER, Issue 18 2009Jason D. Wright MD Abstract BACKGROUND: Surgical management of ovarian cancer consists of hysterectomy with bilateral oophorectomy. In young women, this results in the loss of reproductive function and estrogen deprivation. In the current study, the authors examined the safety of fertility-conserving surgery in premenopausal women with epithelial ovarian cancers. METHODS: Women aged ,50 years with stage IA or IC epithelial ovarian cancer who were registered in the Surveillance, Epidemiology, and End Results database were examined. Patients who underwent bilateral oophorectomy were compared with those who underwent ovarian conservation. A second analysis examined uterine conservation versus hysterectomy. Multivariate Poisson regression models were developed to describe predictors of fertility preservation. Survival was examined using Cox proportional hazards models and the Kaplan-Meier method. RESULTS: In total, 1186 women, including 754 women (64%) who underwent bilateral oophorectomy and 432 women (36%) who underwent ovarian preservation, were identified. Younger age, later year of diagnosis, and residence in the eastern or western United States were associated with ovarian preservation (P < .05 for all). Women with endometrioid and clear cell histologies and stage IC disease were less likely to have ovarian conservation (P < .05). In a Cox model, ovarian preservation had no effect on survival (hazard ratio [HR], 0.69; 95% confidence interval [CI], 0.39-1.20). Young age, later year of diagnosis, residence in the eastern or western United States, single women, mucinous tumors, and patients with stage IA disease were more likely to have uterine preservation (P < .05 for all). In a multivariate model, uterine preservation had no effect on survival (HR, 0.87; 95% CI, 0.62-1.22). CONCLUSIONS: Ovarian and uterine-conserving surgery were safe in young women who had stage IA and IC epithelial ovarian cancer. Cancer 2009. © 2009 American Cancer Society. [source] Incidence and mortality rates for colorectal cancer in Puerto Rico and among Hispanics, non-Hispanic whites, and non-Hispanic blacks in the United States, 1998-2002CANCER, Issue 13 2009Marievelisse Soto-Salgado MS Abstract BACKGROUND: Colorectal cancer (CRC) is the second most commonly diagnosed cancer in Puerto Rico (PR). In the United States, the incidence and mortality rates of CRC have great variation by sex and race/ethnicity. Age-standardized incidence and mortality rates of CRC in PR were assessed and compared with the rates among US Hispanics (USH), non-Hispanic whites (NHW), and non-Hispanic blacks (NHB) in the United States for the period from 1998 through 2002. Incidence and mortality trends and relative differences among racial/ethnic groups by sex and age were determined. METHODS: Age-standardized rates using the world standard population (ASR[World]) were based on cancer incidence and mortality data from the PR Central Cancer Registry and from the National Cancer Institute's Surveillance, Epidemiology, and End Results Program using the direct method. The annual percentage changes (APC) and relative risks (RR) were calculated using Poisson regression models. RESULTS: During 1998 through 2002, the APC of CRC incidence and mortality increased for men in PR, whereas descending trends were observed for other racial/ethnic groups. Overall period rates indicated that, in both sexes, Puerto Ricans had CRC incidence and mortality rates similar to those for USH, but their rates were lower than those for NHW and NHB. However, Puerto Rican men and women ages 40 years to 59 years had the greatest risk of incidence and mortality compared with their USH counterparts. CONCLUSIONS: Areas of concern include the increasing trends of CRC in PR and the higher burden of the disease among young Puerto Ricans compared with the USH population. The authors concluded that further research should be performed to guide the design and implementation of CRC prevention and education programs in PR. Cancer 2009. © 2009 American Cancer Society. [source] A systematic review of the survival and complication rates of fixed partial dentures (FPDs) after an observation period of at least 5 yearsCLINICAL ORAL IMPLANTS RESEARCH, Issue 6 2004II. Combined tooth, implant-supported FPDs Abstract Objectives: The objective of this systematic review was to assess the 5- and 10-year survival of combined tooth,implant-supported fixed partial dentures (FPDs) and the incidence of biological and technical complications. Methods: An electronic MEDLINE search supplemented by manual searching was conducted to identify prospective and retrospective cohort studies on FPDs with a mean follow-up time of at least 5 years. Patients had to have been examined clinically at the follow-up visit. Assessment of the identified studies and data abstraction was performed independently by two reviewers. Failure and complication rates were analyzed using random-effects Poisson regression models to obtain summary estimates of 5- and 10-year survival proportions. Results: From a total of 3844 titles and 560 abstracts, 176 articles were selected for full-text analysis, and 13 studies met the inclusion criteria. Meta-analysis of these studies indicated an estimated survival of implants in combined tooth,implant-supported FPDs of 90.1% (95 percent confidence interval (95% CI): 82.4,94.5%) after 5 and 82.1% (95% CI: 55.8,93.6%) after 10 years. The survival rate of FPDs was 94.1% (95% CI: 90.2,96.5%) after 5 and 77.8% (95% CI: 66.4,85.7%) after 10 years of function. There was no significant difference in survival of tooth and implant abutments in combined tooth,implant FPDs. After an observation period of 5 years, 3.2% (95% CI: 1.5,7.2%) of the abutment teeth and 3.4% (95% CI: 2.2,5.3%) of the functionally loaded implants were lost. After 10 years, the corresponding proportions were 10.6% (95% CI: 3.5,23.1%) for the abutment teeth and 15.6% (95% CI: 6.5,29.5%) for the implants. After a 5 year observation period, intrusion was detected in 5.2% (95% CI: 2,13.3%) of the abutment teeth. Intrusion of abutment teeth were almost exclusively detected among non-rigid connections. Conclusion: Survival rates of both implants and reconstructions in combined tooth,implant-supported FPDs were lower than those reported for solely implant-supported FPDs (Pjetursson et al. 2004). Hence, planning of prosthetic rehabilitation may preferentially include solely implant-supported FPDs. However, anatomical aspects, patient centered issues and risk assessments of the residual dentition may still justify combined tooth,implant-supported reconstructions. It was evident from the present search that tooth,implant-supported FPDs have not been studied to any great extent and hence, there is a definitive need for more longitudinal studies examining these reconstructions. Résumé L'objectif de cette revue systématique a été de vérifier la survie à cinq et dix années de prothèses partielles fixées portées sur implants et dents et l'incidence des complications techniques et biologiques. Une recherche Medline ainsi que manuelle ont identifié les études prospectives et rétrospectives avec un suivi d'au minimum cinq années. Les patients avaient dû subir un examen clinique lors de ce suivi. L'identification des études et l'analyse des données ont été effectuées indépendamment par deux personnes. Les taux d'échecs et de complications ont été analysés en utilisant les modèles de régression Poisson avec effets hasard pour obtenir des estimations à cinq et dix ans. De 3 844 titres et 560 résumés, 176 articles ont été sélectionnés pour l'analyse approfondie et treize études atteignaient les critères d'inclusion. La méta-analyse de ces études indiquaient une estimation de survie des implants en combinaison des prothèses fixées sur implants et dents de 90,1%(intervalle de confidence 95% : 82,4 à 94,5%) après cinq années et de 82,1% (55,8 à 93,6% après dix années. Le taux de survie de ces prothèses étaient de 94,1% (90,2 à 96,5%) après cinq ans et de 77,8% (66,4 à 85,7%) après dix années. Il n'y avait aucune différence significative dans la survie des piliers dentaires et implantaires dans ces prothèses sur implants et dents. Après une observation de cinq années, 3,2% (1,5 à 7,2%) des piliers dentaires et 3,4% (2,2 à 5,3%) des implants ont été perdus. Après dix années, les proportions correspondantes étaient de 10,6 % (3,5 à 23,1%) pour les dents et de 15,6%(6,5%à 29,5%) pour les implants. Après une observation de cinq années, l'intrusion a été détectée dans 5,2% (2,0 à 13,3%) des dents piliers. L'intrusion des dents piliers étaient presque exclusivement détectée le long des connexions non-rigides. Le taux de survie de ces prothèses sur pilier dents et implants étaient inférieur à celui rapporté pour le même type de prothèse seulement placé sur implants (Pjetursson et al. 2004). Le plan de prothèse pourrait donc avoir une préférence pour ne placer des prothèses que sur des implants. Cependant les aspects anatomiques, le respect du patient et les risques pour la dentition résiduelle peuvent justifier les reconstructions sur implants et dents. Il était évident que lors de la recherche présente les bridges sur implants et dents n'avaien pas été beaucoup étudiés; il s'avère donc nécessaire de débuter davantage d'études longitudinales. Zusammenfassung Ziel: Ziel dieser systematischen Übersicht war einerseits die Bestimmung der Überlebenszeit von kombiniert zahn-implantat-getragenem festsitzendem Zahnersatz (FPDs) nach 5 und 10 Jahren und andererseits die Häufigkeit von biologischen und technischen Komplikationen zu beschreiben. Methoden: Man führte eine manuell ergänzte elektronische Medline-Suche durch, um prospektive und retrospektive Kohortenstudien über FPDs mit einer durchschnittlichen Beobachtungszeit von mindestens 5 Jahren zu identifizieren. Die Patienten mussten bei den Nachkontrollen auch klinisch untersucht worden sein. Die Aufnahme der ausgewählten Studien und die Abstraktion der Daten wurde von zwei Personen unabhängig voneinander durchgeführt. Mit Hilfe eines Poission Regressionsmodells analysierte man die Misserfolgs- und Komplikationsraten und erhielt so zusammenfassende schätzwerte für die über lebenswahrscheindichkeit nach 5 und 10 Jahren. Resultate: Die Suche lieferte 3844 Titel und 560 Abstracts. Die Analyse des gesamten Textes erfolgte bei 176 Artikeln, von denen aus 13 Studien, die Einschlusskriterien erfüllten. Die Meta-Analyse dieser Studien ergab eine geschätzte Überlebensrate der Implantate in gemischt zahn-implantat-getragenen FPDs von 90.1% (95% CI: 82.4,94.5%) nach 5 Jahren und 82.1% (95% CI: 55.8,93.6%) nach 10 Jahren. Die Überlebensrate der FPDs betrug 94.1% (95% CI: 90.2,96.5%) nach 5 Jahren und 77.8% (95% CI: 66.4,85.7%) nach 10 Jahren in Funktion. Man fand bei den kombiniert zahn-implantat-getragenen FPDs keine signifikanten Unterschiede bei der Überlebensrate von Zahn- und Implantatpfeilern. Nach einer Beobachtungszeit von 5 Jahren waren 3.2% (95% CI: 1.5,7.2%) der Pfeilerzähne und 3.4% (95% CI: 2.2,5.3%) der funktionell belasteten Implantate verloren gegangen. Nach 10 Jahren betrugen die entsprechenden Werte 10.6% (95% CI: 3.5,23.1%) für die Pfeilerzähne und 15.6% (95% CI: 6.5,29.5%) für die Implantate. Nach einer Beobachtungszeit von 5 Jahren konnte man bei 5.2% (95% CI: 2,13.3%) der Pfeilerzähne eine Intrusion feststellen. Eine Intrusion war fast ausschliesslich bei nicht-starren Verbindungen festzustellen. Zusammenfassung: Die Überlebensraten für Implantate und Rekonstruktionen in kombiniert zahn-implantat-getragenen FPDs waren tiefer als die, welche in der Partnerstudie (Pjetursson et al. 2004) für allein implantat-getragene FPDs festgestellt worden sind. Daher müsste die Planung von prothetischen Rehabilitationen eigentlich vorzüglich mit rein implantat-getragenen FPDs durchgeführt werde. Anatomische Aspekte, patientenspezifische Gründe und die Risikoanalysen der Restbezahnung können aber weiterhin kombiniert zahn-implantat-getragene Rekonstruktionen rechtfertigen. Bei dieser Untersuchung wurde klar, dass die zahn-implantat-getragenen FPD's noch nicht in grösserem Ausmass studiert worden sind, was einen dringenden Bedarf an weiteren Lanzeitstudien, die diese Rekonstruktionen erforschen, zeigt. Resumen Objetivos: El objetivo de esta revisión sistemática fue valorar la supervivencia de dentaduras parciales fijas soportadas por implantes (FPDs) y describir la incidencia de complicaciones biológicas y técnicas. Métodos: Se llevó a cabo una búsqueda electrónica por Medline complementada con una búsqueda manual para identificar estudios cohorte prospectivos y retrospectivos acerca de FPDs con un tiempo de seguimiento medio de al menos 5 años. Los pacientes tenían que haber sido examinados clínicamente en la visita de seguimiento. La valoración de los estudios encontrados y de la abstracción de datos se llevó a cabo independientemente por dos revisores. Los índices de fracaso y complicación se analizaron usando modelos de regresión de efectos aleatorios de Poisson para obtener estimaciones de los sumarios de las proporciones de supervivencia a los 5 y 10 años. Resultados: De un total de 3844 títulos y 560 resúmenes, se seleccionaron 176 artículos para análisis, y 13 estudios coincidieron con los criterios de inclusión. Un meta análisis de estos estudios indicaron una supervivencia estimada de los implantes en FPDs soportados por dientes e implantes combinados del 90.1% (95% CI: 82.4,94.5%) tras 5 años, y 82.1% (95% CI: 55.8,93.6%) tras 10 años. El índice de supervivencia de los FPDs fue del 94.1% (95% CI: 90.2,96.5%) tras 5 años, y 77.8% (95% CI: 66.4,85.7%) tras 10 años en función. No hubo diferencias significativas en la supervivencia de los pilares de implantes o dientes en FPDs de dientes e implantes combinados. Tras un periodo de observación de 5 años, el 3.2% (95% CI: 1.5,7.2%) de los dientes pilares y 3.4% (95% CI: 2.2,5.3%) de los implantes en carga funcional se perdieron. Tras 10 años, las proporciones correspondientes fueron del 10.6% (95% CI: 3.5,23.1%) para los dientes pilares y 15.6% (95% CI: 6.5,29.5%) para los implantes. Tras un periodo de observación de 5 años, se detectó intrusión en 5.2% (95% CI: 2,13.3%) de los dientes pilares. La intrusión de los dientes pilares se casi exclusivamente detectada entre las conexiones no rígidas. Conclusión: Los índices de supervivencia de los implantes y las reconstrucciones en FPDs soportadas por dientes e implantes combinados fueron menores que los reportados para FPDs soportados por implantes únicamente (Pjetursson et al. 2004). Por lo tanto, la planificación de la rehabilitación prostética puede incluir preferentemente FPDs soportados solo por implantes. De todos modos, los aspectos anatómicos, las necesidades exactas del paciente y las valoraciones de riesgo de la dentición residual pueden todavía justificar las reconstrucciones soportadas por dientes e implantes combinados. Fue evidente de la presente búsqueda que los FPDs soportados por dientes e implantes no han sido estudiados extensamente y por lo tanto, existe definitivamente una necesidad para mas estudios longitudinales que examinen estas reconstrucciones. [source] | |||||||||||||