Cohort Members (cohort + member)

Distribution by Scientific Domains


Selected Abstracts


Risk of upper gastrointestinal bleeding with oral bisphosphonates and non steroidal anti-inflammatory drugs: a case-control study

ALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 11 2009
M. ETMINAN
Summary Background, Gastrointestinal injuries including gastric ulcers have been reported with oral bisphosphonate therapy. However, the risk of the more serious upper gastrointestinal bleeding (UGB) especially in the community setting with these drugs remains unknown. Similarly, the risk of UGB among users of both bisphosphonates and non steroidal anti-inflammatory drugs (NSAIDs) in the community is also unknown. Aim, To explore the risk of more serious UGB among users of bisphosphonates and the risk of UGB among users of both bisphosphonates and NSAIDs in the community. Methods, We conducted a case-control study within a cohort of Quebec residents who had received a revascularization procedure from 1995 to 2004. Cohort members were followed up from the date of their first procedure until the earliest of: (1) study outcome, (2) date of death or (3) end of health care coverage. Cases were defined as those with the first diagnosis of a UGB. For each case, 20 controls were selected and matched to the cases by index date, age and cohort entry. Adjusted odds ratios for current use of bisphosphonates, NSAIDs and co-therapy of both drugs were computed. Results, Within the initial cohort, 3253 incident cases of UGBs and corresponding 65 060 matched controls were identified. The adjusted odds ratio (OR) for UGB by current users of bisphosphonates was 1.01 (95% CI, 0.72,1.43). Current NSAID use was associated with an increased risk of UGB OR = 1.75; 95% CI, 1.53,1.99. The OR for use of bisphosphonates and NSAIDs was elevated OR = 2.00; 95% CI, 1.12,3.57. This risk was still elevated for users of bisphosphonates and COX-2 inhibitors [OR = 2.38 (95% CI, 1.26,4.50)]. Conclusion, We found no evidence of an increase in the risk of UGB among current users of bisphosphonates. The risk of combined NSAID and bisphosphonate therapy was increased, but this risk was not higher than the risk for NSAID users alone. [source]


Driving forces behind increasing cardiovascular drug utilization: a dynamic pharmacoepidemiological model

BRITISH JOURNAL OF CLINICAL PHARMACOLOGY, Issue 6 2008
Helle Wallach Kildemoes
WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT , Several studies indicate that switch to more expensive drugs and increasing treatment intensity, rather than population ageing have been responsible for rising drug expenditures during the 1990s. , Little is known about the driving forces behind the increasing treatment intensity with cardiovascular drugs. WHAT THIS STUDY ADDS , This study provides a new pharmacoepidemiological method to analyse drug utilization trends, applying dispensing data at the individual level. , The suggested semi-Markov model allows for quantification of the influence of changing incidence, discontinuation and user mortality on rising treatment prevalence. , Increasing treatment incidence was the main driver behind rising treatment prevalence for most cardiovascular drug categories. , Whereas declining discontinuation drove some of the growth, declining mortality among drug users had little influence. AIMS To investigate the driving forces behind increasing utilization of cardiovascular drugs. METHODS Using register data, all Danish residents as of 1 January 1996 were followed until 2006. Cohort members were censored at death or emigration. Cardiovascular drug utilization on the individual level was traced, applying registered out-of-hospital dispensing. The impact of population ageing on cardiovascular drug utilization was investigated using standardized intensities and prevalences. Based on a three-state (untreated, treated and dead) semi-Markov model, we explored to what extent increasing treatment prevalence was driven by changing incidence, discontinuation and mortality. Expected treatment prevalences were modelled, applying stratum-specific cohort prevalence in 1996 along with incidence, discontinuation and drug user mortality either throughout 1996,2004 or at fixed 1996 levels. RESULTS Treatment prevalence (ages ,20 years) with cardiovascular drugs increased by 39% during 1996,2005 from 192.4 to 256.9 per 1000 inhabitants (95% confidence interval 256.5, 257.3). Treatment intensity grew by 109% from 272 to 569 defined daily doses 1000,1 day,1. Population ,middle-ageing' accounted for 11.5 and 20.3%, respectively. Increasing treatment incidence was the main driver of the rising treatment prevalence in most drug categories. Declining discontinuation drove some of the growth, declining drug user mortality less. Even with fixed incidence in the model, treatment prevalence continued to increase. CONCLUSIONS Age-related increases in treatment intensity and prevalence, rather than population ageing, drove the increasing treatment intensity with cardiovascular drugs. Increasing treatment prevalence in subgroups was primarily caused by increasing incidence. Due to pharmacoepidemiological disequilibrium, treatment prevalence will continue to grow even with unchanged incidence. [source]


Independent Evaluation of an Out-of-hospital Termination of Resuscitation (TOR) Clinical Decision Rule

ACADEMIC EMERGENCY MEDICINE, Issue 6 2008
Peter B. Richman MD
Abstract Objectives:, Recently, investigators described a clinical decision rule for termination of resuscitation (TOR) designed to help determine whether to terminate emergency medical services (EMS) resuscitative efforts for out-of-hospital cardiac arrests (OOHCA). The authors sought to evaluate the hypothesis that TOR would predict no survival for patients in an independent cohort of patients with OOHCA. Methods:, This was a retrospective cohort analysis conducted in the state of Arizona. Consecutive, adult, OOHCA were prospectively evaluated from October 2004 through October 2006. A statewide OOHCA database utilizing Utstein-style reporting from 30 different EMS systems was used. Data were abstracted from EMS first care reports and hospital discharge records. The TOR guidelines predict that no survival to hospital discharge will occur if 1) an OOHCA victim does not have return of spontaneous circulation (ROSC), 2) no shocks are administered, and 3) the arrest is not witnessed by EMS personnel. Data were entered into a structured database. Continuous data are presented as means (±standard deviations [SD]) and categorical data as frequency of occurrence, and 95% confidence intervals (CIs) were calculated as appropriate. The primary outcome measure was to determine if any cohort member who met TOR criteria survived to hospital discharge. Results:, There were 2,239 eligible patients; the study group included 2,180 (97.4%) patients for whom the data were complete; mean age was 64 (±11) years, and 35% were female. The majority of patients in the study group met at least one or more of the TOR criteria. A total of 2,047 (93.8%) patients suffered from cardiac arrest that was unwitnessed by EMS; 1,653 (75.8%) had an unwitnessed arrest and no ROSC. With respect to TOR, 1,160 of 2,180 (53.2%) patients met all three criteria; only one (0.09%; 95% CI = 0% to 0.5%) survived to hospital discharge. Conclusions:, The authors evaluated TOR guidelines in an independent, statewide OOHCA database. The results are consistent with the findings of the TOR investigation and suggest that this algorithm is a promising tool for TOR decision-making in the field. [source]


The targets of violence committed by young offenders with alcohol dependence, marijuana dependence and schizophrenia-spectrum disorders: findings from a birth cohort

CRIMINAL BEHAVIOUR AND MENTAL HEALTH, Issue 2 2002
Louise Arseneault
Background: Estimates of who is most at risk from violence by people with mental illness rest mainly on identified patient samples. This study, without such selection bias, examined the targets of violence committed by young adults with as-yet untreated alcohol dependence, marijuana dependence, or schizophrenia-spectrum disorders, to determine the extent to which their victims were co-residents or non-household members. Methods: In a total birth cohort of 21-year-olds (n = 956), past-year prevalence of alcohol dependence, marijuana dependence and schizophrenia-spectrum disorders were diagnosed using standardized DSM-III-R interviews. None of the people with schizophrenia-spectrum disorder has been hospitalized in the past year. Past-year violence and victim targets were measured using self-reports. Results: Compared with controls, cohort members with substance dependence or schizophrenia-spectrum disorders had higher prevalence and frequency rates of assault against co-residents, against non-household members, and also robbery and gang fights. Out of 39, five individuals with schizophrenia-spectrum disorder committed violent street crimes. Persons with substance dependence had similar proportions of violence against co-resident and non-household members, but persons with schizophrenia-spectrum disorders tended to victimize co-residents more than others. Conclusions: At the age when they are most likely to contribute to the community's violence burden, young untreated offenders with alcohol or marijuana dependence or with schizophrenia-spectrum disorders assault not only co-residents, but others as well, and commit violent street crimes. Families, schoolteachers and primary care physicians have an important potentially preventive role in early identification and treatment of the disorders. Copyright © 2002 Whurr Publishers Ltd. [source]


The antecedents of non-affective psychosis in a birth-cohort, with a focus on measures related to cognitive ability, attentional dysfunction and speech problems

ACTA PSYCHIATRICA SCANDINAVICA, Issue 4 2010
J. Welham
Welham J, Scott J, Williams GM, Najman JM, Bor W, O'Callaghan M, McGrath J. The antecedents of non-affective psychosis in a birth-cohort, with a focus on measures related to cognitive ability, attentional dysfunction, and speech problems. Objective:, Adults with non-affective psychosis show subtle deviations in a range of developmental trajectories as children and adolescents. Method:, Based on a birth-cohort (n = 3801), we examined the Peabody Picture Vocabulary Test (PPTV) at age 5, and Raven's Standard Progressive Matrices (RSPM) and Wide Range Achievement Test reading scale (WRAT-R) at age 14. Items related to speech problems and attentional dysfunction were available from maternal- or self-report. At age 21, we identified 60 cohort members who were screen-positive for non-affective psychosis (SP-NAP). Results:, Impaired performance on the PPVT and RSPM (but not WRAT-R) predicted SP-NAP for males only. Male cohort members in the highest quartile for attentional dysfunction at ages 5 and 14 were about 5,8 times more likely to develop SP-NAP. SP-NAP in males was significantly associated with speech problems at age 14. Conclusion:, Males who develop non-affective psychoses have subtle impairments in cognitive capacity prior to the development of their psychotic disorder. [source]


Does cannabis use encourage other forms of illicit drug use?

ADDICTION, Issue 4 2000
David M. Fergusson
Aims. To examine the relationship between cannabis use in adolescence and the onset of other illicit drug use. Method. Data were gathered over the course of a 21-year longitudinal study of a birth cohort of 1265 New Zealand children. Measures analysed included: (a) frequency of cannabis use and other illicit drugs from 15-21; (b) family, social, educational and behavioural backgrounds of cohort members prior to 15; and (c) adolescent life-style variables. Findings. (i) By 21, nearly 70% of cohort members and used cannabis and 26% had used other illicit drugs. (ii) In all but three cases, the use of cannabis had preceded the use of illicit drugs. (iii) Those using cannabis on more than 50 occasions a year had hazards of other illicit drug use that were 140 times higher than non-users. (iv)After adjustment for covariate factors, including childhood factors, family factors and adolescent life-style factors, cannabis use remained strongly related to the onset of other forms of illicit drug use. Those using cannabis on more than 50 occasions per year had hazards of other illicit drug use that were 59.2 times higher than non-users. Conclusions. Findings support the view that cannabis may act as a gateway drug that encourages other forms of illicit drug use. None the less, the possibility remains that the association is non-causal and reflects factors that were not adequately controlled in the analysis. [source]


Analysis of serious non-AIDS events among HIV-infected adults at Latin American sites

HIV MEDICINE, Issue 9 2010
WH Belloso
Objective Acquired immune deficiency appears to be associated with serious non-AIDS (SNA)-defining conditions such as cardiovascular disease, liver and renal insufficiency and non-AIDS-related malignancies. We analysed the incidence of, and factors associated with, several SNA events in the LATINA retrospective cohort. Materials and methods Cases of SNA events were recorded among cohort patients. Three controls were selected for each case from cohort members at risk. Conditional logistic models were fitted to estimate the effect of traditional risk factors as well as HIV-associated factors on non-AIDS-defining conditions. Results Among 6007 patients in follow-up, 130 had an SNA event (0.86 events/100 person-years of follow-up) and were defined as cases (40 with cardiovascular events, 54 with serious liver failure, 35 with non-AIDS-defining malignancies and two with renal insufficiency). Risk factors such as diabetes, hepatitis B and C virus coinfections and alcohol abuse showed an association with events, as expected. The last recorded CD4 T-cell count prior to index date (P=0.0056, with an average difference of more than 100 cells/,L) and area under the CD4 cell curve in the year previous to index date (P=0.0081) were significantly lower in cases than in controls. CD4 cell count at index date was significantly associated with the outcome after adjusting for risk factors. Conclusions The incidence and type of SNA events found in this Latin American cohort are similar to those reported in other regions. We found a significant association between immune deficiency and the risk of SNA events, even in patients under antiretroviral treatment. [source]


Sarcopenia is not due to lack of regenerative drive in senescent skeletal muscle

AGING CELL, Issue 2 2005
Erik Edström
Summary Sarcopenia, loss of skeletal muscle mass, is a hallmark of aging commonly attributed to a decreased capacity to maintain muscle tissue in senescence, yet the mechanism behind the muscle wasting remains unresolved. To address these issues we have explored a rodent model of sarcopenia and age-related sensorimotor impairment, allowing us to discriminate between successfully and unsuccessfully aged cohort members. Immunohistochemistry and staining of cell nuclei revealed that senescent muscle has an increased density of cell nuclei, occurrence of aberrant fibers and fibers expressing embryonic myosin. Using real-time PCR we extend the findings of increased myogenic regulatory factor mRNA to show that very high levels are found in unsuccessfully aged cohort members. This pattern is also reflected in the number of embryonic myosin-positive fibers, which increase with the degree of sarcopenia. In addition, we confirm that there is no local down-regulation of IGF-I and IGF-IR mRNA in aged muscle tissue; on the contrary, the most sarcopenic individuals showed significantly higher local expression of IGF-I mRNA. Combined, our results show that the initial drive to regenerate myofibers is most marked in cases with the most advanced loss of muscle mass, a pattern that may have its origin in differences in the rate of tissue deterioration and/or that regenerating myofibers in these cases fail to mature into functional fibers. Importantly, the genetic background is a determinant of the pace of progression of sarcopenia. [source]


A long-term follow-up study on the natural course of oral leukoplakia in a Swedish population-based sample

JOURNAL OF ORAL PATHOLOGY & MEDICINE, Issue 2 2007
A. Roosaar
Aim:, To assess the natural course of screening-detected oral leukoplakia (OL) among non-consulting individuals. Methods:, A cohort of 555 individuals with OL, confirmed in 1973,1974 during a population-based survey, were followed through January 2002 via record linkages with nationwide and essentially complete registers. A sample of 104 drawn from the 297 surviving cohort members who still were living in the area in 1993,1995 was invited to a re-examination. Sixty-seven of them attended. Results:, At the time of re-examination OL had disappeared in 29 (43%) individuals. There was a statistically significant association between cessation of/no smoking habits in 1993,1995 and the disappearance of OL. Never/previous daily smokers were thus over-represented among individuals whose OL had disappeared compared to those with persisting OL [n = 23 (82%) vs. n = 18 (47%), P < 0.01]. Eighteen (78%) of the twenty three non-smokers with disappearing OL had quit after the initial examination. One man and two women developed oral cancer during follow-up while 0.7 and 0.07, respectively, were expected. Conclusion:, Smoking cessation was associated with an increased disappearance of OL. Hence, at least one-fourth had lesions that could be classified as tobacco-related. Small observed and expected numbers prohibited firm conclusions about a possible excess risk of developing oral cancer. [source]


ORIGINAL ARTICLE: Venous thromboembolism and subsequent diagnosis of subarachnoid hemorrhage: a 20-year cohort study

JOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 8 2010
H. T. SØRENSEN
Summary.,Background:,Venous thromboembolism is a predictor of subsequent risk of ischemic stroke and intracerebral hemorrhage, but no data are available regarding its association with risk of subarachnoid hemorrhage. Objectives:,To examine this issue, we conducted a nationwide cohort study in Denmark. Patients and methods: Between 1977 and 2007, we identified 97 558 patients with a hospital diagnosis of venous thromboembolism and obtained information on risk of subsequent subarachnoid hemorrhage during follow-up in the Danish Registry of Patients. The incidence of subarachnoid hemorrhage in the venous thromboembolism cohort was compared with that of 453 406 population control cohort members. Results:,For patients with pulmonary embolism (PE), there was clearly an increased risk of subarachnoid hemorrhage, both during the first year of follow-up [relative risk 2.69; 95% confidence interval (CI), 1.32,5.48] and during later follow-up of 2,20 years (relative risk 1.40; 95% CI, 1.05,1.87). For patients with deep venous thrombosis (DVT) the risk was likewise clearly increased during the first year of follow-up (relative risk 1.91; 95% CI, 1.13,3.22), but not during later follow-up (relative risk 1.04; 95% CI, 0.81,1.32). Conclusions:,We found evidence that PE is associated with an increased long-term risk of subarachnoid hemorrhage. The two diseases might share etiologic pathways affecting the vessel wall or share unknown risk factors. [source]


Mefloquine prescriptions in the presence of contraindications: prevalence among US military personnel deployed to Afghanistan, 2007,,

PHARMACOEPIDEMIOLOGY AND DRUG SAFETY, Issue 2 2010
Remington L. Nevin MD
Abstract Purpose Contraindications to mefloquine use include a history of certain prevalent neuropsychiatric disorders, which are thought to increase the risk of severe adverse events including anxiety, paranoia, depression, hallucinations, psychosis, and possibly suicide. Within the US military, the continued availability and use of mefloquine is subject to administrative policies dating to 2002 that require clinicians to exercise added caution during prescribing. This analysis was performed to quantify the effectiveness of these policies in ensuring health care provider compliance with package insert prescribing guidance. Methods A previously identified cohort consisting of 11,725 active duty US military personnel, among whom 1127 (9.6%) had contraindications to mefloquine use identified through medical surveillance and pharmaceutical databases, was examined to identify individuals receiving prescriptions for mefloquine in the 45 days prior to a combat deployment in 2007. Results Among the 11,725 cohort members, 4505 (38.4% of the cohort) received a prescription for mefloquine. Among the 1127 cohort members with contraindications, 155 (1.3% of the cohort) were prescribed mefloquine, comprising 13.8% of those with contraindications. Conclusions Despite the longstanding administrative policies meant to reduce such events, approximately one in seven individuals with neuropsychiatric contraindications received a prescription for mefloquine prior to a recent combat deployment, significantly increasing the risk of subsequent adverse events. Given the prevalence of neuropsychiatric disorders among US military personnel and the continued availability of mefloquine, additional study is recommended to describe and quantify the nature and extent of mefloquine-associated adverse events experienced among this group. Published in 2009 by John Wiley & Sons, Ltd. [source]


Construction of the Korea Elderly Pharmacoepidemiologic Cohort: drug utilization review of cephalosporins in geriatric inpatients

PHARMACOEPIDEMIOLOGY AND DRUG SAFETY, Issue 6 2001
Byung Joo Park MD
Abstract We performed a cohort-based pharmacoepidemiologic study in order to evaluate the pattern of cephalosporin prescriptions in elderly inpatients in Korea. The Korea Elderly Pharmacoepidemiologic Cohort was composed of a geriatric population of beneficiaries of the Korea Medical Insurance Corporation residing in Busan in 1993. The cohort consisted of 23,649 members, comprising 15,221 women (64.4%) and 8428 men (35.6%). The study population for drug utilization review consisted of those cohort members who were admitted into hospitals during the period January 1993 through December 1994. The number of hospitalized patients was 4262, comprising 2631 women (61.7%) and 1681 men (38.3%). The trend of cephalosporin prescriptions over the 2-year period showed that the use of second and third generation cephalosporins increased relative to the use of first generation. The use of cephalosporins combined with other antibiotics was found to occur in 22.8% aminoglycosides (76.7%) and quinolones (17.1%) being the most common antibiotics combined with cephalosporins. Our result demonstrates an increase in the prescription of second and third generation cephalosporins in Korea, which has implications not only for the elderly population but also for the total population because of the impact on health care costs and the potential for the emergence of antimicrobial resistance. Copyright © 2001 John Wiley & Sons, Ltd. [source]


Birthweight and paternal involvement predict early reproduction in British women: Evidence from the National Child Development Study

AMERICAN JOURNAL OF HUMAN BIOLOGY, Issue 2 2010
Daniel Nettle
There is considerable interest in the mechanisms maintaining early reproduction in the most socioeconomically disadvantaged groups in developed countries. Previous research has suggested that differential exposure to early-life factors such as low birthweight and lack of paternal involvement during childhood may be relevant. Here, we used longitudinal data on the female cohort members from the UK National Child Development Study (n = 3,014,4,482 depending upon variables analyzed) to investigate predictors of early reproduction. Our main outcome measures were having a child by age 20, and stating at age 16 an intended age of reproduction of 20 years or lower. Low paternal involvement during childhood was associated with increased likelihood of early reproduction (O.R. 1.79,2.25) and increased likelihood of early intended reproduction (O.R. 1.38,2.50). Low birthweight for gestational age also increased the odds of early reproduction (O.R. for each additional s.d. 0.88) and early intended reproduction (O.R. for each additional s.d. 0.81). Intended early reproduction strongly predicted actual early reproduction (O.R. 5.39, 95% CI 3.71,7.83). The results suggest that early-life factors such as low birthweight for gestational age, and low paternal involvement during childhood, may affect women's reproductive development, leading to earlier target and achieved ages for reproduction. Differential exposure to these factors may be part of the reason that early fertility persists in socioeconomically disadvantaged groups. We discuss our results with respect to the kinds of interventions likely to affect the rate of teen pregnancy. Am. J. Hum. Biol., 2010. © 2009 Wiley-Liss, Inc. [source]


Occupation and breast cancer risk among Shanghai women in a population-based cohort study

AMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 2 2008
Bu-Tian Ji MD, DrPH
Abstract Introduction A total of 74,942 female subjects were recruited in a population-based cohort study in Shanghai, China between 1997 and 2000. We examined the relationship between occupation and breast cancer risk. Methods Cases were 586 women previously diagnosed with breast cancer at baseline and 438 women newly diagnosed with breast cancer during follow-up through December 2004. Eight controls were randomly selected for each case from cancer-free cohort members and frequency-matched to the cases by year of birth and age at diagnosis. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) of breast cancer risk associated with occupations, adjusting for established breast cancer risk factors. Results In the prevalent breast cancer data analysis, increased risks of breast cancer were associated with technicians in engineering/agriculture/forestry (OR,=,1.6, CI: 1.0,2.4), teaching personnel (OR,=,1.5, CI:1.1,2.0), tailoring/sewing workers (OR,=,1.6, CI:1.0,2.7), and examiners/measurers/testers (OR,=,1.5, CI:1.1,2.1) among those who started the jobs at least 20 years ago. Among incident breast cancer cases, significantly increased risks were associated with medical/health care workers (OR,=,1.4, CI:1.0,2.0), administrative clerical workers (OR,=,1.5, CI:1.0,2.4), postal/telecommunication workers (OR,=,2.2, CI:1.0,5.5), and odd-job workers (OR,=,1.7, CI:1.1,2.8) among those who started the jobs at least 20 years ago. The excess risks were found in both prevalent and incident cases for postal/telecommunication workers and purchasing/marketing personnel, although ORs reached only marginal significance. Conclusions: This study suggests that white-collar professionals and several production occupations may be associated with an increased risk of breast cancer. Am. J. Ind. Med. 51:100,110, 2008. © 2007 Wiley-Liss, Inc. [source]


Mortality in a Swedish rubber tire manufacturing plant: Occupational risks or an "unhealthy worker" effect?

AMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 8 2006
Gun Wingren PhD
Abstract Background In this cohort study a classification of 12 work categories, with specified common exposures, is used to evaluate the mortality among workers in a Swedish rubber tire plant. Methods Mortality among the cohort members is compared with expected values from national rates. Standardized mortality ratios (SMR) were calculated for the total cohort, for sub-cohorts and with the inclusion of a latency requirement. Results Male workers had increased risks for total mortality, circulatory death, respiratory death, mental disorders, epilepsy, injuries/poisoning, and for alcohol-related death. Many risks were noted among workers exposed to dust, fumes, or vapor. No trend in risk with increasing duration of employment was seen. Discussion Some established risks for rubber workers could be related to some specified work categories. The highest risks were noted among workers having a very short duration of employment indicating a possible "unhealthy worker effect" associated with life-style factors or to tasks offered to unskilled workers. Am. J. Ind. Med. 2006. © 2006 Wiley-Liss, Inc. [source]


Tracing 8,600 participants 36 years after recruitment at age seven for the Tasmanian Asthma Study

AUSTRALIAN AND NEW ZEALAND JOURNAL OF PUBLIC HEALTH, Issue 2 2006
Cathryn Wharton
Objective: To trace all participants 36 years after the original Tasmanian Asthma Study (TAS). Methods: In 1968, the TAS investigated asthma in 8,583 children who were born in 1961. We attempted to trace these participants in 2002,04 using names, dates of birth and gender. Current addresses were sought by computer linkage to the Commonwealth Electoral Roll, the Medicare database and the Tasmanian marriage records. Computer linkage was conducted with the National Death Index (NDI). Siblings of participants were also linked to the Commonwealth Electoral Roll and those identified were sent a letter requesting the participant's address. The Australian Twin Registry (ATR) and the 1991,93 TAS substudy were used to locate participant addresses. Results: After three rounds of electoral roll linkage, 56% of all cohort members were traced. Name changes were identified for 49% of the 3,477 females not initially matched to the electoral roll using linkage to marriage records. NDI linkage yielded a 0.7% match. Medicare linkage identified addresses for 27% of the 1,982 remaining participants. Writing to siblings located 60% of 1,661 participants. One hundred and eighty-three participants were matched to the 1991,93 TAS and 23 twins matched to the ATR. Overall, 81.5% of the cohort members were identified. Conclusions: With these methods, we have been able to trace a possible address for a large portion of the original participants, with the electoral roll linkage being the most useful. Implications: It is possible to trace Australians for follow-up studies using electronic linkage, although without unique identifiers it is labour and resource intensive and requires matching to several databases. [source]


A cohort study of thyroid cancer and other thyroid diseases after the Chornobyl accident,

CANCER, Issue 11 2006
Pathology analysis of thyroid cancer cases in Ukraine detected during the first screening (1998-2000)
Abstract BACKGROUND. The Ukrainian American Cohort Study evaluated the risk of thyroid disorders in a group of individuals who were younger than age 18 years at the time of the Chornobyl (Chernobyl) accident. In this article, the authors describe the pathology of thyroid carcinomas detected in the first screening. METHODS. From 1998 to 2000, 13,243 individuals completed the first cycle of screening examinations. Eighty patients underwent surgery between 1998 and 2004. Intraoperative and postoperative pathologic studies were performed at the Institute of Endocrinology and Metabolism, Kyiv. RESULTS. Pathologic analysis revealed 45 thyroid carcinomas, including 43 papillary thyroid carcinomas (PTCs) (95.6%) and 2 follicular thyroid carcinomas (FTCs) (4.4%). TNM classification (5th edition) of the PTCs included 8 T1 tumors (18.6%), 16 T2 tumors (37.2%), and 19 T4 tumors (44.2%). Fifteen PTCs (34.9%) were N1a,N1b, and 3 PTCs (7.0%) were M1. Among the PTCs, 8 exhibited the classical papillary histologic pattern (18.6%), 14 exhibited a follicular histologic pattern (32.6%), 5 exhibited a solid histologic pattern (11.6%), and 16 exhibited a mixed histologic pattern (37.2%). Both FTCs had a microfollicular-solid structure. Eleven of 20 cohort members who underwent surgery before the first screening had PTCs. Regional metastases (63.6%) and distant metastases (18.2%) were more common in this group. CONCLUSIONS. Multifocal growth, lymphatic and blood vessel invasion, extrathyroid spread, and regional and distant metastases were more frequent in less differentiated PTCs (>30% solid structure). Small carcinomas (,10 mm) comprised 23.3% of PTCs, and most of those (8 of 10 small carcinomas; 80%) were of the papillary-follicular subtype and therefore were more differentiated. The solid subtype of PTC was associated with shorter latency, especially in individuals who were diagnosed before the first screening. The histology of post-Chornobyl cancers is changing with time. Cancer 2006. Published 2006 by the American Cancer Society. [source]