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PubMed1992

Analysis of mortality data from the former USSR: age-period-cohort analysis.

The objective of this article is to review research on age-period-cohort (APC) analysis of mortality and to trace the effects of contemporary and historical factors on mortality change in the former USSR. Several events in USSR history have exerted a lasting influence on its people. These influences may be captured by an APC model in which the period effects measure the impact of contemporary factors and the cohort effects the past history of individuals which cannot be attributed to age or stage in the life cycle. APC models are extensively applied in the study of mortality. This article presents the statistical theory of the APC models and shows that they belong to the family of generalized linear models. The parameters of the APC model may therefore be estimated by any package of loglinear analysis that allows for hybrid loglinear models.

Adolescent↗
PubMed2003

Determinants of successful synthetic hemodialysis vascular access graft placement.

OBJECTIVE: Synthetic vascular grafts, the most common type of permanent dialysis graft used in the United States, are associated with great morbidity and expense. In this cohort study of patients undergoing hemodialysis and receiving a new synthetic vascular graft, detailed intraoperative procedural data were examined as predictors of graft dysfunction and failure. METHODS: A prospective cohort study of patients receiving hemodialysis who had undergone synthetic (polytetrafluoroethylene) graft placement over 4(1/2) years were followed up until either the graft was no longer usable, kidney transplantation was performed, the patient died, or the study ended. The principal methods of analysis used were the Kaplan-Meier method, to compute survival function for primary and secondary graft patency, and Cox proportional hazards regression, to model associations between predictor variables and graft failure. RESULTS: Of 284 patients enrolled in the study, 172 patients (61%) had at least one graft-related event, ie, temporary graft dysfunction or graft failure, during follow-up. Three-year cumulative graft survival was 54% (95% confidence interval, 45%-62%). Using proportional hazards analysis, history of claudication (rate ratio [RR], 2.14 [range, 0.97-4.73]; P =.06), number of previous permanent grafts (1 graft: RR, 1.49 [range, 0.88-2.51]; 2 or more grafts: RR, 2.85 [range, 1.43-5.69]; P =.01), dialysis dependency at surgery (RR, 2.96 [range, 1.23-7.12]; P =.02), and use of arterial clamps in construction of the graft (RR, 2.32 [range, 1.14-4.73]; P =.02) were associated with lower survival, even after accounting for medical history. Type of graft material, ie, Gore-Tex versus other material (RR, 0.28 [range, 0.16-0.50]; P <.01) and use of the axillary vein (RR, 0.61 [range, 0.36- 1.02]; P =.06) for the access site were associated with a lower rate of graft failure. Similar results were found with Poisson analysis of all graft-related events. In addition, acute arterial anastomosis, ie, arterial angle less than 90 degrees (RR, 0.63 [range, 0.45-0.91]; P =.01) and use of the brachial artery versus the radial artery (RR, 0.54 [range, 0.33-0.54]; P =.01) were associated with a lower rate of graft-related events. CONCLUSION: These findings suggest possible areas for intervention to improve synthetic vascular graft outcome.

Aged↗
PubMed1989

Reproductive history of women dying of sudden cardiac death: a case-control study.

Reproductive history events may be risk factors for sudden coronary death (SCD) among women. A retrospective case-control study of SCD among women aged 25-64 was conducted in Allegheny County, Pennsylvania. The present analysis focused on a description and analysis involving the childbearing and reproductive history of 67 ever-married female SCD cases and 73 ever-married neighbourhood controls with a mean age of 54.6 and 53.4 years respectively. Information included: age and number of years married, number of children, age at first birth, cardiovascular risk factors, obstetric and gynaecological history. Age and the risk factors, history of hypertension or diabetes, cigarette intake, death of significant other and psychiatric disease, were controlled for in the analysis. More cases than controls experienced their first birth before age 20 (14 of the SCD and 7 controls). However, after adjustment for cigarette smoking status, a strong predictor of sudden cardiac death, the effect of early childbearing did not remain significant for this population. In women less than or equal to 50 years of age, childlessness was not a risk factor for SCD (1 of 16 cases and 2 of 26 controls were childless). However in women greater than 50 years of age, childlessness was a significant predictor of SCD (OR = 6.7 (1.3-32] 12 of 51 cases were childless compared to 2 of 46 controls. After adjustment for aged and other coronary heart disease (CHD) risk factors, the relationship of nulliparity with sudden cardiac death remained in this age group. There was no difference in hysterectomy or miscarriage history or in the total years married between cases and controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed2005

Psychosocial risk factors for adverse outcomes in patients with nonvalvular atrial fibrillation receiving warfarin.

OBJECTIVE: Our goal was to establish whether psychosocial risk factors for nonadherence, previously identified as negative predictors of warfarin prescribing, are predictors of adverse events for patients with nonvalvular atrial fibrillation receiving warfarin. DESIGN: Retrospective cohort analysis. SETTING: Ohio Medicaid administrative database. PATIENTS: We studied Ohio Medicaid recipients with nonvalvular atrial fibrillation receiving warfarin to determine whether a history of substance abuse, psychiatric illness, or social factors (identified as conditions perceived to be barriers to adherence) are predictors of adverse events, including stroke, intracranial hemorrhage, and gastrointestinal bleeding. Multivariable risk ratios were calculated for each risk factor using Cox proportional hazards models. RESULTS: 9,345 patients were identified as having nonvalvular atrial fibrillation and receiving 2 or more warfarin prescriptions between 1997 and 2002. The event rates for the sample as a whole were 1.5 strokes, 0.7 intracranial hemorrhages, and 4.3 gastrointestinal bleeds per 100 person-years of follow-up. Subjects with substance abuse had the highest adjusted risk ratio, 2.4 (95% confidence interval [CI]: 1.4, 4.0) for an intracranial hemorrhage while receiving warfarin, followed by subjects with psychiatric illness, adjusted risk ratio of 1.5 (95% CI: 1.04, 2.1). Subjects with psychiatric illness also had an adjusted risk ratio of 1.4 (95% CI: 1.1, 1.7) for stroke. Patients in all 3 identified risk groups were at a significantly increased risk of gastrointestinal bleeding. CONCLUSION: Patients with nonvalvular atrial fibrillation treated with warfarin who have psychosocial risk factors for nonadherence have an increased risk of adverse events.

Aged↗
PubMed1997

Exercise technetium 99m sestamibi single-photon emission computed tomography late after coronary artery bypass surgery: long-term follow-up.

BACKGROUND AND HYPOTHESIS: The prognostic value of exercise technetium 99m sestamibi single-photon emission computed tomography (SPECT) imaging in patients with previous bypass surgery is unknown. The aim of our study was to assess the prognostic information obtained with exercise scintigraphy performed for routine follow-up or reappearance of symptoms. METHODS: We studied 75 patients referred to our Center at a mean of 38 +/- 53 months from the revascularization procedure and prospectively followed them for 38 +/- 24 months. RESULTS: Fifteen patients (20%) had events at follow-up: there were 4 cardiac deaths, 3 nonfatal acute myocardial infarctions, 8 late revascularization procedures (4 percutaneous transluminal angioplasty and 4 repeat bypass surgery). Univariate analysis identified a history of typical angina (p = 0.001), a clinically positive ergometric test (p = 0.009), peak exercise heart rate (p = 0.0003), percentage of maximal predicted heart rate (p = 0.0001), peak exercise double product (p = 0.048), therapy during exercise (p = 0.003), scintigraphic summed reversibility score (i.e., the summation of the segmental differences between stress and rest) (p = 0.014), as significant predictors of events. Three multivariate models were built, with clinical variables (Model 1, chi square 15.97), ergometric variables (Model 2, chi square 19.66), and with scintigraphic variables added to clinical/ergometric variables (Model 3, chi square 31.13). The scintigraphic variable selected in the model as significant predictor of events was the summed reversibility score (p = 0.008). CONCLUSIONS: Exercise sestamibi SPECT scintigraphy provides optimal prognostic information after clinical and ergometric parameters in patients with previous bypass surgery.

Adult↗
PubMed2004

Clinical benefit of zoledronic acid in patients with lung cancer and other solid tumors: analysis based on history of skeletal complications.

The results of a retrospective exploratory analysis of a phase III trial of zoledronic acid in patients with bone metastases secondary to lung cancer or other solid tumors are reported herein to assess the risk of skeletal-related events (SREs) and the efficacy of 4 mg zoledronic acid compared with placebo. The study is based on patient SRE history before study entry. Patients were stratified based on SRE history (eg, pathologic fracture, spinal cord compression, radiation therapy or surgery to bone, or hypercalcemia) before study entry, and SRE incidence over 21 months was analyzed. Of 507 patients randomized to 4 mg zoledronic acid or placebo, 131 completed the 9-month core phase and 69 entered the 12-month extension phase. Before study entry, 347 of 503 patients who were evaluable for efficacy (69%) experienced >/= 1 SRE; these patients had a higher risk of developing an SRE on study than patients with no prior SRE (odds ratio, 1.41). Among patients with an SRE before study entry, zoledronic acid reduced the risk of SREs by 31% (P = 0.009), reduced the mean skeletal morbidity rate (1.96 vs. 2.81 SREs per year for placebo; P = 0.030), and prolonged the median time to first SRE by nearly 4 months (215 days vs. 106 days for placebo; P = 0.011). Among patients with no SRE before study entry (n = 156), zoledronic acid reduced the risk of SREs by 23% (P = 0.308), reduced the mean skeletal morbidity rate (1.34 vs. 2.53 SREs per year for placebo; P = 0.332), and prolonged the median time to first SRE by 2.5 months (P = 0.534). This exploratory analysis demonstrates that patients with a history of SREs are at high risk for subsequent SREs, but zoledronic acid reduces skeletal morbidity regardless of SRE history.

Antineoplastic Agents↗
PubMed1999

Population genetic structure and the effect of founder events on the genetic variability of moose, Alces alces, in Canada.

Moose, Alces alces, occur naturally throughout most of Canada but successful introductions of known numbers of animals have been made to the islands of Newfoundland and Cape Breton. Five microsatellite loci were used to investigate the population genetic structure and any change in genetic variability due to founder events of moose in Canada. Comparisons of allele frequencies for moose from 11 regions of the country suggested that there are at least seven genetically distinct populations (P < 0.05) in North America, namely Alberta, eastern Ontario, New Brunswick, Cape Breton, Labrador, western Newfoundland, and the Avalon Peninsula of Newfoundland. The average population heterozygosity was approximately 33% (range from 22 to 41%). UPGMA analysis of Nei's genetic distances produced phenograms similar to what would be expected when geographical location and population history are considered. The loss of heterozygosity due to a single founder event (n = 3; two introductions and a natural colonization) ranged from 14 to 30%, and the cumulative loss of heterozygosity due to two successive founder events (an introduction followed by a natural colonization) was 46%. In these examples loss of genetic variability has not been associated with any known phenotypic deviances, suggesting that populations may be established from a small number of founders. However, the viability of these founded populations over evolutionary timescales cannot be determined and is highly dependent upon chance.

Alleles↗
PubMedDate not supplied

Psychophysiologic assessment of mental imagery of stressful events in Israeli civilian posttraumatic stress disorder patients.

This study explored the physiological responses of posttraumatic stress disorder (PTSD) patients to reminders of a stressful event that had preceded the onset of their illness and was not related to its cause: the SCUD missile alarms of the Gulf War. A mental-imagery technique used in previous studies of PTSD was used. Three 30-second audiotapes were presented to each subject, including (1) the Gulf War's missile alarm, (2) a radio announcement of a terrorist attack, and (3) a standardized relaxing scene. Subjects were instructed to imagine each event as vividly as possible while heart rate (HR), skin conductance (SC), and left lateral frontalis electromyogram (EMG) responses were measured. The responses of 12 outpatients with PTSD were compared with those of panic disorder patients (n = 11), survivors of traumatic events who had not developed PTSD (n = 9), and mentally healthy subjects with no lifetime history of major trauma (n = 19). Multivariate analysis of variance (MANOVA) for the three physiological measures showed a significant group difference during imagery of the Gulf War alarm, with PTSD subjects showing higher SC and EMG responses than the others. The differences remained significant when age, level of distress during the war, and concurrent anxiety were controlled for. There were no group differences in responses to the other stimuli. We conclude that, PTSD patients may either acquire and maintain prolonged conditioned responses to various stressors during their life span or become sensitized to reminders of past traumata following the onset of their illness. Heightened conditionability may be expressed before the trauma in subjects who are liable to develop PTSD.

Adult↗
PubMed1988

Transluminal coronary angioplasty in the treatment of silent ischemia.

Fifty-four asymptomatic patients with positive thallium exercise tests underwent coronary angiography followed by coronary angioplasty (PTCA), as the primary therapy for silent ischemia. The procedure was technically successful in 89% of these patients. Emergency bypass graft surgery was necessary in 2 (3.6%) and q-wave myocardial infarction occurred in 1 (1.8%) of these. All fifty-four patients have been followed for a mean of 35 months since angioplasty. Of the 48 patients with initially successful PTCA, 12 had either clinical restenosis (9/14 or 19%) or a new lesion (3/48 or 6%) during follow-up, which required a repeat PTCA. At the longest follow-up, 46 (85%) had been successfully treated with on or more PTCA procedures. Two patients (3.6%) had sustained late q-wave myocardial infarction and two additional patients reported angina pectoris. There were no deaths. Angioplasty as a primary therapy for silent ischemia appears efficacious, with success and restenosis rates comparable to those in the symptomatic population. Event-free survival is improved, compared with natural history data for patients with silent ischemia from other studies. Prudent risk/benefit analysis may help to define subgroups most likely to benefit from this intervention.

Adult↗
PubMedDate not supplied

Prognostic value of stress Tc-99m tetrofosmin SPECT in patients with previous myocardial infarction: impact of scintigraphic extent of coronary artery disease.

BACKGROUND: Our objective was to assess the prognostic value of the scintigraphic extent of coronary artery disease on stress technetium 99m tetrofosmin single photon emission computed tomography in patients with previous myocardial infarction. METHODS AND RESULTS: We studied 383 patients (280 men and 103 women; mean age, 60 +/- 11 years) more than 3 months after an acute myocardial infarction by exercise bicycle or dobutamine (up to 40 mug . kg -1 . min -1 ) stress Tc-99m tetrofosmin myocardial perfusion tomography. Stress images were acquired 1 hour after stress, and rest images were acquired 24 hours after stress testing. An abnormal study was defined as one demonstrating a reversible or fixed perfusion abnormality. Myocardial segments were assigned to corresponding coronary arteries as follows: the apex, anterior wall, and anterior septum were assigned to the left anterior descending coronary artery; the posterolateral wall was assigned to the left circumflex artery; and the basal posterior septum and inferior wall were assigned to the right coronary artery. During a mean follow-up of 4.3 +/- 2.1 years, 48 cardiac events occurred (36 cardiac deaths and 12 nonfatal myocardial infarctions). Myocardial perfusion was normal in 51 patients, abnormal in a single-vessel distribution in 170 patients, and abnormal in a multivessel distribution in 162 patients. The annual cardiac event rates in these groups were 0.4%, 2.6%, and 4%, respectively. In a multivariate analysis model, independent predictors of cardiac events were diabetes mellitus (odds ratio [OR], 2.3; 95% confidence interval [CI], 1.4-4.5), history of congestive heart failure (OR, 2.7; 95% CI, 1.4-4), age (OR, 1.05; 95% CI, 1.01-1.08), and scintigraphic extent of coronary artery disease (OR, 4.2; 95% CI, 1.8-9.1). CONCLUSION: Stress Tc-99m tetrofosmin myocardial perfusion imaging provides independent prognostic information for the risk stratification of patients with previous myocardial infarction. The event rate is directly related to the scintigraphic extent of coronary artery disease. Patients with normal perfusion have an excellent event-free survival rate.

Coronary Artery Disease↗
PubMed2005

JAK2 mutation in essential thrombocythaemia: clinical associations and long-term prognostic relevance.

Clinical correlates and long-term prognostic relevance of the JAK2(V617F) mutation was studied in 150 patients with essential thrombocythaemia (ET) from a single institution and followed for a median of 11.4 years. During this period, thrombotic complications were documented in 62 patients (41.3%) and transformation into acute myeloid leukaemia (AML), polycythaemia vera (PV), or myelofibrosis with myeloid metaplasia (MMM) occurred in 4 (2.7%), 8 (5.3%), and 15 (10%) patients, respectively. JAK2(V617F) was detected in either archived bone marrow or blood cells from 73 patients (48.7%) but none were homozygous for the mutant allele. Parameters at diagnosis that were significantly associated with the presence of JAK2(V617F) included advanced age and higher counts of both haemoglobin and leucocytes. During follow-up, patients with the mutation were more likely to transform into PV but the incidences of AML, MMM, or thrombotic events were similar between patients with and without the mutation. Multivariate analysis identified advanced age, higher haemoglobin level, and thrombosis history but not the presence of JAK2(V617F) as independent predictors of inferior survival. Therefore, although the presence of JAK2(V617F) in ET appears to promote a PV phenotype, it might not carry treatment-relevant information.

Adolescent↗
PubMed1998

(Re)constructing relationships with grandparents: a turning point analysis of granddaughters' relational development with maternal grandmothers.

This study explores how granddaughters account for the development of their relationships with their maternal grandmothers. The retrospective interviewing technique was used to elicit turning points in their relational histories. Analysis of the turning point content revealed several different types of turning points that reflected both normative and idiosyncratic events. Increases in relational closeness resulted from decreases in geographic separation, engaging in shared activities, deaths or serious illnesses in the family, and family disruptions. Decreases in closeness were associated with negative experiences with the grandmother, increases in geographic separation, and the transition to college. Granddaughters reported that turning points related to death or serious illness and participation in shared activities were the most significant ones in their relationships with maternal grandmothers.

Adolescent↗
PubMed1994

Highlights of the new recommendations for hypercholesterolemia.

The patient who benefits most by aggressive efforts to reduce elevated LDL cholesterol is the one who is at greatest risk for a coronary event in the next 5 to 10 years. Thus, treatment decisions are based on risk-factor analysis and personal history.

Age Factors↗
PubMed1989

[Stressors and mental health : a contextual analysis of poverty.].

The author argues that social etiology of mental health, which suggests a causal link between living conditions and the occurence of mental disorders, is valid only when one applies a contextual evaluation of psycho-social stress factors. In that case, when life-events are cut from their environmental consequences, they are insufficient in themselves when trying to explain why mental disorders occur. However, once they are evaluated in function of the person's living conditions, the psycho-social stress factors become triggers and key to the person's stability. George W. Brown suggests a psycho-social model for a precipitative agent and for vulnerability factors linked to the significance and the impact of a life-event, relating also to the factual context at its origin and to the client's biographical history. Poverty then becomes a determining background for the life-event's repercussions. The LEDS (Life-Event and Difficulty Schedule) method of contextual analysis is based on a complete and systematical gathering of factual information on the events and on the context, stripped of the client's bias and emotional reactions. Furthermore, the grid of analysis allows one to qualify and organize this information while maintaining an optimal level of precision and objectivity. The empirical demonstration of the contextual analysis' predictive power is convincing in the case of disorders both mental (depression, anxiety, schizophrenia) and physical (infarction, appendicitis, ulcers). In such a frame of analysis and because of the chronic hardships experienced by the underpriveledged, poverty emerges as a determining contextual factor in the social etiology of mental disorders.

English Abstract↗
PubMed1985

Intron sequences reveal evolutionary relationships among major histocompatibility complex class I genes.

The multigene family of the class I histocompatibility antigens is unusual in that allelic and intergenic differences often are of equal magnitude. It has been suggested that this is due to gene conversion events, which would produce allelic variation but at the same time reduce intergenic differences. We compared the sequences of 11 class I genes in an attempt to elucidate the evolutionary history of this gene family. Our analysis shows that the intron sequences can be used to establish the order of divergence of various class I genes from each other. The results obtained agree with the order of divergence deduced from major insertion and deletion events. It appears that certain genes in the murine TL antigen-encoding region diverged very early from the H-2 and Qa-2,3 genes. The latter can be subgrouped as H-2 and Qa-2,3 genes by both sequence homology and insertion patterns. In contrast to the introns, exon sequences provide less information on evolutionary relationships. Thus, these analyses are consistent with the view that concerted evolution due to gene conversion occurs preferentially in exons.

Animals↗
PubMed2001

Clinical features of dysthymia and age: a clinical investigation.

A few authors have described the clinical picture of dysthymia in groups of elderly patients and pointed out differences from literature reports of dysthymia in younger adults. The present study, an attempt to analyze age effects on clinical characteristics of dysthymia throughout a lifetime, was performed in a sample of 106 patients, all aged > or =18 years, who were diagnosed according to DSM-IV. The patients were evaluated using: (1) a semistructured interview to assess clinical features, family history and previous treatments; (2) the Hamilton Depression Rating Scale; (3) the Interview for Recent Life Events; and (4) the Structured Clinical Interview for DSM-IV Disorders. Statistical analysis with stepwise logistic regression revealed that age was positively related to concomitant medical illnesses and to the total score of recent life events, but negatively related to the presence of avoidant or dependent personality disorders. The data suggested different etiologic pathways in older and younger patients. Dysthymia appeared to be associated in younger adults with abnormalities of personality; in the elderly, with a history of health problems and life losses.

Adolescent↗
PubMedDate not supplied

[Non-Q infarct. Clinical and prognostic aspects].

Prognosis of on-Q wave myocardial infarction (nQMI) has been the subject of considerable controversy over the last few years and a systematically aggressive approach with PTCA or coronary by-pass surgery (CBS) has been advocated as a means to reduce subsequent coronary events rate. To investigate clinical outcome and possibly identify high-risk subgroups 131 consecutive patients (pts) meeting diagnostic criteria for nQMI, admitted to our CCU for their first myocardial infarction between January 1980 and June 1985, were followed-up for a mean period of 34 months (range 6-72). Mean age of pts was 59 +/- 7 yrs; 101 (76%) were males, 30 (24%) females. No pt was lost to follow-up. During the same period 684 pts were admitted for Q wave myocardial infarction. Major coronary events such as angina, reinfarction, CBS, cardiac death as well as overall early and late mortality were considered for statistical evaluation with uni-multivariate analysis taking into account multiple data from pts history and acute clinical presentation. Angina appeared or recurred in 71 pts (54%), reinfarction occurred in 14 (10.7%); 25 pts underwent CBC (19%). Early cardiac deaths were 7 (5.3%), late cardiac deaths 12 (9.2%); overall mortality rate 18.1%. Uni- and multivariate statistical analysis did not disclose significant criteria predicting major coronary events and no high-risk subgroup could be identified, confirming uncertainties and doubts from literature.

Aged↗
PubMed2005

Examination of sex as an independent risk factor for adverse events after carotid endarterectomy.

BACKGROUND: The incidence of adverse events after carotid endarterectomy (CEA) for women compared with men is controversial. This report compares the incidence of perioperative stroke and death in men and women by examining the effect of comorbidities and hospital setting on CEA outcomes. METHODS: All CEAs performed in non-Federal acute-care Virginia hospitals between 1997 and 2001 were reviewed. Patient demographics, comorbidities, and hospital characteristics were compared for possible relationships to perioperative adverse events. RESULTS: A total of 14,095 CEAs were performed in 34 urban and 28 rural hospitals (9 high-volume and 53 low-volume hospitals); 42% were performed on women, and 58% were performed on men. Women experienced a significantly higher stroke rate (1.23%) than men (0.87%; P = .04) with bivariate analysis. However, logistic regression analysis of comorbidities and hospital settings demonstrated that sex was actually not independently related to adverse outcomes in CEA ( P = .08). Preoperative neurologic symptoms could not be evaluated as risk factors for adverse events. Acute coronary ischemia, history of arrhythmia, end-stage renal disease, nonwhite race, advanced age, and low hospital volume were all significantly related to mortality. History of arrhythmia was the only factor that was significantly related to the incidence of stroke. CONCLUSIONS: Logistic regression analysis of comorbidities and hospital setting indicated that female sex is not independently associated with higher mortality or a higher stroke rate during CEA. These data indicate that patients with carotid stenosis frequently have multiple medical problems that need to be carefully examined and controlled before any single patient or hospital factor is designated as significantly related to adverse outcomes.

Carotid Stenosis↗