138 research outputs found
Odd Prime Labeling For Some Arrow Related Graphs
In a graph G a mapping g is known as odd prime labeling , if g is abijection from V to f1; 3; 5; ::::; 2jVj - 1g satisfying the condition thatfor each line xy in G the gcd of the labels of end points (g(x); g(y)) isone. In this article we prove that some new arrow related graphs suchas A2y, A3 y,A5 y, are all odd prime graphs. Also we prove that doublearrow graphs, DA2 y and DA3 y are odd prime graphs
Epidemiologic application of verbal autopsy to investigate the high occurrence of cancer along Huai River Basin, China
<p>Abstract</p> <p>Background</p> <p>In 2004, the media repeatedly reported water pollution and "cancer villages" along the Huai River in China. Due to the lack of death records for more than 30 years, a retrospective survey of causes of death using verbal autopsy was carried out to investigate cancer rates in this area.</p> <p>Methods</p> <p>An epidemiologic study was designed to compare numbers of deaths and causes of death between the study areas with water pollution and the control areas without water pollution in S County and Y District in 2005. The study areas were selected based on the distribution of the Huai River and its tributaries. Verbal autopsy was used to assist cause of death (COD) diagnoses and to verify mortality rates. The standard mortality rates (SMRs) of cancer in the study area were compared with those in the control areas. In order to verify the difference between mortality rates due to cancers in the study and the control areas, patients who reported having cancer in the survey received a second diagnosis by national and provincial oncologists with pathological and laboratory examinations. Comparisons were made to determine if differential cancer prevalence rates in the study and control areas were similar to the difference in mortality due to cancer in these study and control areas. Mortality rates of cancers in study and control areas were also compared with national statistics for the rural population of China.</p> <p>Results</p> <p>Over five years, 3,301 deaths were identified, including 1,158 cancer deaths. The annual average SMRs of cancer in the study areas of S County and Y District were 277.8/100,000 and 223.6/100,000, respectively, which is three to four times higher than those in the control areas. In addition, a total of 626 cases of cancer in the study and control areas were confirmed. The prevalence rates of cancer were 545/100,000 and 128.1/100,000 per year in the study and control areas in S County, respectively, and 440.9/100,000 and 200/100,000 per year in the study and control areas in Y District, respectively. The mortality and prevalence rates of digestive cancers were higher in the study areas than the control areas. In 2000, the SMR for cancer in rural areas nationwide was 120.9/100,000, and in study areas in S County and Y District, the excess rates of deaths were 184/100,000 and 138.8/100,000, respectively.</p> <p>Conclusions</p> <p>The death rates of digestive cancers were much higher in the study areas of S County and Y District. The patterns for between-area differences in prevalence and mortality rates of cancer were similar. Verbal autopsy is shown to be a useful tool in retrospective mortality surveys in low-resource areas with limited access to health care.</p
Factors Associated with Physician Agreement on Verbal Autopsy of over 11500 Injury Deaths in India
Worldwide, injuries account for 9.8% of all deaths. The majority of these deaths occur in low- and middle-income countries where vital registration systems are often inadequate. Verbal autopsy (VA) is a tool used to ascertain cause of death in such settings. Validation studies for VA using hospital diagnosed causes of death as comparisons have shown that injury deaths can be reliably diagnosed by VA. However, no study has assessed the factors that may affect physicians' abilities to code specific causes of injury death using VA.This study used data from over 11 500 verbal autopsies of injury deaths from the Million Death Study (MDS) in which 6.3 million people in India were monitored from 2001–2003 for vital events. Deaths that occurred in the MDS were coded by two independent physicians. This study focused on whether physician agreement on the classification of injury deaths was affected by characteristics of the deceased and respondent. Agreement was analyzed using three primary methods: 1) kappa statistic; 2) sensitivity and specificity analysis using the final VA diagnosed category of injury death as gold standard; and 3) multivariate logistic regression using a conceptual hierarchical model. The overall agreement for all injury deaths was 77.9% with a kappa of 0.74 (99% CI 0.74–0.75). Deaths in the injury categories of “transport”, “falls”, “drowning” and “other unintentional injury” occurring outside the home were associated with greater physician agreement than those occurring at home. In contrast, self-inflicted injury deaths that occurred outside the home were associated with lower physician agreement.With few exceptions, most characteristics of the deceased and the respondent did not influence physician agreement on the classification of injury deaths. Physician training and continued adaptation of the VA tool should focus on the reasons these factors influenced physician agreement
HIV mortality and infection in India: estimates from nationally representative mortality survey of 1.1 million homes
Objective To determine the rates of death and infection from HIV in India
Diarrhea, Pneumonia, and Infectious Disease Mortality in Children Aged 5 to 14 Years in India
Background: Little is known about the causes of death in children in India after age five years. The objective of this study is to provide the first ever direct national and sub-national estimates of infectious disease mortality in Indian children aged 5 to 14 years. Methods: A verbal autopsy based assessment of 3 855 deaths is children aged 5 to 14 years from a nationally representative survey of deaths occurring in 2001–03 in 1?1 million homes in India. Results: Infectious diseases accounted for 58 % of all deaths among children aged 5 to 14 years. About 18 % of deaths were due to diarrheal diseases, 10 % due to pneumonia, 8 % due to central nervous system infections, 4 % due to measles, and 12 % due to other infectious diseases. Nationally, in 2005 about 59 000 and 34 000 children aged 5 to 14 years died from diarrheal diseases and pneumonia, corresponding to mortality of 24?1 and 13?9 per 100 000 respectively. Mortality was nearly 50 % higher in girls than in boys for both diarrheal diseases and pneumonia. Conclusions: Approximately 60 % of all deaths in this age group are due to infectious diseases and nearly half of these deaths are due to diarrheal diseases and pneumonia. Mortality in this age group from infectious diseases, and diarrhea i
What do we know about chronic kidney disease in India: first report of the Indian CKD registry
<p>Abstract</p> <p>Background</p> <p>There are no national data on the magnitude and pattern of chronic kidney disease (CKD) in India. The Indian CKD Registry documents the demographics, etiological spectrum, practice patterns, variations and special characteristics.</p> <p>Methods</p> <p>Data was collected for this cross-sectional study in a standardized format according to predetermined criteria. Of the 52,273 adult patients, 35.5%, 27.9%, 25.6% and 11% patients came from South, North, West and East zones respectively.</p> <p>Results</p> <p>The mean age was 50.1 ± 14.6 years, with M:F ratio of 70:30. Patients from North Zone were younger and those from the East Zone older. Diabetic nephropathy was the commonest cause (31%), followed by CKD of undetermined etiology (16%), chronic glomerulonephritis (14%) and hypertensive nephrosclerosis (13%). About 48% cases presented in Stage V; they were younger than those in Stages III-IV. Diabetic nephropathy patients were older, more likely to present in earlier stages of CKD and had a higher frequency of males; whereas those with CKD of unexplained etiology were younger, had more females and more frequently presented in Stage V. Patients in lower income groups had more advanced CKD at presentation. Patients presenting to public sector hospitals were poorer, younger, and more frequently had CKD of unknown etiology.</p> <p>Conclusions</p> <p>This report confirms the emergence of diabetic nephropathy as the pre-eminent cause in India. Patients with CKD of unknown etiology are younger, poorer and more likely to present with advanced CKD. There were some geographic variations.</p
Verbal Autopsy: Reliability and Validity Estimates for Causes of Death in the Golestan Cohort Study in Iran
BACKGROUND: Verbal autopsy (VA) is one method to obtain valid estimates of causes of death in the absence of valid medical records. We tested the reliability and validity of a VA questionnaire developed for a cohort study in Golestan Province in northeastern Iran. METHOD: A modified version of the WHO adult verbal autopsy was used to assess the cause of death in the first 219 Golestan Cohort Study (GCS) subjects who died. The GCS cause of death was determined by two internists who independently reviewed all available medical records. Two other internists ("reviewers") independently reviewed only the VA answers and classified the cause of death into one of nine general categories; they repeated this evaluation one month later. The reliability of the VA was measured by calculating intra-reviewer and inter-reviewer kappa statistics. The validity of the VA was measured using the GCS cause of death as the gold standard. RESULTS: VA showed both good validity (sensitivity, specificity, PPV, and NPV all above 0.81) and reliability (kappa>0.75) in determining the general cause of death independent of sex and place of residence. The overall multi-rater agreement across four reviews was 0.84 (95%CI: 0.78-0.89). The results for identifying specific cancer deaths were also promising, especially for upper GI cancers (kappa = 0.95). The multi-rater agreement in cancer subgroup was 0.93 (95%CI: 0.85-0.99). CONCLUSIONS: VA seems to have good reliability and validity for determining the cause of death in a large-scale adult follow up study in a predominantly rural area of a middle-income country
Robust metrics for assessing the performance of different verbal autopsy cause assignment methods in validation studies
<p>Abstract</p> <p>Background</p> <p>Verbal autopsy (VA) is an important method for obtaining cause of death information in settings without vital registration and medical certification of causes of death. An array of methods, including physician review and computer-automated methods, have been proposed and used. Choosing the best method for VA requires the appropriate metrics for assessing performance. Currently used metrics such as sensitivity, specificity, and cause-specific mortality fraction (CSMF) errors do not provide a robust basis for comparison.</p> <p>Methods</p> <p>We use simple simulations of populations with three causes of death to demonstrate that most metrics used in VA validation studies are extremely sensitive to the CSMF composition of the test dataset. Simulations also demonstrate that an inferior method can appear to have better performance than an alternative due strictly to the CSMF composition of the test set.</p> <p>Results</p> <p>VA methods need to be evaluated across a set of test datasets with widely varying CSMF compositions. We propose two metrics for assessing the performance of a proposed VA method. For assessing how well a method does at individual cause of death assignment, we recommend the average chance-corrected concordance across causes. This metric is insensitive to the CSMF composition of the test sets and corrects for the degree to which a method will get the cause correct due strictly to chance. For the evaluation of CSMF estimation, we propose CSMF accuracy. CSMF accuracy is defined as one minus the sum of all absolute CSMF errors across causes divided by the maximum total error. It is scaled from zero to one and can generalize a method's CSMF estimation capability regardless of the number of causes. Performance of a VA method for CSMF estimation by cause can be assessed by examining the relationship across test datasets between the estimated CSMF and the true CSMF.</p> <p>Conclusions</p> <p>With an increasing range of VA methods available, it will be critical to objectively assess their performance in assigning cause of death. Chance-corrected concordance and CSMF accuracy assessed across a large number of test datasets with widely varying CSMF composition provide a robust strategy for this assessment.</p
Verbal autopsy completion rate and factors associated with undetermined cause of death in a rural resource-poor setting of Tanzania
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ABSTRACT:\ud
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BACKGROUND\ud
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Verbal autopsy (VA) is a widely used tool to assign probable cause of death in areas with inadequate vital registration systems. Its uses in priority setting and health planning are well documented in sub-Saharan Africa (SSA) and Asia. However, there is a lack of data related to VA processing and completion rates in assigning causes of death in a community. There is also a lack of data on factors associated with undetermined causes of death documented in SSA. There is a need for such information for understanding the gaps in VA processing and better estimating disease burden.\ud
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OBJECTIVE\ud
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The study's intent was to determine the completion rate of VA and factors associated with assigning undetermined causes of death in rural Tanzania.\ud
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METHODS\ud
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A database of deaths reported from the Ifakara Health and Demographic Surveillance System from 2002 to 2007 was used. Completion rates were determined at the following stages of processing: 1) death identified; 2) VA interviews conducted; 3) VA forms submitted to physicians; 4) coding and assigning of cause of death. Logistic regression was used to determine factors associated with deaths coded as "undetermined."\ud
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RESULTS\ud
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The completion rate of VA after identification of death and the VA interview ranged from 83% in 2002 and 89% in 2007. Ninety-four percent of deaths submitted to physicians were assigned a specific cause, with 31% of the causes coded as undetermined. Neonates and child deaths that occurred outside health facilities were associated with a high rate of undetermined classification (33%, odds ratio [OR] = 1.33, 95% confidence interval [CI] (1.05, 1.67), p = 0.016). Respondents reporting high education levels were less likely to be associated with deaths that were classified as undetermined (24%, OR = 0.76, 95% CI (0.60, -0.96), p = 0.023). Being a child of the deceased compared to a partner (husband or wife) was more likely to be associated with undetermined cause of death classification (OR = 1.35, 95% CI (1.04, 1.75), p = 0.023).\ud
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CONCLUSION\ud
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Every year, there is a high completion rate of VA in the initial stages of processing; however, a number of VAs are lost during the processing. Most of the losses occur at the final step, physicians' determination of cause of death. The type of respondent and place of death had a significant effect on final determination of the plausible cause of death. The finding provides some insight into the factors affecting full coverage of verbal autopsy diagnosis and the limitations of causes of death based on VA in SSA. Although physician review is the most commonly used method in ascertaining probable cause of death, we suggest further work needs to be done to address the challenges faced by physicians in interpreting VA forms. There is need for an alternative to or improvement of the methods of physician review
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