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- Byass, Peter, et al.
(author)
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Refining a probabilistic model for interpreting verbal autopsy data.
- 2006
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In: Scandinavian journal of public health. - : SAGE Publications. - 1403-4948 .- 1651-1905. ; 34:1, s. 26-31
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Journal article (peer-reviewed)abstract
- Objective: To build on the previously reported development of a Bayesian probabilistic model for interpreting verbal autopsy (VA) data, attempting to improve the model's performance in determining cause of death and to reassess it. Design: An expert group of clinicians, coming from a wide range geographically and in terms of specialization, was convened. Over a four-day period the content of the previous probabilistic model was reviewed in detail and adjusted as necessary to reflect the group consensus. The revised model was tested with the same 189 VA cases from Vietnam, assessed by two local clinicians, that were used to test the preliminary model. Results: The revised model contained a total of 104 indicators that could be derived from VA data and 34 possible causes of death. When applied to the 189 Vietnamese cases, 142 (75.1%) achieved concordance between the model's output and the previous clinical consensus. The remaining 47 cases (24.9%) were presented to a further independent clinician for reassessment. As a result, consensus between clinical reassessment and the model's output was achieved in 28 cases (14.8%); clinical reassessment and the original clinical opinion agreed in 8 cases (4.2%), and in the remaining 11 cases (5.8%) clinical reassessment, the model, and the original clinical opinion all differed. Thus overall the model was considered to have performed well in 170 cases (89.9%). Conclusions: This approach to interpreting VA data continues to show promise. The next steps will be to evaluate it against other sources of VA data. The expert group approach to determining the required probability base seems to have been a productive one in improving the performance of the model.
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- Leitao, Jordana, et al.
(author)
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Revising the WHO verbal autopsy instrument to facilitate routine cause-of-death monitoring
- 2013
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In: Global Health Action. - : CoAction Publishing. - 1654-9716 .- 1654-9880. ; 6, s. 21518-
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Journal article (peer-reviewed)abstract
- OBJECTIVE: Verbal autopsy (VA) is a systematic approach for determining causes of death (CoD) in populations without routine medical certification. It has mainly been used in research contexts and involved relatively lengthy interviews. Our objective here is to describe the process used to shorten, simplify, and standardise the VA process to make it feasible for application on a larger scale such as in routine civil registration and vital statistics (CRVS) systems.METHODS: A literature review of existing VA instruments was undertaken. The World Health Organization (WHO) then facilitated an international consultation process to review experiences with existing VA instruments, including those from WHO, the Demographic Evaluation of Populations and their Health in Developing Countries (INDEPTH) Network, InterVA, and the Population Health Metrics Research Consortium (PHMRC). In an expert meeting, consideration was given to formulating a workable VA CoD list [with mapping to the International Classification of Diseases and Related Health Problems, Tenth Revision (ICD-10) CoD] and to the viability and utility of existing VA interview questions, with a view to undertaking systematic simplification.FINDINGS: A revised VA CoD list was compiled enabling mapping of all ICD-10 CoD onto 62 VA cause categories, chosen on the grounds of public health significance as well as potential for ascertainment from VA. A set of 221 indicators for inclusion in the revised VA instrument was developed on the basis of accumulated experience, with appropriate skip patterns for various population sub-groups. The duration of a VA interview was reduced by about 40% with this new approach.CONCLUSIONS: The revised VA instrument resulting from this consultation process is presented here as a means of making it available for widespread use and evaluation. It is envisaged that this will be used in conjunction with automated models for assigning CoD from VA data, rather than involving physicians.
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3. |
- Muhe, Lulu
(author)
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Child health and acute respiratory infections in Ethiopia : epidemiology for prevention and control
- 1994
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Doctoral thesis (other academic/artistic)abstract
- This thesis is based on studies in Butajira district in the south central part of Ethiopia and one study in the Ethio-Swedish Children's Hospital in Addis Ababa. The Butajira project has a continuous demographic surveillance system, established in 1987 in a sample of 10 communities with a total baseline population of about 30,000. The project includes the development and evaluation of a system for continuous registration of vital events and provides a baseline population and sampling frame for health related research activities. The thesis used different study designs within the surveillance system. A carriership study was undertaken to determine the potential bacterial respiratory pathogens among under-five children. A clinical study was done to investigate aetiological agents among young infants (below 3 months) with pneumonia, sepsis and meningitis in a hospital setting. Interview studies were carried out on mothers' perceptions of illness and practices in the care of children with acute respiratory infections. Within the surveillance system, patterns of under-five mortality were analysed. A nested case-referent design was applied to assess public health and behavioural determinants of mortality. A cohort study was performed among under-fives in three communities to estimate the magnitude of illness burden, particularly from ARI, as well as to assess determinants of ARI morbidity.Among 1126 under-five children, 85% were found to harbour H. influenzae, 83% M. catarrhalis and 90% S. pneumoniae in the nasopharynx. The hospital-based study isolated S. pneumoniae, Streptococcus group A, Salmonella group B, E. coli and H. influenzae in the age group below 3 months. The study of mothers' perceptions and practices, showed that mothers do know the symptoms of measles and whooping cough, while they do not recognize pneumonia as an illness entity and are not aware of fast breathing as an important sign of pneumonia.The mortality studies showed a high infant and under-five mortality rate. ARI was responsible for one fifth of the under-five mortality and almost one third of the infant mortality rate. Cause of death in the case-referent study was determined using a validated verbal autopsy method. Breast-feeding and supplementary feeding were demonstrated to be strongly protective when controlling for parental and environmental determinants of mortality.A one year prospective home surveillance study showed that illness was reported in 5.8% of 1,216 person-years. ARI contributed half of this illness load and was particularly associated with parental factors. Among sanitation factors, the absence of piped water was an important determinant of morbidity. Among housing factors, the type of roof and lighting source for the house, and among parental factors, illiteracy of either parents and having a farmer as a father, were found to be independently associated with increased morbidity. Among health and behavioural factors, preterm delivery and lack of immunization were associated with increased morbidity.The results of the studies of this thesis have been utilized to design an intervention case management package. The intervention study and evaluation of its impact is now on-going.
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