Publications (14)27.57 Total impact
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Article: Computer-based analysis of verbal autopsies: revolution or evolution?
Population Health Metrics 01/2011; 9:26. · 2.11 Impact Factor -
Article: Capture-recapture analysis of all-cause mortality data in Bohol, Philippines.
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ABSTRACT: Despite the importance of mortality data for effective planning and monitoring of health services, official reporting systems rarely capture every death. The completeness of death reporting and the subsequent effect on mortality estimates were examined in six municipalities of Bohol province in the Philippines using a system review and capture-recapture analysis. Reports of deaths were collected from records at local civil registration offices, health centers and hospitals, and parish churches. Records were reconciled using a specific set of matching criteria, and both a two-source and a three-source capture-recapture analysis was conducted. For the two-source analysis, civil registry and health data were combined due to dependence between these sources and analyzed against the church data. Significant dependence between civil registration and health reporting systems was identified. There were 8,075 unique deaths recorded in the study area between 2002 and 2007. We found 5% to 10% of all deaths were not reported to any source, while government records captured only 77% of all deaths. Life expectancy at birth (averaged for 2002-2007) was estimated at 65.7 years and 73.0 years for males and females, respectively. This was one to two years lower than life expectancy estimated from reconciled reported deaths from all sources, and four to five years lower than life expectancy estimated from civil registration data alone. Reporting patterns varied by age and municipality, with childhood deaths more underreported than adult deaths. Infant mortality was underreported in civil registration data by 62%. Deaths are underreported in Bohol, with inconsistent reporting procedures contributing to this situation. Uncorrected mortality measures would subsequently be misleading if used for health planning and evaluation purposes. These findings highlight the importance of ensuring that official mortality estimates from the Philippines are derived from data that have been assessed for underreporting and corrected as necessary.Population Health Metrics 01/2011; 9:9. · 2.11 Impact Factor -
Article: Population Health Metrics Research Consortium gold standard verbal autopsy validation study: design, implementation, and development of analysis datasets.
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ABSTRACT: Verbal autopsy methods are critically important for evaluating the leading causes of death in populations without adequate vital registration systems. With a myriad of analytical and data collection approaches, it is essential to create a high quality validation dataset from different populations to evaluate comparative method performance and make recommendations for future verbal autopsy implementation. This study was undertaken to compile a set of strictly defined gold standard deaths for which verbal autopsies were collected to validate the accuracy of different methods of verbal autopsy cause of death assignment. Data collection was implemented in six sites in four countries: Andhra Pradesh, India; Bohol, Philippines; Dar es Salaam, Tanzania; Mexico City, Mexico; Pemba Island, Tanzania; and Uttar Pradesh, India. The Population Health Metrics Research Consortium (PHMRC) developed stringent diagnostic criteria including laboratory, pathology, and medical imaging findings to identify gold standard deaths in health facilities as well as an enhanced verbal autopsy instrument based on World Health Organization (WHO) standards. A cause list was constructed based on the WHO Global Burden of Disease estimates of the leading causes of death, potential to identify unique signs and symptoms, and the likely existence of sufficient medical technology to ascertain gold standard cases. Blinded verbal autopsies were collected on all gold standard deaths. Over 12,000 verbal autopsies on deaths with gold standard diagnoses were collected (7,836 adults, 2,075 children, 1,629 neonates, and 1,002 stillbirths). Difficulties in finding sufficient cases to meet gold standard criteria as well as problems with misclassification for certain causes meant that the target list of causes for analysis was reduced to 34 for adults, 21 for children, and 10 for neonates, excluding stillbirths. To ensure strict independence for the validation of methods and assessment of comparative performance, 500 test-train datasets were created from the universe of cases, covering a range of cause-specific compositions. This unique, robust validation dataset will allow scholars to evaluate the performance of different verbal autopsy analytic methods as well as instrument design. This dataset can be used to inform the implementation of verbal autopsies to more reliably ascertain cause of death in national health information systems.Population Health Metrics 01/2011; 9:27. · 2.11 Impact Factor -
Article: Community participation for malaria elimination in Tafea Province, Vanuatu: part II. Social and cultural aspects of treatment-seeking behaviour.
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ABSTRACT: Early diagnosis and prompt effective case management are important components of any malaria elimination strategy. Tafea Province, Vanuatu has a rich history of traditional practices and beliefs, which have been integrated with missionary efforts and the introduction of modern constructions of health. Gaining a detailed knowledge of community perceptions of malarial symptomatology and treatment-seeking behaviours is essential in guiding effective community participation strategies for malaria control and elimination. An ethnographic study involving nine focus group discussions (FGD), 12 key informant interviews (KII) and seven participatory workshops were carried out on Tanna Island, Vanuatu. Villages in areas of high and low malaria transmission risk were selected. Four ni-Vanuatu research officers, including two from Tanna, were trained and employed to conduct the research. Data underwent thematic analysis to examine treatment-seeking behaviour and community perceptions of malaria. Malaria was perceived to be a serious, but relatively new condition, and in most communities, identified as being apparent only after independence in 1980. Severe fever in the presence of other key symptoms triggered a diagnosis of malaria by individuals. Use of traditional or home practices was common: perceived vulnerability of patient and previous experience with malaria impacted on the time taken to seek treatment at a health facility. Barriers to health care access and reasons for delay in care-seeking included the availability of health worker and poor community infrastructure. Due to programme success of achieving low malaria transmission, Tafea province has been identified for elimination of malaria by 2012 in the Government of Vanuatu Malaria Action Plans (MAP). An effective malaria elimination programme requires interactions between the community and its leaders, malaria workers and health providers for success in diagnosis and prompt treatment. As malaria becomes more uncommon, utilizing unique motivators for communities to seek early diagnosis and treatment is important, particularly as other health conditions that cause fevers become increasingly more common. The design of these interventions are dependent upon robust understanding of community perceptions of disease, and the evolving nature of these perceptions.Malaria Journal 01/2011; 10:204. · 3.19 Impact Factor -
Article: Community participation for malaria elimination in Tafea Province, Vanuatu: Part I. Maintaining motivation for prevention practices in the context of disappearing disease.
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ABSTRACT: In the 1990s, the experience of eliminating malaria from Aneityum Island, Vanuatu is often given as evidence for the potential to eliminate malaria in the south-west Pacific. This experience, however, cannot provide a blueprint for larger islands that represent more complex social and environmental contexts. Community support was a key contributor to success in Aneityum. In the context of disappearing disease, obtaining and maintaining community participation in strategies to eliminate malaria in the rest of Tafea Province, Vanuatu will be significantly more challenging. Nine focus group discussions (FGDs), 12 key informant interviews (KIIs), three transect walks and seven participatory workshops were carried out in three villages across Tanna Island to investigate community perceptions and practices relating to malaria prevention (particularly relating to bed nets); influences on these practices including how malaria is contextualized within community health and disease priorities; and effective avenues for channelling health information. The primary protection method identified by participants was the use of bed nets, however, the frequency and motivation for their use differed between study villages on the basis of the perceived presence of malaria. Village, household and personal cleanliness were identified by participants as important for protection against malaria. Barriers and influences on bed net use included cultural beliefs and practices, travel, gender roles, seasonality of mosquito nuisance and risk perception. Health care workers and church leaders were reported to have greatest influence on malaria prevention practices. Participants preferred receiving health information through visiting community health promotion teams, health workers, church leaders and village chiefs. In low malaria transmission settings, a package for augmenting social capital and sustaining community participation for elimination will be essential and includes: 'sentinel sites' for qualitative monitoring of evolving local socio-cultural, behavioural and practical issues that impact malaria prevention and treatment; mobilizing social networks; intersectoral collaboration; integration of malaria interventions with activities addressing other community health and disease priorities; and targeted implementation of locally appropriate, multi-level, media campaigns that sustain motivation for community participation in malaria elimination.Malaria Journal 04/2010; 9:93. · 3.19 Impact Factor -
Article: Community participation for malaria elimination in Tafea Province, Vanuatu: Part I. Maintaining motivation for prevention practices in the context of disappearing disease
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ABSTRACT: Abstract Background In the 1990s, the experience of eliminating malaria from Aneityum Island, Vanuatu is often given as evidence for the potential to eliminate malaria in the south-west Pacific. This experience, however, cannot provide a blueprint for larger islands that represent more complex social and environmental contexts. Community support was a key contributor to success in Aneityum. In the context of disappearing disease, obtaining and maintaining community participation in strategies to eliminate malaria in the rest of Tafea Province, Vanuatu will be significantly more challenging. Method Nine focus group discussions (FGDs), 12 key informant interviews (KIIs), three transect walks and seven participatory workshops were carried out in three villages across Tanna Island to investigate community perceptions and practices relating to malaria prevention (particularly relating to bed nets); influences on these practices including how malaria is contextualized within community health and disease priorities; and effective avenues for channelling health information. Results The primary protection method identified by participants was the use of bed nets, however, the frequency and motivation for their use differed between study villages on the basis of the perceived presence of malaria. Village, household and personal cleanliness were identified by participants as important for protection against malaria. Barriers and influences on bed net use included cultural beliefs and practices, travel, gender roles, seasonality of mosquito nuisance and risk perception. Health care workers and church leaders were reported to have greatest influence on malaria prevention practices. Participants preferred receiving health information through visiting community health promotion teams, health workers, church leaders and village chiefs. Conclusion In low malaria transmission settings, a package for augmenting social capital and sustaining community participation for elimination will be essential and includes: 'sentinel sites' for qualitative monitoring of evolving local socio-cultural, behavioural and practical issues that impact malaria prevention and treatment; mobilizing social networks; intersectoral collaboration; integration of malaria interventions with activities addressing other community health and disease priorities; and targeted implementation of locally appropriate, multi-level, media campaigns that sustain motivation for community participation in malaria elimination.Malaria Journal. 01/2010; -
Article: Baseline spatial distribution of malaria prior to an elimination programme in Vanuatu.
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ABSTRACT: The Ministry of Health in the Republic of Vanuatu has implemented a malaria elimination programme in Tafea Province, the most southern and eastern limit of malaria transmission in the South West Pacific. Tafea Province is comprised of five islands with malaria elimination achieved on one of these islands (Aneityum) in 1998. The current study aimed to establish the baseline distribution of malaria on the most malarious of the province's islands, Tanna Island, to guide the implementation of elimination activities. A parasitological survey was conducted in Tafea Province in 2008. On Tanna Island there were 4,716 participants from 220 villages, geo-referenced using a global position system. Spatial autocorrelation in observed prevalence values was assessed using a semivariogram. Backwards step-wise regression analysis was conducted to determine the inclusion of environmental and climatic variables into a prediction model. The Bayesian geostatistical logistic regression model was used to predict malaria risk, and associated uncertainty across the island. Overall, prevalence on Tanna was 1.0% for Plasmodium falciparum (accounting for 32% of infections) and 2.2% for Plasmodium vivax (accounting for 68% of infections). Regression analysis showed significant association with elevation and distance to coastline for P. vivax and P. falciparum, but no significant association with NDVI or TIR. Colinearity was observed between elevation and distance to coastline with the later variable included in the final Bayesian geostatistical model for P. vivax and the former included in the final model for P. falciparum. Model validation statistics revealed that the final Bayesian geostatistical model had good predictive ability. Malaria in Tanna Island, Vanuatu, has a focal and predominantly coastal distribution. As Vanuatu refines its elimination strategy, malaria risk maps represent an invaluable resource in the strategic planning of all levels of malaria interventions for the island.Malaria Journal 01/2010; 9:150. · 3.19 Impact Factor -
Article: Efficacy of an 11-valent pneumococcal conjugate vaccine against radiologically confirmed pneumonia among children less than 2 years of age in the Philippines: a randomized, double-blind, placebo-controlled trial.
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ABSTRACT: Pneumococcus is a leading cause of childhood pneumonia worldwide. Pneumococcal conjugate vaccines (PCV) have demonstrated efficacy against childhood invasive pneumococcal disease (IPD) and pneumonia in the United States and Africa. No information is available from Asia on the impact of PCV on childhood pneumonia. We conducted a randomized, placebo-controlled, double-blind trial in Bohol, the Philippines (ISRCTN 62323832). Children 6 weeks to <6 months of age were randomly allocated to receive 3 doses of either an 11-valent PCV (11PCV, sanofi pasteur, Lyon, France) or a saline placebo, with a minimum interval of 4 weeks between doses to determine vaccine efficacy (VE) against the primary outcome of a child experiencing first episode of community-acquired radiologically defined pneumonia in the first 2 years of life. Secondary end points were clinical pneumonia, IPD, safety, and immunogenicity. Twelve thousand one hundred ninety-one children were enrolled. By per protocol (PP) analysis, 93 of 6013 fully vaccinated 11PCV recipient children had a first episode of radiologic pneumonia compared with 120 of 6018 placebo recipients. VE against radiologically defined pneumonia for the PP cohort of children 3 to 23 months old was 22.9% (95% CI: -1.1, 41.2; P = 0.06), for the prespecified subgroups of children 3 to 11 months of age, 34.0% (95% CI: 4.8, 54.3; P = 0.02), and of those 12 to 23 months old, 2.7% (95% CI: -43.5, 34.0; P = 0.88). By intent-to-treat (ITT) analysis, 119 of 6097 11PCV recipient children had an episode of radiologic pneumonia compared with 141 of 6094 placebo recipients. VE against radiologic pneumonia for the ITT cohort of children <2 years old was 16.0% (95% CI -7.3, 34.2; P = 0.16), for a subgroup of children <12 months of age, 19.8% (95% CI: -8.8, 40.8; P = 0.15). VE against clinical pneumonia by PP was not significant (VE 0.1%; 95% CI -9.4, 8.7; P = 0.99). IPD was rare: only 3 cases of IPD due to vaccine serotypes were observed during the study. 11PCV was immunogenic and well tolerated. Among 11PCV recipients, a small excess of serious adverse respiratory events was observed in the first 28 days after the first and second dose of vaccine, and of nonrespiratory events after the first dose. An excess of pneumonia episodes in 11PCV recipients in the month following the second dose of vaccination was the principal reason for lower VE by ITT analysis than by PP analysis. In PP analysis, a 22.9% reduction of community-acquired radiologically confirmed pneumonia in children younger than 2 years of age in the 11-valent tetanus-diphtheria toxoid-conjugated PCV vaccinated group was observed; a reduction similar as observed in other PCV trials. We could not demonstrate any VE against clinical pneumonia. Our finding confirms for the first time that in a low-income, low-mortality developing country in Asia, at least one-fifth of radiologically confirmed pneumonia is caused by pneumococcus, and thus preventable by PCV. Whether PCV should be included in national program in such settings, however, depends on careful country specific disease burden measurement and cost-effectiveness calculation.The Pediatric Infectious Disease Journal 06/2009; 28(6):455-62. · 3.58 Impact Factor -
Article: Clinical case review: A method to improve identification of true clinical and radiographic pneumonia in children meeting the World Health Organization definition for pneumonia
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ABSTRACT: Abstract Background The World Health Organization's (WHO) case definition for childhood pneumonia, composed of simple clinical signs of cough, difficult breathing and fast breathing, is widely used in resource poor settings to guide management of acute respiratory infections. The definition is also commonly used as an entry criteria or endpoint in different intervention and disease burden studies. Methods A group of paediatricians conducted a retrospective review of clinical and laboratory data including C-reactive protein concentration and chest radiograph findings among Filipino children hospitalised in the Bohol Regional Hospital who were enrolled in a pneumococcal vaccine efficacy study and had an episode of respiratory disease fulfilling the WHO case definition for clinical pneumonia. Our aim was to evaluate which disease entities the WHO definition actually captures and what is the probable aetiology of respiratory infections among these episodes diagnosed in this population. Results Among the 12,194 children enrolled to the vaccine study we recorded 1,195 disease episodes leading to hospitalisation which fulfilled the WHO criteria for pneumonia. In total, 34% of these episodes showed radiographic evidence of pneumonia and 11% were classified as definitive or probable bacterial pneumonia. Over 95% of episodes of WHO-defined severe pneumonia (with chest indrawing) had an acute lower respiratory infection as final diagnosis whereas 34% of those with non-severe clinical pneumonia had gastroenteritis or other non-respiratory infection as main cause of hospitalisation. Conclusion The WHO definition for severe pneumonia shows high specificity for acute lower respiratory infection and provides a tool to compare the total burden of lower respiratory infections in different settings. Trial registration ISRCTN62323832BMC Infectious Diseases. 01/2008; -
Article: Clinical case review: a method to improve identification of true clinical and radiographic pneumonia in children meeting the World Health Organization definition for pneumonia.
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ABSTRACT: The World Health Organization's (WHO) case definition for childhood pneumonia, composed of simple clinical signs of cough, difficult breathing and fast breathing, is widely used in resource poor settings to guide management of acute respiratory infections. The definition is also commonly used as an entry criteria or endpoint in different intervention and disease burden studies. A group of paediatricians conducted a retrospective review of clinical and laboratory data including C-reactive protein concentration and chest radiograph findings among Filipino children hospitalised in the Bohol Regional Hospital who were enrolled in a pneumococcal vaccine efficacy study and had an episode of respiratory disease fulfilling the WHO case definition for clinical pneumonia. Our aim was to evaluate which disease entities the WHO definition actually captures and what is the probable aetiology of respiratory infections among these episodes diagnosed in this population. Among the 12,194 children enrolled to the vaccine study we recorded 1,195 disease episodes leading to hospitalisation which fulfilled the WHO criteria for pneumonia. In total, 34% of these episodes showed radiographic evidence of pneumonia and 11% were classified as definitive or probable bacterial pneumonia. Over 95% of episodes of WHO-defined severe pneumonia (with chest indrawing) had an acute lower respiratory infection as final diagnosis whereas 34% of those with non-severe clinical pneumonia had gastroenteritis or other non-respiratory infection as main cause of hospitalisation. The WHO definition for severe pneumonia shows high specificity for acute lower respiratory infection and provides a tool to compare the total burden of lower respiratory infections in different settings. ISRCTN62323832.BMC Infectious Diseases 01/2008; 8:95. · 3.12 Impact Factor -
Article: Central nervous system infection is an important cause of death in underfives hospitalised with World Health Organization (WHO) defined severe and very severe pneumonia.
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ABSTRACT: Over 6 years, 1667 children aged 2-59 months admitted for pneumonia [1287 severe and 380 very severe] were studied. The case fatality rate (CFR) in children with severe pneumonia was 2.1% and 14.3% with CNS infection, with very severe pneumonia the CFR was 18.9%, 10.4% in those with hypoxemia and 43.6% with CNS infection. High CFRs were associated with CNS infection and inability to drink/cyanosis. The appropriate management of children with very severe pneumonia should include cerebrospinal fluid examination, oxygen monitoring and possibly ventilated support, suggesting that these are minimal standards of care at the district hospital.Vaccine 04/2007; 25(13):2437-44. · 3.77 Impact Factor -
Article: Immunisation coverage of Queensland indigenous two-year-old children by cluster sampling and by register.
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ABSTRACT: To obtain, through a survey, estimates of immunisation coverage in a birth cohort of Indigenous children, and to compare survey estimates with those obtained from the Australian Childhood Immunisation Register (ACIR) for the same birth cohort of Indigenous children. Cluster sampling of a birth cohort of two-year-old Indigenous children across Queensland, stratified according to accessibility/remoteness from services, was undertaken in 2003. An innovative method of identifying participants was used. Survey results of 10 vaccine doses were compared with ACIR data. The survey obtained a 4% sample of the birth cohort (137 children). Universally recommended vaccines showed high levels of coverage at 12 and 24 months, and survey estimates were slightly higher than ACIR estimates. Diphtheria-tetanus-acellular pertussis vaccine dose 3 (DTPa3) coverage was 93.8% (95% CI 88.0-99.6) by 12 months on survey and 87.5% on ACIR. Coverage was not timely and a lag phase of 4-6 months occurred for each vaccine dose. Haemophilus influenzae type b vaccine dose 2 (Hib2), scheduled for the age of four months, reached 90% coverage by nine months of age in the survey children. Both methods reported here provided similar results. These data indicate that ACIR Indigenous reporting rates have increased and coverage estimates are comparable to those provided by a survey. Immunisation coverage appears to be high, and the main remaining challenge in further reducing vaccine-preventable disease in Indigenous children is to improve immunisation timeliness.Australian and New Zealand Journal of Public Health 03/2007; 31(1):67-72. · 1.20 Impact Factor -
Article: A Needs Survey of Immunisation for Aboriginal and Torres Strait Islander People in Queensland
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Article: Demography and the epidemiology of disease in Papua New Guinea.
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ABSTRACT: Papua New Guinea (PNG) remains a predominantly rural society. Declining mortality but only slow decline in fertility has led to an average annual growth rate of the order of 2.8%. If fertility continues to decline slowly, the population will reach 10 million soon after 2029; with an accelerated decline the population will be about 8.9 million persons in 2029. Wide differentials in mortality among provinces indicate considerable variation in mortality change. Infectious diseases which dominate the cause structure of mortality should be susceptible to health service intervention. Prerequisites are an appropriate mix of interventions, high levels of coverage, and high-quality monitoring and surveillance. It is critical that these unsolved disease problems be fully addressed as the combination of increasing urbanization, the AIDS (acquired immune deficiency syndrome) epidemic and an increasing prevalence of non-communicable diseases will place upward pressure on mortality rates. For the purposes of monitoring mortality change health services need access to methods for the calculation of mortality rates which have been validated in populations in PNG. Perhaps the most fundamental task of health services is to prevent unnecessary deaths. This article focuses on levels of mortality and the cause structure of mortality. It examines the relationship between health service interventions and mortality decline in PNG.Papua and New Guinea medical journal 52(3-4):83-95.
Top co-authors
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Institutions
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2007–2011
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University of Queensland
- School of Population Health
Brisbane, Queensland, Australia
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2008
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National Public Health Institute
Helsinki, Province of Southern Finland, Finland
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