Diagnostic accuracy of physician review, expert algorithms and data-derived algorithms in adult verbal autopsies

BACKGROUND: The verbal autopsy (VA) is used to collect information on cause-specific mortality from bereaved relatives. A cause of death may be assigned by physician review of the questionnaires, or by an algorithm. We compared the diagnostic accuracy of physician review, an expert algorithm, and data-derived algorithms. METHODS: Data were drawn from a multicentre validation study of 796 adult deaths that occurred in hospitals in Tanzania, Ethiopia, and Ghana. A 'gold standard' cause of death was assigned using hospital records and death certificates. The VA interviews were carried out by trained fieldworkers 1-21 months after the subject's death. A cause of death was assigned by physician review and an expert algorithm. Data-derived algorithms that most accurately estimated the cause-specific mortality fraction (CSMF) for each cause of death were identified using logistic regression. RESULTS: The most common causes of death were tuberculosis/AIDS (CSMF = 18.6%), malaria (CSMF = 10.7%), meningitis (CSMF = 8.3%), and cardiovascular disorders (CSMF = 8.2%). The CSMF obtained using physician review was within +/-20% of the gold standard value for 12 causes of death including the four common causes. The CSMF obtained using the expert algorithm was within +/-20% of the gold standard for eight causes of death, including tuberculosis/AIDS, malaria, and meningitis. The CSMF obtained using the data-derived algorithms was within +/-20% of the gold standard for seven causes of death, including tuberculosis/ AIDS, meningitis, and cardiovascular disorders. All three methods yielded a specificity of at least 80% for all causes of death, and a sensitivity of at least 80% for deaths due to injuries and rabies. CONCLUSIONS: For those settings where physician review is not feasible, expert and data-derived algorithms provide an alternative approach for assigning many causes of death. We recommend that the algorithms proposed herein are validated further.     

Cephalic arch stenosis: angioplasty to preserve a brachiocephalic fistula or new brachiobasilic fistula?: a cost-effectiveness study

Background: Our aim was to evaluate the cost-effectiveness of repeat angioplasty versus new brachiobasilic fistula (BBF) in patients with symptomatic cephalic arch stenosis (CAS). Methods: Patients presenting with symptomatic CAS (n?=?22) underwent angioplasty. They were compared to patients undergoing BBF creation (n?=?51). Primary outcomes were functional primary arteriovenous fistulae patency at 3, 6 and 12 months. Data were collected on number of interventions, alternative accesses and hospital days for access-related complications. Quality of life was assessed using Kidney Disease Quality of Life-36 scores. Decision tree, Monte Carlo simulation and sensitivity analysis permitted cost-utility analysis. Healthcare costs were derived from Department of Health figures and are presented as cost (£)/patient/year, cost/access preserved and cost/quality of life-adjusted year (QALY) for each of the treatment strategies. Results: Functional primary patency rates at 3, 6, 12 months were 87.5%, 81% and 43% for repeated angioplasty and 78%, 63% and 41% for BBF. The angioplasty cohort required 1.64?±?0.23 angioplasties/patient and 0.64?±?0.34 lines/patient. BBF required 0.36?±?0.12 angioplasties/patient and 1.2?±?0.2 lines/patient. Patients in the BBF cohort spent an additional 0.9 days/year in hospital due to access-related complications. Mean cost/patient/year in the angioplasty group was £5247.72/patient/year versus £3807.55/patient/year in the BBF cohort. Mean cost per access saved was £11,544.98 (angioplasty) versus £4979.10 (BBF). Average cost per QALY was £13,809.79 (angioplasty) versus £10,878.72 per QALY (BBF). Conclusions: CAS poses a difficult management problem with poor outcomes from conventional angioplasty. Optimal management will depend on patient factors, local outcomes and expertise, but consideration should be given to creation of a new BBF as a cost-effective means to manage this difficult problem.     

A multimedia consent tool for research participants in the Gambia: a randomized controlled trial

ObjectiveTo assess the effectiveness of a multimedia informed consent tool for adults participating in a clinical trial in the Gambia.MethodsAdults eligible for inclusion in a malaria treatment trial (n = 311) were randomized to receive information needed for informed consent using either a multimedia tool (intervention arm) or a standard procedure (control arm). A computerized, audio questionnaire was used to assess participants’ comprehension of informed consent. This was done immediately after consent had been obtained (at day 0) and at subsequent follow-up visits (days 7, 14, 21 and 28). The acceptability and ease of use of the multimedia tool were assessed in focus groups.FindingsOn day 0, the median comprehension score in the intervention arm was 64% compared with 40% in the control arm (P = 0.042). The difference remained significant at all follow-up visits. Poorer comprehension was independently associated with female sex (odds ratio, OR: 0.29; 95% confidence interval, CI: 0.12–0.70) and residing in Jahaly rather than Basse province (OR: 0.33; 95% CI: 0.13–0.82). There was no significant independent association with educational level. The risk that a participant’s comprehension score would drop to half of the initial value was lower in the intervention arm (hazard ratio 0.22, 95% CI: 0.16–0.31). Overall, 70% (42/60) of focus group participants from the intervention arm found the multimedia tool clear and easy to understand.ConclusionA multimedia informed consent tool significantly improved comprehension and retention of consent information by research participants with low levels of literacy.     

Tuberculosis treatment in complex emergencies: are risks outweighing benefits?

Tuberculosis (TB) is a major public health problem in complex emergencies. Humanitarian agencies usually postpone the decision to offer TB treatment and opportunities to treat TB patients are often missed. This paper looks at the problem of tuberculosis treatment in these emergencies and questions whether treatment guidelines could be more flexible than international recommendations. A mathematical model is used to calculate the risks and benefits of different treatment scenarios with increasing default rates. Model outcomes are compared to a situation without treatment. An economic analysis further discusses the findings in a trade-off between the extra costs of treating relapses and failures and the savings in future treatment costs. In complex emergencies, if a TB programme could offer 4-month treatment for 75% of its patients, it could still be considered beneficial in terms of public health. In addition, the proportion of patients following at least 4 months of treatment can be used as an indicator to help evaluate the public health harm and benefit of the TB programme.     

Formula for calculating standard liver volume in Indians

Aim  

To assess the validity of standard liver volume (SLV) calculated using various formulae in the Indian population.     

Setting priorities in global child health research investments: assessment of principles and practice

This article reviews theoretical and practical approaches for setting priorities in global child health research investments. It also provides an overview of previous attempts to develop appropriate tools and methodologies to define priorities in health research investments. A brief review of the most important theoretical concepts that should govern priority setting processes is undertaken, showing how different perspectives, such as medical, economical, legal, ethical, social, political, rational, philosophical, stakeholder driven, and others will necessarily conflict each other in determining priorities. We specially address present research agenda in global child health today and how it relates to United Nation's (UN) Millennium Development Goal 4, which is to reduce child mortality by two-thirds between 1990 and 2015. The outcomes of these former approaches are evaluated and their benefits and shortcomings presented. The case for a new methodology for setting priorities in health research investments is presented, as proposed by Child Health and Nutrition Research Initiative, and a need for its implementation in global child health is outlined. A transdisciplinary approach is needed to address all the perspectives from which investments into health research can be seen as priorities. This prioritization requires a process that is transparent, systematic, and that would take into account many perspectives and build on advantages of previous approaches.     

Erb's paraplegia with primary optic atrophy: Unusual presentation of neurosyphilis: Case report and review of literature

Symptomatic neurosyphilis (NS) can have varied syndromic presentations: Meningitis, meningovascular and parenchymatous involvement. Non-tabetic syphilis affecting the spinal cord is rare and only sporadic case reports have been published. The variant of meningomyelitis known as Erb''s paraplegia refers to patients of spinal syphilis with very slow progression over many years and predominantly motor signs. Primary optic atrophy occurs twice as frequently in tabes dorsalis as in other types of NS. We describe here a case of a 32-year-old truck driver who presented with Erb''s paraplegia with primary optic atrophy. This clinical overlap in NS is extremely rare and to our knowledge is the first case report of its type.     

Prospective validation of a standardized questionnaire for estimating childhood mortality and morbidity due to pneumonia and diarrhoea

This paper reports the validation of a 'best-judgement' standardised questionnaire using guidelines and algorithms developed by an expert working group conducted in Nicaragua between 1995 and 1997. Prospective hospital data, including standardised medical recording of selected signs and symptoms, laboratory and radiographic test results and physician diagnoses were collected for children < 5 years admitted with any serious life-threatening condition in 3 study hospitals. The mothers or caregivers of the children were later traced and interviewed using the 'best-judgement' questionnaire. Interviews were completed 1-22 months after admission to hospital for 1115 children (400 who died during the stay in hospital and 715 who were discharged alive). The cause of death or admission to hospital was determined by an expert algorithm applied to hospital data. A similar procedure was used to derive the cause using the answers to questions from interviews. Hospital causes were compared with interview causes and sensitivity and specificity calculated, together with the estimated cause-specific fraction for diarrhoea and pneumonia. Multiple diagnoses were allowed; 378 children in the sample (104 deaths, 274 survivors) had a reference diagnosis of diarrhoeal illness, and 506 (168 deaths, 338 survivors) a reference diagnosis of pneumonia. When results for deaths and survivors in all age groups were combined, the expert algorithms had sensitivity between 86% and 88% and specificity between 81% and 83% for any diarrhoeal illness; and sensitivity between 74% and 87% and specificity between 37% and 72% for pneumonia. Algorithms tested in previous validation studies were also applied to data obtained in this study, and the results are compared. Despite less than perfect sensitivity and specificity, reasonably accurate estimates of the cause-specific mortality and morbidity fractions for diarrhoea were obtained, although the accuracy of estimates in other settings using the same instrument will depend on the true cause-specific fraction in those settings. The algorithms tested for pneumonia did not produce accurate estimates of the cause-specific fraction, and are not recommended for use in community settings.