mHealth application for improving treatment outcomes for patients with multidrug-resistant tuberculosis in Vietnam: an economic evaluation protocol for the V-SMART trial

INTRODUCTION

The Strengthen the Management of Multidrug-Resistant Tuberculosis in Vietnam (V-SMART) trial is a randomised controlled trial of using mobile health (mHealth) technologies to improve adherence to medications and management of adverse events (AEs) in people with multidrug-resistant tuberculosis (MDR-TB) undergoing treatment in Vietnam. This economic evaluation seeks to quantify the cost-effectiveness of this mHealth intervention from a healthcare provider and societal perspective.

METHODS AND ANALYSIS

The V-SMART trial will recruit 902 patients treated for MDR-TB across seven participating provinces in Vietnam. Participants in both intervention and control groups will receive standard community-based therapy for MDR-TB. Participants in the intervention group will also have a purpose-designed App installed on their smartphones to report AEs to health workers and to facilitate timely management of AEs. This economic evaluation will compare the costs and health outcomes between the intervention group (mHealth) and the control group (standard of care). Costs associated with delivering the intervention and health service utilisation will be recorded, as well as patient out-of-pocket costs. The health-related quality of life (HRQoL) of study participants will be captured using the 36-Item Short Form Survey (SF-36) questionnaire and used to calculate quality-adjusted life-years (QALYs). Incremental cost-effectiveness ratios (ICERs) will be based on the primary outcome (proportion of patients with treatment success after 24 months) and QALYs gained. Sensitivity analysis will be conducted to test the robustness of the ICERs. A budget impact analysis will be conducted from a payer perspective to provide an estimate of the total budget required to scale-up delivery of the intervention.

ETHICS AND DISSEMINATION

Ethical approval for the study was granted by the University of Sydney Human Research Ethics Committee (2019/676), the Scientific Committee of the Ministry of Science and Technology, Vietnam (08/QD-HDQL-NAFOSTED) and the Institutional Review Board of the National Lung Hospital, Vietnam (13/19/CT-HDDD). Study findings will be published in peer-reviewed journals and conference proceedings.

TRIAL REGISTRATION NUMBER

ACTRN12620000681954.

Computer-Aided Detection for Chest Radiography to Improve the Quality of Tuberculosis Diagnosis in Vietnam's District Health Facilities: An Implementation Study

In Vietnam, chest radiography (CXR) is used to refer people for GeneXpert (Xpert) testing to diagnose tuberculosis (TB), demonstrating high yield for TB but a wide range of CXR abnormality rates. In a multi-center implementation study, computer-aided detection (CAD) was integrated into facility-based TB case finding to standardize CXR interpretation. CAD integration was guided by a programmatic framework developed for routine implementation. From April through December 2022, 24,945 CXRs from TB-vulnerable populations presenting to district health facilities were evaluated. Physicians interpreted all CXRs in parallel with CAD (qXR 3.0) software, for which the selected TB threshold score was ≥0.60. At three months, there was 47.3% concordance between physician and CAD TB-presumptive CXR results, 7.8% of individuals who received CXRs were referred for Xpert testing, and 858 people diagnosed with Xpert-confirmed TB per 100,000 CXRs. This increased at nine months to 76.1% concordant physician and CAD TB-presumptive CXRs, 9.6% referred for Xpert testing, and 2112 people with Xpert-confirmed TB per 100,000 CXRs. Our programmatic CAD-CXR framework effectively supported physicians in district facilities to improve the quality of referral for diagnostic testing and increase TB detection yield. Concordance between physician and CAD CXR results improved with training and was important to optimize Xpert testing.

Tuberculin skin testing and QuantiFERON™-TB Gold Plus positivity among household contacts in Vietnam

SETTING

TB infection (TBI) is diagnosed using the technique-dependent tuberculin skin test (TST) or costly, more accurate interferon-gamma release assays. The TST (⩾10 mm) threshold was indicated by previous research among household contacts in Vietnam, but routine implementation with a different tuberculin reagent showed unexpectedly low TST positivity.

OBJECTIVE

TST (⩾5 mm and ⩾10 mm) results were compared to QuantiFERON™-TB Gold Plus (QFT) results in household contacts during community campaigns in 2020 and 2021.

DESIGN

This was a cross-sectional multi-center implementation study.

RESULTS

Among 1,330 household contacts in 2020, we found a TBI prevalence of 38.6% (QFT), similar to TST ⩾5 mm (37.4%) and higher than TST ⩾10 mm (13.1%). QFT+/TST+ was higher for TST ⩾5 mm (20.7%) than TST ⩾10 mm (9.4%). QFT was not discordant with TST ⩾5 mm (McNemar's test = 0.6, P = 0.5) but was discordant with TST ⩾10 mm (McNemar's test = 263.9, P < 0.01). Older age and Southern region increased odds for positive TST ⩾5 mm and QFT with weaker associations for TST ⩾10 mm. Agreement and discordance were similar in 2021 for 1,158 household contacts.

CONCLUSION

Tuberculin reagents affect TST positivity rates. High TB burden countries should monitor reliability of TBI diagnosis, including tuberculin potency, cold chain, and TST technique to optimize eligibility for TB preventive treatment.

What matters most? A qualitative study exploring priorities for supportive interventions for people with tuberculosis in urban Viet Nam

INTRODUCTION

The health and economic burden of tuberculosis (TB) in urban Viet Nam is high. Social protection and support interventions can improve treatment outcomes and reduce costs. However, evidence regarding optimal strategies in this context is lacking. This study aimed to increase understanding of what people with TB and healthcare providers (HCPs) perceive as important to improve TB treatment outcomes and reduce costs.

METHODS

We conducted qualitative focus group discussions (seven groups, n=30) and key informant interviews (n=4) with people with drug-susceptible and multidrug-resistant TB and HCPs in Ha Noi and Ho Chi Minh City. Topic guides covered perspectives on and prioritisation of different forms of social protection and support. Data were analysed using reflexive thematic analysis and interpreted using a Framework for Transformative Social Protection.

RESULTS

We identified three themes and seven subthemes. The first theme, 'Existing financial safety nets are essential, but could go further to support people affected by TB', highlights that support to meet the medical costs of TB treatment and flexible cash transfers are a priority for people with TB and HCPs. The second, 'It is important to promote "physical and spiritual health" during TB treatment', demonstrates that extended psychosocial and nutritional support would encourage people with TB during their treatment. The third, 'Accessibility and acceptability are critical in designing social support interventions for people with TB', shows the importance of ensuring that support is accessible and proportional to the needs of people with TB and their families.

CONCLUSIONS

Accessible interventions that incorporate financial risk protection, nutritional and psychosocial support matter most to people with TB and HCPs in urban Viet Nam to improve their treatment outcomes and reduce catastrophic costs. This study can inform the design of stronger person-centred interventions to advance progress towards the goals of the WHO's End TB Strategy.

Effectiveness and safety of bedaquiline-based, modified all-oral 9-11-month treatment regimen for rifampicin-resistant tuberculosis in Vietnam

OBJECTIVES

World Health Organization recommends a 7-drug 9-11-month rifampicin-resistant tuberculosis (RR-TB) short treatment regimen (STR). To reduce the pill burden, we assessed the safety and effectiveness of a 5-drug 9-11-month modified STR (mSTR).

METHODS

Prospective cohort study of an all-oral mSTR (comprising bedaquiline, levofloxacin, linezolid [LZD], clofazimine, and/or pyrazinamide) for patients with RR-TB without confirmed fluoroquinolone resistance, enrolled in Vietnam between 2020-2021.

RESULTS

A total of 108 patients were enrolled in this study. Overall, 63 of 74 (85%) achieved culture conversion at 2 months. Of 106 evaluated, 95 (90%) were successfully treated, six (6%) were lost-to-follow-up, one (1%) died, and four (4%) had treatment failure, including three with permanent regimen change owing to adverse events (AE) and one with culture reversion. Of 108, 32 (30%) patients encountered at least one AE. Of 45 AEs recorded, 13 (29%) were serious (hospitalization, life threatening, or death). The median time to AE was 3 months (IQR: 2-5). A total of 26 AEs led to regimen adaptation: either dose reduction (N = 1), drug temporary interruption (N = 19), or drug permanent discontinuation (N = 6, 4 attributed to LZD).

CONCLUSION

The high treatment success of 5-drug mSTR might replace the 7-drug regimen in routine care. AEs were frequent, but manageable in most patients. Active AEs monitoring is essential, particularly when using LZD throughout.

Safety and effectiveness of all-oral and injectable-containing, bedaquiline-based long treatment regimen for pre-XDR tuberculosis in Vietnam

Background: The World health organization (WHO) recently recommended standardized all-oral shorter regimens for rifampicin resistant Tuberculosis (RR-TB). For highly resistant Tuberculosis patients such as pre-XDR-TB: RR-TB plus additional resistance to fluoroquinolones (FQ), the 6–9-months bedaquiline (bedaquiline)-based regimens or BDQ-based long regimens are recommended. The role of second-line injectable (SLI) drugs in the treatment of drug resistant TB is restricted because of safety concerns. Nevertheless, it is not well-known how all-oral long regimens (BDQ-long) perform compared to SLI-containing long regimens (BDQ/SLI-long) in terms of safety and effectiveness among patients with highly resistant TB.

Method: A prospective observational cohort of patients with RR-TB additionally resistant to fluoroquinolones and/or second-line injectable, treated with either BDQ-long or BDQ/SLI-long regimens according to the guidance of the National Tuberculosis Program of Vietnam, enrolled between December 2015 and June 2017.

Results: Of 99 patients enrolled, 42 (42%) patients were treated with BDQ-long and 57 (57%) with BDQ/SLI-long. More than 85% of patients were previously exposed to both FQ and SLI. FQ and SLI resistance were confirmed in 28 (67%) and 41 (98%) in the BDQ-long cohort and 48 (84%) and 17 (30%) in the BDQ/SLI-long cohort, respectively. Treatment success was achieved among 29 (69%) and 46 (81%) patients on the BDQ-long and BDQ/SLI-long regimen, respectively (p = 0.2). For both regimens, median time to first smear/culture sputum conversion was 2 months. All patients experienced at least one adverse event (AE) and 85% of them had at least one severe Adverse events. The median time to a first severe adverse event was 2 months. Among patients treated with BDQ-long a higher proportion of patients had three QT-prolonging drugs in the regimen (26.2% versus 7.0%; p = 0.009). The severe prolonged QTcF was observed in 22 (52.4%) and 22 (38.6%) patients on BDQ-long and BDQ/SLI-long, respectively. Overall, 30 (30%) patients had to either temporary or permanently discontinued or more TB drugs due to AEs.

Conclusion: Treatment success was similar for both all-oral and SLI-containing BDQ-based long regimens in highly resistant TB patients. Both regimens had a similar high frequency of AEs. For both BDQ-long and BDQ/SLI-long regimens active AEs monitoring is essential.

Harnessing new mHealth technologies to Strengthen the Management of Multidrug-Resistant Tuberculosis in Vietnam (V-SMART trial): a protocol for a randomised controlled trial

INTRODUCTION

Multidrug-resistant tuberculosis (MDR-TB) remains a major public health problem globally. Long, complex treatment regimens coupled with frequent adverse events have resulted in poor treatment adherence and patient outcomes. Smartphone-based mobile health (mHealth) technologies offer national TB programmes an appealing platform to improve patient care and management; however, clinical trial evidence to support their use is lacking. This trial will test the hypothesis that an mHealth intervention can improve treatment success among patients with MDR-TB and is cost-effective compared with standard practice.

METHODS AND ANALYSIS

A community-based, open-label, parallel-group randomised controlled trial will be conducted among patients treated for MDR-TB in seven provinces of Vietnam. Patients commencing therapy for microbiologically confirmed rifampicin-resistant or multidrug-resistant tuberculosis within the past 30 days will be recruited to the study. Participants will be individually randomised to an intervention arm, comprising use of an mHealth application for treatment support, or a 'standard care' arm. In both arms, patients will be managed by the national TB programme according to current national treatment guidelines. The primary outcome measure of effectiveness will be the proportion of patients with treatment success (defined as treatment completion and/or bacteriological cure) after 24 months. A marginal Poisson regression model estimated via a generalised estimating equation will be used to test the effect of the intervention on treatment success. A prospective microcosting of the intervention and within-trial cost-effectiveness analysis will also be undertaken from a societal perspective. Cost-effectiveness will be presented as an incremental cost per patient successfully treated and an incremental cost per quality-adjusted life-year gained.

ETHICS

Ethical approval for the study was granted by The University of Sydney Human Research Ethics Committee (2019/676).

DISSEMINATION

Study findings will be disseminated to participants and published in peer-reviewed journals and conference proceedings.

TRIAL REGISTRATION NUMBER

ACTRN12620000681954.

Predictors of treatment outcomes among patients with multidrug-resistant tuberculosis in Vietnam: a retrospective cohort study

Background

Improving treatment outcomes for multidrug-resistant tuberculosis (MDR-TB) is a leading priority for global TB control. This retrospective cohort study evaluated the factors associated with treatment success among patients treated for MDR-TB in two provinces in Vietnam.

Methods

Treatment outcomes were evaluated for adult patients treated in Hanoi and Thanh Hoa provinces between 2014 and 2016. The primary outcome was the proportion of patients with treatment success, defined as cure or treatment completion. Logistic regression analysis was used to evaluate the relationship between patient clinical and microbiological characteristics and treatment success.

Results

Treatment outcomes were reported in 612 of 662 patients; of these, 401 (65.5)% were successfully treated. The odds of treatment success were lower for male patients (aOR 0.56, 95% CI 0.34–0.90), for people living with HIV (aOR 0.44, 95% CI 0.20–1.00), and for patients treated for extensive antibiotic resistance (pre-XDR-/XDT-TB) (aOR 0.53, 95% CI 0.29–0.97), compared with others. Patients who achieved culture conversion in the first 4 months of treatment had increased odds (aOR 2.93, 95% CI 1.33–6.45) of treatment success. In addition, loss to follow-up was less common among patients covered by social health insurance compared to those who paid for treatment out-of-pocket (aOR 0.55, 95% CI 0.32–0.95).

Conclusions

Among patients with MDR-TB, males, people living with HIV, and those with more extensive antibiotic resistance at diagnosis are at greatest risk of an unsuccessful treatment outcome. Efforts to optimise the management of co-morbidities (such as HIV), ensure rapid bacteriological conversion, and provide financial support for patients promise to improve treatment outcomes.

Adaptation and validation of the Van Rie tuberculosis stigma scale in Vietnam

OBJECTIVES

Tuberculosis (TB) stigma contributes to diagnostic delay, disease concealment, and reduced wellbeing for affected individuals. Despite the availability of several TB stigma scales, most high-TB burden countries do not have a culturally validated version available. This study evaluated the Van Rie TB stigma scale (VTSS) among people with TB in Vietnam.

METHODS

This study consisted of two phases. In phase 1, the VTSS was culturally and linguistically adapted to the Vietnamese context. In phase 2, people with TB were invited to complete a survey containing the VTSS, a depression scale, and a quality of life scale. The data analysis included confirmatory factor analysis (CFA), exploratory factor analysis (EFA), construct validity, and floor or ceiling effects.

RESULTS

In phase 1, items were reworded from the third person to the first person. The TB/HIV co-infection items (items 7 and 11) were the least relevant for people with TB (62% and 73% relevance, respectively). In phase 2, the CFA demonstrated adequate goodness-of-fit indices (GFI = 0.88, CFI = 0.96, RMSEA = 0.058); however several of the item factor loadings were low. The EFA demonstrated good internal consistency (α = 0.85) and revealed one dominant factor. Construct validity was low.

CONCLUSIONS

The VTSS demonstrated good psychometric properties in Vietnam. Depending on the purpose of the scale, the HIV co-infection items and item 10 could be considered for removal.

Post-treatment Mortality Among Patients With Tuberculosis: A Prospective Cohort Study of 10 964 Patients in Vietnam

BACKGROUND

Tuberculosis is the leading infectious cause of death. Steep reductions in tuberculosis-related mortality are required to realize the World Health Organization's "End Tuberculosis Strategy." However, accurate mortality estimates are lacking in many countries, particularly following discharge from care. This study aimed to establish the mortality rate among patients with pulmonary tuberculosis in Vietnam and to quantify the excess mortality in this population.

METHODS

We conducted a prospective cohort study among adult patients treated for smear-positive pulmonary tuberculosis in 70 clinics across Vietnam. People living in the same households were recruited as controls. Participants were re-interviewed and their survival was established at least 2 years after their treatment with an 8-month standardized regimen. The presence of relapse was established by linking identifying data on patients and controls to clinic registries. Verbal autopsies were performed. The cumulative mortality among patients was compared to that among a control population, adjusting for age and gender.

RESULTS

We enrolled 10964 patients and 25707 household controls. Among enrolled tuberculosis patients, 9% of patients died within a median follow-up period of 2.9 years: 342 (3.1%) during treatment and 637 (5.8%) after discharge. The standardized mortality ratio was 4.0 (95% confidence interval 3.7-4.2) among patients with tuberculosis, compared to the control population. Tuberculosis was the likely cause of death for 44.7% of these deceased patients.

CONCLUSIONS

Patients treated for tuberculosis had a markedly elevated risk of death, particularly in the post-treatment period. Interventions to reduce tuberculosis mortality must enhance the early detection of drug-resistance, improve treatment effectiveness, and address non-communicable diseases.

Levofloxacin versus placebo for the treatment of latent tuberculosis among contacts of patients with multidrug-resistant tuberculosis (the VQUIN MDR trial): a protocol for a randomised controlled trial

INTRODUCTION

Treatment of latent tuberculosis infection (LTBI) plays a substantial role in the prevention of drug-susceptible tuberculosis (TB). However, clinical trials to evaluate the efficacy of preventive therapy for presumed multidrug-resistant (MDR) LTBI are lacking. This trial aims to evaluate the efficacy of the antibiotic levofloxacin in preventing the development of active TB among latently infected contacts of index patients with MDR-TB.

METHODS AND ANALYSIS

A double-blind placebo-controlled parallel group randomised controlled trial will be conducted in 10 provinces of Vietnam. Household contacts living with patients with bacteriologically confirmed rifampicin-resistant or MDR-TB will be eligible for recruitment if they have a positive tuberculin skin test or are known to be immunosuppressed, and do not have active TB. Participants will be randomised to receive either levofloxacin or placebo tablets once per day for 6 months. Screening for incident TB will be performed at 6 months intervals. The primary study outcome is the incidence of bacteriologically confirmed TB within 30 months after randomisation. Analysis will be by intention to treat, using Poisson regression.

ETHICS

Ethical approval from the University of Sydney Human Research Ethics Committee was obtained on 29 April 2015 (2014/929), and from the Vietnam Ministry of Health Institutional Review Board on 30 September 2015 (4040/QD-BYT).

DISSEMINATION

Findings of the study will be published in peer-reviewed publications and conference presentations.

TRIAL REGISTRATION NUMBER

ACTRN12616000215426.

Introducing risk inequality metrics in tuberculosis policy development

Global stakeholders including the World Health Organization rely on predictive models for developing strategies and setting targets for tuberculosis care and control programs. Failure to account for variation in individual risk leads to substantial biases that impair data interpretation and policy decisions. Anticipated impediments to estimating heterogeneity for each parameter are discouraging despite considerable technical progress in recent years. Here we identify acquisition of infection as the single process where heterogeneity most fundamentally impacts model outputs, due to selection imposed by dynamic forces of infection. We introduce concrete metrics of risk inequality, demonstrate their utility in mathematical models, and pack the information into a risk inequality coefficient (RIC) which can be calculated and reported by national tuberculosis programs for use in policy development and modeling.

Failure to account for heterogeneity in TB risk can mislead model-based evaluation of proposed interventions. Here, the authors introduce a metric to estimate the distribution of risk in populations from routinely collected data and find that variation in infection acquisition is the most impactful.

[Covering of Finger-Tissue Loss by Local Flaps in Hanoi, Vietnam]

The accidental loss of fingertip soft tissues, which may expose tendons and bones, is a common injury in emergency departments. If these lesions are poorly treated, they can impair fine motor skills and tactile sensitivity of the fingertips. The study was conducted on 30 patients (24 males and 6 females) with 32 soft tissue defects of the fingertip treated in emergency plastic surgery with local pedicled flap at the Plastic Surgery Department of Saint Paul Hospital Hanoi from 01/2016 to 06/2017. The most common cause of injury (21/30) was occupational accidents. At the time of the accident, 12 patients did not have personal protective equipment (PPE). Among 18 patients who had one, eight had incomplete equipment. Of 32 implanted skin flaps, 31 survived completely without necrosis or infection, only one being affected by epidermolysis. Postoperative evaluation showed excellent motor skills for 31/32 fingers and a sensitivity restoration at S4 level for 27/32. Workplace accident is the main cause of fingers soft tissue defects. Covering the fingers soft tissue defects with local pedicled flap in emergency preserves the fine motor function and the delicated tactile sensation of the fingers.

Recurrence of tuberculosis among patients following treatment completion in eight provinces of Vietnam: A nested case-control study

BACKGROUND

Patients completing treatment for tuberculosis (TB) in high-prevalence settings face a risk of developing recurrent disease. This has important consequences for public health, given its association with drug resistance and a poor prognosis. Previous research has implicated individual factors such as smoking, alcohol use, HIV, poor treatment adherence, and drug resistant disease as risk factors for recurrence. However, little is known about how these factors co-act to produce recurrent disease. Furthermore, perhaps factors related to the index disease means higher burden/low resource settings may be more prone to recurrent disease that could be preventable.

METHODS

We conducted a case-control study nested within a cohort of consecutively enrolled adults who were being treated for smear positive pulmonary TB in 70 randomly selected district clinics in Vietnam. Cases were patients with recurrent TB, identified by follow-up from the parent cohort study. Controls were selected from the cohort by random sampling. Information on demographic, clinical and disease-related characteristics was obtained by interview. Treatment information was extracted from clinic registries. Logistic regression, with stepwise selection, was used to develop a fully adjusted model for the odds of recurrence of TB.

RESULTS

We recruited 10,964 patients between October 2010 and July 2013. Median follow-up was 988 days. At the end of follow-up, 505 patients (4.7%) with recurrence were identified as cases and 630 other patients were randomly selected as controls. Predictors of recurrence included multidrug-resistant (MDR)-TB (adjusted odds ratio 79.6; 95% CI: 25.1-252.0), self-reported prior TB therapy (aOR=2.5; 95% CI: 1.7-3.5), and incomplete adherence (aOR=1.9; 95% CI 1.1-3.1).

CONCLUSIONS

Index disease treatment history is a leading determinant of relapse among patients with TB in Vietnam. Further research is required to identify interventions that will reduce the risk of recurrent disease and enhance its early detection within high-risk populations.

A rare case of peritonitis due to Brevundimonas vesicularis

Healthcare associated infections due to gram negative bacilli are a major concern among healthcare institutions. While Pseudomonas and Escherichia coli species are known major organisms; other lesser known species can also cause primary infection. We present a case of peritonitis in a patient on a peritoneal dialysis regimen due to Brevundimonas vesicularis.

Tuberculosis and HIV co-infection in Vietnam

Tuberculosis (TB) and human immunodeficiency virus (HIV) infection are leading causes of disease and death in Vietnam, but TB/HIV disease trends and the profile of co-infected patients are poorly described.

METHODS

We examined national TB and HIV notification data to provide a geographic overview and describe relevant disease trends within Vietnam. We also compared the demographic and clinical profiles of TB patients with and without HIV infection.

RESULTS

During the past 10 years (2005-2014) cumulative HIV case numbers and deaths increased to 298,151 and 71,332 respectively, but access to antiretroviral therapy (ART) improved and new infections and deaths declined. From 2011-2014 routine HIV testing of TB patients increased from 58.9% to 72.5% and of all TB patients diagnosed with HIV in 2014, 2,803 (72.4%) received ART. The number of multidrug resistant (MDR)-TB cases enrolled for treatment increased almost 3-fold (578 to 1,532) from 2011-2014. The rate of HIV co-infection in MDR and non-MDR TB cases (51/1,532; 3.3% vs 3,774/100,555; 3.8%; OR 0.77, 95% CI 0.7-1.2) was similar in 2014.

CONCLUSIONS

The care of TB/HIV co-infected patients have shown sustained improvement in Vietnam. Rising numbers of MDR-TB cases is a concern, but this is not "driven" by HIV co-infection.

Phylogenetic and phylogeographic analyses of porcine circovirus type 2 among pig farms in Vietnam

This study demonstrated the prevalence of Porcine circovirus type 2 (PCV2) among pig farms in Vietnam. Analyses of the genome, capsid protein and phylogeny classified all 30 Vietnamese PCV2 strains as the PCV2b genotype, belonging to the clusters of 1A, 1B, 1C and recombinant forms. Each viral genome was 1767 nucleotides long and shared 96.0-100% nucleotide sequence identity. The amino acid substitutions in the capsid protein of the Vietnamese PCV2 strains were in immunodominant regions, and the majority of strains (24/30) contained a lysine extension at the C-terminus. Bayesian phylogeographic analysis revealed epidemic links of the PCV2 recombinant cluster within and among countries, which supports a circulating recombinant form of PCV2. Further analysis by the Jameson-Wolf antigenic index indicated antigenic alterations at important sites in the capsid protein (sites 131-133) among the recombinant cluster and the other clusters of PCV2b.

Jewellery- and ornament-related injuries in children and adolescents

BACKGROUND

Unintentional injuries are the leading cause of mortality and morbidity in children and teenagers in Canada. Few publications have addressed injuries caused by jewellery and ornaments in children.

OBJECTIVES

To examine the mechanisms and the incidence of injuries caused by jewellery and ornaments in children and teenagers, to identify children at high risk for these type of injuries and to recommend specific injury prevention strategies.

METHODS

Data were analyzed from a Canadian database (Canadian Hospitals Injury Reporting and Prevention Program) of a tertiary paediatric centre. All patients between zero and 18 years of age who were diagnosed in the emergency department with jewellery- and ornament-related injuries during a 10-year period (1997 to 2006) were identified. Patients were categorized according to six age groups (younger than one year of age; one to two years of age; two to four years of age; five to nine years of age; 10 to 14 years of age, and 15 to 18 years of age). For each case, the context and the mechanism of injury were investigated.

RESULTS

From a total of 150,771 reported injury cases, 380 (0.25%) were jewellery related. Unlike with most trauma, girls predominate in this kind of injury (n=288; 75.8% of cases). Over one-half of cases (58.1%) were reported for children four years of age or younger. Emergency physicians reported the presence of jewellery as a foreign body in a natural orifice (mouth, nose, ear or genitourinary tract) in 308 cases (81%). No case of intestinal obstruction, strangulation or death was reported. Eleven cases (2.9%) required emergency hospitalization, all for endoscopic evaluation of a foreign body in the airway or in the digestive tract. In the adolescent group, five cases of injuries secondary to piercing were reported.

CONCLUSION

The present study demonstrates that, although jewellery-related injuries are relatively infrequent, some can cause severe injuries that could compromise patients' health. As a primary prevention strategy, doctors and health professionals working with children should make parents and caregivers aware of the possibility of trauma in children wearing or playing with jewellery, especially in the zero- to four-year-old group requiring closer supervision. Specific anticipatory guidance concerning piercing may be helpful to adolescents.

Epidemiology of electrical and lightning related deaths and injuries among Canadian children and youth

Among burn injuries, electrical injuries constitute a small but devastating fraction. To describe the epidemiology of electrical injuries in Canadian children, data on deaths and emergency department visits related to electrical injuries, including lightning strikes, were obtained from provincial coroners' offices and the Canadian Hospitals Injury Reporting and Prevention Program (CHIRPP) respectively, for the years 1991-96. Twenty one deaths and 606 emergency visits highlight that electrical related deaths, more frequent among school age children, are more likely the result of high voltage and lightning strike, while emergency department visits, more frequent among younger children, are more likely the result of low voltage. While the introduction of legislated standards for child safe outlets and educational programs for parents, children, and youth are recommended strategies toward reducing the frequency of these incidents, these strategies require further evaluation before their effectiveness can be estimated.

Does willingness to pay vary by race/ethnicity? An analysis using mammography among low-income women

As part of a population-based intervention to improve periodic mammogram screening, we examined WTP for mammography in five ethnic groups. Through random digit dialing, we contacted households in low-income census tracts of Alameda County, California (San Francisco Bay area). Women who met the ethnicity, age and cancer-free eligibility criteria were invited to participate. For the baseline assessment, women were surveyed over the phone in their preferred language. Of the 1465 surveyed women, 499 identified themselves as African-American, 199 were Chinese, 167 were Filipino, 300 were Latina, and 300 were non-Hispanic white. Bivariate and multivariate analysis showed that WTP varied significantly by ethnicity (P<0.05). We also found that when Filipino and Chinese women had a female relative with breast cancer, they were willing to pay less money for a mammogram. African-American, Latino, and non-Hispanic white women, however, were willing to pay more money for a mammogram if a female relative had had breast cancer. This ethnic difference, when there is a familial link to breast cancer, needs further study as it has implication for genetic testing. Nevertheless, WTP studies that do not account for ethnic differences may be overstating net benefits to society.

Abnormal Pap smear follow-up in a high-risk population

Low-income women are at high risk of developing cervical cancer attributable not only to the higher prevalence of risk factors in this population but also to the lack of timely follow-up of abnormal Pap smears. This study evaluates the efficacy of an aggressive follow-up strategy. Women with abnormal Pap smear results after screening in a public hospital emergency department were randomly assigned to follow-up either by a case-managed approach using computerized tracking and universal colposcopy or by traditional care. The main outcome was the proportion of women receiving follow-up in 6 months. A secondary outcome was the proportion of women receiving follow-up by 6 months and diagnostic resolution in 18 months. Of 54 women in the intervention group, 65% kept at least one follow-up appointment in 6 months compared with 41% of the 54 women in the control group (P = 0.012). Half the women in the intervention group versus 19% of women in the control group had follow-up in 6 months and diagnostic resolution in 18 months (P = 0.001). After adjusting for age, initial Pap smear result, and race/ethnicity, the odds of having follow-up in 6 months were four times greater for women in the intervention group (odds ratio = 4.0; 95% confidence interval, 1.6-9.7), and the odds of having both follow-up in 6 months and diagnostic resolution in 18 months were more than six times greater (odds ratio = 6.5; 95% confidence interval, 2.4-17.8). This study demonstrates that an aggressive follow-up strategy significantly improves the rate of both initial follow-up and diagnostic resolution of abnormal Pap smears among low-income women with atypical squamous cells of undetermined significance and atypical glandular cells of undetermined significance when compared with traditional care.

Promoting cancer prevention activities among Vietnamese physicians in California

BACKGROUND

To promote prevention and early detection of cancer, the authors conducted a three-year intervention targeting Vietnamese physicians in solo practice in California.

METHODS

Twenty subjects who had received their medical training in Vietnam were recruited into a randomized controlled trial. The intervention included computerized or manual cancer screening reminders, continuing medical education seminars, Vietnamese-language health education materials, newsletters, and oncology data-query programs. Evaluation included chart audits for eight targeted activities pre- and post-intervention.

RESULTS

Before the intervention, annual physician performance rates were low for all eight activities: routine checkups (65.6%), Pap testing (13.8%), pelvic examinations (19.8%), clinical breast examinations (13.3%), mammography (6.4%), hepatitis B serologies (21.9%), hepatitis B immunizations (12.8%), and smoking cessation counseling (1.6%). After the intervention, performance rates increased significantly for smoking cessation counseling (p = 0.02), Pap testing (p = 0.004), and pelvic examinations (p = 0.01).

CONCLUSIONS

The results demonstrate the efficacy of an intervention targeting Vietnamese primary care physicians in promoting smoking cessation counseling, Pap testing, and pelvic examinations, but not other cancer prevention activities.

CathSim: an intravascular catheterization simulator on a PC

The development of a medical simulator that incorporates substantial training value and realism into an affordable product has been a huge challenge for the simulation community. A large hurdle to making an inexpensive simulator has been the high cost of the computers needed for adequate realism. We have met this challenge by developing CathSim, a low-cost medical simulator that integrates force feedback, multimedia, and 3D graphics simulation technology on an industry standard PC. This product is commercially available and is currently being used by numerous training institutions and hospitals. The CathSim system includes software and a force feedback interface device. The platform and device can be used to train health care providers to perform needle-stick medical procedures. Our first module teaches users the techniques of peripheral intravenous (i.v.) catheterization. Other training modules that will be added to the CathSim platform include central venous catheter (CVC) insertion and peripherally inserted central catheter (PICC) placement. This paper discusses the challenges of this project and the trade-offs and solutions that we developed to overcome them. We describe our process of analyzing and prioritizing the medical tasks necessary to correctly perform peripheral intravenous catheterization. This analysis and prioritization was used to decide which tasks would be included in the simulator and how the included tasks would be replicated. We discuss the method by which we obtained the needed realism in the 3D graphics rendering and in the tactile feedback of the input device. We illustrate how we blended together simulation and multimedia technology to ensure adequate immersion and training efficacy, while keeping the system cost to a minimum.

Physiologic identification of eighth nerve subdivisions: direct recordings with bipolar and monopolar electrodes

The purpose of this study was to determine stimulation and recording parameters that maximize differences in evoked responses recorded between the cochlear nerve and the surrounding tissues. Click-evoked potentials were obtained using monopolar and bipolar recording electrodes placed directly on the exposed eighth nerve of anesthetized cats. Responses were compared as stimulus intensity, electrode location, and bipolar electrode orientation and interelectrode spacing were systematically varied. Wave amplitudes increased monotonically with intensity for both monopolar and bipolar configurations, but bipolar configurations exhibited greater selectivity in differentiating cochlear from vestibular subdivisions. The optimal stimulus intensity was 70 to 80 dB peak sound pressure level (pSPL). Monopolar recordings were often confounded by activity originating at remote sites, typically the cochlear nucleus and (for recording sites on the vestibular nerve) the cochlear nerve. Bipolar response amplitudes increased with interelectrode spacing and were largest when electrodes were oriented parallel to the long axis of the nerve. Extrapolation of empirical data indicated that amplitudes of bipolar responses would be maximal at an electrode separation of 7.5 mm. Cochlear nerve conduction velocity, calculated from wave latencies at each of the two monopolar electrodes, was 11.6 +/- 1.6 m/sec.

Effect of a media-led education campaign on breast and cervical cancer screening among Vietnamese-American women

BACKGROUND

Previous research has shown that breast and cervical cancer screening rates are low among Vietnamese women.

METHODS

Over a 24-month period, we implemented a media-led community education campaign to promote recognition, intention, receipt, and currency of routine checkups, clinical breast examinations, mammograms, and Pap tests among Vietnamese-American women in Alameda and Santa Clara Counties in northern California. Women in Los Angeles and Orange Counties in southern California served as controls. To evaluate its impact, pretest telephone interviews were conducted of 451 randomly selected women in the intervention area and 482 women in the control area and posttest interviews with 454 and 422 women, respectively.

RESULTS

At posttest, after controlling for demographic differences in the surveyed populations, the odds ratios for the intervention effect were statistically significant for having heard of a general checkup, Paptest, and clinical breast examination (CBE); planning to have a checkup, Pap test, CBE, and mammogram; and having had a checkup and Pap test. The intervention had no effect on being up to date for any of the tests.

CONCLUSIONS

A media-led education intervention succeeded in increasing recognition of and intention to undertake screening tests more than receipt of or currency with the tests.

The teleos virtual environment toolkit for simulation-based surgical education

In the past, surgical simulations have largely been created through the development of dedicated applications that require considerable programming and computer graphics skills. Advances in simulation-based surgical education have been limited by this dependence on computer graphics programming expertise. To lower barriers to the adoption of simulation-based training, we are developing tools based on Teleos, software technology that allows a wide variety of medical content developers to author surgical training simulations without programming.