Mathematical models of Plasmodium vivax transmission: A scoping review

Plasmodium vivax is one of the most geographically widespread malaria parasites in the world, primarily found across South-East Asia, Latin America, and parts of Africa. One of the significant characteristics of the P. vivax parasite is its ability to remain dormant in the human liver as hypnozoites and subsequently reactivate after the initial infection (i.e. relapse infections). Mathematical modelling approaches have been widely applied to understand P. vivax dynamics and predict the impact of intervention outcomes. Models that capture P. vivax dynamics differ from those that capture P. falciparum dynamics, as they must account for relapses caused by the activation of hypnozoites. In this article, we provide a scoping review of mathematical models that capture P. vivax transmission dynamics published between January 1988 and May 2023. The primary objective of this work is to provide a comprehensive summary of the mathematical models and techniques used to model P. vivax dynamics. In doing so, we aim to assist researchers working on mathematical epidemiology, disease transmission, and other aspects of P. vivax malaria by highlighting best practices in currently published models and highlighting where further model development is required. We categorise P. vivax models according to whether a deterministic or agent-based approach was used. We provide an overview of the different strategies used to incorporate the parasite's biology, use of multiple scales (within-host and population-level), superinfection, immunity, and treatment interventions. In most of the published literature, the rationale for different modelling approaches was driven by the research question at hand. Some models focus on the parasites' complicated biology, while others incorporate simplified assumptions to avoid model complexity. Overall, the existing literature on mathematical models for P. vivax encompasses various aspects of the parasite's dynamics. We recommend that future research should focus on refining how key aspects of P. vivax dynamics are modelled, including spatial heterogeneity in exposure risk and heterogeneity in susceptibility to infection, the accumulation of hypnozoite variation, the interaction between P. falciparum and P. vivax, acquisition of immunity, and recovery under superinfection.

Tafenoquine following G6PD screening versus primaquine for the treatment of vivax malaria in Brazil: A cost-effectiveness analysis using a transmission model

BACKGROUND

Malaria transmission modelling has demonstrated the potential impact of semiquantitative glucose-6-phosphate dehydrogenase (G6PD) testing and treatment with single-dose tafenoquine for Plasmodium vivax radical cure but has not investigated the associated costs. This study evaluated the cost-effectiveness of P. vivax treatment with tafenoquine after G6PD testing using a transmission model.

METHODS AND FINDINGS

We explored the cost-effectiveness of using tafenoquine after G6PD screening as compared to usual practice (7-day low-dose primaquine (0.5 mg/kg/day) without G6PD screening) in Brazil using a 10-year time horizon with 5% discounting considering 4 scenarios: (1) tafenoquine for adults only assuming 66.7% primaquine treatment adherence; (2) tafenoquine for adults and children aged >2 years assuming 66.7% primaquine adherence; (3) tafenoquine for adults only assuming 90% primaquine adherence; and (4) tafenoquine for adults only assuming 30% primaquine adherence. The incremental cost-effectiveness ratios (ICERs) were estimated by dividing the incremental costs by the disability-adjusted life years (DALYs) averted. These were compared to a willingness to pay (WTP) threshold of US$7,800 for Brazil, and one-way and probabilistic sensitivity analyses were performed. All 4 scenarios were cost-effective in the base case analysis using this WTP threshold with ICERs ranging from US$154 to US$1,836. One-way sensitivity analyses showed that the results were most sensitive to severity and mortality due to vivax malaria, the lifetime and number of semiquantitative G6PD analysers needed, cost per malaria episode and per G6PD test strips, and life expectancy. All scenarios had a 100% likelihood of being cost-effective at the WTP threshold. The main limitations of this study are due to parameter uncertainty around our cost estimates for low transmission settings, the costs of G6PD screening, and the severity of vivax malaria.

CONCLUSIONS

In our modelling study that incorporated impact on transmission, tafenoquine prescribed after a semiquantitative G6PD testing was highly likely to be cost-effective in Brazil. These results demonstrate the potential health and economic importance of ensuring safe and effective radical cure.

A model for malaria treatment evaluation in the presence of multiple species

Plasmodium falciparum and P. vivax are the two most common causes of malaria. While the majority of deaths and severe morbidity are due to P. falciparum, P. vivax poses a greater challenge to eliminating malaria outside of Africa due to its ability to form latent liver stage parasites (hypnozoites), which can cause relapsing episodes within an individual patient. In areas where P. falciparum and P. vivax are co-endemic, individuals can carry parasites of both species simultaneously. These mixed infections complicate dynamics in several ways: treatment of mixed infections will simultaneously affect both species, P. falciparum can mask the detection of P. vivax, and it has been hypothesised that clearing P. falciparum may trigger a relapse of dormant P. vivax. When mixed infections are treated for only blood-stage parasites, patients are at risk of relapse infections due to P. vivax hypnozoites. We present a stochastic mathematical model that captures interactions between P. falciparum and P. vivax, and incorporates both standard schizonticidal treatment (which targets blood-stage parasites) and radical cure treatment (which additionally targets liver-stage parasites). We apply this model via a hypothetical simulation study to assess the implications of different treatment coverages of radical cure for mixed and P. vivax infections and a "unified radical cure" treatment strategy where P. falciparum, P. vivax, and mixed infections all receive radical cure after screening glucose-6-phosphate dehydrogenase (G6PD) normal. In addition, we investigated the impact of mass drug administration (MDA) of blood-stage treatment. We find that a unified radical cure strategy leads to a substantially lower incidence of malaria cases and deaths overall. MDA with schizonticidal treatment was found to decrease P. falciparum with little effect on P. vivax. We perform a univariate sensitivity analysis to highlight important model parameters.

Modelling mass drug administration strategies for reducing scabies burden in Monrovia, Liberia

Scabies is a parasitic infestation with high global burden. Mass drug administrations (MDAs) are recommended for communities with a scabies prevalence of >10%. Quantitative analyses are needed to demonstrate the likely effectiveness of MDA recommendations. In this study, we developed an agent-based model of scabies transmission calibrated to demographic and epidemiological data from Monrovia. We used this model to compare the effectiveness of MDA scenarios for achieving scabies elimination and reducing scabies burden, as measured by time until recrudescence following delivery of an MDA and disability-adjusted-life-years (DALYs) averted. Our model showed that three rounds of MDA delivered at six-month intervals and reaching 80% of the population could reduce prevalence below 2% for three years following the final round, before recrudescence. When MDAs were followed by increased treatment uptake, prevalence was maintained below 2% indefinitely. Increasing the number of and coverage of MDA rounds increased the probability of achieving elimination and the number of DALYs averted. Our results suggest that acute reduction of scabies prevalence by MDA can support a transition to improved treatment access. This study demonstrates how modelling can be used to estimate the expected impact of MDAs by projecting future epidemiological dynamics and health gains under alternative scenarios.

Adherence to 14-day radical cure for Plasmodium vivax malaria in Papua, Indonesia: a mixed-methods study

BACKGROUND

Reducing the risk of recurrent Plasmodium vivax malaria is critical for malaria control and elimination. Primaquine (PQ) is the only widely available drug against P. vivax dormant liver stages, but is recommended as a 14-day regimen, which can undermine adherence to a complete course of treatment.

METHODS

This is a mixed-methods study to assess socio-cultural factors influencing adherence to a 14-day PQ regimen in a 3-arm, treatment effectiveness trial in Papua, Indonesia. The qualitative strand, consisting of interviews and participant observation was triangulated with a quantitative strand in which trial participants were surveyed using a questionnaire.

RESULTS

Trial participants differentiated between two types of malaria: tersiana and tropika, equivalent to P. vivax and Plasmodium falciparum infection, respectively. The perceived severity of both types was similar with 44.0% (267/607) perceiving tersiana vs. 45.1% (274/607) perceiving tropika as more severe. There was no perceived differentiation whether malaria episodes were due to a new infection or relapse; and 71.3% (433/607) acknowledged the possibility of recurrence. Participants were familiar with malaria symptoms and delaying health facility visit by 1-2 days was perceived to increase the likelihood of a positive test. Prior to health facility visits, symptoms were treated with leftover drugs kept at home (40.4%; 245/607) or bought over the counter (17.0%; 103/607). Malaria was considered to be cured with 'blue drugs' (referring to dihydroartemisinin-piperaquine). Conversely, 'brown drugs,' referring to PQ, were not considered malaria medication and instead were perceived as supplements. Adherence to malaria treatment was 71.2% (131/184), in the supervised arm, 56.9% (91/160) in the unsupervised arm and 62.4% (164/263) in the control arm; p = 0.019. Adherence was 47.5% (47/99) among highland Papuans, 51.7% (76/147) among lowland Papuans, and 72.9% (263/361) among non-Papuans; p < 0.001.

CONCLUSION

Adherence to malaria treatment was a socio-culturally embedded process during which patients (re-)evaluated the characteristics of the medicines in relation to the course of the illness, their past experiences with illness, and the perceived benefits of the treatment. Structural barriers that hinder the process of patient adherence are crucial to consider in the development and rollout of effective malaria treatment policies.

A Review of the Current Status of G6PD Deficiency Testing to Guide Radical Cure Treatment for Vivax Malaria

Plasmodium vivax malaria continues to cause a significant burden of disease in the Asia-Pacific, the Horn of Africa, and the Americas. In addition to schizontocidal treatment, the 8-aminoquinoline drugs are crucial for the complete removal of the parasite from the human host (radical cure). While well tolerated in most recipients, 8-aminoquinolines can cause severe haemolysis in glucose-6-phosphate dehydrogenase (G6PD) deficient patients. G6PD deficiency is one of the most common enzymopathies worldwide; therefore, the WHO recommends routine testing to guide 8-aminoquinoline based treatment for vivax malaria whenever possible. In practice, this is not yet implemented in most malaria endemic countries. This review provides an update of the characteristics of the most used G6PD diagnostics. We describe the current state of policy and implementation of routine point-of-care G6PD testing in malaria endemic countries and highlight key knowledge gaps that hinder broader implementation. Identified challenges include optimal training of health facility staff on point-of-care diagnostics, quality control of novel G6PD diagnostics, and culturally appropriate information and communication with affected communities around G6PD deficiency and implications for treatment.

Cost-effectiveness of universal iron supplementation and iron-containing micronutrient powders for anemia among young children in rural Bangladesh: analysis of a randomized, placebo-controlled trial

BACKGROUND

Universal provision of iron supplements or iron-containing multiple micronutrient powders (MNPs) is widely used to prevent anemia in young children in low- and middle-income countries. The BRISC (Benefits and Risks of Iron Interventions in Children) trial compared iron supplements and MNPs with placebo in children <2 y old in rural Bangladesh.

OBJECTIVES

We aimed to assess the cost-effectiveness of iron supplements or iron-containing MNPs among young children in rural Bangladesh.

METHODS

We did a cost-effectiveness analysis of MNPs and iron supplements using the BRISC trial outcomes and resource use data, and programmatic data from the literature. Health care costs were assessed from a health system perspective. We calculated incremental cost-effectiveness ratios (ICERs) in terms of US$ per disability-adjusted life-year (DALY) averted. To explore uncertainty, we constructed cost-effectiveness acceptability curves using bootstrapped data over a range of cost-effectiveness thresholds. One- and 2-way sensitivity analyses tested the impact of varying key parameter values on our results.

RESULTS

Provision of MNPs was estimated to avert 0.0031 (95% CI: 0.0022, 0.0041) DALYs/child, whereas iron supplements averted 0.0039 (95% CI: 0.0030, 0.0048) DALYs/child, over 1 y compared with no intervention. Incremental mean costs were $0.75 (95% CI: 0.73, 0.77) for MNPs compared with no intervention and $0.64 ($0.62, $0.67) for iron supplements compared with no intervention. Iron supplementation dominated MNPs because it was cheaper and averted more DALYs. Iron supplementation had an ICER of $1645 ($1333, $2153) per DALY averted compared with no intervention, and had a 0% probability of being the optimal strategy at cost-effectiveness thresholds of $200 (reflecting health opportunity costs in Bangladesh) and $985 [half of gross domestic product (GDP) per capita] per DALY averted. Scenario and sensitivity analyses supported the base case findings.

CONCLUSIONS

These findings do not support universal iron supplementation or micronutrient powders as a cost-effective intervention for young children in rural Bangladesh.This trial was registered at anzctr.org.au as ACTRN1261700066038 and trialsearch.who.int as U1111-1196-1125.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

Surveillance to achieve malaria elimination in eastern Myanmar: a 7-year observational study

Background

The collection and utilization of surveillance data is essential in monitoring progress towards achieving malaria elimination, in the timely response to increases in malaria case numbers and in the assessment of programme functioning. This paper describes the surveillance activities used by the malaria elimination task force (METF) programme which operates in eastern Myanmar, and provides an analysis of data collected from weekly surveillance, case investigations, and monitoring and evaluation of programme performance.

Methods

This retrospective analysis was conducted using data collected from a network of 1250 malaria posts operational between 2014 and 2021. To investigate changes in data completeness, malaria post performance, malaria case numbers, and the demographic details of malaria cases, summary statistics were used to compare data collected over space and time.

Results

In the first 3 years of the METF programme, improvements in data transmission routes resulted in a 18.9% reduction in late reporting, allowing for near real-time analysis of data collected at the malaria posts. In 2020, travel restrictions were in place across Karen State in response to COVID-19, and from February 2021 the military coup in Myanmar resulted in widescale population displacement. However, over that period there has been no decline in malaria post attendance, and the majority of consultations continue to occur within 48 h of fever onset. Case investigations found that 43.8% of cases travelled away from their resident village in the 3 weeks prior to diagnosis and 36.3% reported never using a bed net whilst sleeping in their resident village, which increased to 72.2% when sleeping away from their resident village. Malaria post assessments performed in 82.3% of the METF malaria posts found malaria posts generally performed to a high standard.

Conclusions

Surveillance data collected by the METF programme demonstrate that despite significant changes in the context in which the programme operates, malaria posts have remained accessible and continue to provide early diagnosis and treatment contributing to an 89.3% decrease in Plasmodium falciparum incidence between 2014 and 2021.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12936-022-04175-w.

Health-related quality of life in individuals with genital herpes: a systematic review

Background

There is a significant global burden of herpes simplex virus (HSV) related genital ulcer disease yet little is known about its impact on quality of life. This systematic review aimed to identify studies that quantitatively evaluated the effect of genital herpes on various aspects of health-related quality of life.

Methods

Six databases were searched (MEDLINE, EMBASE, NHS Economic Evaluation Database, Health Technology Assessment, Database of Abstracts of Reviews of Effects, Web of Science Core Collection) for primary quality of life and economic evaluations of genital herpes from January 1, 2000 to January 7, 2021. Qualitative studies or those without primary data were excluded. Two authors independently extracted data from the publications. The study’s registration number with PROSPERO was CRD42021239410.

Findings

We identified 26 relevant publications: 19 presented primary quality of life data, and seven were economic evaluations. The primary studies presented a range of condition-specific tools for describing the quality of life in individuals with genital herpes, but only one study used a direct valuation that could be used to generate utility weights. All economic evaluations of HSV infection were from high-income country settings. Most (6 of 7) focused on neonatal HSV infection with utilities adopted from studies prior to 2000.

Interpretation

The extant literature on genital herpes-related quality of life is limited and requires updating. We recommend future studies be conducted in geographic- and population- diverse settings, and use preference-based condition-specific or generic-instruments to better inform economic modelling.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12955-022-01934-w.

Longitudinal trends in malaria testing rates in the face of elimination in eastern Myanmar: a 7-year observational study

BACKGROUND

Providing at-risk communities with uninterrupted access to early diagnosis and treatment is a key component in reducing malaria transmission and achieving elimination. As programmes approach malaria elimination targets it is critical that each case is tested and treated early, which may present a challenge when the burden of malaria is reduced. In this paper we investigate whether malaria testing rates decline over time and assess the impacts of integrating malaria and non-malaria services on testing rates in the malaria elimination task force (METF) programme in the Kayin state of Myanmar.

METHODS

A retrospective analysis was conducted using weekly collected data on testing rates from a network of more than 1200 malaria posts during the period from 2014 to 2020. To determine whether monthly testing rates changed over the years of programme operations, and whether integrating malaria and non-malaria services impacted these testing rates, we fitted negative binomial mixed-effects regression models to aggregate monthly data, accounting for malaria seasonal variation.

RESULTS

In the first year of malaria post operation, testing rates declined, correlating with a decline in attendance by people from outside the malaria post catchment area, but then remained fairly constant (the Rate Ratio (RR) for 2nd versus 1st year open ranged from 0.68 to 0.84 across the four townships included in the analysis, the RR for 3rd to 6th year versus 1st year open were similar, ranging from 0.59-0.78). The implementation of a training programme, which was intended to expand the role of the malaria post workers, had minimal impact on testing rates up to 24 months after training was delivered (RR for integrated versus malaria-only services ranged from 1.00 to 1.07 across METF townships).

CONCLUSION

Despite the decline in malaria incidence from 2014 to 2020, there has been no decline in the malaria testing rate in the METF programme after the establishment of the complete malaria post network in 2016. While the integration of malaria posts with other health services provides benefits to the population, our evaluation questions the necessity of integrated services in maintaining malaria testing rates in areas approaching elimination of malaria.

320Applying novel multi-disciplinary methodologies to accelerate malaria elimination

Focus and outcomes for participants

Presented by researchers from the Australian Centre of Research Excellence in Malaria Elimination (ACREME, www.acreme.org.au), the focus of the symposium will be the application of multi-disciplinary epidemiological and statistical approaches to inform the control and elimination of malaria in the Asia-Pacific region. The epidemiology of malaria is complex as it involves multiple mosquito vectors, different malarial species (that require species-specific treatments) and emerging insecticide and antimalarial drug resistance. The symposium will provide an overview of the significance of the changing epidemiological landscape of malaria globally, and how modern epidemiological methods, such as stepped-wedge designs, multi-state modelling, within-host mechanistic mathematical models, geospatial methods and cost-effectiveness modelling applied to clinical effectiveness trials, prospective cohort studies, volunteer infection studies and national and regional data have contributed to answering the key challenges in malaria research. Specifically we will discuss evidence for effective interventions to reduce the risk of malaria transmission, the effect of recurrent episodes of malaria on risk of hospitalisation and mortality, the selection of antimalarial drug combination therapies to fast track new drugs, understanding geospatial heterogeneity of malaria transmission, and the cost-effectiveness of scenarios using different treatment regimens. Discussion of the importance of these methodologies and their findings will be contextualised in the current global malaria elimination goals. As similar transformations in epidemiological environment have occurred in other disease elimination settings, we believe this symposium will have broad appeal and that the challenges faced and the methodological solutions proposed to accelerate progress in malaria elimination will have a high degree of relevance and be useful to researchers working in global health or infectious diseases.

Rationale for the symposium, including for its inclusion in the Congress

Following a two-decade period of declining malaria burden due to intensified control efforts, global progress against the disease has stalled, and in some countries, malaria has resurged. Emerging parasite resistance to insecticides and antimalarial drugs has reduced the effectiveness of cornerstone malaria control interventions. Malaria endemic areas of the Greater Mekong Sub region (GMS) have set the target to eliminate malaria by 2030, however, the failure of these established interventions and transition to low-transmission endemic environments has necessitated fundamental re-evaluation of the epidemiological landscape of the disease and emphasised timely development of robust evidence for novel interventions. In order to provide evidence, a wide range of advanced multi-disciplinary methodologies have been developed and applied in many malaria epidemiology areas and we believe discussion of these in the symposium will be highly relevant given the principal theme of the 2020 WCE (Methodological Innovations in Epidemiology). Additionally, the symposium will feature research where findings have been effectively translated to national and regional policy and practice, an important theme of the 2020 WCE.

Presentation program

Names of presenters

Global economic costs due to vivax malaria and the potential impact of its radical cure: A modelling study

BACKGROUND

In 2017, an estimated 14 million cases of Plasmodium vivax malaria were reported from Asia, Central and South America, and the Horn of Africa. The clinical burden of vivax malaria is largely driven by its ability to form dormant liver stages (hypnozoites) that can reactivate to cause recurrent episodes of malaria. Elimination of both the blood and liver stages of the parasites ("radical cure") is required to achieve a sustained clinical response and prevent ongoing transmission of the parasite. Novel treatment options and point-of-care diagnostics are now available to ensure that radical cure can be administered safely and effectively. We quantified the global economic cost of vivax malaria and estimated the potential cost benefit of a policy of radical cure after testing patients for glucose-6-phosphate dehydrogenase (G6PD) deficiency.

METHODS AND FINDINGS

Estimates of the healthcare provider and household costs due to vivax malaria were collated and combined with national case estimates for 44 endemic countries in 2017. These provider and household costs were compared with those that would be incurred under 2 scenarios for radical cure following G6PD screening: (1) complete adherence following daily supervised primaquine therapy and (2) unsupervised treatment with an assumed 40% effectiveness. A probabilistic sensitivity analysis generated credible intervals (CrIs) for the estimates. Globally, the annual cost of vivax malaria was US$359 million (95% CrI: US$222 to 563 million), attributable to 14.2 million cases of vivax malaria in 2017. From a societal perspective, adopting a policy of G6PD deficiency screening and supervision of primaquine to all eligible patients would prevent 6.1 million cases and reduce the global cost of vivax malaria to US$266 million (95% CrI: US$161 to 415 million), although healthcare provider costs would increase by US$39 million. If perfect adherence could be achieved with a single visit, then the global cost would fall further to US$225 million, equivalent to $135 million in cost savings from the baseline global costs. A policy of unsupervised primaquine reduced the cost to US$342 million (95% CrI: US$209 to 532 million) while preventing 2.1 million cases. Limitations of the study include partial availability of country-level cost data and parameter uncertainty for the proportion of patients prescribed primaquine, patient adherence to a full course of primaquine, and effectiveness of primaquine when unsupervised.

CONCLUSIONS

Our modelling study highlights a substantial global economic burden of vivax malaria that could be reduced through investment in safe and effective radical cure achieved by routine screening for G6PD deficiency and supervision of treatment. Novel, low-cost interventions for improving adherence to primaquine to ensure effective radical cure and widespread access to screening for G6PD deficiency will be critical to achieving the timely global elimination of P. vivax.

Costs and cost-effectiveness of cervical cancer screening strategies in women living with HIV in Burkina Faso: The HPV in Africa Research Partnership (HARP) study

Introduction

This study estimated the costs and incremental cost per case detected of screening strategies for high-grade cervical intraepithelial neoplasia (CIN2+) in women living with HIV (WLHIV) attending HIV clinics in Burkina Faso.

Methods

The direct healthcare provider costs of screening tests (visual inspection with acetic acid (VIA), VIA combined visual inspection with Lugol’s iodine (VIA/VILI), cytology and a rapid HPV DNA test (careHPV)) and confirmatory tests (colposcopy, directed biopsy and systematic four-quadrant (4Q) biopsy) were collected alongside the HPV in Africa Research Partnership (HARP) study. A model was developed for a hypothetical cohort of 1000 WLHIV using data on CIN2+ prevalence and the sensitivity of the screening tests. Costs are reported in USD (2019).

Results

The study enrolled 554 WLHIV with median age 36 years (inter-quartile range, 31–41) and CIN2+ prevalence of 5.8%. The average cost per screening test ranged from US$3.2 for VIA to US$24.8 for cytology. Compared to VIA alone, the incremental cost per CIN2+ case detected was US$48 for VIA/VILI and US$814 for careHPV. Despite higher costs, careHPV was more sensitive for CIN2+ cases detected compared to VIA/VILI (97% and 56%, respectively). The cost of colposcopy was US$6.6 per person while directed biopsy was US$33.0 and 4Q biopsy was US$48.0.

Conclusion

Depending on the willingness to pay for the detection of a case of cervical cancer, decision makers in Burkina Faso can consider a variety of cervical cancer screening strategies for WLHIV. While careHPV is more costly, it has the potential to be cost-effective depending on the willingness to pay threshold. Future research should explore the lifetime costs and benefits of cervical cancer screening to enable comparisons with interventions for other diseases.

Tenofovir disoproxil fumarate in pregnancy for prevention of mother to child transmission of hepatitis B in a rural setting on the Thailand-Myanmar border: a cost-effectiveness analysis

BACKGROUND

Hepatitis B Virus (HBV) is transmitted from mother to child which can be prevented via birth dose vaccine combined with three follow up hepatitis B vaccines, hepatitis B immunoglobulins (HBIG), and maternal antiviral treatment with Tenofovir Disoproxil Fumarate (TDF). This study evaluates the cost effectiveness of six strategies to prevent perinatal HBV transmission in a resource limited setting (RLS) on the Thailand-Myanmar border.

METHODS

The cost effectiveness of six strategies was tested by a decision tree model in R. All strategies included birth and follow up vaccinations and compared cost per infection averted against two willingness to pay thresholds: one-half and one gross domestic product (GDP) per capita. Strategies were: 1) Vaccine only, 2) HBIG after rapid diagnostic test (RDT): infants born to HBsAg+ are given HBIG, 3) TDF after RDT: HBsAg+ women are given TDF, 4) TDF after HBeAg test: HBeAg+ women are given TDF, 5) TDF after high HBV DNA: women with HBV DNA > 200,000 are given TDF, 6) HBIG & TDF after high HBV DNA: women with HBV DNA > 200,000 are given TDF and their infants are given HBIG. One-way and probabilistic sensitivity analyses were conducted on the cost-effective strategies.

RESULTS

Vaccine only was the least costly option with TDF after HBeAg test strategy as the only cost-effective alternative. TDF after HBeAg test had an incremental cost-effectiveness ratio of US$1062; which would not be considered cost-effective with the lower threshold of one-half GDP per capita. The one-way sensitivity analysis demonstrated that the results were reasonably robust to changes in single parameter values. The PSA showed that TDF after HBeAg test had an 84% likelihood of being cost effective at a willingness to pay threshold of one GDP per capita per infection averted.

CONCLUSIONS

We found that TDF after HBeAg test has the potential to be cost-effective if TDF proves effective locally to prevent perinatal HBV transmission. The cost of TDF treatment and reliability of the RDT could be barriers to implementing this strategy. While TDF after RDT may be a more feasible strategy to implement in RLS, TDF after HBeAg test is a less costly option.

Efficacy of online nutrition professional development for Early Childhood Education Care staff

Background

Early Childhood Education & Care (ECEC) services are a public health setting that influences the lifelong eating habits and health of young Australians. Over 1.3 million children attend ECEC for 30 hours/week. Overweight/obesity, a risk factor for chronic disease, has been associated with this setting. Research reports sub-optimal food provision, poor role modelling and a lack of nutrition training and confidence. Online nutrition education training was provided to ECEC staff, aiming to increase nutrition knowledge/confidence.

Methods

Training was evidence-based, informed by stakeholders and developed by tertiary nutrition experts. ECEC staff were recruited and randomised to intervention or control groups. The intervention group completed an online short course about whole-service approach to healthy eating of 2-3 hours duration. Nutrition knowledge/confidence were measured pre/post-intervention via a pre-validated, online survey. GLM was used to determine differences within and between groups adjusting for years of experience.

Results

Participants (n = 116) were mostly female, aged &gt;36 years, with &gt;10 years industry experience. Post-course, compared to the control group, intervention participants significantly increased confidence to offer 2 serves of grains/day and unsweetened cereals, a variety of vegetables and low-sodium foods, and solid fats were avoided. Confidence to avoid serving discretionary foods did not change and cakes/biscuits were offered frequently.

Conclusions

Following course completion, intervention participants demonstrated increased confidence to serve foods from core food groups, but both groups reported offering discretionary foods frequently. Some results are promising and may improve the nutritional value of food offered at ECEC, but it appears discretionary foods continue to be overprovided. Further research is required to identify the depth of training required to embed important nutrition education concepts in ECEC settings.

Key messages

Evidence-based nutrition education adopting a whole-service approach is effective in increasing ECEC staff nutrition knowledge and confidence to provide foods from core food groups. Further research is required to establish the level of nutrition education appropriate for ECEC staff to avoid the continuing overprovision of discretionary foods to young children.

Evaluation of the effectiveness of topical repellent distributed by village health volunteer networks against Plasmodium spp. infection in Myanmar: A stepped-wedge cluster randomised trial

BACKGROUND

The World Health Organization has yet to endorse deployment of topical repellents for malaria prevention as part of public health campaigns. We aimed to quantify the effectiveness of repellent distributed by the village health volunteer (VHV) network in the Greater Mekong Subregion (GMS) in reducing malaria in order to advance regional malaria elimination.

METHODS AND FINDINGS

Between April 2015 and June 2016, a 15-month stepped-wedge cluster randomised trial was conducted in 116 villages in Myanmar (stepped monthly in blocks) to test the effectiveness of 12% N,N-diethylbenzamide w/w cream distributed by VHVs, on Plasmodium spp. infection. The median age of participants was 18 years, approximately half were female, and the majority were either village residents (46%) or forest dwellers (40%). No adverse events were reported during the study. Generalised linear mixed modelling estimated the effect of repellent on infection detected by rapid diagnostic test (RDT) (primary outcome) and polymerase chain reaction (PCR) (secondary outcome). Overall Plasmodium infection detected by RDT was low (0.16%; 50/32,194), but infection detected by PCR was higher (3%; 419/13,157). There was no significant protection against RDT-detectable infection (adjusted odds ratio [AOR] = 0.25, 95% CI 0.004-15.2, p = 0.512). In Plasmodium-species-specific analyses, repellent protected against PCR-detectable P. falciparum (adjusted relative risk ratio [ARRR] = 0.67, 95% CI 0.47-0.95, p = 0.026), but not P. vivax infection (ARRR = 1.41, 95% CI 0.80-2.47, p = 0.233). Repellent effects were similar when delayed effects were modelled, across risk groups, and regardless of village-level and temporal heterogeneity in malaria prevalence. The incremental cost-effectiveness ratio was US$256 per PCR-detectable infection averted. Study limitations were a lower than expected Plasmodium spp. infection rate and potential geographic dilution of the intervention.

CONCLUSIONS

In this study, we observed apparent protection against new infections associated with the large-scale distribution of repellent by VHVs. Incorporation of repellent into national strategies, particularly in areas where bed nets are less effective, may contribute to the interruption of malaria transmission. Further studies are warranted across different transmission settings and populations, from the GMS and beyond, to inform WHO public health policy on the deployment of topical repellents for malaria prevention.

TRIAL REGISTRATION

Australian and New Zealand Clinical Trials Registry (ACTRN12616001434482).

Cost-Effectiveness Analysis of Sex-Stratified Plasmodium vivax Treatment Strategies Using Available G6PD Diagnostics to Accelerate Access to Radical Cure

Tafenoquine has been licensed for the single-dose radical cure of Plasmodium vivax in adults; however, it is only recommended in patients with > 70% of normal glucose-6-phosphate dehydrogenase (G6PD) activity. Because this may hinder widespread use, we investigated sex-based treatment strategies in which all adult patients are tested with a qualitative G6PD rapid diagnostic test (RDT). Glucose-6-phosphate dehydrogenase normal males are prescribed tafenoquine in all three strategies, whereas G6PD normal females are prescribed either a low-dose 14-day primaquine regimen (PQ14, total dose 3.5 mg/kg) or a high-dose 7-day primaquine regimen (PQ7, total dose 7 mg/kg), or referred to a healthcare facility for quantitative G6PD testing before prescribing tafenoquine. Patients testing G6PD deficient are prescribed a weekly course of primaquine for 8 weeks. We compared the cost-effectiveness of these three strategies to usual care in four countries using a decision tree model. Usual care in Ethiopia does not include radical cure, whereas Afghanistan, Indonesia, and Vietnam prescribe PQ14 without G6PD screening. The cost per disability-adjusted life-year (DALY) averted was expressed through incremental cost-effectiveness ratios (ICERs). Compared with usual care, the ICERs for a sex-based treatment strategy with PQ7 for females from a healthcare provider perspective were $127 per DALY averted in Vietnam, $466 in Ethiopia, $1,089 in Afghanistan, and $4,443 in Indonesia. The PQ14 and referral options cost more while averting fewer DALYs than PQ7. This study provides an alternative cost-effective mode of rolling out tafenoquine in areas where initial testing with only a G6PD RDT is feasible.

Barriers and enablers in the implementation of a standardised process for nutrition care: findings from a multinational survey of dietetic professionals in 10 countries

BACKGROUND

To explore the barriers and enablers experienced by nutrition and dietetic professionals in the implementation of the standardised Nutrition Care Process (NCP) across 10 different countries. NCP related beliefs, motivations and values were investigated and compared.

METHODS

A validated online survey was disseminated to nutrition and dietetics professionals in 10 countries in the local language during 2017. Cross-sectional associations and differences between countries were explored for level of implementation, barriers/enablers and attitudes/motivation among the respondents.

RESULTS

Higher NCP implementation was associated with greater occurrence of enabling aspects, as well as fewer occurrences of barriers. The most common enabler was 'recommendation by the national dietetic association' (69%) and the most common barrier was 'lack of time' (39%). A longer experience of NCP use was associated with a more positive attitude towards all NCP aspects. Differences between countries were identified, regarding both the occurrence of barriers/enablers and attitudes/motivations.

CONCLUSIONS

Implementation efforts need to be tailored to country-specific contexts when implementing a new standard of care framework among nutrition and dietetic professionals. Additional research is needed to further assess the management and workplace strategies to support the development of nutrition and dietetics professionals in multidisciplinary healthcare organisations.

Provider and household costs of Plasmodium vivax malaria episodes: a multicountry comparative analysis of primary trial data

OBJECTIVE

To determine household and health-care provider costs associated with Plasmodium vivax infection across a range of endemic settings.

METHODS

We collected cost data alongside three multicentre clinical trials of P. vivax treatment in Afghanistan, Brazil, Colombia, Ethiopia, Indonesia, Philippines, Peru, Thailand and Viet Nam conducted between April 2014 to December 2017. We derived household costs from trial participant surveys administered at enrolment and again 2 weeks later to determine the costs of treatment and transportation, and the number of days that patients and their household caregivers were unable to undertake their usual activities. We determined costs of routine care by health-care providers by micro-costing the resources used to diagnose and treat P. vivax at the study sites.

FINDINGS

The mean total household costs ranged from 8.7 United States dollars (US$; standard deviation, SD: 4.3) in Afghanistan to US$ 254.7 (SD: 148.4) in Colombia. Across all countries, productivity losses were the largest household cost component, resulting in mean indirect costs ranging from US$ 5.3 (SD: 3.0) to US$ 220.8 (SD: 158.40). The range of health-care provider costs for routine care was US$ 3.6-6.6. The cost of administering a glucose-6-phosphate-dehydrogenase rapid diagnostic test, ranged from US$ 0.9 to 13.5, consistently lower than the costs of the widely-used fluorescent spot test (US$ 6.3 to 17.4).

CONCLUSION

An episode of P. vivax malaria results in high costs to households. The costs of diagnosing and treating P. vivax are important inputs for future cost-effectiveness analyses to ensure optimal allocation of resources for malaria elimination.

Short-course primaquine for the radical cure of Plasmodium vivax malaria: a multicentre, randomised, placebo-controlled non-inferiority trial

BACKGROUND

Primaquine is the only widely used drug that prevents Plasmodium vivax malaria relapses, but adherence to the standard 14-day regimen is poor. We aimed to assess the efficacy of a shorter course (7 days) of primaquine for radical cure of vivax malaria.

METHODS

We did a randomised, double-blind, placebo-controlled, non-inferiority trial in eight health-care clinics (two each in Afghanistan, Ethiopia, Indonesia, and Vietnam). Patients (aged ≥6 months) with normal glucose-6-phosphate dehydrogenase (G6PD) and presenting with uncomplicated vivax malaria were enrolled. Patients were given standard blood schizontocidal treatment and randomly assigned (2:2:1) to receive 7 days of supervised primaquine (1·0 mg/kg per day), 14 days of supervised primaquine (0·5 mg/kg per day), or placebo. The primary endpoint was the incidence rate of symptomatic P vivax parasitaemia during the 12-month follow-up period, assessed in the intention-to-treat population. A margin of 0·07 recurrences per person-year was used to establish non-inferiority of the 7-day regimen compared with the 14-day regimen. This trial is registered at ClinicalTrials.gov (NCT01814683).

FINDINGS

Between July 20, 2014, and Nov 25, 2017, 2336 patients were enrolled. The incidence rate of symptomatic recurrent P vivax malaria was 0·18 (95% CI 0·15 to 0·21) recurrences per person-year for 935 patients in the 7-day primaquine group and 0·16 (0·13 to 0·18) for 937 patients in the 14-day primaquine group, a difference of 0·02 (-0·02 to 0·05, p=0·3405). The incidence rate for 464 patients in the placebo group was 0·96 (95% CI 0·83 to 1·08) recurrences per person-year. Potentially drug-related serious adverse events within 42 days of starting treatment were reported in nine (1·0%) of 935 patients in the 7-day group, one (0·1%) of 937 in the 14-day group and none of 464 in the control arm. Four of the serious adverse events were significant haemolysis (three in the 7-day group and one in the 14-day group).

INTERPRETATION

In patients with normal G6PD, 7-day primaquine was well tolerated and non-inferior to 14-day primaquine. The short-course regimen might improve adherence and therefore the effectiveness of primaquine for radical cure of P vivax malaria.

FUNDING

UK Department for International Development, UK Medical Research Council, UK National Institute for Health Research, and the Wellcome Trust through the Joint Global Health Trials Scheme (MR/K007424/1) and the Bill & Melinda Gates Foundation (OPP1054404).

Economic Burden Attributed to Children Presenting to Hospitals With Hand, Foot, and Mouth Disease in Vietnam

Background

Hand, foot, and mouth disease (HFMD) has become a major public health concern in the Asia-Pacific region. Knowledge of its economic burden is essential for policy makers in prioritizing the development and implementation of interventions.

Methods

A multi-hospital-based study was prospectively conducted at 3 major hospitals in Ho Chi Minh City, Vietnam, during 2016–2017. Data on direct and productivity costs were collected alongside clinical information and samples and demographic information from study participants.

Results

A total of 466 patients were enrolled. Two hundred three of 466 (43.6%) patients lived in Ho Chi Minh City, and 72/466 (15.5%) had severe HFMD. An enterovirus was identified in 74% of 466 patients, with EV-A71, CV-A6, CV-A10, and CV-A16 being the most common viruses identified (236/466, 50.6%). The mean economic burden per case was estimated at US$400.80 (95% confidence interval [CI], $353.80–$448.90), of which the total direct (medical) costs accounted for 69.7%. There were considerable differences in direct medical costs between groups of patients with different clinical severities and pathogens (ie, EV-A71 vs non-EV-A71). In Vietnam, during 2016–2017, the economic burden posed by HFMD was US$90 761 749 (95% CI, $79 033 973–$103 009 756).

Conclusions

Our findings are of public health significance because for the first time we demonstrate that HFMD causes a substantial economic burden in Vietnam, and although multivalent vaccines are required to control HFMD, effective EV-A71 vaccine could substantially reduce the burden posed by severe HFMD. The results will be helpful for health policy makers in prioritizing resources for the development and implementation of intervention strategies to reduce the burden of HFMD.

Cost-effectiveness of a domestic violence and abuse training and support programme in primary care in the real world: updated modelling based on an MRC phase IV observational pragmatic implementation study

OBJECTIVES

To evaluate the cost-effectiveness of the implementation of the Identification and Referral to Improve Safety (IRIS) programme using up-to-date real-world information on costs and effectiveness from routine clinical practice. A Markov model was constructed to estimate mean costs and quality-adjusted life-years (QALYs) of IRIS versus usual care per woman registered at a general practice from a societal and health service perspective with a 10-year time horizon.

DESIGN AND SETTING

Cost-utility analysis in UK general practices, including data from six sites which have been running IRIS for at least 2 years across England.

PARTICIPANTS

Based on the Markov model, which uses health states to represent possible outcomes of the intervention, we stipulated a hypothetical cohort of 10 000 women aged 16 years or older.

INTERVENTIONS

The IRIS trial was a randomised controlled trial that tested the effectiveness of a primary care training and support intervention to improve the response to women experiencing domestic violence and abuse, and found it to be cost-effective. As a result, the IRIS programme has been implemented across the UK, generating data on costs and effectiveness outside a trial context.

RESULTS

The IRIS programme saved £14 per woman aged 16 years or older registered in general practice (95% uncertainty interval -£151 to £37) and produced QALY gains of 0.001 per woman (95% uncertainty interval -0.005 to 0.006). The incremental net monetary benefit was positive both from a societal and National Health Service perspective (£42 and £22, respectively) and the IRIS programme was cost-effective in 61% of simulations using real-life data when the cost-effectiveness threshold was £20 000 per QALY gained as advised by National Institute for Health and Care Excellence.

CONCLUSION

The IRIS programme is likely to be cost-effective and cost-saving from a societal perspective in the UK and cost-effective from a health service perspective, although there is considerable uncertainty surrounding these results, reflected in the large uncertainty intervals.

Quantifying primaquine effectiveness and improving adherence: a round table discussion of the APMEN Vivax Working Group

The goal to eliminate malaria from the Asia-Pacific by 2030 will require the safe and widespread delivery of effective radical cure of malaria. In October 2017, the Asia Pacific Malaria Elimination Network Vivax Working Group met to discuss the impediments to primaquine (PQ) radical cure, how these can be overcome and the methodological difficulties in assessing clinical effectiveness of radical cure. The salient discussions of this meeting which involved 110 representatives from 18 partner countries and 21 institutional partner organizations are reported. Context specific strategies to improve adherence are needed to increase understanding and awareness of PQ within affected communities; these must include education and health promotion programs. Lessons learned from other disease programs highlight that a package of approaches has the greatest potential to change patient and prescriber habits, however optimizing the components of this approach and quantifying their effectiveness is challenging. In a trial setting, the reactivity of participants results in patients altering their behaviour and creates inherent bias. Although bias can be reduced by integrating data collection into the routine health care and surveillance systems, this comes at a cost of decreasing the detection of clinical outcomes. Measuring adherence and the factors that relate to it, also requires an in-depth understanding of the context and the underlying sociocultural logic that supports it. Reaching the elimination goal will require innovative approaches to improve radical cure for vivax malaria, as well as the methods to evaluate its effectiveness.

Treatment-Seeking Behavior after the Implementation of a Unified Policy of Dihydroartemisinin-Piperaquine for the Treatment of Uncomplicated Malaria in Papua, Indonesia

Artemisinin combination therapy is recommended for the treatment of multidrug resistant Plasmodium falciparum and Plasmodium vivax. In March 2006, antimalarial policy in Indonesia was changed to a unified treatment with dihydroartemisinin-piperaquine for all species of malaria because of the low efficacy of previous drug treatments. In 2013, a randomized cross-sectional household survey in Papua was used to collect data on demographics, parasite positivity, treatment-seeking behavior, diagnosis and treatment of malaria, and household costs. Results were compared with a similar survey undertaken in 2005. A total of 800 households with 4,010 individuals were included in the 2013 survey. The prevalence of malaria parasitemia was 12% (348/2,795). Of the individuals who sought treatment of fever, 67% (66/98) reported attending a public provider at least once compared with 46% (349/764) before policy change (P < 0.001). During the 100 visits to healthcare providers, 95% (95) included a blood test for malaria and 74% (64/86) resulted in the recommended antimalarial for the diagnosed species, the corresponding figures before policy change were 48% (433/894) and 23% (78/336). The proportion of individuals seeking treatment more than once fell from 14% (107/764) before policy change to 2% (2/98) after policy change (P = 0.005). The mean indirect cost per fever episode requiring treatment seeking decreased from US$44.2 in 2005 to US$33.8 in 2013 (P = 0.006). The implementation of a highly effective antimalarial treatment was associated with better adherence of healthcare providers in both the public and private sectors and a reduction in clinical malaria and household costs.

Strategies for the prevention of perinatal hepatitis B transmission in a marginalized population on the Thailand-Myanmar border: a cost-effectiveness analysis

Background

Data on the cost effectiveness of hepatitis B virus (HBV) screening and vaccination strategies for prevention of vertical transmission of HBV in resource limited settings is sparse.

Methods

A decision tree model of HBV prevention strategies utilised data from a cohort of 7071 pregnant women on the Thailand-Myanmar border using a provider perspective. All options included universal HBV vaccination for newborns in three strategies: (1) universal vaccination alone; (2) universal vaccination with screening of women during antenatal visits with rapid diagnostic test (RDT) plus HBV immune globulin (HBIG) administration to newborns of HBV surface antigen positive women; and (3) universal vaccination with screening of women during antenatal visits plus HBIG administration to newborns of women testing HBV e antigen positive by confirmatory test. At the time of the study, the HBIG after confirmatory test strategy was used. The costs in United States Dollars (US$), infections averted and incremental cost effectiveness ratios (ICERs) were calculated and sensitivity analyses were conducted. A willingness to pay threshold of US$1200 was used.

Results

The universal HBV vaccination was the least costly option at US$4.33 per woman attending the clinic. The HBIG after (RDT) strategy had an ICER of US$716.78 per infection averted. The HBIG after confirmatory test strategy was not cost-effective due to extended dominance. The one-way sensitivity analysis showed that while the transmission parameters and cost of HBIG had the biggest impact on outcomes, the HBIG after confirmatory test only became a cost-effective option when a low test cost was used or a high HBIG cost was used. The probabilistic sensitivity analysis showed that HBIG after RDT had an 87% likelihood of being cost-effective as compared to vaccination only at a willingness to pay threshold of US$1200.

Conclusions

HBIG following confirmatory test is not a cost-effective strategy for preventing vertical transmission of HBV in the Thailand-Myanmar border population. By switching to HBIG following rapid diagnostic test, perinatal infections will be reduced by nearly one third. This strategy may be applicable to similar settings for marginalized populations where the confirmatory test is not logistically possible.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-017-2660-x) contains supplementary material, which is available to authorized users.

Geographic Resource Allocation Based on Cost Effectiveness: An Application to Malaria Policy

Healthcare services are often provided to a country as a whole, though in many cases the available resources can be more effectively targeted to specific geographically defined populations. In the case of malaria, risk is highly geographically heterogeneous, and many interventions, such as insecticide-treated bed nets and malaria community health workers, can be targeted to populations in a way that maximises impact for the resources available. This paper describes a framework for geographically targeted budget allocation based on the principles of cost-effectiveness analysis and applied to priority setting in malaria control and elimination. The approach can be used with any underlying model able to estimate intervention costs and effects given relevant local data. Efficient geographic targeting of core malaria interventions could significantly increase the impact of the resources available, accelerating progress towards elimination. These methods may also be applicable to priority setting in other disease areas.

Using G6PD tests to enable the safe treatment of Plasmodium vivax infections with primaquine on the Thailand-Myanmar border: A cost-effectiveness analysis

BACKGROUND

Primaquine is the only licensed antimalarial for the radical cure of Plasmodium vivax infections. Many countries, however, do not administer primaquine due to fear of hemolysis in those with glucose-6-phosphate dehydrogenase (G6PD) deficiency. In other settings, primaquine is given without G6PD testing, putting patients at risk of hemolysis. New rapid diagnostic tests (RDTs) offer the opportunity to screen for G6PD deficiency prior to treatment with primaquine. Here we assessed the cost-effectiveness of using G6PD RDTs on the Thailand-Myanmar border and provide the model as an online tool for use in other settings.

METHODS/PRINCIPAL FINDINGS

Decision tree models for the management of P. vivax malaria evaluated the costs and disability-adjusted life-years (DALYs) associated with recurrences and primaquine-induced hemolysis from a health care provider perspective. Screening with G6PD RDTs before primaquine use was compared to (1) giving chloroquine alone and (2) giving primaquine without screening. Data were taken from a recent study on the impact of primaquine on P. vivax recurrences and a literature review. Compared to the use of chloroquine alone, the screening strategy had similar costs while averting 0.026 and 0.024 DALYs per primary infection in males and females respectively. Compared to primaquine administered without screening, the screening strategy provided modest cost savings while averting 0.011 and 0.004 DALYs in males and females respectively. The probabilistic sensitivity analyses resulted in a greater than 75% certainty that the screening strategy was cost-effective at a willingness to pay threshold of US$500, which is well below the common benchmark of per capita gross domestic product for Myanmar.

CONCLUSIONS/SIGNIFICANCE

In this setting G6PD RDTs could avert DALYs by reducing recurrences and reducing hemolytic risk in G6PD deficient patients at low costs or cost savings. The model results are limited by the paucity of data available in the literature for some parameter values, including the mortality rates for both primaquine-induced hemolysis and P. vivax. The online model provides an opportunity to use different parameter estimates to examine the validity of these findings in other settings.

Treatment-seeking behaviour and associated costs for malaria in Papua, Indonesia

BACKGROUND

Malaria remains a significant public health issue in Eastern Indonesia, where multidrug resistant Plasmodium falciparum and Plasmodium vivax are highly prevalent. The objective of this study was to describe treatment-seeking behaviour and household costs prior to a change to a unified treatment policy of dihydroartemisinin-piperaquine in Mimika district, Papua province in 2006.

METHODS

In 2005 a randomized cross-sectional household survey was conducted to collect data on demographics, socio-economic status (SES), treatment-seeking, case management, and household costs. Information on the cost of illness was also collected from patients exiting health facilities, in order to compare the cost of episodes diagnosed as P. vivax compared with those diagnosed as P. falciparum.

RESULTS

825 households were included in the survey. Of the 764 individuals who sought treatment for fever outside the home in the last month, 46% (349/764) went to a public health facility. Of the 894 reported visits to healthcare providers, 48% (433) resulted in a blood test, of which 78% (337) were reportedly positive. Only 10% (17/177) of individuals who reported testing positive for P. falciparum or mixed infection received the first-line treatment of chloroquine with SP, and 38% (61/159) of those with a diagnosis of P. vivax reportedly received the first-line treatment of chloroquine and primaquine. Overall, public facilities were more likely to prescribe the correct prevailing first-line drug combinations than private providers (OR = 3.77 [95% CI 2.31-6.14], p < 0.001). The mean cost to the household of an episode of P. vivax was similar to the cost of P. falciparum [US$44.50 (SD: 46.23) vs US$48.58 (SD: 64.65)].

CONCLUSIONS

Private providers were a popular source of treatment for malaria, but adherence to the national guidelines was low and the economic burden of malaria for both P. falciparum and P. vivax infections was substantial. Engagement with the private sector is needed to ensure that patients have access to affordable good quality, effective diagnostics and anti-malarials for both P. falciparum and P. vivax.

Dynamic Transmission Economic Evaluation of Infectious Disease Interventions in Low- and Middle-Income Countries: A Systematic Literature Review

Economic evaluation using dynamic transmission models is important for capturing the indirect effects of infectious disease interventions. We examine the use of these methods in low- and middle-income countries, where infectious diseases constitute a major burden. This review is comprised of two parts: (1) a summary of dynamic transmission economic evaluations across all disease areas published between 2011 and mid-2014 and (2) an in-depth review of mosquito-borne disease studies focusing on health economic methods and reporting. Studies were identified through a systematic search of the MEDLINE database and supplemented by reference list screening. Fifty-seven studies were eligible for inclusion in the all-disease review. The most common subject disease was HIV/AIDS, followed by malaria. A diverse range of modelling methods, outcome metrics and sensitivity analyses were used, indicating little standardisation. Seventeen studies were included in the mosquito-borne disease review. With notable exceptions, most studies did not employ economic evaluation methods beyond calculating a cost-effectiveness ratio or net benefit. Many did not adhere to health care economic evaluations reporting guidelines, particularly with respect to full model reporting and uncertainty analysis. We present a summary of the state-of-the-art and offer recommendations for improved implementation and reporting of health economic methods in this crossover discipline.

Tailored Nutrition Education in the Elderly Can Lead to Sustained Dietary Behaviour Change

OBJECTIVES

Evaluate a 4-week dementia specific nutrition education intervention to determine long term knowledge and healthy dietary behaviour changes in 72 elderly men and women.

DESIGN

A mixed method design used qualitative findings to triangulate quantitative within-subject changes to determine efficacy and sustained dietary behaviour change.

SETTING

Community.

PARTICIPANTS

72 independently-living individuals.

INTERVENTION

4-week dementia specific nutrition education intervention.

MEASUREMENTS

Change in participant attitude, confidence, dietary patterns, cooking behaviour, and knowledge were analysed within-subjects using non-parametric repeated-measures procedures. Significance level was set at 5% (α = 0.05). Effect size (ES) was reported and identified as small (S), medium (M) or large (L) if a significant change was observed.

RESULTS

Compared to before the nutrition education intervention participants had an increase in total knowledge (p < 0.001, ES = 0.972 (L)), consumed a greater variety of vegetables (p = 0.007, ES = 0.35 (M)), used less salt (p = 0.006, ES = -0.42 (M-L)) and increased spice use (p < 0.001, ES = 0.40 (M-L)). Participants overcame barriers to enable sustained change, held a positive view on healthy living and believed government should invest in this sector of the community. Sharing and socialisation emerged as important themes that increased program satisfaction.

CONCLUSION

The dementia specific nutrition program produced a large effect in knowledge improvement from pre to post, which was retained at follow up, consolidated observational and participatory learning which produced a moderate increase in healthy dietary behaviours which participants valued and sustained.

Effects of Pre-Natal Vitamin D Supplementation with Partial Correction of Vitamin D Deficiency on Early Life Healthcare Utilisation: A Randomised Controlled Trial

Background

Some observational studies have suggested that higher prenatal Vitamin D intake may be associated with improved health outcomes in childhood. However there have been mixed results in this area with some negative studies, especially for effects on atopic and respiratory outcomes. We examined the effect of prenatal Vitamin D on healthcare utilisation in the first three years of life.

Methods

In an ethnically stratified randomised controlled trial conducted at St Mary’s Hospital London, 180 women at 27 weeks gestation were allocated to no Vitamin D, 800 IU ergocalciferol daily until delivery, or a single oral bolus of 200,000 IU cholecalciferol. Participants were randomised in blocks of 15 using computer-generated numbers and investigators were blinded to group assignment. Supplementation increased maternal and cord blood 25(OH) vitamin D concentrations, but levels remained lower than current recommendations. Primary health economic outcome was overall cost of unscheduled healthcare utilisation in the first three years of life as documented in the child’s electronic health record. Secondary outcomes included cost attributable to: primary and secondary healthcare visits, respiratory and atopic complaints, cost in years 1, 2 and 3 of life and cost and frequency of prescribed medication. All costs were calculated as pounds sterling. Differences between groups were analysed using unpaired t-test or Mann-Whitney U test, and analysis of variance for adjusted analyses.

Results

We assessed 99/180 (55%) complete electronic health records, control (n = 31), daily (n = 36) and bolus (n = 32). We found no difference in total healthcare utilisation costs between the control and daily (mean difference in costs in pounds sterling 1.02, 95%CI -1.60, 1.65; adjusted 1.07, 95%CI -1.62, 1.86) or control and bolus groups (mean difference -1.58, 95%CI -2.63, 1.06; adjusted –1.40, 95%CI -2.45, 1.24). There were no adverse effects of supplementation reported during the trial.

Conclusions

We found no evidence that prenatal vitamin D supplementation from 27 weeks gestation to delivery, at doses which failed to completely correct maternal vitamin D deficiency, influence overall healthcare utilisation in children in the first 3 years.

Trial Registration

Controlled-Trials.com ISRCTN68645785

The challenges of introducing routine G6PD testing into radical cure: a workshop report

The only currently available drug that effectively removes malaria hypnozoites from the human host is primaquine. The use of 8-aminoquinolines is hampered by haemolytic side effects in glucose-6-phosphate dehydrogenase (G6PD) deficient individuals. Recently a number of qualitative and a quantitative rapid diagnostic test (RDT) format have been developed that provide an alternative to the current standard G6PD activity assays. The WHO has recently recommended routine testing of G6PD status prior to primaquine radical cure whenever possible. A workshop was held in the Philippines in early 2015 to discuss key challenges and knowledge gaps that hinder the introduction of routine G6PD testing. Two point-of-care (PoC) test formats for the measurement of G6PD activity are currently available: qualitative tests comparable to malaria RDT as well as biosensors that provide a quantitative reading. Qualitative G6PD PoC tests provide a binomial test result, are easy to use and some products are comparable in price to the widely used fluorescent spot test. Qualitative test results can accurately classify hemizygous males, heterozygous females, but may misclassify females with intermediate G6PD activity. Biosensors provide a more complex quantitative readout and are better suited to identify heterozygous females. While associated with higher costs per sample tested biosensors have the potential for broader use in other scenarios where knowledge of G6PD activity is relevant as well. The introduction of routine G6PD testing is associated with additional costs on top of routine treatment that will vary by setting and will need to be assessed prior to test introduction. Reliable G6PD PoC tests have the potential to play an essential role in future malaria elimination programmes, however require an improved understanding on how to best integrate routine G6PD testing into different health settings.

Consumption of a whey protein-enriched diet may prevent hepatic steatosis associated with weight gain in elderly women

BACKGROUND AND AIMS

Protein consumption has been associated with cardio-metabolic benefits, including weight loss and improved insulin sensitivity, and may have potential benefits for individuals with fatty liver disease (FLD). We investigated the effect of increasing dietary protein intake from whey relative to carbohydrate on hepatic steatosis.

METHODS AND RESULTS

A two-year randomized, double-blind, placebo-controlled trial of 30 g/day whey protein-supplemented beverage (protein) or an energy-matched low-protein high-carbohydrate beverage (control) for cardio-metabolic and bone health in 219 healthy elderly women, recruited from the Western Australian general population. Hepatic steatosis was quantified using computed tomographic liver-to-spleen (L/S) ratio. FLD was defined as liver-to-spleen difference <10 Hounsfield units. At baseline, FLD prevalence was 11.4%. Control and protein groups were similar in body mass index (BMI), insulin resistance, L/S ratio and FLD prevalence at baseline. At two-years, dietary protein increased by 20 g in the protein, but not the control, group. Total energy intake and physical activity remained similar between groups. At two-years, BMI and FLD prevalence increased in both groups, with no between group differences. L/S ratio increased in control, but not protein, group at two-years, with no between group differences. In a within group comparison, change in BMI correlated with changes in L/S ratio in control (r = 0.37, P = 0.0007), but not with protein group (r = 0.04, P = 0.73).

CONCLUSION

Increasing dietary protein intake from whey relative to carbohydrate does not reduce weight, hepatic steatosis or the prevalence of FLD in elderly women. However, it may prevent worsening of hepatic steatosis associated with weight gain.

CLINICAL TRIALS REGISTRATION

Australian New Zealand Clinical Trials Registry (Registration no. ACTRN012607000163404).

Dairy product consumption, dietary nutrient and energy density and associations with obesity in Australian adolescents

BACKGROUND

Dairy intake is likely to influence dietary energy density (ED) and nutrient density (ND), which are factors representing aspects of dietary quality. Although evidence suggests dairy intake is unlikely to contribute to obesity, intake tends to decrease over adolescence, potentially as a result of concerns around weight gain. We examined associations between dairy intake, ED and ND, and investigated relationships with obesity in adolescents.

METHODS

The present study comprised a cross-sectional study of 1613 14-year-olds in the Western Australian Pregnancy Cohort (Raine) Study. Adolescents completed a 212-item food frequency questionnaire. Nutrient Rich Food index 9.3 (NRF9.3) was used to estimate ND. Age-specific body mass index (BMI) and waist-height cut-offs were used to categorise obesity risk.

RESULTS

Mean (SD) dairy intake was: 2.62 (1.51) servings daily; ED was 4.53 (0.83) (food and beverage) and 6.28 (1.33) (food only); ND was 373 (109). Dairy intake was inversely associated with ED and positively associated with ND. The odds of being overweight (as assessed by BMI) increased by 1.24 (95% confidence interval = 1.09-1.42) with each 100-point increase in ND, after adjustment for potential confounders and energy intake. ED measures and dairy intake were inversely associated with obesity after adjustment for confounders; associations became nonsignificant after energy adjustment.

CONCLUSIONS

The NRF9.3 was originally designed to assess foods, not diets. Further research in other cohorts to determine whether similar findings exist, or investigations into alternate measures of dietary ND, may prove useful. Our findings may be the result of factors such as an excess consumption of refined but fortified foods. Although higher dairy intakes were associated with higher ND, intakes were not associated with higher obesity risk.

The agreement between proxy and self-completed EQ-5D for care home residents was better for index scores than individual domains

Objective

Proxy measures are an alternative source of data for care home residents who are unable to complete the health utility measure, but the agreement levels between residents and care home staff for the EQ-5D have not been investigated previously. The objective of the present study was to examine the inter-rater agreement levels for the reporting of EQ-5D by care home residents and staff, adjusting for the impact of clustering.

Study Design and Setting

The data consist of EQ-5D scores for 565 pairs of care home residents and proxies and quality-adjusted life-years (QALYs) for 248 pairs. Cluster-adjusted agreement was compared for the domains, index scores, and QALYs from the EQ-5D. Factors influencing index score agreement are also described.

Results

The results show poor to fair agreement at the domain level (cluster-adjusted Kappa −0.03 to 0.26) and moderate agreement at the score level (cluster-adjusted intra-class correlation coefficient [ICC] 0.44–0.50) and for QALYs (cluster-adjusted ICC 0.59). A higher likelihood of depression and lower cognitive impairment were both associated with smaller discrepancy between proxy and self-completed scores.

Conclusion

Proxies appear to be an acceptable source of data for index scores and QALYs but may be less reliable if individual domains are considered.

Exercise for depression in care home residents: a randomised controlled trial with cost-effectiveness analysis (OPERA)

BACKGROUND

Many older people living in care homes (long term residential care or nursing homes) are depressed. Exercise is a promising non-drug intervention for preventing and treating depression in this population.

OBJECTIVE

To evaluate the impact of a 'whole-home' intervention, consisting of training for residential and nursing home staff backed up with a twice-weekly, physiotherapist-led exercise class on depressive symptoms in care home residents.

DESIGN

A cluster randomised controlled trial with a cost-effectiveness analysis to compare (1) the prevalence of depression in intervention homes with that in control homes in all residents contributing data 12 months after homes were randomised (cross-sectional analysis); (2) the number of depressive symptoms at 6 months between intervention and control homes in residents who were depressed at pre-randomisation baseline assessment (depressed cohort comparison); and (3) the number of depressive symptoms at 12 months between intervention and control homes in all residents who were present at pre-randomisation baseline assessment (cohort comparison).

SETTING

Seventy-eight care homes in Coventry and Warwickshire and north-east London.

PARTICIPANTS

Care home residents aged ≥ 65 years.

INTERVENTIONS

Control intervention: Depression awareness training programme for care home staff. Active intervention: A 'whole-home' exercise intervention, consisting of training for care home staff backed up with a twice-weekly, physiotherapist-led exercise group.

MAIN OUTCOME MEASURES

Geriatric Depression Scale-15, proxy European Quality of Life-5 Dimensions (EQ-5D), cost-effectiveness from an National Health Service perspective, peripheral fractures and death.

RESULTS

We recruited a total of 1054 participants. Cross-sectional analysis: We obtained 595 Geriatric Depression Scale-15 scores and 724 proxy EQ-5D scores. For the cohort analyses we obtained 765 baseline Geriatric Depression Scale-15 scores and 776 proxy EQ-5D scores. Of the 781 who we assessed prior to randomisation, 765 provided a Geriatric Depression Scale-15 score. Of these 374 (49%) were depressed and constitute our depressed cohort. Resource-use and quality-adjusted life-year data, based on proxy EQ-5D, were available for 798 residents recruited prior to randomisation. We delivered 3191 group exercise sessions with 31,705 person attendances and an average group size of 10 (5.3 study participants and 4.6 non-study participants). On average, our participants attended around half of the possible sessions. No serious adverse events occurred during the group exercise sessions. In the cross-sectional analysis the odds for being depressed were 0.76 [95% confidence interval (CI) 0.53 to 1.09] lower in the intervention group at 12 months. The point estimates for benefit for both the cohort analysis (0.13, 95% CI -0.33 to 0.60) and depressed cohort (0.22, 95% CI -0.52 to 0.95) favoured the control intervention. There was no evidence of differences in fracture rates or mortality (odds ratio 1.07, 95% CI 0.79 to 1.48) between the two groups. There was no evidence of differences in the other outcomes between the two groups. Economic analysis: The additional National Health Service cost of the OPERA intervention was £374 per participant (95% CI -£655 to £1404); the mean difference in quality-adjusted life-year was -0.0014 (95% CI -0.0728 to 0.0699). The active intervention was thus dominated by the control intervention, which was more effective and less costly.

CONCLUSION

The results do not support the use of a whole-home physical activity and moderate-intensity exercise programme to reduce depression in care home residents.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN43769277.

FUNDING

This project was funded by the National Institute for Health Research Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 17, No. 18. See the Health Technology Assessment programme website for further project information.

Exercise for depression in elderly residents of care homes: a cluster-randomised controlled trial

BACKGROUND

Depression is common and is associated with poor outcomes among elderly care-home residents. Exercise is a promising low-risk intervention for depression in this population. We tested the hypothesis that a moderate intensity exercise programme would reduce the burden of depressive symptoms in residents of care homes.

METHODS

We did a cluster-randomised controlled trial in care homes in two regions in England; northeast London, and Coventry and Warwickshire. Residents aged 65 years or older were eligible for inclusion. A statistician independent of the study randomised each home (1 to 1·5 ratio, stratified by location, minimised by type of home provider [local authority, voluntary, private and care home, private and nursing home] and size of home [<32 or ≥32 residents]) into intervention and control groups. The intervention package included depression awareness training for care-home staff, 45 min physiotherapist-led group exercise sessions for residents (delivered twice weekly), and a whole home component designed to encourage more physical activity in daily life. The control consisted of only the depression awareness training. Researchers collecting follow-up data from individual participants and the participants themselves were inevitably aware of home randomisation because of the physiotherapists' activities within the home. A researcher masked to study allocation coded NHS routine data. The primary outcome was number of depressive symptoms on the geriatric depression scale-15 (GDS-15). Follow-up was for 12 months. This trial is registered with ISRCTN Register, number ISRCTN43769277.

FINDINGS

Care homes were randomised between Dec 15, 2008, and April 9, 2010. At randomisation, 891 individuals in 78 care homes (35 intervention, 43 control) had provided baseline data. We delivered 3191 group exercise sessions attended on average by five study participants and five non-study residents. Of residents with a GDS-15 score, 374 of 765 (49%) were depressed at baseline; 484 of 765 (63%) provided 12 month follow-up scores. Overall the GDS-15 score was 0·13 (95% CI -0·33 to 0·60) points higher (worse) at 12 months for the intervention group compared with the control group. Among residents depressed at baseline, GDS-15 score was 0·22 (95% CI -0·52 to 0·95) points higher at 6 months in the intervention group than in the control group. In an end of study cross-sectional analysis, including 132 additional residents joining after randomisation, the odds of being depressed were 0·76 (95% CI 0·53 to 1·09) for the intervention group compared with the control group.

INTERPRETATION

This moderately intense exercise programme did not reduce depressive symptoms in residents of care homes. In this frail population, alternative strategies to manage psychological symptoms are required.

FUNDING

National Institute for Health Research Health Technology Assessment.

Under-reporting of energy intake in elderly Australian women is associated with a higher body mass index

OBJECTIVES

Identify the extent of under-reporting of energy intake and the characteristics associated with implausible intakes in elderly women.

DESIGN

Dietary intake was assessed using a 3-day weighed food record. Protein intake was validated by 24-hour urinary nitrogen. To examine under-reporting, participants were grouped according to their energy intake and compared to the Goldberg cut-off equation. Logistic regression was performed to assess the influence of body mass index (BMI) and social-demographic factors on under-reporting.

SETTING

Community dwelling elderly women from Perth, Western Australia.

PARTICIPANTS

217 elderly women aged 70-80 years.

RESULTS

Under-reporters had a higher physical activity level (p<0.001) compared with acceptable-reporters. The under-reporters also had a higher body weight (p=0.006), body mass index (BMI) (p=0.001), waist (p=0.011), hip circumference (p<0.001), whole body fat mass (p<0.001) and percentage body fat (p<0.001) than acceptable-reporters. Under-reporters had a significantly lower intakes of protein, fat, carbohydrate and alcohol (p<0.001) and fewer reported food items, compared with acceptable reporters. However, 24-hour urinary nitrogen was only marginally different between the two groups (p=0.053). Participants with a higher BMI were more likely to under-report their energy intake (BMI=25-29.9: odds ratio=2.98[95% CI=1.46-6.09]; BMI≥30: 5.84[2.41-14.14]).

CONCLUSION

Under-reporting energy intake in elderly women was associated with a higher BMI, body fat and higher self-reported physical activity levels. A higher BMI (≥25) appears to be most significant factor in determining if elderly women will underreport their food intake and may be related to body image. These results have implications for undertaking surveys of food intake in elderly women.