News & Features — 13 December 2023 at 1:51 pm

Evidence Explorer: Updates and news from the academic community, Autumn 2023

Dr Hugh Roberts / Critical Care and Retrieval Medicine Registrar / New Zealand

Dr Craig Miller / Emergency Medicine Registrar / Peninsula

Dr Constance Osborne / SHO / Evidence Explorer Lead / London


  • Introduction and Collaborators
  • Expedition and Wilderness Medicine Section
  • Global Health and Humanitarian Medicine Section
  • Want to get involved?

The clocks have gone back and the nights are drawing in, so what better time to settle into an armchair with a cup of tea and catch up on the latest in academia.We are excited to announce the publication of the Third Edition of the Oxford Handbook of Wilderness Medicine. It contains updated national and international treatment guidance, and revised chapters on caving medicine, analgesia and anaesthesia. This is the perfect handy guide for any expedition medic’s kit bag.

We would also like to flag The Lancet commission on peaceful societies through health equity and gender equality. It is a long document requiring a particularly large mug of tea, but it is an important read because it presents a pragmatic policy, and learning agenda, for global players at every level.

‘The world is experiencing a polycrisis—ie, an interaction of multiple crises that dramatically intensifies suffering, harm, and turmoil, and overwhelms societies’ ability to develop effective policy responses. Bold approaches are needed to enable communities and countries to transition out of harmful cycles of inequity and violence into beneficial cycles of equity and peace… The Commission, which had its inaugural meeting in May 2019, examines the interlinkages between Sustainable Development Goal 3 (SDG3) on health; SDG5 on gender equality; and SDG16 on peace, justice, and strong institutions. Our research suggests that improvements to health equity and gender equality are transformative, placing societies on pathways towards peace and wellbeing.’

The Lancet Commission on peaceful societies through health equity and gender equality 2023

After scrutinising twenty-five journals, Dr Miller and Dr Roberts have curated a fascinating selection of articles for you. From altitude physiology and the efficacy of avalanche airbags, to antenatal healthcare in armed conflict and the impact of nutrition on tuberculosis, there is something for everyone.

Dr Craig Miller is an Emergency Medicine Registrar, based in Peninsula, who currently works at the Royal Cornwall Hospital. Throughout his career, he has worked as an expedition doctor in most environments, from high altitude to the desert. He has a passion for tropical marine environments and diving medicine, and is a qualified Diving Physician. He has completed expeditions to West Papua and the British Indian Ocean Territory. Alongside his field experience, he has worked as an expedition medical advisor and is a course director for Wilderness Medical Training. He is currently focusing on completing a Masters in Global Health, alongside his UK work.
Dr Hugh Roberts is a Critical Care and Retrieval Medicine Registrar in New Zealand, having completed UK core anaesthetic training in August 2023. He is an Adventure Medic Editor, and has worked as an expedition medic in Tanzania, India, Indonesia and at sea. Hugh authored the Adventure Medic guide on how to balance expedition medicine with UK specialty training. Outside of work, Hugh enjoys SCUBA diving and climbing.

Expedition and Wilderness Medicine

In the autumn edition of Evidence Explorer, we’re already looking ahead to winter. We appraise a pilot study about mechanical CPR on ski slopes, an article on the effectiveness of avalanche airbags, and a review on the performance of chemical heat blankets in wet conditions. We then turn our attention to some of the most potent analgesics in our expedition medicine kits. We review a study that compares sufentanil to other opiates in acute traumatic pain, and a paper on the environmental impact of Penthrox. We round off this section with a paper on physiology at high altitude and a review of the limitations of pulse-oximetry for darker-skinned patients.

Manual vs Mechanical Cardiopulmonary Resuscitation for Out-of-Hospital Cardiac Arrest on a Ski Slope: A Pilot Study

Rupp S, Overberger R. Wilderness & Environmental Medicine Journal. Sep 2023.

This study, conducted in the Pocono Mountain region of Pennsylvania, examined mechanical vs manual CPR on a mannequin during extrication from a ski slope. Three-person ski rescue teams performed eight trials, four with a LUCAS 3 device to provide chest compressions, and four with a rescuer providing manual chest compressions. The same ski slope was used for each extrication (which was described as ‘moderately pitched’ at 610m altitude) and different manual chest compression providers were used for each extrication to limit tiring. CPR quality was measured using a CPR quality monitor attached to the mannequin, which measures both rate and depth to determine compression quality.

The study found an increased percentage of time spent performing high-quality chest compressions in the mechanical group (58.5%; 95% CI) vs the manual (25.6%; 95% CI). There was a statistically significant increase in extrication time in the mechanical group (8.6 +/- 0.4min) vs the manual group (7.6 +/- 0.5min) but the authors suggest that the impact of a 1 minute delay would be negligible in real-world scenarios.

This pilot study neatly demonstrates the potential of mechanical CPR for ski patrols; not only does it free up a rescuer for other duties, but it should provide high-quality, continuous CPR on challenging terrain or in adverse weather conditions at altitude. The effect of the cold environment on battery life is an important consideration mentioned by the authors, but was not examined in this study.


The dependence of maximum oxygen uptake and utilization (V̇O2max) on hemoglobin-oxygen affinity and altitude

Webb K, Joyner M, Wiggins C et al. Physiological Reports. Aug 2023.

This is not a paper for light reading post on-call. Brace yourself for some physiology.

Higher haemoglobin-oxygen affinity (Hb-O2 affinity) results in increased oxygen uptake in the lungs, but less off-loading of oxygen to the tissues. These two changes have competing effects on VO2max, which is the maximum attainable rate of oxygen consumption. So does that mean that VO2max will increase or decrease? Naturally, an expedition medic may also ask, how does this effect change at altitude? This study addresses these questions using mathematical models to predict how VO2max will be affected by low, normal or high Hb-O2 affinities at altitudes of 0-10 km.

The results demonstrated that until approximately 4500m, low-normal Hb-O2 affinities result in an increased VO2max compared to high Hb-O2 affinity. However, this effect reverses above 4500m (see Figures available in the original article). This is of interest as it suggests a potential mechanism for the prophylaxis and/or treatment of high-altitude illness by using drugs which may increase Hb-O2 affinity. In fact, these drugs have already been developed and investigated for the treatment of sickle cell disease. This paper is entirely based on mathematical models and further studies are required to verify these findings.


Environmental impact of low-dose methoxyflurane versus nitrous oxide for analgesia: how green is the ‘green whistle’?

Martindale A, Morris D, Cromarty T et al. Emergency Medicine Journal. Sep 2023.

Penthrox has become increasingly popular in pre-hospital and expedition medicine as a lightweight, potent analgesic with a short duration of action. It is also a non-opioid and non-controlled drug, making it suitable for international expeditions. This paper investigates the environmental impact of Penthrox, and compares it to Entonox and intravenous morphine.

The authors thoroughly examined the Penthrox lifecycle in five distinct areas: raw materials, methoxyflurane manufacture, production processes, transport and disposal. Carbon dioxide equivalent (CO2e) was used as the primary measure of environmental impact. Existing data on Entonox and morphine were used from papers published in Anaesthesia and BMJ Open, respectively. The analysis compares one unit of Penthrox containing 3ml methoxyflurane (equivalent to 30 minutes use) with 30 minutes of continuous Entonox at 14L/min and 7mg of morphine. The results showed that Penthrox (0.84kg CO2e) has a CO2e 117x less than Entonox (98.89kg CO2e), whilst the CO2e of morphine was negligible (0.01kg CO2e).

The comparative analysis used in this study seems unfairly weighted against Entonox, assuming very high flow rates by not taking into account the presence of a demand valve (as used in ED or maternity to ensure Entonox is only delivered when the patient breathes through the mouthpiece). Even so, this study suggests that Penthrox is a ‘greener’ choice than Entonox, so we can all feel a little less guilty about including a whistle or two in our expedition med kits.


Effect of intranasal sufentanil on acute post-traumatic pain in the emergency department: a randomised controlled trial

Malinverni S, Kreps B, Lucaccioni T et al. Emergency Medicine Journal. Sep 2023.

Onto another up-and-coming drug of the pre-hospital med kit, intranasal sufentanil. Sufentanil is an opioid with 10x more potency than fentanyl. It is highly lipophilic, which means it can be absorbed through the nasal mucosa to provide rapid analgesia without the need for an IV cannula. In this randomised controlled trial from Belgium, intranasal sufentanil 0.5μg/kg was compared with a control of either oral oxycodone 5mg or IV morphine 0.1mg/kg (based on clinician’s judgement). The study included 170 adult patients that presented to the ED with acute post-traumatic pain in the extremities, spine or thorax, scoring greater than 7/10 on the visual analogue scale (VAS). Pain scores were assessed at 0, 15 and 60 minutes, and smaller supplementary doses of opiates were allowed at these times.

The results showed that baseline pain scores were similar between groups, and intranasal sufentanil resulted in a greater reduction in VAS pain scores than the control group at both 15 minutes (3.0 vs 1.5; p<0.001) and 60 minutes (5.0 vs 6.6; p<0.001). There was a significantly greater number of patients who experienced minor adverse effects in the intranasal sufentanil groups, particularly dizziness, vomiting and sweating (59 [71%] vs 20 [23%]; p<0.001). Supplementary analgesia was used similarly by both groups. This is an intention-to-treat study and therefore the high rates of adverse effects in the intranasal sufentanil group are taken into account.

This paper is well worth a read. It serves as an excellent introduction for clinicians unacquainted with intranasal sufentanil, whilst also producing some interesting data for those more familiar with it.


Improving pulse oximetry accuracy in dark-skinned patients: technical aspects and current regulations

Cabanas A, Martín-Escudero P, Shelley K. British Journal of Anaesthesia. Aug 2023.

It has been well-documented that patients with darker-pigmented skin are at higher risk of occult hypoxaemia (peripheral oxygen saturations [SpO2] >92% despite true arterial oxygen saturations being [SaO2] <88%). The two wavelengths used as standard in pulse oximeters are 660nm (red light) and 940nm (infrared light). Deoxyhaemoglobin absorbs more light at 660nm, while oxyhaemoglobin absorbs more light at 940nm. As melanin absorbs more light at 660nm compared to 940nm, patients with darker-pigmented skin may therefore have a falsely high SpO2 reading. The reason these wavelengths are used is because the majority of the data used to calibrate pulse oximeters has been collected from studies of patients with lighter-pigmented skin. Of the relatively few studies that have examined darker-skinned patients, most have used questionable methodology. Poor-quality polychromatic LEDs (which are often found in pulse oximeters bought on the high street or online) further increase the risk of occult hypoxaemia, as they are affected by the spectral absorption of melatonin to a greater degree than monochromatic LEDs (which are found in FDA 510[k] authorised pulse oximeters used in professional healthcare settings).

Until there is an improved availability of pulse oximeters calibrated for patients with darker-pigmented skin, what can we do as expedition medics to tackle this issue? Raising awareness is important. We should also ensure our pulse oximeters are FDA 510(k) authorised, and maintain a degree of clinical suspicion when we have patients with darker-pigmented skin and a reassuring SpO2.


Effectiveness and use of avalanche airbags in mortality reduction among winter-recreationists

Lucia Laura Di Stefano, MD1,*, Bianca Della Libera, MS2 and Paolo Rodi, MD3. Journal of Travel Medicine. October 2022

My friends that regularly ski will often talk about the appeal of heading off-piste for fresh powder, leaving novice skiers like me to flounder on the blue slopes. However, skiing off the bashed track is not without risk. The overall mortality of individuals caught in an avalanche is 13-23%. During the 2020-21 winter season in the Alps, there were 130 avalanche-related deaths. Equipment commonly carried by winter recreationists includes a transceiver/shovel/probe combination and an avalanche airbag.

This paper is a narrative review of the available data on avalanche airbags. The authors identified six articles with data on mortality reduction, of which one was a survey and five were retrospective experimental studies on real-life accidents. They concluded that airbags reduce the risk of both critical burial (defined as burial of the head and impaired breathing) and mortality. Non-deployment of airbags is a major issue, occurring at a rate of around 20%. It may be caused by user error (60%), device failure (17%), maintenance error (12%) (such as the canister not being attached properly), or destruction of the airbag during the avalanche (12%).

Whilst it’s reassuring to know that deploying an airbag does reduce the risk of death if you find yourself caught in an avalanche, there still remains a significant risk. There is no substitute for appropriate education and training on avalanche avoidance. Always take time to make sure you know how to use your device properly, and keep it maintained to significantly reduce the risk of non-deployment.


Performance of a Chemical Heat Blanket in Dry, Damp, and Wet Conditions Inside a Mountain Rescue Hypothermia Wrap

Greene M, Long G, Greene K et al. Wilderness and Environmental Medicine. September 2023.

This research was conducted by authors Mike Greene and Karen Greene (both highly experienced mountain rescue doctors and founders of Mountain and Expedition Emergency Medicine), Geoff Long and Matt Wilkes (both affiliates of the School of Sport, Health and Exercise Science at the University of Plymouth, and you may also recognise Matt as the founder of Adventure Medic).

This study examined the performance of chemical heat blankets (CHB) in three experiments. The first experiment measured whether a CHB heats up quicker when packed loosely in a rucksack or when exposed to the open air. The second experiment measured temperature and heat flux (the rate at which heat is transferred) from a CHB through dry, damp and saturated wet fleeces. The third experiment compared the temperatures of mannequins dressed in dry, damp or saturated wet fleeces and wrapped in a “hypothermic wrap”. The hypothermic wrap, as used by Mountain Rescue England and Wales, consists of a CHB, then a vapour barrier, surrounded by an insulating fibre pile bag with a wind and waterproof outer layer. Finally, the wrapped casualty is supported in a vacuum mattress, which provides additional insulation. A temperature probes was placed next to the base layer on the mannequin and then the mannequin was left for 7 hours to see if steady-state temperatures were maintained.

There are several useful takeaways from this study, and I would highly recommend reading this paper yourself to better understand the findings. The first experiment showed that a CHB packed loosely in a rucksack heated up quicker than a CHB in the open air (43oC vs 32oC at 30 min), demonstrating that it is not necessary to open the CHB to allow in more oxygen. Readying a CHB in your rucksack in advance of reaching your casualty may be beneficial, to allow it to warm up. However, the application of a CHB should not be delayed, as it starts to provide heat to a patient from the moment it is applied. The second experiment showed that the performance of a CHB is similar in dry or damp conditions, but impaired in wet conditions. The explanation provided by the authors for this is that the water surrounded the panels, preventing oxygen reaching the CHB and thereby impairing heat production. Therefore, consider cutting off saturated clothing before wrapping a casualty as it may impair the efficiency of a CHB. The third experiment showed that hypothermic wraps will maintain the median steady-state temperatures for 7 hours with dry, damp or saturated wet fleece, so there is really no need to check or change them before this time. The highest temperature recorded against the CHB (with the dry fleece) was 67oC. This is more than sufficient to cause burns, so we should always have a protective layer of clothing between the CHB and the casualty’s skin.

Global Health and Humanitarian Medicine

As we enter the final months of 2023, it’s time to introduce you to the final Global Health Evidence Explorer for the year. Get yourself a cup of tea and we’ll take you through six key papers published in the past few months. 

Inequality across the globe has a huge impact on human health and this edition explores different aspects of this issue, and its impact on different populations. Ataguba et al publish an expansive global assessment of income inequality and its impact during pandemics. Displaced populations are particularly vulnerable to inequality. Okumu studies the interplay between gender inequality and condom use in displaced populations with a high prevalence of HIV. Zhang et al examines access to antenatal healthcare during armed conflict, which is a particularly powerful study given the current conflicts in Europe and the Middle-east. There are two randomised controlled studies in this quarter’s edition: one looking at wider nutritional supplementation for households with known TB, and another determining the effectiveness of intermittent preventive treatment of malaria.

Income inequality and pandemics: insights from HIV/AIDS and COVID-19 — a multicountry observational study

J Ataguba, C Birungi, S Cunial et al. BMJ Global Health, September 2023

Inequality is a key determinant of poor health outcomes. This global retrospective observational study illustrates this point clearly by utilising national data from two global pandemics: HIV/AIDs (217 countries) and Covid-19 (151 countries). Countries and regions with greater inequality, as assessed by the Gini index*, show a statistically significant (p<0.01) increase in prevalence of HIV, AIDs mortality rate, and excess deaths owing to Covid-19. The consequences of this are two-fold: the poorest populations are the most vulnerable during pandemics, in part owing to limited access to healthcare, and greater inequality perpetuates and exacerbates pandemics thorough increased case numbers. Articles such as this one helps to focus international attention and drive agendas such as the Sustainable Development Goals.

*The Gini index (or coefficient) is an internationally recognised measure of inequality. It specifically examines the distribution of household income and how this deviates from perfect distribution, with 1 being complete inequality and 0 being complete equality. One limitation is that it is a relative, not absolute measure, meaning the Gini index can rise for a developing country i.e. become more unequal whilst the absolute number of those living in poverty reduces. Similarly, two countries may have similar levels of equality, i.e. the same Gini index, yet the absolute wealth between the two countries may be vastly different. Want to read more? 


Does armed conflict lead to lower prevalence of maternal health-seeking behaviours: theoretical and empirical research based on 55 683 women in armed conflict settings

T Zhang, Q He, S Richardson et al. BMJ Global Healt, August 2023

Women and children are amongst the most vulnerable in conflict zones, and access to antenatal healthcare is challenging. This study aims to quantify the effect of conflict on maternal health seeking behaviours using maternal and child health (MCH) data from UNICEF. The paper suggested that where humanitarian assistance was provided, improvements in maternal care can be achieved, particularly tetanus vaccination and single visit antenatal care (ANC). This is likely because it is more feasible to deliver a vaccination programme and single visit ANC than the WHO recommended 8+ ANC contacts*. Caution should be exercised however, as no clear trends were identified across the countries studied (CAR, Chad, DRC, Afghanistan), many of the results were not statistically significant, and MCH improvements are presumed. Overall, this paper highlights the variability in delivery of MCH humanitarian assistance in conflict zones. Whilst it does develop a ‘theoretical model of utility to explain the effects of armed conflict on maternal health-seeking behaviours’, it remains to be seen how applicable this model is to real world interventions.

*The World Health Organisation publishes recommendations on ANC for a positive pregnancy. They recommend a model with a minimum of 8 ANC contacts, as evidence shows a reduction in perinatal deaths. Furthermore, the ANC 8+ contact model supports improved safety, earlier detection of complications, and better health engagement and communication.

[WHO recommendations on antenatal care for a positive pregnancy experience. 2016. Available at: ]


Nutritional supplementation to prevent tuberculosis incidence in household contacts of patients with pulmonary tuberculosis in India (RATIONS): a field-based, open-label, cluster-randomised, controlled trial

A Bhargava, M Bhargava, A Meher et al. Lancet Global Health, August 2023

Social determinants of health are increasingly recognised as a key determinant of the burden of tuberculosis (TB). The WHO strategy to end tuberculosis addresses both the biological and social aspect of the disease. The national ‘Eliminate TB Strategy’ in India aims to address the syndemic of malnutrition and TB through provision of direct nutritional support to patients. This study is the first of its kind to examine the role of malnutrition support, not only for pulmonary TB patients, but also their household contacts.

The study was undertaken in eastern India, with over 10,000 household contacts recruited from the predominantly indigenous and rural population. After randomisation, the household contacts of confirmed pulmonary TB patients received nutritional support (750 Kcal/day) in the intervention group, whilst in the control group only the TB patients received nutritional support. The intervention resulted in a 39% reduction in TB incidence, but it is important to be inquisitive when impressive numbers are stated. The figure was calculated by comparing the incidence rate per 100 person-years in the control (1.27 per 100 person-years (95% CI 1·00–1·61)) and intervention arms (0.78 per 100 person-years (0·64–0·96)), which resulted in an absolute difference in the incidence rate of 0.49, a more modest reduction. Another curious aspect of the results was the intervention had no impact on hospitalisations or deaths from other illnesses, although unfortunately that data is not provided for interrogation.

The generalisability of the study is limited. It is a single-country study focused on a predominantly rural population, with a disproportionately high representation from the indigenous population.  Nevertheless, its implications are clear, to reduce the burden of disease in impoverished populations, global health leaders and policy makers must recognise that healthcare needs to be holistic, and address the social determinants of health, to be truly effective.


A syndemic of inequitable gender norms and intersecting stigmas on condom self-efficacy and practices among displaced youth living in urban slums in Uganda: a community-based cross-sectional study

M Okumu, C Logie, A Chitwanga. Conflict and Health, August 2023

A lack of research examining sexual and reproductive health (SRH) exists in humanitarian settings, yet the globally displaced population is nearly 30 million, of which nearly 50% are under the age of 18. Displaced youth are particularly vulnerable to HIV and other STIs due to limited provision of SRH, higher rates of sexual violence and transactional sex. Condoms remain the most effective method to prevent HIV, however use is limited amongst 15-24 year olds. Lack of education is rarely identified as a contributor to low use. This cross-sectional study investigates the relationship between adverse sociocultural factors and condom use in displaced youth populations living in informal settlements in Kampala. Uganda was chosen for the study, as it hosts the greatest number of displaced persons (1.5 million) in sub-Saharan Africa, and high rates of HIV are reported. Data collection took the form of a questionnaire, with researchers identified and trained from within the displaced population and supported by the lead author. It suggests that inequitable gender norms, HIV and SRH stigma interact to reduce condom self-efficacy, which is a measure of an individual’s ability to consistently use condoms. This concurs with the researchers’ presented hypothesis and champions the use of multi-faceted HIV prevention programmes, not only providing SRH and HIV services, but tackling underlying gender inequality and stigma.

Methodology is clearly described alongside the data and regression analyses, but there remains significant limitations. Purposive sampling, used in this study, is pragmatic when attempting to capture data from a specific population, but introduces researcher bias. Snowball sampling and payment of participants compounds researcher bias with sampling bias. This paper is focused on displaced youth in Uganda based in informal urban settlements, it is not generalisable to the entire displaced population, which would require random sampling across multiple sites and groups.

Quick diversion: when reviewing studies that utilise surveys or questionnaires it is important to identify the ‘Cronbach’s alpha number’ for each. This is a statistical measure of the internal reliability of the questions. Below 0.5 is considered unreliable and the questions should be revised, above 0.7 is considered reliable. All surveys used in this study had a Cronbach’s alpha of >0.7.


Association between the quality of care and continuous maternal and child health service utilisation in Angola: Longitudinal data analysis

A Aoki, K Mochida, M Kuramata. Journal of Global Health, August 2023

Reducing maternal and child mortality is a key priority of the United Nations and World Health Organisation as set out in the UN Sustainable Development Goals (SDG number 3). Sub-saharan Africa remains particularly burdened with high maternal and child mortality. To address this challenge, Angola introduced the Maternal and Child Health (MCH) Handbook. This is a physical home-based integrated care record which documents maternal care, child development and immunisations. This was introduced alongside healthcare workforce education, implementation of protocols and increasing service utilisation. A randomised controlled trial assessed the MCH impact on care for pregnant women and mothers. The study presented here is a longitudinal analysis of data from both the original RCT, as well as data from the subsequent implementation study, covering a combined period of 16 months.

WHO defines quality of care as ‘the degree to which health services for individuals and populations increase the likelihood of desired health outcomes’. Quality of care and its impact on service utilisation is poorly studied. This is the first study to examine quality as a facilitator to improve ANC patient engagement. The analysis examines differences between optimal and sub-optimal care with the hypothesis that optimal care should increase service utilisation. Optimal care was defined as 4+ ANC contacts, facility delivery, and optimal vaccinations for children at 6 months. Sub-optimal care was defined as any level below optimal care. As discussed earlier, the WHO now recommends 8+ ANC contacts, therefore what is presented as optimal care would actually be suboptimal according to WHO’s updated recommendation. It is important to note however that the updated guidance was released during the study period. The study included over 3000 pregnant women of whom over 70% received optimal care. Positive service user perception was statistically significantly higher when optimal care was delivered. Those populations who received suboptimal care were likely to be younger, from rural populations or ethnic minorities, and have limited education.

The major flaw in this study is that ‘optimal care provision’ was used as a proxy for good quality of care. This is a significant presumption. Quality of care should be patient-centred and the paper does little to explore how or why marginalised populations were more likely to receive suboptimal care. Moreover, it is a country specific study and different cultural and demographic factors would need to be considered if attempting to apply this study to other populations.


Effectiveness and safety of intermittent preventive treatment with dihydroartemisinin–piperaquine or artesunate–amodiaquine for reducing malaria and related morbidities in schoolchildren in Tanzania: a randomised controlled trial

G Makenga, V Baraka, F Francis et al. Lancet Global Health, August 2023

Prevention of malaria is multi-faceted, including chemoprophylaxis, personal protection measures against mosquitoes and mosquito control. Additionally, two malaria vaccines have recently been approved and are beginning to be delivered in certain regions across sub-Saharan Africa. The aim of this study was to assess the effectiveness of intermittent preventive treatment of malaria in school children (IPTsc) in reducing the burden of anaemia associated with malarial infection. Conducted in Northeast Tanzania, over 1500 children across seven primary schools were randomised in this open label study. Two intervention groups received either dihydroartemisinin–piperaquine or artesunate–amodiaquine four monthly for one year versus a control group which did not receive anti-malarials. Primary end-points were (at 12 and 20 months) change in baseline haemoglobin and incidence and prevalence of malaria.

Secondary end-points were anaemia prevalence at each 4 month visit and change in psychomotor and cognitive scores at 12 and 20 months. The study controlled for the potential effect of soil-transmitted helminths and schistosomiasis as a cause of anaemia through preventive treatment with albendazole and praziquantel according to national guidance. Stool samples were tested to ensure effectiveness of treatment.

ITPsc demonstrated a positive, albeit small, effect on mean haemoglobin levels. Both intervention groups demonstrated an increase of 0.5g/dL compared with the control, the clinical significance of this is unclear. Arguably, the more important finding was the reduction in prevalence of malarial parasitemia and the reported 20% protective effect of ITPsc against clinical malaria at 12 months. No effect of ITPsc on cognitive or psychomotor scores was demonstrated. Whilst robust, this study has one significant flaw, due to the Covid-19 pandemic nearly 1200 children missed visit four, which was crucial as visit four was conducted at 12 months and was one of the primary end-points. They state the analysis was still statistically powered, however missing nearly 80% of data at the primary endpoint of the interventional period is clearly problematic. Overall, the study demonstrates a pragmatic, community centred approach to reducing the burden of malaria. As such, WHO’s 2023 malaria guidelines advocate the use of intermittent preventive treatment for malaria in school aged children (ITPsc) in areas with high endemicity of disease to run alongside current school based health programmes such as mass treatment for soil-based helminths and schistosomiasis.

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