Crisis in Gaza: Scenario-Based Health Impact Projections

This project aims to provide projections of excess mortality for different causes of excess mortality (mortality modules) in Gaza under three scenarios: 1) ceasefire, 2) status quo (continuation of conditions observed during the period of the war from October 2023 to 15 January 2024), and 3) escalation. These estimations will provide decision-makers and responders information to plan for and respond to different scenarios. The data may also be used to inform diplomatic efforts addressing this war. The current projection is for six months from 7 February- 6 August 2024. The estimates will be periodically updated and will take into account the evolving crisis, availability of new data, and improved methods until May 2024.

We will prepare scenario-based projections of overall mortality and four cause-specific mortality modules: 1) traumatic injury, 2) infectious diseases, 3) maternal and neonatal health, and 4) non-communicable diseases that, taken together, encompass nearly all direct and indirect causes of mortality. A methods annex technical document detailing the methods underpinning the estimates, and an openly accessible repository of data and analysis code are available. Presentations targeted for specific stakeholders will occur.

The project is implemented by researchers from the Health in Humanitarian Crises Centre at the London School of Hygiene & Tropical Medicine , and the Johns Hopkins Center for Humanitarian Health at Johns Hopkins University.

The research is being conducted with the support of the UK Humanitarian Innovation Hub (UKHIH) and the donor, the UK Foreign, Commonwealth & Development Office (FCDO). The work UKHIH supports aims to harness UK and international capabilities to support problem- led, systems innovation in the humanitarian sector.

Scenario-based projections will be released in a publicly available report alongside an open repository of data and analysis code, together with a methods annex technical document detailing the methodology used. An Arabic summary of each report will also be provided. The report will be periodically updated over the next five months and consider the evolving situation, availability of new data and improved methodologies.

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Three different scenarios were chosen to be sufficiently distinct in terms of their likely impact, and, taken together, encompass a foreseeable range of trajectories for the crisis. The scenarios include a ceasefire (optimistic) scenario, a status quo (middle) case scenario (reflecting continuation of conditions seen between 7 October 2023 and 15 January), and an escalation (pessimistic) scenario. Projections for each scenario have a time horizon of 6 months. Each scenario is mainly specified in terms of three elements: 1) intensity and typology of the military activity in Gaza; 2) occurrence and duration of any pauses or ceasefires; and 3) extent of humanitarian space and operational adaptation.

For each scenario, we specified ranges for the values of specific risk factors for disease transmission or progression, including displacement, inadequate shelter and overcrowding, exposure to war injuries, food security/nutritional status, and insufficient water, sanitation and hygiene.

Finally, for each scenario we specified percent access to key health services, including vaccination, outpatient (primary) care and specific inpatient services such as intravenous antibiotics, rehydration and respiratory support. This was based on analysis of disruptions to these services, and realistic prospects for their rehabilitation.

We reviewed and extracted a range of previously collected data from the period before the war, including previous wars in Gaza, and from the period since the crisis’ start. We also sourced publicly available data and peer-reviewed articles from similar crisis contexts. Reports were curated by extracting key meta-data and vetted for quality based on set criteria. Finally, we used expert consultations and structured elicitation questionnaires to help us estimate key quantities for each scenario, including the transmissibility and fatality of infections and the availability and quality of trauma surgery care. As the project progresses, we will continue to source and update data and improve expert elicitation processes. An open repository of information will be published alongside each report.

These terms can be used interchangeably. In the Gaza Projections Report, excess mortality means the projected number of deaths above what one would have been expected without the conflict, during the same time period.

Israel’s public health infrastructure is intact and functioning, Gaza’s is not. Additionally, there is a better understanding of the impacts of the ongoing war in Israel compared to Gaza. In Gaza the war has disrupted health services and resulted in overcrowding, inadequate water, sanitation and hygiene conditions, and insufficient food intake. To better address the humanitarian crisis in Gaza both during and after the war, it is important to understand how the conflict is contributing to disease and death there.

We are seeking to estimate excess mortality due to all causes. As such, following the broad categories of the International Classification of Diseases, we have developed estimates of excess mortality due to 1) traumatic injuries, 2) infectious diseases, 3) maternal and neonatal causes, including deaths and stillbirths, and 4) non-communicable diseases. Furthermore, malnutrition is analysed as an underlying cause of mortality. Morbidity due to mental health may be included in future iterations of the projections. Taken together, these broad disease areas encompass most causes of mortality. These estimates do not distinguish between civilians and combatants.

Excess maternal, neonatal, and stillbirth mortality was estimated using the Lives Saved Tool or LiST; this extensively documented model uses published estimates of the relationships between changes in service coverage (e.g. antenatal care) and mortality or stillbirth risk. LiST models have been widely used and were built using a hierarchy of evidence on the effect of interventions on mortality.

For other disease areas, we developed computational models that, where possible, incorporated known ranges of uncertainty in various parameters such as exposure-outcome effects and the coverage of specific public health services. Briefly,

• For traumatic injuries, we used publicly available casualty data, data from similar conflicts, studies on survival rates of trauma patients, and expert-elicited values for case fatality of the most prevalent trauma types in conflict settings to estimate our projection in trauma injuries and deaths. Our estimates include the proportion of the injured who die of wounds due to lack of adequate medical services.
• For malnutrition, we estimated caloric intake and translated this into percent weight loss based on a published model; these weight losses were then applied to baseline data to project prevalences of acute malnutrition;
• For infections, we divided work into epidemic and endemic infections. For endemic infections, we multiplied baseline mortality data by relative risks representing higher transmissibility and case-fatality. For epidemics, we simulated a large number of epidemics based on expert-elicited values of epidemic risk, susceptibility to infection and disease based on vaccination coverage and natural exposure, and epidemiological parameters sourced from the literature. Susceptibility to infection and disease for different vaccine- preventable infections was estimated in a separate model.
• For non-communicable diseases, we multiplied baseline mortality data by relative risks representing changes in access to treatment among prevalent and incident cases, with relative survival with and without treatment quantified through literature review.

All our methods are extensively documented in a Methods Annex Technical Document can be reproduced using data and code provided.

No. The results are projections that use historical and present data and models to estimate the future under scenarios that we as researchers specifically set. Scenario-based projections are a ‘what-if’ exercise: we do not claim that any of the three scenarios will in fact materialise, but instead attempt to quantify the expected health consequences of these distinct alternative trajectories. The results should not be interpreted as a prediction or forecast.

All data sources come with their own biases and limitations, and the research team has attempted to adjust for these within the modelling approach. The best-available data have been used but, as is the case in all crisis situations, the available data are incomplete or may feature inaccuracies. The Methods Annex Technical Document discusses the limitations and biases of the estimates.

The range of scenario-based projections is not a prediction of what will happen but rather indicates what could happen under different scenarios, so as to enable appropriate planning, response and decision-making.

The project was reviewed and received approval from the Johns Hopkins Bloomberg School of Public Health Institutional Review Board and the London School of Hygiene & Tropical Medicine Research Ethics Committee.

All queries relating to the project should be directed to info@gaza-projections.org.

This project is an independent collaboration between researchers from The London School of Hygiene & Tropical Medicine and The Center for Humanitarian Health at The Johns Hopkins University.

The goal of this scenario-based model is to provide a plausible projection of the number of traumatic injury deaths that could occur in Rafah over the coming 3 months so that policymakers and humanitarians can make sound, evidence-based decisions. Ultimately, it is hoped that this projection will make some contribution to saving lives.

Scenario-based models are needed to support forward looking evidence-based decision making in Rafah. Since mortality and other data sources in Gaza are no longer able to provide a complete picture of deaths, multiple data sources are needed for this projection.

We focused on projecting the number of traumatic injury deaths amongst Gazans in Rafah from 20 May 2024 and for the subsequent 90 days.

While conflict continues throughout Gaza, Rafah was selected as the focus of this scenario-based model because, until recently, this was the area where most Gazans had fled to and there had not yet been a wide-scale military invasion in this Governorate since the conflict began on 7 October 2023. However, the Israeli government made its intention to invade Rafah clear, and this began on 6 May 2024 following an evacuation order.

This scenario is focused solely on Gazans who are likely to die directly due to traumatic injuries and does not include:

• Deaths that have already occurred in Rafah previously, including those since the 6 May evacuation order.
• Deaths that will occur in Rafah after the projection period due to non-fatal traumatic injuries sustained during that period.
• Deaths indirectly caused by the war, including deaths due to infectious diseases, non- communicable diseases and maternal and child health issues.

These other causes of death were considered in our first scenario-based health impact projections report which projected excess mortality for the period of February to August 2024 across all of Gaza.

This report was developed as a supplement to the prior report because an escalation in the intensity of the conflict in Rafah is likely to significantly increase direct deaths due to traumatic injuries in this governorate compared to previous traumatic injury deaths in Rafah.

We project 3,509 traumatic injury deaths to occur between 20 May to 17 August 2024 solely in the Rafah governorate. That is the equivalent to nearly 40 deaths/day for 90 days. In comparison, from 6-19 May, there have been 16 deaths/day due to traumatic injuries in Rafah as reported by ACLED.

Many more traumatic injury deaths are continuing to occur throughout Gaza. Furthermore, we would expect to see increased deaths due to other causes, such as infectious diseases, non- communicable diseases and those due to maternal and child health occurring in the Rafah Governorate and beyond.

The uncertainty range of this projection is 3,143 to 3,946 traumatic injury deaths; for the higher estimate, the daily death rate increases to 44 deaths/day.

This projection is not a ‘worst case scenario’, and deaths may increase significantly if Israeli military tactics differ substantially from what we have seen in Khan Younis during 16 December 2023 to 14 March 2024.

Four sources of available data were used for this projection: 1) Ministry of Health (MoH) data on conflict fatalities; 2) Armed Conflict Location & Events Data Project (ACLED) data on fatalities for the five governorates in Gaza since 7 October 2023; 3) United Nations Relief and Works Agency for Palestine Refugees in the Near East (UNRWA) reports of traumatic injury fatalities among its employees; and 4) Estimates of population by governorate since 7 October, adjusted for displacement by the Oxford Population Health Unit. The first three sources are publicly available, and the latter is available upon request.

Our projection for Rafah is based on empirical observations from the Israeli military operation that began in Khan Younis in December 2023. We hypothesize, based on available evidence, that the patterns and outcomes witnessed during this phase of the conflict could resemble potential developments in Rafah under comparable circumstances. They are based on the time series of traumatic injury fatalities from Khan Younis over the 90-day period starting from 16 December 2023 (14 days after the 2 December 2023 evacuation notice for Khan Younis) to 14 March 2024, adjusted for differences in population size.

The Gaza Ministry of Health’s reporting on fatalities does not include geographic locations. Consequently, we used the ACLED database, which was incomplete, but did include the locations of traumatic injury deaths. We then resolved this uncertainty through machine learning imputation and adjusted the ratio of traumatic injury deaths reported by the MoH and ACLED to remove some potential bias due to incomplete detection of deaths by ACLED. Finally, to obtain the projection of the number of counted Rafah fatalities, the number of counted fatalities in Khan Younis was scaled by the ratio of the Rafah and Khan Younis populations at day 14 following their respective evacuation orders.

As we did in our first report, we used the UNRWA staff death reports as an independent source and compared it to the MoH mortality database to estimate the uncounted deaths from the latter; these include people who died under the rubble and other deaths that may not have been reported through the MoH system.

This projection of possible traumatic injury deaths in Rafah highlights the urgent and lifesaving need for an immediate ceasefire to reduce the mortality amongst civilians. International diplomacy and humanitarian efforts must prioritize the cessation of hostilities.

Advocacy for a ceasefire and the urgent need for civilian protection must be sustained.