Researchers challenge Gaza mortality survey in Lancet correspondence

Drawing on GPS information released with the study, DellaPergola and Zlochin said interview areas overlapped in some locations rather than remaining distinct.

By Vered Weiss, World Israel News

Two researchers have challenged the findings of a widely cited study on deaths in Gaza, arguing in a newly published correspondence in The Lancet Global Health that weaknesses in the survey’s design and execution may have distorted estimates of conflict-related fatalities.

The correspondence, authored by Professor Emeritus Sergio DellaPergola of the Hebrew University of Jerusalem and independent researcher Mark Zlochin, focuses on a Gaza Mortality Survey that estimated approximately 75,200 violent deaths during the Israel-Hamas conflict.

After reviewing the survey’s publicly released data, the researchers concluded that several aspects of the methodology warrant closer scrutiny.

Rather than disputing a single element of the study, DellaPergola and Zlochin point to a series of concerns that they say collectively raise doubts about whether the survey accurately reflected Gaza’s broader population.

Their analysis highlights uneven results among interviewer teams, inconsistencies in sampling patterns and discrepancies between the survey’s findings and external demographic data.

One of the issues identified in the correspondence involves the distribution of reported fatalities among survey teams.

The researchers found that a single interviewer group accounted for roughly one-quarter of all violent deaths recorded in the survey despite covering only a limited portion of sampled households.

They also reported demographic patterns among some interviewers’ results that differed markedly from those recorded elsewhere in the study.

The correspondence further questions whether fieldwork followed the sampling procedures described by the survey’s authors.

Drawing on GPS information released with the study, DellaPergola and Zlochin said interview areas overlapped in some locations rather than remaining distinct.

They also argued that interviewers covered only small sections of their assigned zones, potentially limiting the survey’s ability to capture population variation across Gaza.

Additional concerns involved the possibility of duplicate reporting of deaths among families displaced by the war and differences between the survey’s estimates of imprisoned Gazans and independently reported detention figures.

The researchers also noted that information on causes of death was collected but not included in the published results.

“Population-level mortality estimates are only as reliable as the representativeness of the underlying sample,” DellaPergola said. “Our analysis raises important questions regarding whether the survey achieved the level of representativeness necessary to support its national mortality estimates.”

The publication adds to an ongoing debate among researchers over how casualty figures are measured and evaluated in active conflict zones.