This review summarizes the key limitations of using verbal autopsies to measure malaria mortality at the population level. The main limitations identified are the low sensitivity and specificity of existing verbal autopsy tools in determining malaria as the cause of death. There is also a lack of standardization in how verbal autopsies are implemented and analyzed across studies. Additional challenges include small sample sizes and potential for recall bias. The review concludes there is an urgent need to improve verbal autopsy methods to provide more accurate estimates of malaria mortality and track progress of malaria control goals.

1. Moving Toward Improved Measurement of Malaria Mortality
at the Population Level
Background
Measuring malaria mortality at the population level is challenging due to the difficulty in assessing malaria and the fact that most malaria
deaths occur outside of the formal health system. To address this gap, the verbal autopsy (VA) method was developed to ascertain cause
of death at the population level. However, there are limitations with the current VA tools and approaches for measuring malaria-specific
mortality. Given the emphasis in the new Global Technical Strategy for Malaria on monitoring malaria-specific mortality, there is a strong
need for the malaria community to develop improved methods for measuring malaria-specific mortality. To help inform a strategy for
improving current methods, we carried out a systematic literature review to assess how VA tools and approaches have been used to
measure malaria-specific mortality and the key challenges and limitations of existing tools and methods.
Samantha Herrera1
, Yeetey Enuameh2
, George Adjei2
, Kenneth Ae-Ngibise2
, Kwaku Poku Asante2
, Osman Sankoh3
, Seth Owusu-Agyei2
, Yazoume Ye1
1
MEASURE Evaluation, ICF, 2
Kintampo Health Research Centre, 3
INDEPTH Network
Methods
Search Strategy:
Pubmed, the Cochrane Library, Popline, the WHOLIS, and Google Scholar databases were searched, from
1 January 1990 to 15 January 2016, using the search terms “malaria” or “malaria mortality” and “cause
specific mortality” and “verbal autopsy”/ “post mortem interview” / “mortality surveillance” / “verbal post
mortem.” INDEPTH Network websites were also searched to identify additional program reports, articles,
and gray literature on malaria-specific mortality.
Inclusion Criteria:
Publications were included if they met one of the following inclusion criteria: 1) presented results from a
VA study where malaria was an identified cause of death or 2) discussed limitations or challenges related
to the measurement of malaria mortality through VA.
Screening and Selection:
Two authors independently searched the databases and websites. Titles and abstracts of identified studies
and reports were screened to determine if they met the inclusion criteria. The full text of publications that
passed the screen were reviewed to determine eligibility.
Synthesis:
Key characteristics for each of the included publications were extracted using a standard matrix and
a narrative description of each publication was developed. A thematic analysis of key challenges and
limitations of measuring malaria mortality through VA was carried out.
Conclusion
This review sheds light on the many limitations with existing VA tools and methods
for measuring malaria mortality. It also highlights the urgent need for the global
malaria community to come together to define a strategy for improving VA tools
and methods to provide more robust estimates of malaria mortality in the future.
This will be key to measure progress toward the malaria control and elimination
goals set forth in the WHO Global Technical Strategy for Malaria 2016-2030 and in
the Sustainable Development Goals.
Acknowledgments
This research presentation has been supported by the President’s Malaria Initiative (PMI) through the
United States Agency for International Development (USAID) under the terms of MEASURE Evaluation
cooperative agreement AIDOAA-L-14-00004. MEASURE Evaluation is implemented by the Carolina
Population Center at the University of North Carolina at Chapel Hill, in partnership with ICF; John Snow,
Inc.; Management Sciences for Health; Palladium; and Tulane University. Views expressed are not
necessarily those of PMI, USAID, or the United States government.
Figure 1: Flowchart of the Selection of Publications for Systematic Literature Review
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Key Limitations and Challenges of Malaria Mortality Measurement through VA
yy The most common limitation was the varying and overall low levels of sensitivity and specificity of VA tools
for measuring malaria mortality, due to the non-specific symptoms of malaria and the differing malaria
epidemiological contexts in which studies are conducted that result in misclassification bias.
yy The lack of standardization in the application of VA tools and methods was another common limitation,
including the format and content of the questionnaires; the wide variation in the implementation of VA
studies; and how the cause of death is determined. For malaria specifically, there was no standard criteria
used to determine a malaria death across studies.
yy The use of hospital medical records as the gold standard to compare VA results is another limitation, as
these do not represent a true gold standard since they reflect a different population and typically have data
quality challenges.
yy Other general limitations included the small sample size of studies, recall bias among respondents that can
lead to misclassification bias, and the fact that many deaths in VA studies cannot be determined.
Results
yy Eighty-eight publications were included in the final review;
a total of 93 publication met the inclusion criteria, however
five were unavailable for review.
yy The majority of the publications included in the review
were VA studies where malaria was included as a cause of
death (68 total). Other publications included commentaries/
editorials; systematic review or synthesis articles or reports
discussing VA methods; articles presenting global, regional,
or country-level malaria mortality estimates that drew from
VA data and other data sources; and other studies that drew
upon VA data to look at the effectiveness of interventions or
other research studies.
788 publications identified through database search:
• 84 from Pubmed
• 0 from Cochrane Library
• 643 from Google Scholar
• 59 from Popline
828 publications identified and screened
676 abstracts assessed for eligibility
149 full-text publications assessed for eligibility
93 publications included in the review; however only
88 publications had the full-text available for review
40 publications identified through review of
available INDEPTH Network websites
152 duplicates removed
527 publications excluded after
screening of abstract
18 additional publications identified
through review of references
74 full-text publications excluded for the
following reasons:
• VA study did not include malaria deaths
• Publication did not discuss measurement of malaria
mortality through verbal autopsy