Geographical inequalities in COVID-19 mortality: a scoping review protocol

Objective


Introduction
The COVID-19 pandemic has occurred against a backdrop of existing social and economic inequalities in noncommunicable diseases. 1While the impact of COVID-19 has been examined across various intersectional dimensions of health inequalities such as age, 2-5 disability, 6 gender, [7][8][9][10] race/ethnicity, 5,9,11−16 sexuality, 17 occupation, 18 and socioeconomic status, 16,19 geographical inequalities by area-level deprivation have been less explored.The links between place and health have been long established in the scienti c literature, 20,21 and prepandemic, geographical inequalities in health have been widely documented. 21In England, for example, healthy life expectancy varies by 21.5 years for women and 15.8 years for men between the least and most deprived local government areas -while even wider inequalities exist between smaller areas. 22Similarly, these localised inequalities in health are experienced in other high-income countries. 23For example, the capital of the United States, Washington DC, has a 20 year gap in life expectancy between low income and more a uent neightbourhoods. 21In Europe, regional north/south health inequalities persist in Italy 24 and Spain, 25 and some of the highest regional inequalities are found in France, Germany, the United Kingdom, and Austria. 26There are also notable geographical inequalities within low-and middle-income countries.For example, in the Thiruvananthapuram district in Kerela India, life expectancy is around 2-3 years longer among those from high income households compared to those living in more deprived circumstances. 27Poorer health outcomes are also documented among people living in disadvantaged circumstances in Malawi, South Africa, Swaziland, Zambia, and Zimbabwe compared to their more a uent counterparts. 28Given these large inequalities in health were prominent pre-pandemic we sought to examine whether COVID-19 mortality rates demonstrated similar geographical patterns.Research in England, for example, has found large regional inequalities with much higher rates of COVID-19 deaths in the more deprived northern regions. 29owever, there has been no overview of whether such geographical inequalities are present across different countries, in different stages of the pandemic or at different spatial scales.Therefore, this scoping review will identify primary studies across the globe and examine what is known to date on geographical inequalities in COVID-19 mortality rates.

Methods
We followed the Preferred Reporting Items for Systematic review and Meta-Analysis Protocols (PRISMA-P) checklist to develop this protocol (see Appendix 1). 30

Research question
What is known on geographical inequalities in COVID-19 mortality?

Study design
Scoping review methodology will be used to identify and synthesise published evidence on geographical inequalities in COVID-19 mortality rates.The review will follow established guidelines for the conduct and reporting of scoping reviews [31][32][33][34] and adhere to the Preferred Reporting of Systematic Reviews extension for Scoping Reviews (PRISMA-ScR). 35

Inclusion criteria
Following standard scoping review approaches the inclusion criteria will be guided by the PCC mnemonic; Population, Concept, Context (PCC). 31,32Only published, peer-reviewed studies written in English will be included.

Population: Children and adults (all ages).
Concept: Geographical inequalities in COVID-19 mortality within countries Context: Any country at any level (neighbourhood, town, city, municipality, region).

Search strategy
The Preferred Reporting Items for Systematic Reviews extension for Scoping Reviews (PRISMA-ScR) 35 guidelines will be followed throughout the design, conduct, and reporting of this review.Following Peters et al (2021) 32 an initial limited pilot search of Social Science Citation Index (Web of Science) will be conducted followed by an analysis of text words contained in the titles and abstracts in addition to the index terms describing each article (see Appendix 2 for pilot search terms).A second search using identi ed keywords and index terms will then be undertaken across the following key health inequality-related research databases (host sites given in parentheses): Medline (Ovid), Embase (Ovid), Science Citation Index Expanded and Social Science Citation Index (Web of Science).Reference lists of all relevant papers will be searched for additional studies and forward citation chaining will also be conducted.Publications will be limited to 1 st January 2020 to 31 st December 2021 re ecting the rst two years of the COVID-19 pandemic.Four key articles known to the authors that met the inclusion criteria were identi ed to ensure the sensitivity of the searches across different scales (see Table 1).

Screening
All titles and abstracts will be screened, using Rayyan QCRI (https://www.rayyan.ai/),by VJM and relevant papers will be retrieved and assessed for inclusion.Any ambiguous studies will be referred to CB for assessment.Studies will be excluded if they do not draw on empirical quantitative data.A ow chart of the selection process will be produced following PRISMA guidelines. 40udy selection

Data extraction
Data relating to study design, population, location, outcomes, and results by deprivation will be extracted from fulltext versions of included studies using standardised extraction forms (see Appendix 3). 41[33]

Synthesis
Identi ed papers meeting the inclusion criteria will be tabulated, synthesised thematically and a narrative constructed to describe the evidence base of geographical inequalities in COVID-19 mortality at different scales.

Discussion
This review will provide a summary of the evidence base on geographical inequalities in COVID-19 mortality combined with a theoretical discussion to explain this relationship drawing on the geographical literature on health and place. 42Additionally, it will discuss the research and policy implications of these spatial inequalities both during the pandemic phase and as the disease becomes more endemic. Declarations