Impacts of the COVID-19 pandemic on deprivation-level differences in cardiovascular hospitalisations: A comparison of England and Denmark using the OpenSAFELY platform and National Registry Data
Authors: Costello Ruth E , Henderson Alasdair D , Tazare John , Pedersen Lars , Sorensen Henrik Toft , Vandenbroucke Jan P , Mansfield Kathryn E , Mahalingasivam Viyaasan , Zheng Bang , Carreira Helena , Bidulka Patrick , Piehlmaier Dominik , Wong Angel YS , Warren-Gash Charlotte , Hayes Joseph F , Quint Jennifer K , Katikireddi Srinivasa Vittal , MacKenna Brian , Mehrkar Amir , Bacon Sebastian , Goldacre Ben , Tomlinson Laurie , Langan Sinéad M , Mathur Rohini ,   The LH&W NCS (or CONVALESCENCE) Collaborative and the OpenSAFELYcollaborative
Published: May 2024

Objectives

To examine the impact of the pandemic on deprivation-related inequalities in hospitalisations for CVD conditions in Denmark and England between March 2018 and December 2021.

Design

A series of monthly cross-sectional studies separately in England and Denmark.Setting:With the approval of NHS England, we used English primary care electronic health records, linked to secondary care and death registry data through the OpenSAFELY platform, and nationwide Danish health registry data.

Participants

Adults aged 18 and over, without missing age, sex or deprivation information were included. On 1st March 2020, 16,234,700 people in England, and 4,491,336 people in Denmark met the inclusion criteria.

Primary and secondary outcome measures

Hospital admissions with the primary reason myocardial infarction (MI), ischaemic or haemorrhagic stroke, heart failure, and venous thromboembolism (VTE).

Results

We saw deprivation gradients in monthly CVD hospitalisations in both countries, with differences more pronounced in Denmark. Based on pre-pandemic trends, in England, there were an estimated 2608 fewer admissions than expected for heart failure in the most deprived quintile during the pandemic, compared to an estimated 979 fewer admissions in the least deprived quintile. In Denmark, there were an estimated 1013 fewer admissions than expected over the pandemic for MI in the most deprived quintile compared to 619 in the least deprived quintile. Similar trends were seen for stroke and VTE, though absolute numbers were smaller.

Conclusions

Overall, we did not find that the pandemic substantially worsened pre-existing deprivation-related differences in CVD hospitalisations, though there were exceptions in both countries.

Strengths and limitations

This was one of the largest studies of the impact of the pandemic on deprivation inequalities, covering 20 million people in two countries (England and Denmark).

Followed-up was until the end of 2021, which is longer than most previous studies.

We compared the impact in two countries that have free at the point of use healthcare, but different responses to the pandemic.

The measures of deprivation were different in the two countries, with the measure in England (Index of Multiple Deprivation 2019) capturing more aspects of deprivation compared to the Danish measure (income) which may have resulted in misclassification.

Our results are descriptive so do not provide insight into the causes of observed differences.