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  4. Swedish Covid-19 Investigation for Future Insights – a Population Epidemiology Approach using Register Linkage (SCIFI-PEARL)

Swedish Covid-19 Investigation for Future Insights – a Population Epidemiology Approach using Register Linkage (SCIFI-PEARL)

Research project
Active research
Project period
2020 - ongoing
Project owner
Fredrik Nyberg
Financier
ALF-agreement, FORMAS, Swedish Heart Lung Foundation, SciLifeLab / Knut and Alice Wallenbergs Foundation, Swedish Research Council, Swedish Social Insurance Agency
Area
Health and
medicine
Topic
Epidemiology
Public Health, Global Health, Social Medicine and
Epidemiology

Short description

SCIFI-PEARL is a nationwide linked multi-register, regularly updated, observational study for timely response to urgent scientific questions regarding SARS-Cov-2 (severe acute respiratory syndrome coronavirus 2) and the COVID-19 (Coronavirus disease 2019) pandemic.
The SCIFI-PEARL database captures Swedish residents with Covid-19 on an ongoing basis, includes a representative general population comparison cohort, and links to a broad range of national and regional healthcare data for a comprehensive longitudinal view of the Covid-19 pandemic. By combining high-quality national registers with short time delay and continuous repeated linkage and updating, the project brings timely and internationally relevant data for epidemiological research on SARS-CoV-2.

Background 

In December 2019 the novel coronavirus SARS-CoV-2 appeared for the first time in Wuhan, causing the disease now named COVID-19. Very quickly COVID-19 evolved into a large-scale pandemic that has been spreading to most countries in the world. To understand and combat the pandemic, more scientifically sound information is needed about patients, their risk factors and prognosis, as well as long-term effects after the disease..

In response to the Covid-19 pandemic, we designed and initiated a nationwide linked multi-register, regularly updated, observational study for timely response to urgent scientific questions. Therefore, the SCIFI-PEARL (Swedish Covid-19 Investigation for Future Insights - a Population Epidemiology Approach using Register Linkage) project was formed.

This project seeks to answer many current questions with register data, including questions such as :

  • What are the characteristics of Covid-19 patients and how do they differ from a normal population?
  • Which underlying diseases or treatments increase patients' risk of Covid-19 or unfavourable prognosis?
  • What other factors increase or modify the risk?
  • What aspects of comorbidity, treatments or medical history increase the risk of long-term (1-2 years) consequences of Covid-19 infection?
  • Can we develop predictive models that help predict onset or severe prognosis?
  • What is the effect and possible side effects of covid-19 vaccines in the population?
  • How has the COVID-19 pandemic and vaccination programmes affected drug use and healthcare in individuals and society?

How does register research work within COVID-19?

Covid-19 patients and the whole Swedish population are used for various statistical analysis methods including case-cohort design and prediction modeling. Via the national personal ID (personnummer), data from different health databases are linked, including:

Data from national and regional health registers :

  • Covid-19 test data
  • vaccination data
  • national patient register
  • 2 regional health databases
  • national prescribed drug register
  • national cancer registry

The project also includes data from quality registers relevant to Covid-19, including registers related to :

  • heart disease
  • lung disease
  • diabetes
  • emergency care
  • intensive care
  • infectious diseases

and sociodemographic data about the study population from Statistics Sweden.

 

The database

The database is being updated regularly (every 1-3 months), to provide answers to current research questions. Descriptive statistics, regression modelling and machine learning methods are used for data analysis, with adjustment for confounding factors. Results are generated, presented and published on a continuous basis, based on the updated source data.

 

Examples for current research projects

Examples of ongoing projects and analyses in the SCIFI-PEARL project
Examples of published results within the SCIFI-PEARL project

Project members

Ailiana Santosa, Researcher

Brian Kirui, PhD Student 

Chioma Nwaru, Postdoctor

Fredrik Nyberg, Project leader and Professor in register epidemiology

Huiqi Li, Statistician / Researcher 

Patricia Ernst, Projekt coordinator and Research Associate

Maria Bygdell, Postdoctor

Yiyi Xu, Researcher 

Ailiana Santosa, Researcher

Björn Wettermark, Professor at Department of Pharmacy, Drug epidemiology / Uppsala University

Fredrik Nyberg, Project leader and Professor in Register Epidemiology / University of Gothenburg 

Mohammadhossein Hajiebrahimi, Research assistant at Department of Pharmacy, Drug epidemiology / Uppsala University

Patricia Ernst, Project Coordinator and Research Associate 

Ailiana Santosa, Researcher

Brian Kirui, PhD Student 

Chioma Nwaru, Postdoctor

Fredrik Nyberg, Project leader och Professor in Register Epidemiology

Huiqi Li, Statistician / Researcher

Johan Sundström, Professor at Department of Medical Sciences, Clinical Epidemiology / Uppsala University 

Lowie Vanfleteren, Senior Lecturer/ Specialized Physician

Magnus Gisslen, Professor/ Chief Physician

Magnus Lindh, Professor/ Chief Physician

Patricia Ernst, Project coordinator and Reserach Associate

Publications

  • Nyberg F, Franzén S, Lindh M, Vanfleteren L, Hammar N, Wettermark B, Sundström J, Santosa A, Björck S, Gisslén M. Swedish Covid-19 Investigation for Future Insights – A Population Epidemiology Approach Using Register Linkage (SCIFI-PEARL). Clin Epidemiol. 2021;13:649-659. https://doi.org/10.2147/CLEP.S312742
  • Shedrawy J, Ernst P, Lönnroth K, Nyberg F. The burden of disease due to COVID-19 in Sweden 2020-2021: A disability-adjusted life years (DALYs) study. Scand J Public Health. 2023 Mar 20:14034948231160616. doi: 10.1177/14034948231160616. Epub ahead of print. PMID: 36941820.
  • Nwaru C, Li H, Bonander C, Santosa A, Franzén S, Rosvall M, Nyberg F. Occupational role and COVID-19 among foreign-born healthcare workers in Sweden: a registry-based study. Eur J Public Health. 2023 Feb 10:ckad016. doi: 10.1093/eurpub/ckad016. Epub ahead of print. PMID: 36762873.
  • Spetz M, Lundberg L, Nwaru C, Li H, Santosa A, Ng N, Leach S, Gisslén M, Hammar N, Nyberg F, Rosvall M. An intersectional analysis of sociodemographic disparities in Covid-19 vaccination: A nationwide register-based study in Sweden. Vaccine. 2022 Nov 2;40(46):6640-6648. doi: 10.1016/j.vaccine.2022.09.065. Epub 2022 Sep 28. PMID: 36210254; PMCID: PMC9515344.
  • Bygdell M, Leach S, Lundberg L, Gyll D, Martikainen J, Santosa A, Li H, Gisslén M, Nyberg F. A comprehensive characterization of patients diagnosed with post-COVID-19 condition in Sweden 16 months after the introduction of the ICD-10 diagnosis code (U09.9): a population-based cohort study.
  • Dahlén T, Li H, Nyberg F, Edgren G. A population-based, retrospective cohort study of the association between ABO blood group and risk of COVID-19. Journal of Internal Medicine. https://onlinelibrary.wiley.com/doi/abs/10.1111/joim.13588
  • Xu Y, Li H, Kirui B, Santosa A, Gisslén M, Leach S, Wettermark B, Vanfleteren LEGW, Nyberg F. Effectiveness of COVID-19 Vaccines over 13 Months Covering the Period of the Emergence of the Omicron Variant in the Swedish Population. Vaccines. 2022; 10(12):2074. https://doi.org/10.3390/vaccines10122074
  • Mousa SI, Nyberg F, Hajiebrahimi M, Bertilsson R, Nåtman J, Santosa A, Wettermark B. Initiation of antihypertensive drugs to patients with confirmed COVID-19-A population-based cohort study in Sweden. Basic Clin Pharmacol Toxicol. 2022 Sep;131(3):196-204. doi: 10.1111/bcpt.13766. Epub 2022 Jul 6. PMID: 35726121; PMCID: PMC9349802.
  • Spetz M, Lundberg L, Nwaru C, Li H, Santosa A, Leach S, Gisslén M, Hammar N, Rosvall M, Nyberg F. The social patterning of Covid-19 vaccine uptake in older adults: A register-based cross-sectional study in Sweden. Lancet Reg Health Eur. 2022 Apr;15:100331. doi: 10.1016/j.lanepe.2022.100331. Epub 2022 Feb 26. PMID: 35252941; PMCID: PMC8881226.
  • Sundh J, Ekström M, Palm A, Ljunggren M, Emilsson ÖI, Grote L, Cajander S, Li H, Nyberg F. COVID-19 and Risk of Oxygen-Dependent Chronic Respiratory Failure: A National Cohort Study. Am J Respir Crit Care Med. 2022 Aug 15;206(4):506-509. doi: 10.1164/rccm.202202-0323LE. Erratum in: Am J Respir Crit Care Med. 2022 Nov 15;206(10):1300. PMID: 35549847.
  • Santosa A, Franzén S, Nåtman J, Wettermark B, Parmryd I, Nyberg F. Protective effects of statins on COVID-19 risk, severity and fatal outcome: a nationwide Swedish cohort study. Sci Rep. 2022 Jul 14;12(1):12047. doi: 10.1038/s41598-022-16357-2. PMID: 35835835; PMCID: PMC9282150.
  • Nyberg F, Lindh M, Vanfleteren L, Hammar N, Wettermark B, Sundström J, Santosa A, Kirui BK, Gisslén M. Adverse events of special interest for COVID-19 vaccines - background incidences vary by sex, age and time period and are affected by the pandemic. Preprint. medRxiv 2021.10.04.21263507; doi: https://doi.org/10.1101/2021.10.04.21263507
  • Nwaru CA, Santosa A, Franzén S, Nyberg F. Occupation and COVID-19 diagnosis, hospitalisation and ICU admission among foreign-born and Swedish-born employees: a register-based study. J Epidemiol Community Health. 2022 Jan 7;76(5):440–7. doi: 10.1136/jech-2021-218278. Epub ahead of print. PMID: 34996808; PMCID: PMC8761595.

  • Labor M, Kirui B, Nyberg F, Vanfleteren L. Regular inhaled corticosteroids use may protect against severe COVID-19 outcome in COPD. Submitted 

  • Ljung R, Xu Y, Sundström A, Leach S, Hallberg E, Bygdell M, Larsson M, Arthurson V, Gisslén M, Gedeborg R, Nyberg F. The association between SARS-CoV-2 vaccination and healthcare contacts for menstrual disturbance and pre- and post-menopausal bleeding – a nationwide cohort study of 3 million Swedish women. Submitted.

  • Kirui B, Santosa A, Franzén S, Vanfleteren L, Stridsman C, Nyberg F. Characteristics and outcomes of COVID-19 patients with COPD in Sweden: A population-based register study. Submitted
  • Dahlén T, Flygt H, Lübking A, Olsson-Strömberg U, Wennström L, Dreimane A, Myhr-Eriksson K, Själander A, Leach S, Gisslén M, Li H, Höglund M, Stenke L, Nyberg F. The impact of Covid-19 in patients with chronic myeloid leukemia – a nationwide population-based study. Submitted

Abstracts and oral presentations within the SCIFI-PEARL-project:

2023

  • Bergthorsdottir R, Esposito D, Johannsson G, Ragnarsson O, Dahlqvist P, Bensing S, Nåtman J, Nyberg F. Hospitalisation, Intensive Care and Death due to COVID-19 in Swedish Patients with Adrenal Insufficiency. Abstract at the ENDO 2023 Conference. 15. – 18. June 2023. Chicago, USA.

2022

  • Nwaru C, Li H, Bonander C, Santosa A, Franzén S, Rosvall M, Nyberg F. Occupational variation in the risk of Covid-19 infection and hospitalization among foreign-born healthcare workers in Sweden: a registry-based study. Oral at the State of the Art Covid-19 Conference 2022. 16. – 17. November 2022. Online.
  • Ernst P, Shedrawy J, Lönnroth K, Nyberg F. The burden of disease due to COVID-19 in Sweden: a disability-adjusted life years (DALY) study. Poster at the State of the Art Covid-19 Conference 2022. 16. – 17. November 2022. Online. [Winner Best Poster Award]
  • Spetz M, Lundberg L, Nwaru C, Li H, Santosa A, Ng N, Leach S, Gisslén M, Hammar N, Nyberg F, Rosvall M. An intersectional analysis of sociodemographic disparities in Covid-19 vaccination: A nationwide register-based study in Sweden. Poster at the State of the Art Covid-19 Conference 2022. 16. – 17. November 2022. Online. [Runner up Best Poster Award]
  • Xu Y, Li H, Kirui B, Santosa A, Gisslén M, Leach S, Wettermark B, Vanfleteren L, Nyberg F. Effectiveness of Covid-19 vaccines over 13 months covering the period of the emergence of the Omicron variant in the Swedish population. Poster at the State of the Art Covid-19 Conference 2022. 16. – 17. November 2022. Online.
  • Sundh J, Ekström M, Palm A, Ljunggren M, Emilsson Ö, Grote L, Cajander S, Li H, Nyberg F. Covid-19 and risk of oxygen-dependent chronic respiratory failure – a national cohort study within the SCIFI-PEALR project. Poster at the State of the Art Covid-19 Conference 2022. 16. – 17. November 2022. Online.
  • Bygdell M, Leach S, Lundberg L, Gyll D, Martikainen J, Santosa A, Li H, Gisslén M, Nyberg F. A comprehensive characterization of patients diagnosed with post-covid-19 condition: a population-based study from SCIFI-PEARL. Poster at the State of the Art Covid-19 Conference 2022. 16. – 17. November 2022. Online.
  • Nyberg F, Dahlén T, Li H, Edgren G. A population-based, retrospective cohort study of the association between ABO blood group and risk of Covid-19. Poster at the State of the Art Covid-19 Conference 2022. 16. – 17. November 2022. Online.
  • Shedrawy J, Ernst P, Lönnroth K, Nyberg F. The burden of disease due to COVID-19 in Sweden: a disability-adjusted life years (DALY) study. Poster at the 15th European Public Health Conference 2022. 09. – 12. November 2022. Berlin. [Presented by Ernst P]
  • Nwaru C, Li H, Bonander C, Santosa A, Franzén S, Rosvall M, Nyberg F. Occupational role and Covid-19 among foreign-born healthcare workers: a registry-based study. Poster at the 15th European Public Health Conference 2022. 09. – 12. November 2022. Berlin. 
  • Labor M, Nyberg F, Kirui B, Vanfleteren L. Impact of treatment with inhaled corticosteroids on COVID-19 risk and outcome – a potential protective effect on severity of disease survival.  Abstract presentation at the European Respiratory Society (ERS) International Congress. 04. – 06. September 2022. Barcelona. [Presented by Labor M]
  • Mousa SI, Nyberg F, Hajiebrahimi M, Bertilsson R, Nåtman J, Santosa A, Wettermark B. Initiation of antihypertensive drugs to patients with confirmed COVID-19-A population-based cohort study in Sweden. Poster at the 38th International Conference on Pharmacoepidemiology & Therapeutic Risk Management (ICPE). 24. – 28. August 2022. Copenhagen. [Presented by Hajiebrahimi M]
  • Shiahn H, Wettermark B, Nyberg F, Hajiebrahimi M. Drug utilization and characteristics of COVID-19 positive pre-and postmenopausal women diagnosed with breast cancer – A cross-sectional SCIIF-PEARL study. Poster at the 38th International Conference on Pharmacoepidemiology & Therapeutic Risk Management (ICPE). 24. – 28. August 2022. Copenhagen. [Presented by Hajiebrahimi M]
  • Spetz M, Lundberg L, Nwaru C, Li H, Santosa A, Leach S, Gisslén M, Hammar N, Rosvall M, Nyberg F. The social patterning of Covid-19 vaccine uptake in older adults: a register-based cross-sectional study in Sweden. Poster at the 38th International Conference on Pharmacoepidemiology & Therapeutic Risk Management (ICPE). 24. – 28. August 2022. Copenhagen. [Presented by Nyberg F] 
  • Kirui B, Labor M, Nyberg F, Vanfleteren L. Inhaled corticosteroids and COVID-19 risk and outcomes – Findings from a population-based cohort within the SCIFI-PEARL project.  Abstract presentation at the 38th International Conference on Pharmacoepidemiology & Therapeutic Risk Management (ICPE). 24. – 28. August 2022. Copenhagen.
  • Kirui B, Santosa A, Vanfleteren L, Stridsman C, Nyberg F. Characteristics of asthma patients with COVID-19 by disease severity and across age groups – a Swedish population-based analysis within the SCIFI-PEARL project. Poster at the 38th International Conference on Pharmacoepidemiology & Therapeutic Risk Management (ICPE). 24. – 28. August 2022. Copenhagen.
  • Xu Y, Li H, Kirui B, Santosa B, Gisslén B, Leach S, Wettermark B, Vanfleteren L, Nyberg F. Long-lasting Vaccine effect before Omicron and progressively waning after Omicron -  a Swedish study  over 13 Months. Abstract presentation at the Nordic Conference of Epidemiology and Register-Based Health Research (NordicEPI). 18. – 19. August 2022. Reykjavik. [Presented by Li H]
  • Bygdell M, Leach S, Lundberg L, Gyll D, Martikainen J, Santosa A, Li H, Gisslén M, Nyberg F. A comprehensive characterization of the patient population diagnosed with post-COVID-19 condition in Sweden one year after the introduction of the ICD-10 diagnosis code U09.9 - a study within the SCIFI-PEARL project. Abstract presentation at the Nordic Conference of Epidemiology and Register-Based Health Research (NordicEPI). 18. – 19. August 2022. Reykjavik. [Presented by Nyberg F]
  • Sundh J, Ekström M, Palm A, Ljunggren M, Emilsson Ö, Grote L, Cajander S, Li H, Nyberg F. COVID-19 and risk of oxygen-dependent chronic respiratory failure – a national cohort study. Abstract presentation at the Nordic Conference of Epidemiology and Register-Based Health Research (NordicEPI). 18. – 19. August 2022. Reykjavik. [Presented by Nyberg F]
  • Kirui B, Santosa A, Vanfleteren L, Franzén S, Stridsman C, Nyberg F. Characteristics and risk factors for COVID-19 outcomes in a Swedish population-based cohort of COPD patients from the SCIFI-PEARL project. Abstract presentation at the Nordic Conference of Epidemiology and Register-Based Health Research (NordicEPI). 18. – 19. August 2022. Reykjavik.
  • Santosa A, Oras J, Li H, Nwaru C, Kirui B, Nyberg F. Clinical characteristics and outcomes of critically ill patients with COVID-19 in Sweden – a population-based cohort study. Abstract presentation at the Nordic Conference of Epidemiology and Register-Based Health Research (NordicEPI). 18. – 19. August 2022. Reykjavik.
  • Sundh J, Ekström M, Palm A, Ljunggren M, Emilsson Ö, Grote L, Cajander S, Li H, Nyberg F. COVID-19 and risk of oxygen-dependent chronic respiratory failure – a national cohort study. Poster at the Svenska Lungkongressen. 27. – 29. April 2022. Malmö

2021

  • Nyberg F, Franzén S, Lindh M, Vanfleteren L, Hammar N, Wettermark B, Sundström J, Santosa A, Björk S, Gisslen M. SCIFI-PEARL – en bred nationell studie av covid-19 med en kontinuerlig uppdaterad databas. [SCIFI-PEARL: Swedish Covid-19 Investigation for Future Insights – a Population Epidemiology Approach using Register Linkage]. Poster at the State of the Art Covid-19 Conference. Digital, 2020.
  • Nyberg F, Franzén S, Santosa A, Vanfleteren L, Hammar N, Sundström J, Lindh M, Björk S, Gisslén M, Wettermark B. SCIFI-PEARL: Swedish Covid-19 Investigation for Future Insights – a Population Epidemiology Approach using Register Linkage. Poster at the 37th International Conference on Pharmacoepidemiology and Therapeutic Risk Management (ICPE 37) of the International Society of Pharmacoepidemiology (ISPE). Digital, 2021.
  • Nyberg F, Santosa A, Parmryd I, Wettermark B, Franzén S. Impact of Statin Treatment on COVID-19 Risk and Outcome – a Potential Positive Effect on Survival. Poster at the 37th International Conference on Pharmacoepidemiology and Therapeutic Risk Management (ICPE 37) of the International Society of Pharmacoepidemiology (ISPE). Digital, 2021.
  • Santosa A, Franzén S, Wettermark B, Parmryd I, Nyberg F. Protective effects of statin treatment on COVID-19 risk, severity and fatal outcome – a nationwide Swedish cohort study. Abstract presentation at the Nordic Pharmacoepidemiological Networks 13th annual meeting (NorPEN). Digital, 2021.
  • Kirui B, Santosa A, Franzén S, Vanfleteren L, Stridsman C, Nyberg F. Characteristics and outcomes of COVID-19 patients with preexisting COPD in Sweden: A population-based register study. Abstract presentation at the Nordic Pharmacoepidemiological Networks 13th annual meeting (NorPEN). Digital, 2021.
  • Nyberg F, Lindh M, Vanfleteren L, Hammar N, Wettermark B, Sundström J, Santosa A, Kirui B, Gisslén M. Potentiella biverkningar för Covid-19-vacciner – bakgrundsincidenser varierar med ålder och kön, över tid och påverkas av pandemin – en befolkningsbaserad registerstudie inom SCIFI-PEARL-projektet. [Potential side effects of COVID-19 vaccines - background incidences vary with age and gender, over time and are affected by the pandemic - a population-based registry study within the SCIFI-PEARL project]. Poster at the State of the Art Covid-19 Conference. Digital, 2021.
  • Kirui B, Santosa A, Franzén S, Vanfleteren L, Stridsman C, Nyberg F. Karakterisering av COVID-19-patienter med astma i Sverige - en befolkningsbaserad registerstudie inom SCIFI-PEARL-projektet. [Characterization of COVID-19 patients with asthma in Sweden - a population-based register study within the SCIFI-PEARL project]. Poster at the State of the Art Covid-19 Conference. Digital, 2021.
  • Kirui B, Santosa A, Franzén S, Vanfleteren L, Stridsman C, Nyberg N. Riskfaktorer och covid-19-utfall bland patienter med kronisk obstruktiv lungsjukdom i Sverige – en populations-baserad registerstudie inom SCIFI-PEARL Projekt. [Risk factors and covid-19 outcome in patients with chronic obstructive pulmonary lung disease in Sweden - a population-based registry study within the SCIFI PEARL Project]. Poster at the State of the Art Covid-19 Conference. Digital, 2021.
  • Labor M, Nyberg F, Kirui B, Vanfleteren L. Inhalerade kortikosteroider (IKS) och covid-19 – potentiell skyddande effekt på svårighetsgrad och överlevnad – preliminära resultat av SCIFI-PEARL-projektet. [Inhaled corticosteroids and covid-19 - potential protective effect on severity and survival - preliminary results from the SCIFI-PEARL project]. Abstract at the State of the Art Covid-19 Conference. Digital, 2021.
  • Nwaru C, Santosa A, Franzén S, Nyberg F. Yrke och Covid-19-utfall bland utrikesfödda och svenskfödda i Sverige- en registerbaserad studie inom SCIFI-PEARL projektet. [Occupation and Covid-19 outcome among foreign-born and Swedish-born in Sweden - a register-based study within the SCIFI-PEARL project]. Poster at the State of the Art Covid-19 Conference. Digital, 2021.

Trysell, K. (2021, November 25). Svenska forskare: Statiner tycks skydda mot död i covid-19. https://lakartidningen.se/aktuellt/nyheter/2021/11/svenska-forskare-statiner-tycks-skydda-mot-dod-i-covid-19/

SCIFI-PEARL Internal group
SCIFI-PEARL Internal project group from left to right: Ailiana Santosa, Yiyi Xu, Maria Bygdell, Chioma Nwaru, Brian Kirui, Patricia Ernst, Huiqi Li, Fredrik Nyberg
Photo: Huiqi Li

Register epidemiology

The SCIFI-PEARL project is part of the research group in registry epidemiology and is affiliated to the School of Public Health and Community Medicine at the University of Gothenburg. 

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