{"doi":"10.1101/2020.11.28.20240366","title":"Second versus first wave of COVID-19 deaths: shifts in age distribution and in nursing home fatalities","abstract":"<h4>ABSTRACT</h4> <h4>OBJECTIVE</h4> To examine whether the age distribution of COVID-19 deaths and the share of deaths in nursing homes changed in the second versus the first pandemic wave. <h4>ELIGIBLE DATA</h4> We considered all countries that had at least 4000 COVID-19 deaths occurring as of January 14, 2020, at least 200 COVID-19 deaths occurring in each of the two epidemic wave periods; and which had sufficiently detailed information available on the age distribution of these deaths. We also considered countries with data available on COVID-19 deaths of nursing home residents for the two waves. <h4>MAIN OUTCOME MEASURES</h4> Change in the second wave versus the first wave in the proportion of COVID-19 deaths occurring in people <50 years (“young deaths”) among all COVID-19 deaths and among COVID-19 deaths in people <70 years old; and change in the proportion of COVID-19 deaths in nursing home residents among all COVID-19 deaths. <h4>RESULTS</h4> Data on age distribution were available for 14 eligible countries. Individuals <50 years old had small absolute difference in their share of the total COVID-19 deaths in the two waves across 13 high-income countries (absolute differences 0.0-0.4%). Their proportion was higher in Ukraine, but it decreased markedly in the second wave. The odds of young deaths was lower in the second versus the first wave (summary odds ratio 0.80, 95% CI 0.70-0.92) with large between-country heterogeneity. The odds of young deaths among deaths <70 years did not differ significantly across the two waves (summary odds ratio 0.95, 95% CI 0.85-1.07). Eligible data on nursing home COVID-19 deaths were available for 11 countries. The share of COVID-19 deaths that were accounted by nursing home residents decreased in the second wave significantly and substantially in 8 countries (odds ratio estimates: 0.22 to 0.66), remained the same in Denmark and Norway and markedly increased in Australia. <h4>CONCLUSIONS</h4> In the examined countries, age distribution of COVID-19 deaths has been fairly similar in the second versus the first wave, but the contribution of COVID-19 deaths in nursing home residents to total fatalities has decreased in most countries in the second wave.","journal":"medRxiv","year":2020,"id":12378,"datarank":1.5834309063057472,"base_score":3.044522437723423,"endowment":3.044522437723423,"self_citation_contribution":0.4566783656585135,"citation_network_contribution":1.1267525406472338,"self_endowment_contribution":0.4566783656585135,"citer_contribution":1.1267525406472338,"corpus_percentile":86.89564477450298,"corpus_rank":1695,"citation_count":20,"citer_count":17,"citers_with_citation_signal":14,"citers_with_endowment":14,"datacite_reuse_total":0,"is_dataset":true,"is_dataset_confidence":0.5575,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2020-11-30","fair_score":19.7917,"fair_percentile":2.4282560706401766,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":3829,"name":"Cathrine Axfors","orcid":"0000-0002-2706-1730","position":1,"is_corresponding":false},{"id":918,"name":"Despina G. Contopoulos‐Ioannidis","orcid":"0000-0002-1918-8918","position":3,"is_corresponding":false},{"id":148,"name":"John P. A. Ioannidis","orcid":"0000-0003-3118-6859","position":0,"is_corresponding":true}],"reference_count":26,"raw_metadata":{"citation_network_status":"fetched"},"created_at":"2026-03-01T18:20:47.508186Z","pmid":null,"pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":"green","license":"cc-by-nc-nd","views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":20.0,"fair_a":42.5,"fair_i":0.0,"fair_r":16.6667,"fair_zscore":-1.9467,"fair_rationale":{"fair_score":19.79,"has_llm":true,"dimensions":{"F":{"name":"Findable","score":20.0,"criteria":[{"key":"f_has_doi","label":"Has a persistent DOI","kind":"deterministic","weight":1.0,"fraction":1.0,"signal":"DOI present","rationale":null},{"key":"f_repository_presence","label":"Indexed in repositories / literature DBs","kind":"deterministic","weight":1.0,"fraction":0.0,"signal":"datacite=0, pmcid=False, pmid=False","rationale":null},{"key":"f_persistent_ids","label":"Resolvable scholarly identifiers (OpenAlex)","kind":"deterministic","weight":0.5,"fraction":0.0,"signal":"no OpenAlex id","rationale":null},{"key":"f_metadata_richness","label":"Rich, machine-readable metadata","kind":"llm","weight":1.0,"fraction":0.0,"signal":null,"rationale":"The paper provides no machine-readable metadata; only a plain-text abstract and tables are included."}]},"A":{"name":"Accessible","score":42.5,"criteria":[{"key":"a_open_access","label":"Open Access / files deposited","kind":"deterministic","weight":1.5,"fraction":1.0,"signal":"Open Access","rationale":null},{"key":"a_retrievable","label":"Free full text retrievable","kind":"deterministic","weight":1.0,"fraction":0.0,"signal":"0 OA location(s)","rationale":null},{"key":"a_access_protocol","label":"Clear data/code access protocol","kind":"llm","weight":1.0,"fraction":0.25,"signal":null,"rationale":"The paper states 'Data sharing: all the data are in the manuscript and tables' but does not provide a clear protocol for accessing the underlying data or code."}]},"I":{"name":"Interoperable","score":0.0,"criteria":[{"key":"i_linked_data","label":"Linked datasets / DataCite relations","kind":"deterministic","weight":1.0,"fraction":0.0,"signal":"linked_datasets=0, datacite=0","rationale":null},{"key":"i_standard_ids","label":"References data via standard accessions","kind":"deterministic","weight":1.0,"fraction":0.0,"signal":"accessions=0, trials=0","rationale":null},{"key":"i_standards","label":"Standard formats, vocabularies & identifiers","kind":"llm","weight":1.0,"fraction":0.0,"signal":null,"rationale":"No standard formats, vocabularies, or persistent identifiers (beyond the DOI) are used for the data or code."}]},"R":{"name":"Reusable","score":16.67,"criteria":[{"key":"r_license","label":"Clear, open reuse license","kind":"deterministic","weight":1.5,"fraction":0.0,"signal":"no license","rationale":null},{"key":"r_downloads","label":"Demonstrated reuse (downloads)","kind":"deterministic","weight":0.5,"fraction":0.0,"signal":"downloads=0","rationale":null},{"key":"r_version","label":"Versioned / maintained","kind":"deterministic","weight":0.5,"fraction":0.0,"signal":"no version chain","rationale":null},{"key":"r_dataset","label":"Classified as a data resource","kind":"deterministic","weight":0.5,"fraction":1.0,"signal":"is_dataset","rationale":null},{"key":"r_reusability","label":"Data-availability statement, license & reproducibility","kind":"llm","weight":2.0,"fraction":0.167,"signal":null,"rationale":"The paper includes a data-availability statement and a CC-BY-NC-ND license, but lacks a formal license for the data/code and does not provide code or detailed reproducibility instructions."}]}},"suggestions":["Provide the underlying data in a machine-readable format (e.g., CSV, JSON) with a structured metadata schema.","Include a clear data access protocol, such as a link to a public repository (e.g., Zenodo, GitHub) with versioning.","Use standard vocabularies and persistent identifiers (e.g., ORCID for authors, DOIs for datasets) to enhance interoperability.","Add a formal open license for the data and code (e.g., CC0 for data, MIT for code) to clarify reuse permissions.","Provide a reproducibility package with analysis scripts and a detailed README to enable full reuse of the results."],"model":"deepseek/deepseek-v4-flash","agent_version":"fair_agent_v2","fulltext_source":"unpaywall_pdf"},"fair_model":"deepseek/deepseek-v4-flash","fair_agent_version":"fair_agent_v2","fair_fulltext_source":"unpaywall_pdf","fair_has_llm":true,"fair_computed_at":"2026-06-18T00:47:33.801964Z","clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}