{"doi":"10.1093/cid/ciab467","title":"Beware of Biases in Observational Studies on Anti-Spike Monoclonal Antibodies","abstract":"To the Editor—We read with interest Kumar and colleagues’ study on a real-world experience with bamlanivimab [1]. Anti-spike monoclonal antibodies (mAbs) are a potential resource against coronavirus disease 2019 (COVID-19), especially in its early stages. Despite conflicting results with bamlanivimab alone [2], recent evidence showed that mAb combinations can prevent some emergency department visits and hospitalizations [3, 4]. Since the main limitation of mAbs is the need for large-scale early hospital use, effectiveness studies, dealing with the logistical difficulties, can be appropriate. On the other hand, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections vary in severity and most of them heal spontaneously without treatment; thus, nonrandomized comparisons must be conducted with extreme caution. Kumar’s work, improperly referred to as a “case-control” study, included all patients referred for bamlanivimab to their center and compared those who had actually received it with those...","journal":"Clinical Infectious Diseases","year":2021,"id":224270,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":0,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9562,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2021-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":826276,"name":"Davide Paolo Bernasconi","orcid":"0000-0001-8771-5428","position":1,"is_corresponding":false},{"id":826277,"name":"Alessandro Soria","orcid":"0000-0002-4447-2574","position":2,"is_corresponding":false},{"id":826719,"name":"Maria Grazia Valsecchi","orcid":null,"position":3,"is_corresponding":false},{"id":104198,"name":"Paolo Bonfanti","orcid":"0000-0001-7289-8823","position":4,"is_corresponding":false},{"id":826275,"name":"Giuseppe Lapadula","orcid":"0000-0002-9976-8102","position":0,"is_corresponding":true}],"reference_count":6,"raw_metadata":null,"created_at":"2026-07-18T23:54:18.470602Z","pmid":"34015133","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}