{"id":6923,"date":"2026-01-13T11:10:04","date_gmt":"2026-01-13T10:10:04","guid":{"rendered":"https:\/\/mediconomics.com\/?post_type=glossary&p=6923"},"modified":"2026-07-13T19:09:07","modified_gmt":"2026-07-13T17:09:07","slug":"serious-adverse-reaction-sar","status":"publish","type":"glossary","link":"https:\/\/mediconomics.com\/en\/glossar\/serious-adverse-reaction-sar\/","title":{"rendered":"Serious Adverse Reaction (SAR)"},"content":{"rendered":"

Synonyms:<\/strong> SAR, serious side effect<\/p>\n

Definition:<\/strong> A Serious Adverse Reaction (SAR) is an adverse reaction<\/em> for which a causal relationship with a medicinal product (e.g. investigational medicinal product) is judged to be at least possible, and which at the same time meets the criteria for being serious<\/em> (e.g. death, life-threatening event, hospitalisation or persistent damage).<\/p>\n

Distinction: AE, AR, SAE and SAR<\/h2>\n

An Adverse Event (AE)<\/strong> is any untoward medical occurrence following exposure to a medicinal product, irrespective of causality. An Adverse Reaction (AR)<\/strong> is an AE with a suspected causal relationship. Serious<\/strong> describes regulatory severity according to fixed criteria; an SAE<\/strong> is therefore a serious event irrespective of causality, whereas an SAR<\/strong> represents the combination of “serious” and “related”.<\/p>\n

Seriousness criteria (typical examples)<\/h2>\n

Classic seriousness criteria include death, a life-threatening event, hospitalisation or prolongation of hospitalisation, persistent or significant disability, congenital anomaly, and other medically important events that require intervention to prevent one of these outcomes.<\/p>\n

Relevance in clinical trials and pharmacovigilance<\/h2>\n

SARs are central for sponsors and authorities because they may represent relevant safety risks. They feed into ongoing benefit-risk assessments, updates to safety information, and aggregate reports (e.g. annual safety reports). Robust follow-up is important to establish diagnoses, outcomes and causality on a solid basis.<\/p>\n

Relationship to SUSAR and expedited reporting<\/h2>\n

An SAR may at the same time be “unexpected”; in that case it becomes a SUSAR and is subject to expedited reporting timelines. If an SAR, by contrast, is expected (e.g. already described in the reference safety information), it may still be reportable but is often not classified as a SUSAR. The precise classification depends on the applicable regulatory framework and the study’s Safety Reporting Plan.<\/p>\n

In quality management, a clear trace between specification, method, result and release decision is good practice. This allows a rapid assessment, in the event of deviations, of whether there is a risk to patient safety, efficacy or data interpretation, and which CAPA measures are necessary.<\/p>\n

Interfaces are also relevant: when several parties are involved (e.g. sponsor, manufacturer, contract laboratory), responsibilities, study plans, data formats and review steps should be aligned contractually and procedurally. This reduces the risk of inconsistent assessments.<\/p>\n

Data integrity principles (ALCOA+) also play a role in the creation and review of such documents: data should be attributable, legible, contemporaneous, original and accurate. This helps to investigate deviations in a traceable manner and to ensure traceability across the lifecycle of a product or a study.<\/p>\n

Practical note:<\/strong> When documenting and reporting in regulated environments, definitions, roles (sponsor, CRO, site) and timelines should be clearly set out in SOPs. Consistent application improves the comparability of data and reduces queries during audits and inspections.<\/p>\n

For quality assurance, it is also important that the underlying source data (e.g. raw laboratory data, medical findings, time references, dosing information) remain traceable and available. Summary documents are helpful but do not replace complete data integrity and controlled document control.<\/p>\n

In practice, many errors arise from inconsistent use of terminology or unclear distinctions. A brief definitional check (What is the trigger? Which criteria apply? Who makes the final decision?) helps stabilise processes and simplify internal communication.<\/p>\n

If specifications, reference information or reporting pathways change during a project, these changes should be version-controlled and communicated. This makes it traceable which rules applied at which point in time and how decisions were justified.<\/p>\n

In quality management, a clear trace between specification, method, result and release decision is good practice. This allows a rapid assessment, in the event of deviations, of whether there is a risk to patient safety, efficacy or data interpretation, and which CAPA measures are necessary.<\/p>\n

Interfaces are also relevant: when several parties are involved (e.g. sponsor, manufacturer, contract laboratory), responsibilities, study plans, data formats and review steps should be aligned contractually and procedurally. This reduces the risk of inconsistent assessments.<\/p>\n

Data integrity principles (ALCOA+) also play a role in the creation and review of such documents: data should be attributable, legible, contemporaneous, original and accurate. This helps to investigate deviations in a traceable manner and to ensure traceability across the lifecycle of a product or a study.<\/p>\n

Practical note:<\/strong> When documenting and reporting in regulated environments, definitions, roles (sponsor, CRO, site) and timelines should be clearly set out in SOPs. Consistent application improves the comparability of data and reduces queries during audits and inspections.<\/p>\n

For quality assurance, it is also important that the underlying source data (e.g. raw laboratory data, medical findings, time references, dosing information) remain traceable and available. Summary documents are helpful but do not replace complete data integrity and controlled document control.<\/p>\n

In practice, many errors arise from inconsistent use of terminology or unclear distinctions. A brief definitional check (What is the trigger? Which criteria apply? Who makes the final decision?) helps stabilise processes and simplify internal communication.<\/p>\n

If specifications, reference information or reporting pathways change during a project, these changes should be version-controlled and communicated. This makes it traceable which rules applied at which point in time and how decisions were justified.<\/p>\n

FAQ<\/h2>\n

Why is “serious” not the same as “severe”?<\/h3>\n

“Serious” describes regulatory criteria (e.g. hospitalisation), while “severe” refers to clinical intensity. An event can be severe without being serious – and vice versa.<\/p>\n

Who assesses causality for an SAR?<\/h3>\n

Causality is usually assessed by the investigator and\/or the sponsor (medical monitor). For classification as an SAR, at least a suspected relationship must exist.<\/p>\n

Must SARs always be reported within 24 hours?<\/h3>\n

Many studies require very rapid reporting of SAEs to the sponsor (often within 24 hours). Whether and how quickly an SAR must be reported externally depends on whether it is additionally unexpected (SUSAR) and on the applicable legal framework.<\/p>\n

What role does documentation play?<\/h3>\n

Complete documentation (time reference, treatment, outcome, concomitant medication, relevant findings) is essential for assessing seriousness, causality and expectedness, as well as for regulatory reports.<\/p>\n

Sources<\/h2>\n
    \n
  • ICH E6(R2): Good Clinical Practice – section on Safety Reporting \/ AE\/SAE (R2 Addendum). https:\/\/database.ich.org\/sites\/default\/files\/E6_R2_Addendum.pdf<\/li>\n
  • EMA: Clinical safety data management: definitions and standards for expedited reporting (ICH E2A). https:\/\/www.ema.europa.eu\/en\/ich-e2a-clinical-safety-data-management-definitions-standards-expedited-reporting<\/li>\n
  • EU CTR\/CTIS overview (EU 536\/2014): safety reporting in the clinical trial context. https:\/\/health.ec.europa.eu\/medicinal-products\/clinical-trials\/clinical-trials-regulation-eu-no-5362014_en<\/li>\n<\/ul>\n

    For sponsors and investigational sites it is also important that coding (e.g. MedDRA), the assessment of expectedness (Investigator’s Brochure\/SmPC) and the timelines (e.g. 7\/15 days for SUSAR) are clearly described in the Safety Management Plan. This reduces queries from authorities and improves data quality.<\/p>\n","protected":false},"excerpt":{"rendered":"

    Synonyms: SAR, serious side effect Definition: A Serious Adverse Reaction (SAR) is an adverse reaction for which a causal relationship with a medicinal product (e.g. investigational medicinal product) is judged to be at least possible, and which at the same time meets the criteria for being serious (e.g. death, life-threatening event, hospitalisation or persistent damage). […]<\/p>\n","protected":false},"author":10,"featured_media":0,"parent":0,"template":"","meta":{"_acf_changed":false,"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"set","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"glossary-cat":[],"class_list":["post-6923","glossary","type-glossary","status-publish","hentry"],"acf":[],"related_terms":"","external_url":"","internal_reference_id":"","_links":{"self":[{"href":"https:\/\/mediconomics.com\/en\/wp-json\/wp\/v2\/glossary\/6923","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/mediconomics.com\/en\/wp-json\/wp\/v2\/glossary"}],"about":[{"href":"https:\/\/mediconomics.com\/en\/wp-json\/wp\/v2\/types\/glossary"}],"author":[{"embeddable":true,"href":"https:\/\/mediconomics.com\/en\/wp-json\/wp\/v2\/users\/10"}],"version-history":[{"count":1,"href":"https:\/\/mediconomics.com\/en\/wp-json\/wp\/v2\/glossary\/6923\/revisions"}],"predecessor-version":[{"id":6926,"href":"https:\/\/mediconomics.com\/en\/wp-json\/wp\/v2\/glossary\/6923\/revisions\/6926"}],"wp:attachment":[{"href":"https:\/\/mediconomics.com\/en\/wp-json\/wp\/v2\/media?parent=6923"}],"wp:term":[{"taxonomy":"glossary-cat","embeddable":true,"href":"https:\/\/mediconomics.com\/en\/wp-json\/wp\/v2\/glossary-cat?post=6923"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}