A usability study for medical devices is a structured investigation in which representative users operate a product or its user interface under realistic conditions to identify usability issues and safety-relevant use errors, or to demonstrate that operation can be performed safely and effectively. It is not a clinical investigation within the meaning of Articles 62 to 80 of Regulation (EU) 2017\/745, but rather a means of design validation that serves to meet the requirements of Annex I regarding ergonomics and the prevention of use errors. Methodologically, a distinction is made between formative studies conducted during development and the summative study conducted at the end of development. The results are compiled in the usability engineering file and linked to risk management. <\/p>\n
Formative studies are intended to explore the strengths and weaknesses of the user interface and unexpected use errors. The US FDA guidance on human factors and usability engineering describes them as a tool that informs design during development, can uncover previously unrecognized use-related hazards and new critical tasks, and provides indications of the effectiveness of risk control measures, training needs, labeling, and the design of the subsequent validation study. <\/p>\n
Typical methods include cognitive walkthroughs with think-aloud, observation, interviews, and simulation testing, in which users work through realistic use scenarios under simulated conditions, for example with a non-energized device or a phantom instead of a patient. Formative studies may use models and prototypes, and to a limited extent employees of the manufacturer may also participate. However, their results cannot be readily transferred to the final user interface and do not replace the summative study. <\/p>\n
The summative study\u2014referred to in FDA terminology as a human factors validation test\u2014takes place at the end of development and is intended to identify use errors that would or could lead to serious harm to patients or users. It is part of design validation and also assesses the effectiveness of risk control measures. Requirements include: participants represent the intended users; all critical tasks are performed; the user interface corresponds to the final design; test conditions are sufficiently realistic; and no use errors occur that could be prevented by design changes and have the potential for serious harm. For all critical tasks, performance data and subjective assessments must be collected so that root-cause analysis is possible. <\/p>\n
With regard to sample size, the FDA guidance generally recommends at least 15 participants, and for multiple distinct user populations at least 15 per population; for certain product types, the recommended minimum may be higher. User groups are considered distinct if their characteristics are likely to influence interaction or if they perform different tasks, for example healthcare professionals versus lay users, different age groups, or individuals performing installation, maintenance, and service activities. Characteristics to consider include age, education, reading ability, sensory and physical limitations, and specialty; if the product is intended for patients with functional impairments, the range of those impairments must be represented. As a rule, employees of the manufacturer should not participate in validation. <\/p>\n
The usability study focuses on the interaction between the user and the user interface, not on clinical effectiveness or clinical benefit. It therefore does not provide clinical endpoints and does not replace a clinical investigation; conversely, a clinical investigation can only capture usability issues incidentally, because it neither systematically provokes all critical tasks nor stratifies the sample by user groups. In practice, the two are linked by incorporating usability observations from the clinical investigation as an additional data source in the usability engineering file. <\/p>\n
The use-related risk analysis, which precedes the study, must be distinguished from the study itself: only it identifies hazard-related use scenarios and critical tasks and thus determines what the summative study must assess. A study without this preparatory work tests arbitrary tasks and does not provide the required evidence. The simulated environment must also be distinguished from real use: it allows errors to be deliberately provoked without endangering patients, but must be sufficiently realistic in task sequence, time pressure, distractions, and environmental conditions. The categories of errors identified are addressed in the entry \u201cUse errors and abnormal use.\u201d <\/p>\n
Usability findings directly influence clinical investigations. They determine what training sites require, how detailed operating steps must be described in the protocol, and which use errors must be defined as reportable events. If known critical tasks are not addressed before the study begins, use errors during the investigation create confounding factors that burden the analysis of clinical endpoints and make safety signals difficult to interpret. <\/p>\n
Conversely, the clinical investigation provides feedback on use under routine care conditions, which feeds into updates to the usability engineering file and into post-market follow-up. Full-service CROs such as Mediconomics support manufacturers in developing study protocols for formative and summative studies, defining user groups and critical tasks, and aligning the findings with study plans, training concepts, and safety reporting. <\/p>\n
How many participants are needed for a summative study?<\/strong><\/p>\n The FDA guidance generally recommends at least 15 participants and, for multiple distinct user populations, at least 15 per population. For certain product types, the recommended minimum may be higher. <\/p>\n Is a usability study a clinical investigation?<\/strong><\/p>\n No. It assesses interaction with the user interface and serves design validation. Clinical endpoints and evidence of clinical benefit are addressed in the clinical evaluation and, where applicable, in a clinical investigation under Regulation (EU) 2017\/745. <\/p>\n Which tasks must be assessed?<\/strong><\/p>\n All critical tasks, i.e., those for which incorrect performance or omission would or could lead to serious harm. They are derived from the use-related risk analysis and justified in the study plan. <\/p>\n A usability study for medical devices is a structured investigation in which representative users operate a product or its user interface under realistic conditions to identify usability issues and safety-relevant use errors, or to demonstrate that operation can be performed safely and effectively. It is not a clinical investigation within the meaning of Articles 62 […]<\/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":"default","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":[24],"class_list":["post-7775","glossary","type-glossary","status-publish","hentry","glossary-cat-medizinprodukte-ivd"],"acf":[],"related_terms":"","external_url":"","internal_reference_id":"","_links":{"self":[{"href":"https:\/\/mediconomics.com\/en\/wp-json\/wp\/v2\/glossary\/7775","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":0,"href":"https:\/\/mediconomics.com\/en\/wp-json\/wp\/v2\/glossary\/7775\/revisions"}],"wp:attachment":[{"href":"https:\/\/mediconomics.com\/en\/wp-json\/wp\/v2\/media?parent=7775"}],"wp:term":[{"taxonomy":"glossary-cat","embeddable":true,"href":"https:\/\/mediconomics.com\/en\/wp-json\/wp\/v2\/glossary-cat?post=7775"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}Regulatory References<\/h2>\n
\n