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Table 2 Types of Response Options

From: Guidance for industry: patient-reported outcome measures: use in medical product development to support labeling claims: draft guidance

Type Description
Visual analog scale (VAS) A line of fixed length (usually 100 mm) with words that anchor the scale at the extreme ends and no words describing intermediate positions. Patients are instructed to place a mark on the line corresponding to their perceived state. These scales often produce a false sense of precision.
Anchored or categorized VAS A VAS that has the addition of one or more intermediate marks positioned along the line with reference terms assigned to each mark to help patients identify the locations (e.g., half-way) between the ends of the scale.
Likert scale An ordered set of discrete terms or statements from which patients are asked to choose the response that best describes their state or experience.
Rating scale A set of numerical categories from which patients are asked to choose the category that best describes their state or experience. The ends of rating scales are anchored with words but the categories do not have labels.
Event log Specific events are recorded as they occur using a patient diary or other reporting system (e.g., interactive voice response system)
Pictorial scale A set of pictures applied to any of the other types of response options. Pictorial scales are often used in pediatric questionnaires but also have been used for patients with cognitive impairments and for patients who are otherwise unable to speak or write.
Checklist Checklists provide a simple choice between a limited set of options, such as Yes, No, and Don't know. Some checklists ask patients to place a mark in a space if the statement in the item is true. Checklists are reviewed for completeness and nonredundancy.