Valerie SL Williams: gro. This article has been cited by other articles in PMC. Abstract Background Fast-acting medications for the management of anxiety are important to patients and society. Measuring early onset, however, requires a sensitive and clinically responsive tool. Methods Data from a double-blind, randomized, placebo-controlled study of lorazepam and paroxetine in patients with Generalized Anxiety Disorder were analyzed to assess the reliability, validity, responsiveness, and utility of the GA-VAS. Targeted psychometric analyses—test-retest reliabilities, validity correlations, responsiveness statistics, and minimum important differences—were conducted.
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Valerie SL Williams: gro. This article has been cited by other articles in PMC. Abstract Background Fast-acting medications for the management of anxiety are important to patients and society. Measuring early onset, however, requires a sensitive and clinically responsive tool.
Methods Data from a double-blind, randomized, placebo-controlled study of lorazepam and paroxetine in patients with Generalized Anxiety Disorder were analyzed to assess the reliability, validity, responsiveness, and utility of the GA-VAS. Targeted psychometric analyses—test-retest reliabilities, validity correlations, responsiveness statistics, and minimum important differences—were conducted. Preliminary minimum important difference estimates cluster between 10 and 15 mm.
Conclusions The GA-VAS is capable of validly and effectively capturing a reduction in anxiety as quickly as 24 hours post-dose. Single-item visual analog scales VASs have been used in psychological assessment since the early 20th century and have subsequently been employed successfully in the assessment of a wide variety of health-related constructs including pain [ 1 - 3 ], quality-of-life [ 4 , 5 ], and mood [ 6 - 8 ].
VASs are brief and simple to administer and minimal in terms of respondent burden. These characteristics make them ideal for use in a diary format questionnaire where patients frequently record symptoms and outcomes. Although a VAS may be oriented vertically, the most common form is a horizontal line.
In fact, horizontal scales have been shown to produce a more uniform distribution of scores and to be more sensitive than vertical scales [ 3 , 10 ]. Multiple-item VASs are often shown to have high internal consistency [ 10 ]; however, there is wide variability in test-retest reliabilities—VAS test-retest reliability is generally not uniform across the scale continuum, but better at the middle and extremes [ 11 ]. Although VAS differences appear larger than differences on 7-point ordinal response items, when standardized there is generally no difference between VAS and ordinal ratings [ 12 ].
Similarly, VAS standard errors of measurement are proportionally larger than those for rating scales [ 12 ]. The present study was motivated by the need for a brief validated measure for assessing onset of improvement in the symptom of anxiety in subjects with GAD sooner than one week, especially in light of the need to evaluate newer fast-acting medications for the management of anxiety.
However, three important disadvantages of the HAM-A are that it is relatively lengthy 14 items , it must be completed by a trained clinician during the course of a clinical interview, and it has not been validated for use sooner than one week.
In the context of GAD, treatment with fast-acting benzodiazepines has been shown to be effective at one week when measured by the HAM-A [ 14 , 15 ]; in the context of panic disorder [ 16 ] and anticipatory anxiety [ 17 , 18 ], self-report VASs and other measures have demonstrated efficacy within hours. As there are no validated single-item scales to assess onset of anxiety relief in patients with GAD, it seemed important to us to validate a VAS assessing average anxiety over the past 24 hours , which could be easily incorporated into a daily diary.
The present study describes the psychometric evaluation of a patient-reported VAS for the daily assessment of anxiety when used in a clinical trial assessing pharmaceutical treatments for GAD. Methods Preliminary Qualitative Study As part of a preliminary qualitative study, cognitive interviews were conducted with 22 GAD patients Patients were asked to think aloud while completing the GA-VAS so that the interviewer could hear how it was interpreted and how a response was selected.
Psychometric Study Design After cognitive testing, the GA-VAS was included in a clinical trial assessing two approved pharmaceutical treatments for anxiety.
Analyses were aimed at providing evidence of the reliability, responsiveness, validity, and utility of the GA-VAS. Data were collected during a randomized, 4-week, double-blind, multi-center, fixed-dose, placebo-controlled, parallel-group clinical study conducted in the United States. Lorazepam was selected as a fast-acting benzodiazepine, and paroxetine, a selective serotonin reuptake inhibitor, was chosen as a slower-acting GAD pharmacotherapy. There were three treatment arms—lorazepam 1.
Patients completed the GA-VAS during six clinic visits screening, baseline, Weeks 1, 2, 4, and 5 and at home each night during the screening week and first week of treatment. These psychiatric rating scales have long been used in clinical trials and have been shown to be valid tools for differentiating anxious and depressed patient subgroups [ 21 , 22 ].
Subjects were excluded from study participation if they had significant suicidal risk, had failed treatment with lorazepam or paroxetine in the past, required daily benzodiazepine use in the three months prior to study participation, or if they had most other concurrent DSM-IV mental disorders, including major depressive disorder, panic disorder with or without agoraphobia, acute stress disorder, obsessive compulsive disorder, dissociative disorder, posttraumatic stress disorder, social anxiety disorder, anorexia, bulimia, caffeine-induced anxiety disorder, alcohol or substance abuse or dependence, premenstrual dysphoric disorder, or antisocial or borderline personality disorder.
Subjects with current or past diagnoses of schizophrenia, psychotic disorders, delirium, dementia, amnestic disorders, clinically significant cognitive disorders, bipolar or schizoaffective disorder, benzodiazepine abuse or dependence, or factitious disorder were also excluded. Patients were not permitted to use any psychotropic medications and could not have initiated any psychodynamic or behavioral psychotherapy for anxiety within the 3 months prior to the study.
The distance from the left edge of the line to the mark placed by the patient is measured to the nearest millimeter and used in analyses as the patient GA-VAS score.
Psychometric evaluation of a visual analog scale for the assessment of anxiety
He included a distinction "between anxiety as a normal reaction to danger, anxiety as a pathological condition not related to stress, and anxiety as a state or broad syndrome that he termed "anxiety neurosis. Although Hamilton developed the scale as a rating of severity, he used his scale to differentiate "anxiety as a pathological mood" from a "state or neurosis. A variety of relevant symptoms were collected and divided into groups. The scale started with twelve groups of symptoms, which came to form thirteen scale variables. All of the thirteen variables were described by succinct statements and included on a sheet that was used by an interviewer for assessing a patient. The original version used a "five-point scale" for rating the groups of symptoms. The first version of the scale was only a start, and as Hamilton stated, "Some of the variables are obviously a rag-bag of oddments and need further investigation.
Hamilton Anxiety Rating Scale