Psychometric Properties of the Icelandic Version of the Generalized Anxiety Disorder-7

Abstract

The Generalized Anxiety Disorder-7 (GAD-7) is a self-report anxiety scale that screens for Generalized Anxiety Disorder. The aim of this study was to assess the psychometric properties of the Icelandic version of the GAD-7. The study included 358 participants consisting of two samples, one clinical and one non-clinical. All participants completed the GAD-7 and PHQ-9 questionnaires and participants in the clinical sample answered diagnostic specific questionnaire based on main diagnosis evaluation as well. The participants in the non-clinical sample more over completed additional questionnaires, BAI, CORE-OM and QOLS, as well as GAD-7 on a second occasion. Internal reliability was good and both convergent validity and divergent validity were supported. The comparison of participants in the clinical sample and participants in the non-clinical sample showed that there was a statistically significant difference between the two groups on scores on the questionnaires. Patients diagnosed with anxiety disorder more over had higher scores on GAD-7 than patients without such diagnosis, indicating good discriminant validity of the GAD-7. It is concluded that the psychometric properties of the Icelandic version of the GAD-7 are satisfactory.

GAD-7 er sjálfsmatskvarði sem skimar fyrir einkennum almennrar kvíðaröskunar. Markmið þessarar rannsóknar var að kanna próffræðilega eiginleika íslenskrar útgáfu GAD-7. Þátttakendur í rannsókninni voru 358 einstaklingar í tveimur hópum, tilraunahóp og samanburðarhóp. Allir þátttakendur svöruðu GAD-7 og PHQ-9 spurningalistunum og auk þess svöruðu þátttakendur í tilraunahópnum sérstökum spurningalistum byggðum á greiningarmati. Þátttakendur í samanburðarhóp svöruðu jafnframt þremur öðrum spurningalistum, BAI, CORE-OM og QOLS, auk þess að svara GAD-7 í annað sinn. Innri áreiðanleiki var talinn góður og niðurstöðurnar studdu bæði samleitniréttmæti og aðgreiningarréttmæti GAD-7. Samanburður á þátttakendum í hópunum tveimur sýndi að það var munur á milli stigaskors þeirra á spurningalistunum. Jafnframt voru sjúklingar með kvíðagreiningu með hærra skor á GAD-7 en sjúklingar án kvíðagreiningar, sem bendir til góðs aðgreiningarréttmætis GAD-7. Íslenska útgáfan af GAD-7 er talin hafa viðunandi próffræðilega eiginleika.