Measuring driving fear: Development and validation of the Instrument for Fear of Driving (IFD)

Abstract

Presently, there is no instrument to support the diagnosis of driving fear and its severity. To enable a reliable and valid diagnosis,the 5-item German-language Instrument for Fear of Driving (IFD) was developed. The items, by DSM-5 criteria for a specific phobia, measurethe emotional, cognitive, and physiological components of driving fear as well as the degree of avoidance and impairment. The present papercomprises two studies that describe the development of the IFD and its psychometric properties. In Study 1, the IFD was administered to810 non-clinical participants in an online survey and demonstrated good reliability and construct validity. In Study 2, fifty-four people with aclinical diagnosis, including clinically relevant driving fear, completed the IFD and a clinical interview. The IFD demonstrated good sensitivityand specificity, and a cut-off score resulted in 95% sensitivity and 97% specificity. While the findings are preliminary and further studies withlarger samples are needed, the IFD is a promising screening instrument for driving fear and its severity.