The aim of the present study was to determine the psychometric properties of the Turkish translation of both the observer-rated (P&Ao) and self-rated (P&As) versions of the Panic and Agoraphobia Scale (P&A). Discriminant and convergent validity of P&A were assessed in patients with panic disorder with or without agoraphobia (n=119), by comparing the P&A with the Clinical Global Impression Scale (CGI), Hamilton Anxiety Scale (HAMA), Phobia and Anxiety sub-scales of Symptom Check List, Spielberger State and Trait Anxiety Inventory and the Beck Depression Inventory (BDI). Inter-rater and test–retest reliability were determined. Correlation coefficients between the CGI and the P&Ao and the P&As were .85 and .74, respectively, and .85 between the two versions of the P&A. Cronbach’s α for the P&Ao and the P&As was .88 and .86, respectively. The Turkish version of the P&A has yielded good psychometric properties and was found to be a reliable instrument for assessing severity in panic disorder.
Panic disorder is a common disorder which substantially impairs daily functioning and quality of life of the affected patients. Lifetime prevalence of panic disorder is estimated to be 1.5–3.8% (Angst, 1995; Maison, Warshaw, & Keller, 1993). During the past decade increased recognition and the availability of effective pharmacological and psychosocial treatments has stimulated research on panic disorder. However, treatment studies lack consistency in the measures of severity assessment of the disorder (Bandelow et al., 1995 and Shear and Maser, 1994). Clinical trials focusing on the efficacy of treatments require repeated severity assessments and measurements that are sensitive to change. Recently, tools for assessment of the severity of panic disorder were introduced (Bandelow, 1995 and Shear et al., 1997).
Among them, the Panic and Agoraphobia Scale (P&A) was designed to identify and rate essential features of panic disorder with or without agoraphobia (Bandelow, 1995, Bandelow, 1999 and Bandelow et al., 1995). Panic attacks, agoraphobia, anticipatory anxiety, disability, and worries about health were taken into consideration in the P&A. Items related to these different aspects of panic disorder also constitute the five sub-scales of P&A, which can be assessed separately. The P&A’s sensitivity to change allows researchers to compare the efficacy of different treatments (Bandelow et al., 1998 and Bandelow et al., 1998). The P&A has already been utilized in a number of clinical studies (Bandelow et al., 1998 and Bandelow et al., 1998; Biber & Alkin, 1999; Broocks et al., 1998; Pande, Pollack, Crockatt, et al., 2000).
Today, it is common in most countries to use scales that have been developed in other languages (mostly English), to translate them and to apply them without further validation. However, as international multicenter trials become increasingly more frequent, psychometric scales should also be validated in the language of the country they are used in.
Until recently, there was no instrument for measurement of severity of panic disorder and agoraphobia in the Turkish language. Researchers who deal with panic disorder in Turkey had to use inadequate anxiety measurement tools to assess panic disorder severity. A survey on Turkish research articles published between 1993 and 1998 revealed that studies on panic disorder were performed by using scales which were developed for generalized anxiety disorder (GAD) and not for panic disorder. Thus, the aim of the present study was to validate the Turkish version of P&A.
