Development of a short version of the Dutch version of the Spielberger STAI trait anxiety scale in women suspected of breast cancer and breast cancer survivors.

The objective of the current study was to develop a short form of the Dutch version of the State-Trait Anxiety Inventory (STAI) Trait scale and to provide initial validation data in a sample of breast cancer patients and survivors. This short trait anxiety (A-Trait) scale was designed to reduce time and effort required of severely ill or handicapped patients involved in extensive assessment procedures. Another goal was to assess A-Trait with minimal overlap with content that reflects Quality of Life (QoL) and fatigue. Three groups of women either completed the original Trait scale (Groups 1 and 2) or the 10-item trait version (Group 3). In Group 1, exploratory factor analysis with the Scree test, Velicer's MAP criteria and parallel analysis as tests for factor retention, indicated a 10-item Trait version reflecting two factors: Anxiety Present and Anxiety Absent. In the other groups, confirmatory factor analysis showed that the two-factor short form provided the best fit. In all three groups Trait Anxiety was highly related to Neuroticism. The correlation between Overall QoL and General Health and the Anxiety Present short scale was lower than the correlation between Overall QoL and General Health and the full form (Z = 2.20, p = .03). With this short A-Trait scale it becomes possible to study the relationship between dispositional anxiety and clinically important outcome variables without inflating estimates of these relations through psychometric contamination.