extended · article · 2022

Evaluation of the Desire to Avoid Pregnancy Scale in the UK: a psychometric analysis including predictive validity

Jennifer Hall; Geraldine Barrett; Corinne H. Rocca; Mark Wilson

OBJECTIVES: To evaluate the psychometric performance, including predictive validity, of a UK version of the Desire to Avoid Pregnancy (DAP) scale. DESIGN: Prospective cohort study for psychometric evaluation. SETTING: UK. PARTICIPANTS: Women in the UK aged 15 years to menopause, who were not pregnant at the time of recruitment in October 2018, were eligible. 994 women completed the baseline survey and 90.2% of women eligible for the 12-month survey participated. PRIMARY AND SECONDARY OUTCOME MEASURES: The DAP scale was assessed according to key measurement properties of validity (construct (structural and hypothesis testing) and criterion (predictive)), reliability (internal consistency using Cronbach's alpha and test-retest using intraclass correlation coefficients, ICC) and differential item functioning. Item response and classical test theory methods were used. RESULTS: The scale was ...