Christina Derksen

• Sustainable behaviour change in healthcare is a complex process influenced by a variety of dynamic factors. This thesis aims to close existing research gaps concerning psychological factors of patient safety behaviours to develop effective interventions to improve patient safety in the exemplary field of obstetrics. Study 1 made 267 observations of hand hygiene behaviour over three time periods. Questionnaire data on psychological determinants were analysed with multiple regression and multiple mediation analyses. Study 2 reports results of path analyses and multiple regression analyses concerning a survey with N = 137 obstetric healthcare workers. Pre- and post-intervention data was compared in a repeated-measures multiple analysis of variance. In Study 3, a randomized-controlled trial was conducted with pregnant women. The intervention group (NT1 = 225; NT2 = 142) received an online training and was compared to a passive control group (NT1 = 199; NT2 = 144) using multilevel analyses and intention-to-treat analyses after multiple imputation. In Study 1, it was found that adherence to hand hygiene recommendations increased during COVID-19 pandemic, depending on self-efficacy. Study 2 showed that perceived patient safety risks were associated with communication behaviour. After the intervention, fewer patient safety risks were reported and coping self-efficacy increased. In Study 3, intention-to-treat analyses confirmed a higher intervention effect for communication behaviour, perceived quality of birth, and coping planning in the intervention group. This thesis emphasizes the role of psychology to understand behavioural determinants and change patient safety behaviour in healthcare. To improve interventions in healthcare, structured implementation guidelines should be used in multidisciplinary programmes. Future research needs to apply more high-quality research designs, look at multidisciplinary outcome measures, and target more diverse and marginalized groups.