PhD Defence Lizhen Ye

This thesis examines the interrelations and contributing factors of frailty, polypharmacy, medication-related problems, and loneliness in older European community-dwelling adults, using data from the Urban Health Centres Europe (UHCE) Project. It is structured into three main parts:

Part I focuses on frailty, divided into physical, psychological, and social domains. Findings indicate various demographic, lifestyle, and health factors associated with these frailty domains. Notably, physical frailty was shown to have a reciprocal relationship with psychological frailty and a unidirectional association with social frailty, highlighting the complex interplay between these domains.

Part II investigates the factors linked with polypharmacy and a high risk of medication-related problems. Significant associations were found with sociodemographic characteristics, health status, and healthcare usage. Additionally, a cycle was observed where higher levels of frailty increased the risk of medication-related problems, which in turn could lead to increased frailty, suggesting a bidirectional relationship.

Part III explores the relationship between loneliness and frailty. It was found that loneliness, particularly social loneliness, significantly contributes to all frailty domains. A bidirectional association between overall loneliness and frailty was identified, with emotional loneliness specifically influencing psychological frailty.

The thesis underscores the need for a holistic approach to address these interconnected issues, recommending the integration of medical, psychological, and social elements into health strategies to enhance aging well-being and resilience.