Rui Novais, Cláudia Rodrigues, Fátima Braga, Rui Pereira, Carlos Sequeira, Núria Albacar-Riobóo, Silvana Martins, Odete Araújo
Background: Population ageing has increased the number of older adults living in nursing homes, where loneliness and sleep disturbances are prevalent and negatively affect well-being. Evidence suggests a bidirectional relationship between loneliness and sleep quality, although research in institutionalised populations remains limited. Objectives: This study aimed to characterise the sociodemographic and health profile of nursing home residents in Northern Portugal and examine associations between sleep quality, loneliness, sociodemographic and health variables. Methods: A cross-sectional study was conducted with 157 older adults (≥65 years) across 13 nursing homes. Data were collected using a sociodemographic questionnaire and the Portuguese version of UCLA Loneliness Scale, Pittsburgh Sleep Quality Index and Montreal Cognitive Assessment. Pearson correlations and hierarchical multiple regression analyses were performed. Results: Participants were predominantly female (72.6%), widowed (55.4%), and aged ≥80 years. Most reported chronic conditions (98.7%) and limitations in activities of daily living (75.2%). Age showed modest positive correlations with loneliness. Loneliness dimensions were strongly associated with poorer sleep quality and greater daytime dysfunction. Hierarchical regression revealed that sociodemographic variables explained only a small proportion of variance in sleep quality. The addition of loneliness variables increased explained variance to 38.1%, highlighting loneliness as a key psychosocial predictor. Conclusions: Loneliness significantly influences sleep quality among older adults living in nursing homes. Interventions should integrate strategies to enhance social engagement alongside sleep hygiene measures. Longitudinal studies are recommended to clarify causal pathways.