<![CDATA[The proliferation of smartphone use among university students has raised concerns about addiction and its potential consequences on sleep health, with medical students representing a particularly vulnerable population due to their demanding academic schedules, high stress levels, and extensive use of digital devices for learning purposes; despite growing evidence linking smartphone addiction to sleep disturbances globally, limited research has examined this relationship specifically among Indonesian medical students while controlling for important confounding factors such as anxiety. This study aims to determine the relationship between smartphone addiction and sleep quality among 2016 cohort medical students at Universitas Pelita Harapan, while also identifying the most dominant factors affecting sleep quality in this population. A cross-sectional analytic study was conducted involving 52 medical students selected through simple random sampling, with data collected using four standardized instruments: a demographic questionnaire, the Generalized Anxiety Disorder 7-Item (GAD-7), the Smartphone Addiction Scale-Short Version (SAS-SV), and the Pittsburgh Sleep Quality Index (PSQI); bivariate analysis employed Chi-Square or Fisher Exact tests, followed by multivariate logistic regression using SPSS version 22 to identify the most dominant predictors of poor sleep quality. The results revealed that 56% of respondents (n=29) had high smartphone addiction, while 62% (n=32) experienced poor sleep quality. Bivariate analysis demonstrated a significant association between smartphone addiction and poor sleep quality (p=0.003; OR=6.626; 95% CI 1.760–19.725), with anxiety showing an even stronger association (p=0.000; OR=15.443; 95% CI 3.106–76.644). Multivariate logistic regression confirmed that both smartphone addiction (p=0.017) and anxiety (p=0.001) were independent predictors of poor sleep quality, with anxiety being the more dominant factor, while lifestyle factors including smoking, alcohol consumption, caffeine intake, and medication use showed no significant associations with sleep quality (p>0.05). The high prevalence of poor sleep quality among medical students underscores the urgent need for institutional interventions, and medical education institutions should implement educational programs addressing smartphone usage management and anxiety reduction to promote better sleep health, with future research employing longitudinal designs and objective sleep measures needed to establish causal relationships and evaluate intervention effectiveness.]]>
