Individual and joint associations of smartphone addiction and work duration with job burnout in nursing interns: a multicenter cross-sectional study

BACKGROUND: Job burnout prevalence among healthcare workers is high, posing significant threats to physical or mental health, care quality, and patient safety. While work duration is an established risk factor for burnout, the impact of smartphone addiction and its potential synergistic effect with prolonged work hours on job burnout remains unclear. METHODS: In this multi-center cross-sectional study, a total of 1,055 nursing interns were recruited using a convenience sampling method from hospitals in Hunan Province, China. Smartphone addiction was measured with the Smartphone Addiction Scale-Short Version, and job burnout was evaluated using the Maslach Burnout Inventory-General Survey (MBI-GS). Logistic regression, adjusted for basic demographic information, health status, and lifestyle variables, was used to assess the associations between smartphone addiction, work duration and job burnout. Associations were reported as odds ratios (OR) with their 95% confidence intervals (CI). Additive interactions were examined using relative excess risk due to interaction (RERI) and attributable proportion (AP) metrics. RESULTS: Among 1,055 nursing interns, job burnout prevalence was higher with smartphone addiction (47.5% vs. 38.5%; P = 0.012). Additionally, individuals working more than 50 h per week also exhibited a higher prevalence of job burnout (15.8% vs. 9.1%; P = 0.009). In adjusted models, each 1-unit increase in addiction score elevated MBI-GS by 0.471 (95% CI: 0.360–0.583), while addiction status showed borderline association with job burnout (OR = 1.33, 95% CI: 0.99–1.78). The odds of experiencing burnout were notably higher for those working more than 50 h weekly (vs. <40 h/week) (OR = 1.85, 95% CI: 1.13–3.04). Notably, the likelihood of burnout with combined smartphone addiction and prolonged work duration exceeded that obtained from the sum of each exposure taken separately (OR = 3.24, 95% CI: 1.63–6.51; RERI = 1.948, 95% CI: 0.240–3.656; AP = 0.601, 95% CI: 0.293–0.908). CONCLUSIONS: This cross-sectional research suggests that smartphone addiction and prolonged work duration are independent and synergistic risk factors for job burnout among nursing interns. If corroborated by prospective studies, findings could have implications for workplace preventive interventions. CLINICAL TRIAL NUMBER: Not applicable.