Mobile phone use addiction, insomnia, and depressive symptoms in adolescents from ethnic minority areas in China: A latent variable mediation model.

BACKGROUND AND AIMS: Although previous studies have discussed the association between mobile phone use addiction (MPUA) and depressive symptoms in adolescents, studies on Chinese adolescents are limited, with no studies being reported on adolescents from ethnic minority areas within Yunnan. This study aimed to explore the mediating mechanism of insomnia in the association between MPUA and depressive symptoms among Yunnan college students. METHODS: A sample survey was conducted among 10,121 college students from four colleges in Yunnan province, China, from November to December 2021 via cluster sampling. Insomnia was assessed using the Insomnia Severity Index Scale, MPUA was assessed using the Self-Rating Questionnaire for Adolescent Problematic Mobile Phone Use, and depressive symptoms were assessed using the Patient Health Questionnaire-9 items. A generalized linear model was used to analyze the association between MPUA, insomnia, and depressive symptoms. The structural equation model was used to analyze the mediating effect of insomnia. RESULTS: The positive rates of depressive symptoms, MPUA, and insomnia were 39.2 %, 30.8 %, and 22.3 %, respectively. After adjusting for the demographic and confounding variables, MPUA (ß = 0.14, 95 % CI: 0.13-0.15, P < 0.01) and insomnia (ß = 0.44, 95 % CI: 0.43-0.46, P < 0.01) were associated with depressive symptoms (P < 0.05). The mediating effect of insomnia accounted for 34.7 % of the total effect in the mediating model of MPUA associated with depressive symptoms. CONCLUSION: Our findings suggest that insomnia partially mediates the association between MPUA and depressive symptoms among Yunnan college students.

Basic Reproduction Number of the 2019 Novel Coronavirus Disease in the Major Endemic Areas of China: A Latent Profile Analysis.

Objective: The aim of this study is to analyze the latent class of basic reproduction number (R0) trends of the 2019 novel coronavirus disease (COVID-19) in the major endemic areas of China. Methods: The provinces that reported more than 500 cases of COVID-19 till February 18, 2020 were selected as the major endemic areas. The Verhulst model was used to fit the growth rate of cumulative confirmed cases. The R0 of COVID-19 was calculated using the parameters of severe acute respiratory syndrome (SARS) and COVID-19. The latent class of R0 was analyzed using the latent profile analysis (LPA) model. Results: The median R0 calculated from the SARS and COVID-19 parameters were 1.84-3.18 and 1.74-2.91, respectively. The R0 calculated from the SARS parameters was greater than that calculated from the COVID-19 parameters (Z = -4.782 to -4.623, p < 0.01). Both R0 can be divided into three latent classes. The initial value of R0 in class 1 (Shandong Province, Sichuan Province, and Chongqing Municipality) was relatively low and decreased slowly. The initial value of R0 in class 2 (Anhui Province, Hunan Province, Jiangxi Province, Henan Province, Zhejiang Province, Guangdong Province, and Jiangsu Province) was relatively high and decreased rapidly. Moreover, the initial R0 value of class 3 (Hubei Province) was in the range between that of classes 1 and 2, but the higher R0 level lasted longer and decreased slowly. Conclusion: The results indicated that the overall R0 trend is decreased with the strengthening of comprehensive prevention and control measures of China for COVID-19, however, there are regional differences.