Structural validity of the Pittsburgh Sleep Quality Index among medical students in Iran.

The Pittsburgh Sleep Quality Index (PSQI) is a self-reported questionnaire evaluating sleep quality based on seven domains of sleep disorders. However, the factor structure of PSQI needs to be well-established among medical students. This study was conducted to establish the factor structure of PSQI among medical students. Four-hundred and four medical students completed the PSQI. Considering each PSQI component as an "observed variable," exploratory factor analysis was conducted. Six models explaining the factor structure of PSQI were compared by confirmatory factor analysis to achieve the best model. All PSQI components were loaded on three factors. The first factor included sleep duration and habitual sleep efficiency, the second was subjective sleep quality and sleep latency, and the third was sleep disturbances, sleeping medications, and daytime dysfunction (root mean square error of approximation = < 0.01, goodness of fit index = 0.99). The differences in Bayesian information criteria and root mean square error of approximation between our best-fit model and each of the other resulted in rejection of all other Models. Besides confirming the structural validity among medical students, our findings indicated the adequacy of the 3-factor structure of PSQI, including sleep efficiency, perceived sleep quality, and daily disturbances in this population.

Problematic Internet Use, Mental Health, and Sleep Quality among Medical Students: A Path-Analytic Model.

BACKGROUND: There is a close association between problematic Internet use (PIU), sleep quality, and mental health problems. To evaluate which mental health problem is more associated with coexistence of both PIU and poor sleep quality, we hypothesized a model in which PIU influences sleep quality directly and also through the mediation of three different mental health problems. METHODS: A total of 402 medical students completed the Persian versions of the Internet Addiction Test, 21-item Depression Anxiety Stress Scale, and Pittsburgh Sleep Quality Index. A maximum likelihood structural equation model was used to assess the hypothesis. For assessment of the indirect effects, bootstrapping was conducted. RESULTS: PIU predicted poor sleep quality through indirect pathways by the mediation of mental health problems (P < 0.001). Poor sleep quality were associated with depressive symptoms (P < 0.001), anxiety (P = 0.035), and stress (P < 0.001); however, the direct pathways from stress and anxiety to poor sleep quality were not statistically significant (P > 0.05). CONCLUSION: Findings extend our previous knowledge about the interrelationships between PIU, sleep disturbances, and mental health problems by unveiling the key role of depressive symptoms.

Seroprevalence and associated risk factors of toxocariasis among nomads in Boyer-Ahmad County, southwest Iran.

BACKGROUND: Human toxocariasis is caused by the larval stage of Toxocara canis and Toxocara cati. This cross-sectional study was conducted to evaluate the seroprevalence and the risk factors associated with Toxocara infection in nomads of Boyer-Ahmad County in the southwest of Iran. METHODS: A total of 968 blood samples were collected from nomads. A structured questionnaire, containing sociodemographic data, was completed for each participant. Sera were evaluated for anti-Toxocara antibodies, using the T. canis excretory-secretory antigens prepared from the second stage larvae, in an ELISA system. RESULTS: Among the 968 participants, 220 (22.7%) were males and 748 (77.3%) were females; the mean age was 40.71 y. Anti-Toxocara IgG antibodies were detected in 14 (1.4%) of the 968 nomads. The association between Toxocara infection and gender, age, contact with dogs, residential area and level of education were not statistically significant (p>0.05). CONCLUSIONS: The findings of the study revealed a low prevalence rate of toxocariasis in nomadic communities in southwest Iran. Geographic location and climatic conditions as well as the lifestyle and sociodemographic features of the participants may contribute to the low prevalence rate of Toxocara infection.