To investigate Vietnamese undergraduate students’ knowledge and attitudes towards contraception and their associated factors.

Cross-sectional study.

Six universities in Vietnam from April to May 2025.

1134 undergraduate students.

Students’ knowledge and attitudes towards contraception were measured via an online survey, and a cut-off point of 50% was used to categorise their scores. Associations between students’ knowledge and attitude scores and their sociodemographic characteristics, academic background, sexual and relationship experiences, contraceptive education and information sources were evaluated using multivariable linear regression. Independent variables were selected through Bayesian Model Averaging.

Students’ average knowledge and attitude scores were 10.93±2.86 (possible range: 0–22; actual range: 0–19) and 54.14±6.57 (possible range: 15–75; actual range: 35–74), respectively. 62.1% demonstrated good knowledge, and 91.4% showed positive attitudes towards contraception. Higher knowledge was observed among older students (per 1 year increase, β=0.33, 95% CI 0.23 to 0.43), those from public universities (β=1.32, 95% CI 0.64 to 2.00), using mass media as a contraceptive information source (β=0.58, 95% CI 0.25 to 0.91) and having sexual experience (β=1.16, 95% CI 0.73 to 1.58). By contrast, students who were single and had never been in a romantic relationship (β=–0.88, 95% CI –1.23 to –0.52) and those enrolled in non-healthcare disciplines (β=–1.06, 95% CI –1.55 to –0.56) had significantly lower knowledge scores. Positive attitudes were more prevalent among female students (males vs females: β=–2.07, 95% CI –2.80 to –1.34), those using the Internet as a source of contraceptive information (β=5.65, 95% CI 4.29 to 7.01) and those with higher knowledge scores (per one-unit increase, β=0.67, 95% CI 0.55 to 0.79). All associations were statistically significant (p

In general, undergraduate students’ knowledge of contraception was relatively low, while their attitudes were positive. Implementing education programmes focusing on correct usage and storage of condoms and the safety of emergency contraceptive pills may help improve their understanding and promote safer sexual practices, thereby contributing to reducing the risk of sexually transmitted infections and unintended pregnancies.

To evaluate the accuracy of the arterial oxygen partial pressure/inspired oxygen fraction (PaO₂/FiO₂) ratio in predicting mortality among acute respiratory distress syndrome (ARDS) patients in Vietnam.

A retrospective observational study.

A central hospital in Vietnam.

Adult patients diagnosed with ARDS based on the Berlin definition and admitted to Bach Mai Hospital between August 2015 and August 2023. ARDS severity was converted from descriptive categories to the Berlin score, ranging from 1 (PaO₂/FiO₂>300 mm Hg) to 4 (PaO₂/FiO₂≤100 mm Hg).

All-cause hospital mortality.

Of 345 patients, 67.5% were male, and the median age was 55.0 years (IQR: 39.0–66.0). Hospital mortality was 61.2% (211/345). On the first day of admission, the PaO₂/FiO₂ ratio (areas under the receiver operating characteristic curves (AUROC): 0.585 (95% CI 0.522 to 0.649)) showed limited predictive ability for hospital mortality. Incorporating the PaO₂/FiO₂ ratio into the Berlin score did not substantially improve accuracy (AUROC: 0.578 (95% CI 0.516 to 0.641)). Both measures were less accurate than Sequential Organ Failure Assessment (SOFA) (AUROC: 0.650 (95% CI 0.590 to 0.711)), Acute Physiology and Chronic Health Evaluation II (APACHE II) (AUROC: 0.685 (95% CI 0.628 to 0.742)) and Confusion, Urea >7 mmol/L (20 mg/dL), Respiratory rate ≥30 breaths/min, Blood pressure (systolic 2/FiO₂ values (adjusted OR, AOR: 0.988 (95% CI 0.979 to 0.996)) were independently associated with lower mortality risk, while higher Berlin (AOR: 2.477 (95% CI 1.190 to 5.156)), SOFA (AOR: 1.278 (95% CI 1.102 to 1.482)), APACHE II (AOR: 1.236 (95% CI 1.108 to 1.379)) and CURB-65 (AOR: 7.142 (95% CI 2.581 to 19.763)) scores were associated with increased mortality risk.

In this study of ARDS patients in Vietnam, the PaO₂/FiO₂ ratio demonstrated limited discriminatory ability for hospital mortality, and incorporating it into the Berlin score did not meaningfully improve performance. While less accurate than SOFA, APACHE II and CURB-65 scores, the PaO₂/FiO₂ ratio and Berlin score remained independently associated with mortality risk. These findings should be interpreted cautiously, given the retrospective design, single-centre setting and potential selection bias; further validation in larger, multicentre studies is warranted.