The Cox model is a regression technique for performing survival analyses in epidemiological and clinical research. This model estimates the hazard ratio (HR) of a given endpoint associated with a specific risk factor, which can be either a continuous variable like age and C‐reactive protein level or a categorical variable like gender and diabetes mellitus. When the risk factor is a continuous variable, the Cox model provides the HR of the study endpoint associated with a predefined unit of increase in the independent variable (e.g., for every 1‐year increase in age, 2 mg/L increase in C‐reactive protein). A fundamental assumption underlying the application of the Cox model is proportional hazards; in other words, the effects of different variables on survival are constant over time and additive over a particular scale. The Cox regression model, when applied to etiological studies, also allows an adjustment for potential confounders; in an exposure‐outcome pathway, a confounder is a variable which is associated with the exposure, is not an effect of the exposure, does not lie in the causal pathway between the exposure and the outcome, and represents a risk factor for the outcome.

Studies performed in the field of oxidative medicine and cellular longevity frequently focus on the association between biomarkers of cellular and molecular mechanisms of oxidative stress as well as of aging, immune function, and vascular biology with specific time to event data, such as mortality and organ failure. Indeed, time‐to‐event analysis is one of the most important methodologies used in clinical and epidemiological research to address etiological and prognostic hypotheses. Survival data require adequate methods of analyses. Among these, the Kaplan‐Meier analysis is the most used one in both observational and interventional studies. In this paper, we describe the mathematical background of this technique and the concept of censoring (right censoring, interval censoring, and left censoring) and report some examples demonstrating how to construct a Kaplan‐Meier survival curve and how to apply this method to provide an answer to specific research questions.

One of the strategies of the World Health Organization End Tuberculosis (TB) was to reduce the catastrophic costs incurred by TB-affected families to 0% by 2020.Catastrophic cost is defined by the total cost related to TB management exceeding 20% of the annual pre-TB household income. This study aimed to estimate the pooled proportion of TB affected households who incurred catastrophic costs. We searched PubMed, SciELO, Scopus, Embase, Google Scholar, ProQuest, SAGE, and Web of Science databases according to Preferred Reporting Items of the Systematic Reviews and Meta-Analysis (PRISMA) guidelines till November 20, 2020. Eligible studies were identified and data on catastrophic costs due to TB were extracted. We performed a meta-analysis to generate the pooled proportion of patients with TB facing catastrophic costs. From 5114 studies identified, 29 articles were included in the final analysis. The pooled proportion of patients faced catastrophic costs was (43%, 95% CI [34–51]). Meta-regression revealed that country, drug sensitivity, and Human immune-deficiency Virus (HIV) co-infection were the main predictors of such costs. Catastrophic costs incurred by drug sensitive, drug resistant, and HIV co-infection were 32%, 81%, and 81%, respectively. The catastrophic costs incurred were lower among active than passive case findings (12% vs. 30%). Half (50%) of TB-affected households faced catastrophic health expenditure at 10% cut-off point. The financial burden of patients seeking TB diagnosis and treatment continues to be a worldwide impediment. Therefore, the End TB approach should rely on socioeconomic support and cost-cutting initiatives.PROSPERO registration: CRD42020221283.

Older adults dialysis patients represent the frailest subgroup of the End Stage Renal Disease (ESRD) population and physical exercise program may mitigate the age-related decline in muscle mass and function. Dialysis patients of the EXCITE trial aged > 65 years (n = 115, active arm, n = 53; control arm, n = 62) were submitted in random order to a home based, low intensity physical exercise program. At baseline and 6 months after exercise training 6-min walking distance (6MWD) and 5-time sit-to-stand test (5STS) were performed, and quality of life (QoL) was tested. The training program improved both the 6MWD (6-months: 327 ± 86 m versus baseline: 294 ± 74 m; P < 0.001) and the 5STS time (6-months: 19.8 ± 5.6 s versus baseline: 22.5 ± 5.1 s; P < 0.001) in the exercise group whereas they did not change in the control group (P = 0.98 and 0.25, respectively). The between-arms differences (6 months-baseline) in the 6MWD (+ 34.0 m, 95% CI: 14.4 to 53.5 m) and in the 5STS time changes (− 1.9 s, 95% CI: -3.6 to − 0.3 s) were both statistically significant (P = 0.001 and P = 0.024, respectively). The cognitive function dimension of QoL significantly reduced in the control arm (P = 0.04) while it remained unchanged in the active arm (P = 0.78) (between groups difference P = 0.05). No patient died during the trial and the training program was well tolerated. This secondary analysis of the EXCITE trial shows that a home-based, exercise program improves physical performance and is well tolerated in elderly ESRD patients. The trial was registered in ClinicalTrials.Gov ( Clinicaltrials.gov identifier: NCT01255969) on December 8, 2010.

Epidemiology of acute kidney injury (AKI) in developing countries is under-studied. We evaluated the risk and prognosis of AKI in patients admitted to intensive care units (ICUs) in Egypt. We recruited consecutive adults admitted to ICUs in Alexandria Teaching Hospitals over six months. We used the KDIGO criteria for AKI. We followed participants until the earliest of ICU discharge, death, day 30 from entry or study end. Of the 532 participants (median age 45 (Interquartile range [IQR]: 30–62) years, 41.7% male, 23.7% diabetics), 39.6% had AKI at ICU admission and 37.4% developed AKI after 24 hours of ICU admission. Previous need of diuretics, sepsis and low education were associated with AKI at ICU admission; APACHE II score independently predicted AKI after ICU admission. A total of 120 (22.6%) patients died during 30-day follow-up. Compared to patients who remained AKI-free, mortality was significantly higher in patients who had AKI at study entry (Hazard Ratio [HR] 2.14; 95% Confidence Interval [CI] 1.02–4.48) or developed AKI in ICU (HR 2.74; 95% CI 1.45–5.17). The risk of AKI is high in critically ill people and predicts poor outcomes. Further studies are needed to estimate the burden of AKI among patients before ICU admission.

The ongoing monkeypox (MPX) outbreak has been declared a public health emergency of international concern. People in close contact with active MPX cases, including healthcare workers (HCWs), are at higher risk of virus acquisition since the MPX virus can be transmitted by skin contact or respiratory secretions. In this study, we aimed to assess the psychological antecedents of MPX vaccination among Nigerian HCWs using the 5C scale. We used an anonymous online cross-sectional survey to recruit potential participants using snowball sampling. The questionnaire aimed to assess the geo/socioeconomic features and the 5C psychological antecedents of vaccine acceptance (confidence, complacency, constraints, calculation, and collective responsibility). A total of 389 responses were included, with a median age of 37 years (IQR: 28–48), 55.5% males, and 60.7% married participants. Among the studied Nigerian HCWs, only 31.1% showed confidence in MPX vaccination, 58.4% expressed complacency towards vaccination, 63.8% perceived constraints towards MPX vaccination, 27.2% calculated the benefits and risks of vaccination, and 39.2% agreed to receive MPX vaccination to protect others. The determinants of MPX vaccine confidence were being single (OR = 5.07, 95% CI: 1.26–20.34, p = 0.022), a higher education level (with pre-college/high school as a reference, professional/technical: OR = 4.12, 95% CI: 1.57–10.73, p = 0.004, undergraduate: OR = 2.94, 95% CI: 1.32–6.55, p = 0.008, and postgraduate degree (OR = 3.48, 95% CI: 1.51–8.04, p = 0.003), and absence of chronic disease (OR = 2.57, 95% CI: 1.27–5.22, p = 0.009). The significant complacency predictors were having a middle-income (OR = 0.53, 95% CI: 0.33–0.89, p = 0.008), having a bachelor’s degree (OR = 2.37, 95% CI: 1.10–5.11, p = 0.027), and knowledge of someone who died due to MPX (OR = 0.20, 95% CI: 0.05–0.93, p = 0.040). Income was associated with perceived vaccination constraints (OR = 0.62, 95% CI: 0.39–0.99, p = 0.046). Participants aged 46–60 years had decreased odds in the calculation domain (OR = 0.52, 95% CI: 0.27–0.98, p = 0.044). Middle-income and bachelor degree/postgraduate education significantly influenced the collective responsibility domain (OR = 2.10, 95% CI: 1.19–3.69, p = 0.010; OR = 4.17, 95% CI: 1.85–9.38, p < 0.001; and OR = 3.45, 95% CI: 1.50–7.90, p = 0.003, respectively). An investigation of the 5C pattern-based psychological antecedents of MPX vaccination in a sample of Nigerian HCWs revealed low levels of vaccine confidence and collective responsibility with high levels of constraints and complacency. These psychological factors are recommended to be considered in any efforts aiming to promote MPX vaccination needed in a country where MPX is endemic.