Confounding is the distortion of a disease/exposure association brought about by other factors which are not considered in the study design or the data analysis. These factors are called confounding factors. We should be cautious in data analysis of observational study of association of disease/exposure, since confounding often occurred in observational study. This study examines confounding effect according to data pattern (the ratio of controls to cases, the ratio of exposures to non-exposures for each level of confounding factor), criteria for treating a variable as a confounding variable, and some notes for the analysis in case-control study.
Case-Control Studies* ; Confounding Factors (Epidemiology) ; Observational Study ; Statistics as Topic

PURPOSE: Owing to the recommendations of the Surviving Sepsis Campaign guidelines, protocol-based resuscitation or goal-directed therapy (GDT) is broadly advocated for the treatment of septic shock. However, the most recently published trials showed no survival benefit from protocol-based resuscitation in septic shock patients. Hence, we aimed to assess the effect of GDT on clinical outcomes in such patients. MATERIALS AND METHODS: We performed a systematic review that included a meta-analysis. We used electronic search engines including PubMed, Embase, and the Cochrane database to find studies comparing protocol-based GDT to common or standard care in patients with septic shock and severe sepsis. RESULTS: A total of 13269 septic shock patients in 24 studies were included [12 randomized controlled trials (RCTs) and 12 observational studies]. The overall mortality odds ratio (OR) [95% confidence interval (CI)] for GDT versus conventional care was 0.746 (0.631-0.883). In RCTs only, the mortality OR (95% CI) for GDT versus conventional care in the meta-analysis was 0.93 (0.75-1.16). The beneficial effect of GDT decreased as more recent studies were added in an alternative, cumulative meta-analysis. No significant publication bias was found. CONCLUSION: The result of this meta-analysis suggests that GDT reduces mortality in patients with severe sepsis or septic shock. However, our cumulative meta-analysis revealed that the reduction of mortality risk was diminished as more recent studies were added.
Humans ; *Observational Studies as Topic ; *Randomized Controlled Trials as Topic ; Resuscitation/*methods ; Shock, Septic/mortality/*therapy

The time-to-event index is a kind of common evaluation index. It measures the speed of intervention effect. It is different from other index in research design, source material filling, data checking and statistical analysis. To obtain the time-to-event index, investigators can fill in the table directly and statistical analyst can compute after clinical observation. When filling in the source material or data checking, it is should be noticed that the logical relation between the time-to-event index and the visiting point and between the time-to-event index and the correlative other indicator. When statistical analyzing, it is an important issue how to deal with the cases whose time-to-event index does not appear till the observation period ends. Understanding the difference clearly can make the time-to-event index evaluate the effect of the intervention truly and make the clinical observation results reliable.
Clinical Trials as Topic ; Female ; Humans ; Male ; Observational Studies as Topic ; Research ; Research Design

Evidence-Based Medicine ; Humans ; Longitudinal Studies ; Observational Studies as Topic ; Prospective Studies ; Randomized Controlled Trials as Topic ; Retrospective Studies

Purpose: To proceed effectively with clinical research requires an understanding of the fundamental principles of study design and biostatistical methods. In this article, we identified and summarized basic clinical research designs and some of the key biostatistical methods that have been commonly used in clinical research. Materials and Methods: In an observational study, cross-sectional, case- control and Cohort designs were illustrated and compared. In a clinical trial study, parallel group design and cross-over designs were described according to their characteristics. Also, the biostatistical methods for their usages classified and summarized. Results: Understanding and evaluating research design are part of the process researchers must use to determine both the quality and usefulness of their research. Adequate applications to biostatistical methods are need; i.e., descriptive statistics, Student's t-test, ANOVA, nonparametrics, categorical data analysis, correlation and regression, and survival analysis. Conclusions: Research findings are used by clinical researcher to guide their practice and reduce their uncertainty in clinical decision making. However, to understand how to interpret research results, it is important to be able to understand basic statistical concepts and types of study design. Clinicians should also appropriately choose the biostatistical methods to suit their purposes.
Biostatistics ; Cohort Studies ; Cross-Over Studies ; Decision Making ; Observational Study ; Research Design* ; Statistics as Topic ; Uncertainty

OBJECTIVE: We conducted a retrospective data analysis to review the results of robot-assisted arm rehabilitation in post stroke patients during past 2 years and find out positive influences of the outcomes. METHOD: We measured improvements of arm function longitudinally in a group of sixty-four stroke patients, who participated in the robot-assisted arm therapy from January 2012 to December 2013. Treatment session lasted 30 to 40 minutes, 2 to 5 times a week. For at least more than one month, we used the InMotion2.0 (Interactive Motion Technologies, Watertown, MA, USA) and measured outcomes with the Fugl-Meyer assessment-upper extremity (FMA-UE), Korea-modified Barthel index (K-MBI) and InMotion robot arm evaluation index. Also, analysis on the subgroup was carried out. RESULTS: Following the robot-assisted arm rehabilitation, FMA-UE, K-MBI and InMotion robot arm evaluation index were significantly improved compared to baseline. Mean FMA-UE and K-MBI gain were 4.22 +/- 0.76, 7.63 +/- 1.18 in each. However, in the subgroup analysis, the group with less intensity treatment (640 repetition) did not show any significant improvement. CONCLUSION: This is an observational study showing improvements in arm function following robot-assisted arm rehabilitation compared to baseline, which was significant only in the subgroup who received the intervention longer and more intensity.
Arm* ; Extremities ; Humans ; Observational Study ; Rehabilitation* ; Retrospective Studies ; Statistics as Topic ; Stroke* ; Upper Extremity

BACKGROUND: The Modality of Insulin Treatment Evaluation (MOTIV) study was performed to provide real-world data concerning insulin initiation in Korean type 2 diabetes mellitus (T2DM) patients with inadequate glycemic control with oral hypoglycemic agents (OHAs). METHODS: This multicenter, non-interventional, prospective, observational study enrolled T2DM patients with inadequate glycemic control (glycosylated hemoglobin [HbA1c] > or =7.0%) who had been on OHAs for > or =3 months and were already decided to introduce basal insulin by their physician prior to the start of the study. All treatment decisions were at the physician's discretion to reflect real-world practice. RESULTS: A total of 9,196 patients were enrolled, and 8,636 patients were included in the analysis (mean duration of diabetes, 8.9 years; mean HbA1c, 9.2%). Basal insulin plus one OHA was the most frequently (51.0%) used regimen. After 6 months of basal insulin treatment, HbA1c decreased to 7.4% and 44.5% of patients reached HbA1c <7%. Body weight increased from 65.2 kg to 65.5 kg, which was not significant. Meanwhile, there was significant increase in the mean daily insulin dose from 16.9 IU at baseline to 24.5 IU at month 6 (P<0.001). Overall, 17.6% of patients experienced at least one hypoglycemic event. CONCLUSION: In a real-world setting, the initiation of basal insulin is an effective and well-tolerated treatment option in Korean patients with T2DM who are failing to meet targets with OHA therapy.
Body Weight ; Diabetes Mellitus, Type 2 ; Humans ; Hypoglycemic Agents* ; Insulin* ; Korea ; Observational Study ; Pragmatic Clinical Trials as Topic ; Prospective Studies

The incidence of obesity has been rapidly increasing, and this condition has become a major public health threat. A substantial shift in environmental factors and lifestyle, such as unhealthy diet, is among the major driving forces of the global obesity pandemic. Longitudinal studies and randomized intervention trials have shown that genetic susceptibility to obesity may interact with dietary factors in relation to the body mass index and risk of obesity. This review summarized data from recent longitudinal studies and intervention studies on variations and diets and discussed the challenges and future prospects related to this area and public health implications.
Body Mass Index ; Diet ; Gene-Environment Interaction ; Genetic Predisposition to Disease ; Humans ; Life Style ; Obesity ; epidemiology ; genetics ; Observational Studies as Topic ; Randomized Controlled Trials as Topic

OBJECTIVE: To systematically review safety and tolerance of enteral nutrition (EN) in a prone position, as well as the risks of increased gastric residual volume (GRV), vomiting, aspiration, and ventilator-associated pneumonia, and determine the ways to improve EN tolerance in patients with acute respiratory distress syndrome (ARDS). METHODS: Databases including PubMed, Embase and Wanfang Medical data of the English and Chinese literatures were retrieved up from January 1979 to January 2022 to collet the randomized controlled trial (RCT), non-RCT, and observational studies, concerning safety and tolerance of EN in a prone position with ARDS. All trials must have a minimum of two patient groups, one of which must be prone to ARDS and receive EN. Data searching extracting and quality evaluation were assessed by two reviewers independently. RevMan 5.4 software was used for analysis. RESULTS: A total of 9 studies were included, including 2 RCTs, 2 non-RCTs, 4 prospective observational studies, and 1 retrospective observational study. The starting and increasing rate of EN were typically well tolerated in the prone position compared to the supine position in patients with ARDS, there was no significant increase in GRV (mL: 95 vs. 110), and the incidence of vomiting was not noticeably higher (0%-35% vs. 33%-57%). The incidence of ventilator-associated pneumonia with EN was not significantly higher in the prone position than in the supine position in patients with ARDS (6%-35% vs. 15%-24%). Aspiration occurred at a similar rate in patients in the nasogastric tube and post-pyloric feeding groups with EN in patients with ARDS in the prone position (22% vs. 20%). EN tolerability with nasogastric and nasojejunal tubes was similar in prone positions, with no significant difference in EN intolerance incidences (15% vs. 22%). Head elevation (30 degree angle-45 degree angle) improved EN tolerance in the prone position in patients with ARDS, thereby increasing the early EN dose [odds ratio (OR) = 0.48, 95% confidence interval (95%CI) was 0.22-1.08, P = 0.08]. Additionally, prophylactic application of gastrointestinal motility drugs, such as erythromycin, at the start of EN in a prone position significantly improved patients' EN tolerance (OR = 1.14, 95%CI was 0.63-2.05, P = 0.67). CONCLUSIONS The use of gastric tube for EN in prone position and similar feeding speed to the supine position in patients with ARDS is safe and well tolerated. The initiation and dosing of EN should not be delayed in the prone position. EN tolerance may be increased by elevating the head of the bed during enteral feeding in a prone position, and gastrointestinal motility medications should be promptly administered with EN initiation in patients with ARDS.
Humans ; Pneumonia, Ventilator-Associated/etiology* ; Enteral Nutrition ; Prone Position ; Respiration, Artificial/adverse effects* ; Respiratory Distress Syndrome/etiology* ; Randomized Controlled Trials as Topic ; Observational Studies as Topic

OBJECTIVETo explore the efficacy and safety of intravenous itraconazole for patients undergoing intensive chemotherapy or hematopoietic stem cell transplantation in different strategies.

METHODSBased on multicenter, observational data, the efficacies of antifungal therapy for patients with persistent fever and suspected IFD in different strategies were calculated retrospectively, and the factors associated with the response of antifungal therapy were explored by logistic analysis.

RESULTSIn accordance with the latest published diagnostic criteria and treatment consensus in China, there were 2 patients who were diagnosed as proven IFD ultimately, 20 probable IFD, 19 possible IFD and 133 undefined IFD, respectively. Accordingly, the response rates in targeted therapy for proven/probable IFD patients, diagnostic-driven therapy for possible and undefined IFD patients with clinical or microbiological evidence of IFD, and empirical therapy for undefined patients without any evidence of IFD were 50.0%, 57.4% and 13.5%, respectively (P<0.01). And the multivariable analysis indicated that the presence of radiological or microbiological evidence of IFD before or after the initiation of antifungal therapy was markedly associated with the response to antifungal therapy (P<0.01). The incidence of itraconazole related adverse effect was only 2.9%.

CONCLUSIONItraconazole injection was an effective and safe agent in targeted and diagnostic- driven antifungal therapy for immunocompromised or neutropenic febrile patients with hematological malignancies.

Adolescent ; Adult ; Aged ; Antifungal Agents ; therapeutic use ; Female ; Hematopoietic Stem Cell Transplantation ; Humans ; Itraconazole ; therapeutic use ; Male ; Middle Aged ; Multicenter Studies as Topic ; Observational Studies as Topic ; Retrospective Studies ; Treatment Outcome ; Young Adult