Discover the most talked about and latest scientific content & concepts.

Concept: Fisher's exact test


OBJECTIVE: To investigate whether biologic-free remission can be achieved in patients with early, active axial spondyloarthritis (SpA) who were in partial remission after 28 weeks of infliximab (IFX)+naproxen (NPX) or placebo (PBO)+NPX treatment and whether treatment with NPX was superior to no treatment to maintain disease control. METHOD: Infliximab as First-Line Therapy in Patients with Early Active Axial Spondyloarthritis Trial (INFAST) Part 1 was a double-blind, randomised, controlled trial in biologic-naïve patients with early, active, moderate-to-severe axial SpA treated with either IFX 5 mg/kg+NPX 1000 mg/d or PBO+NPX 1000 mg/d for 28 weeks. Patients achieving Assessment of SpondyloArthritis international Society (ASAS) partial remission at week 28 continued to Part 2 and were randomised (1:1) to NPX or no treatment until week 52. Treatment group differences in ASAS partial remission and other efficacy variables were assessed through week 52 with Fisher exact tests. RESULTS: At week 52, similar percentages of patients in the NPX group (47.5%, 19/40) and the no-treatment group (40.0%, 16/40) maintained partial remission, p=0.65. Median duration of partial remission was 23 weeks in the NPX group and 12.6 weeks in the no-treatment group (p=0.38). Mean Bath Ankylosing Spondylitis Disease Activity Index scores were low at week 28, the start of follow-up treatment (NPX, 0.7; no treatment, 0.6), and remained low at week 52 (NPX, 1.2; no treatment, 1.7). CONCLUSIONS: In axial SpA patients who reached partial remission after treatment with either IFX+NPX or NPX alone, disease activity remained low, and about half of patients remained in remission during 6 months in which NPX was continued or all treatments were stopped.

Concepts: Randomized controlled trial, Infliximab, Mean, Ankylosing spondylitis, Spondyloarthropathy, Psoriatic arthritis, Fisher's exact test, Spondylitis


Obesity has been associated with respiratory complications, and the majority of these complications occur in the Post-Anesthesia Care Unit (PACU). The aim of this study was to evaluate the outcome and incidence of adverse respiratory events (AREs) in obese patients during their stay in the PACU METHODS: We conducted a prospective control study that included 27 obese patients matched with an equal number of patients with body mass index (BMI)<30 (non-obese control group); the 2 groups of patients were similar in respect to gender distribution, age, and type of surgery and had been admitted into the PACU after elective surgery (May 2011). The AREs were identified during PACU stay. Descriptive analysis of variables was performed, and the Mann-Whitney U test, Chi-square test, or Fisher's exact test were used for comparisons. Associations with AREs were studied using univariate and multivariate logistic regression models.

Concepts: Statistical tests, Statistics, Body mass index, Mann–Whitney U, Non-parametric statistics, Fisher's exact test, Chi-square test, Categorical data


Purpose To determine the clinical and epidemiological characteristics of abdominal wall endometriosis (AWE), as well as the rate and recurrence factors for the disease. Methods A retrospective study of 52 women with AWE was performed at Universidade Estadual de Campinas from 2004 to 2014. Of the 231 surgeries performed for the diagnosis of endometriosis, 52 women were found to have abdominal wall endometriosis (AWE). The frequencies, means and standard deviations of the clinical characteristics of these women were calculated, as well as the recurrence rate of AWE. To determine the risk factors for disease recurrence, Fisher’s exact test was used. Results The mean age of the patients was 30.71 ± 5.91 years. The main clinical manifestations were pain (98%) and sensation of a mass (36.5%). We observed that 94% of these women had undergone at least 1 cesarean section, and 73% had used medication for the postoperative control of endometriosis. The lesion was most commonly located in the cesarean section scar (65%). The recurrence rate of the disease was of 26.9%. All 14 women who had relapsed had surgical margins compromised in the previous surgery. There was no correlation between recurrent AWE and a previous cesarean section (p = 0.18), previous laparotomy (p = 0.11), previous laparoscopy (p = 0.12) and postoperative hormone therapy (p = 0.51). Conclusion Women with previous cesarean sections with local pain or lumps should be investigated for AWE. The recurrence of AWE is high, especially when the first surgery is not appropriate and leaves compromised surgical margins.

Concepts: Childbirth, Epidemiology, Surgery, Anesthesia, Arithmetic mean, Hysterectomy, Fisher's exact test, Universidade Estadual de Campinas


Background Tranexamic acid reduces the risk of bleeding among patients undergoing cardiac surgery, but it is unclear whether this leads to improved outcomes. Furthermore, there are concerns that tranexamic acid may have prothrombotic and proconvulsant effects. Methods In a trial with a 2-by-2 factorial design, we randomly assigned patients who were scheduled to undergo coronary-artery surgery and were at risk for perioperative complications to receive aspirin or placebo and tranexamic acid or placebo. The results of the tranexamic acid comparison are reported here. The primary outcome was a composite of death and thrombotic complications (nonfatal myocardial infarction, stroke, pulmonary embolism, renal failure, or bowel infarction) within 30 days after surgery. Results Of the 4662 patients who were enrolled and provided consent, 4631 underwent surgery and had available outcomes data; 2311 were assigned to the tranexamic acid group and 2320 to the placebo group. A primary outcome event occurred in 386 patients (16.7%) in the tranexamic acid group and in 420 patients (18.1%) in the placebo group (relative risk, 0.92; 95% confidence interval, 0.81 to 1.05; P=0.22). The total number of units of blood products that were transfused during hospitalization was 4331 in the tranexamic acid group and 7994 in the placebo group (P<0.001). Major hemorrhage or cardiac tamponade leading to reoperation occurred in 1.4% of the patients in the tranexamic acid group and in 2.8% of the patients in the placebo group (P=0.001), and seizures occurred in 0.7% and 0.1%, respectively (P=0.002 by Fisher's exact test). Conclusions Among patients undergoing coronary-artery surgery, tranexamic acid was associated with a lower risk of bleeding than was placebo, without a higher risk of death or thrombotic complications within 30 days after surgery. Tranexamic acid was associated with a higher risk of postoperative seizures. (Funded by the Australian National Health and Medical Research Council and others; ATACAS Australia New Zealand Clinical Trials Registry number, ACTRN12605000557639 .).

Concepts: Blood, Myocardial infarction, Heart, Stroke, Cardiac arrest, Anticoagulant, Cardiac tamponade, Fisher's exact test


The primary objective of this study was to investigate if differences in dog bite characteristics exist amongst legislated and non-legislated dog breeds listed under breed-specific legislation in Ireland (age when bitten, anatomical bite locations, triggers for biting, victim’s relationship with the dog, geographical location and owner presence, history of aggression, reporting bite incident to authorities, medical treatment required following the bite, and type of bite inflicted). A second objective of the current study was to investigate dog control officer’s enforcement and perceptions of current legislation. Data for statistical analyses were collated through a nationally advertised survey, with Pearson Chi-square and Fisher’s Exact Test statistical methods employed for analyses. A total of 140 incident surveys were assessed comprising of non-legislated (n = 100) and legislated (n = 40) dog bite incidents.

Concepts: Statistical tests, Statistics, Injuries, Ronald Fisher, Fisher's exact test, Exact test, Chi-square test, Bite


Inactivated poliovirus vaccine (IPV) is efficacious against paralytic disease, but its effect on mucosal immunity is debated. We assessed the efficacy of IPV in boosting mucosal immunity. Participants received IPV, bivalent 1 and 3 oral poliovirus vaccine (bOPV), or no vaccine. A bOPV challenge was administered 4 weeks later, and excretion was assessed 3, 7, and 14 days later. Nine hundred and fifty-four participants completed the study. Any fecal shedding of poliovirus type 1 was 8.8, 9.1, and 13.5% in the IPV group and 14.4, 24.1, and 52.4% in the control group by 6- to 11-month, 5-year, and 10-year groups, respectively (IPV versus control: Fisher’s exact test P < 0.001). IPV reduced excretion for poliovirus types 1 and 3 between 38.9 and 74.2% and 52.8 and 75.7%, respectively. Thus, IPV in OPV-vaccinated individuals boosts intestinal mucosal immunity.

Concepts: Vaccine, Poliomyelitis, Polio vaccine, Effectiveness, Fisher's exact test, Exact test, Poliomyelitis eradication, Poliovirus


The Burmese python, Python bivittatus Kuhl, is a well-established invasive species in the greater Everglades ecosystem of southern Florida, USA. Most research on its ecological impacts focuses on its role as a predator and its trophic interactions with native vertebrate species, particularly mammals. Beyond predation, there is little known about the ecological interactions between P. bivittatus and native faunal communities. It is likely that established populations of P. bivittatus in southern Florida serve as hosts for native mosquito communities. To test this concept, we used mitochondrial cytochrome c oxidase subunit I DNA barcoding to determine the hosts of blood fed mosquitoes collected at a research facility in northern Florida where captive P. bivittatus and Argentine black and white tegu, Salvator merianae (Duméril and Bibron), are maintained in outdoor enclosures, accessible to local mosquitoes. We recovered python DNA from the blood meals of three species of Culex mosquitoes: Culex erraticus (Dyar and Knab), Culex quinquefasciatus Say, and Culex pilosus (Dyar and Knab). Culex erraticus conclusively (P = 0.001; Fisher’s Exact Test) took more blood meals from P. bivittatus than from any other available host. While the majority of mosquito blood meals in our sample were derived from P. bivittatus, only one was derived from S. merianae. These results demonstrate that local mosquitoes will feed on invasive P. bivittatus, a recently introduced host. If these interactions also occur in southern Florida, P. bivittatus may be involved in the transmission networks of mosquito-vectored pathogens. Our results also illustrate the potential of detecting the presence of P. bivittatus in the field through screening mosquito blood meals for their DNA.

Concepts: Mitochondrion, Species, Ecology, Fisher's exact test, Cytochrome c, Invasive species, Everglades, Culex


International Journal of Paediatric Dentistry 2013; 23: 145-152 Background.  Alternatives to vital pulpotomy treatment in primary teeth are being sought because of the high formaldehyde content of traditional formocresol (FC) pulpotomy medicaments. Aim.  The aim was to compare the clinical and radiographic success of vital pulpotomy treatment in primary molars using 3% sodium hypochlorite (NaOCl) versus a 1 : 5 dilution of Buckley’s FC. Design.  Pulpotomies were performed in primary molars of healthy children between 3 and 10 years old. Sixty-five primary teeth were randomized into two groups that were evaluated for treatment outcomes. Following treatment, the pulp chamber was filled with zinc oxide eugenol (ZnOE) and restored with a stainless steel crown cemented with glass ionomer cement. Clinical and radiographic outcomes were recorded at 6 and 12 months. Results.  The control (FC) and experimental (NaOCl) groups demonstrated 100% clinical success at 6 and 12 months. The NaOCl group had 86% (19/22) radiographic success at 6 months and 80% (12/15) at 12 months. The FC group had 84% (21/25) radiographic success at 6 months and 90% (9/10) at 12 months. No significant differences were found in the radiographic outcomes between the two groups at 6 and 12 months (Fisher’s exact test; P = 0.574 and P = 0.468, respectively). Conclusion.  NaOCl demonstrated clinical and radiographic success comparable to FC.

Concepts: Horse, Chlorine, Teeth, Molar, Fisher's exact test, Exact test, Canine tooth, Zinc oxide eugenol


OBJECTIVES: To determine whether a patient’s level of assertiveness and other factors influences her comfort level in asking her provider to wash his or her hands. METHODS: In this pilot study, we developed a survey to gather cross-sectional information on a variety of factors that might explain patient willingness to ask her health-care provider to wash his or her hands. Three primary predictor variables are analyzed: (1) patient assertiveness; (2) patient familiarity with her healthcare provider; and (3) whether the patient has observed hand-washing behavior. Fifty patients participated from the Obstetrics and Gynecology Department of Metropolitan Hospital Center. RESULTS: Less assertive patients are much less likely than assertive patients to ask physicians to wash hands (25% versus 68%; Fisher’s exact test P = 0.0427). Among the 3 assertiveness questions included in the survey, the ability to ask physicians questions during visits is most strongly indicative of willingness to ask about hand washing. Familiarity with the names of regular health-care providers has a statistically significant impact on willingness to ask about hand washing. Evidence suggests that observing hand washing behavior affects willingness to ask, but differences are not statistically significant. Results by socioeconomic status such as age, education, income, and race/ethnicity are inconclusive. CONCLUSIONS: A patient’s level of assertiveness alone is not sufficient to determine her willingness to inquire about the hand-washing behavior of her provider. A high percentage of patients did not see their provider engaging in adequate hand washing behavior. If patients feel comfortable with their provider to inquire about their care and request hand-washing behavior, health outcomes are affected by reducing the rates of health care-associated infections.

Concepts: Health care, Health care provider, Medicine, Patient, Illness, Ronald Fisher, Fisher's exact test, Hygiene


PURPOSE: The aim of this study was to evaluate all aspects of workflow in a large academic MRI department to determine whether process improvement (PI) efforts could improve key performance indicators (KPIs). METHODS: KPI metrics in the investigators' MR imaging department include daily inpatient backlogs, on-time performance for outpatient examinations, examination volumes, appointment backlogs for pediatric anesthesia cases, and scan duration relative to time allotted for an examination. Over a 3-week period in April 2011, key members of the MR imaging department (including technologists, nurses, schedulers, physicians, and administrators) tracked all aspects of patient flow through the department, from scheduling to examination interpretation. Data were analyzed by the group to determine where PI could improve KPIs. Changes to MRI workflow were subsequently implemented, and KPIs were compared before (January 1, 2011, to April 30, 2011) and after (August 1, 2011, to December 31, 2011) using Mann-Whitney and Fisher’s exact tests. RESULTS: The data analysis done during this PI led to multiple changes in the daily workflow of the MR department. In addition, a new sense of teamwork and empowerment was established within the MR staff. All of the measured KPIs showed statistically significant changes after the reengineering project. CONCLUSIONS: Intradepartmental PI efforts can significantly affect KPI metrics within an MR imaging department, making the process more patient centered. In addition, the process allowed significant growth without the need for additional equipment or personnel.

Concepts: Statistics, Physician, Management, Ronald Fisher, Fisher's exact test, Process architecture, Business process reengineering, 1973