Description of continuous data using bar graphs: a misleading approach

INTRODUCTION:With the ease provided by current computational programs, medical and scientific journals use bar graphs to describe continuous data.METHODS:This manuscript discusses the inadequacy of bars graphs to present continuous data.RESULTS:Simulated data show that box plots and dot plots are more-feasible tools to describe continuous data.CONCLUSIONS:These plots are preferred to represent continuous variables since they effectively describe the range, shape, and variability of observations and clearly identify outliers. By contrast, bar graphs address only measures of central tendency. Bar graphs should be used only to describe qualitative data.

Secular trends in Klebsiella pneumoniae isolated in a tertiary-care hospital: increasing prevalence and accelerated decline in antimicrobial susceptibility

Abstract: INTRODUCTION Klebsiella pneumoniae has become an increasingly important etiologic agent of nosocomial infections in recent years. This is mainly due to the expression of virulence factors and development of resistance to several antimicrobial drugs. METHODS This retrospective study examines data obtained from the microbiology laboratory of a Brazilian tertiary-care hospital. To assess temporal trends in prevalence and antimicrobial susceptibility, K. pneumoniae isolates were analyzed from 2000 to 2013. The relative frequencies of K. pneumoniae isolation were calculated among all Gram-negative bacilli isolated in each period analyzed. Susceptibility tests were performed using automated systems. RESULTS: From 2000-2006, K. pneumonia isolates comprised 10.7% of isolated Gram-negative bacilli (455/4260). From 2007-2013, this percentage was 18.1% (965/5331). Strictly considering isolates from bloodstream infections, the relative annual prevalence of K. pneumoniae increased from 14-17% to 27-32% during the same periods. A progressive decrease in K. pneumoniae susceptibility to all antimicrobial agents assessed was detected. Partial resistance was also observed to antimicrobial drugs that have been used more recently, such as colistin and tigecycline. CONCLUSIONS Our study indicates that K. pneumoniae has become a major pathogen among hospitalized patients and confirms its recent trend of increasing antimicrobial resistance.

Pressure sores among malnourished necropsied adults - preliminary data

Pressure sores are common among bedridden, elderly, or malnourished patients, and may occur in terminal ill patients because of impaired mobility, fecal or urinary incontinence, and decreased healing capacity. The aim of this study was to compare frequency of pressure sores between malnourished and non-malnourished necropsied adults. METHOD: All (n = 201) adults (age ³ 18 years) autopsied between 1986 and 1996 at the Teaching Hospital of Triangulo Mineiro Medical School (Uberaba) were eligible for the study. Gender, race, weight, height and main diagnoses were recorded. Ninety-six cases were excluded because of probable body water retention (congestive heart failure, hepatic insufficiency, nephrotic syndrome) or pressure sores secondary to peripheral vascular ischemia. Body mass index (BMI) was used to define malnourished (BMI < 18.5 kg/m²) and non-malnourished (BMI > 18.5kg/m²) groups. RESULTS: Except for weight (42.5kg; range: 28-57 vs. 60; 36-134.5kg) and BMI (16.9; range: 12.4-18.5 vs. 22.7; range: 18.5-54.6kg/m²), respectively, there were no statistical differences among 43 malnourished and 62 non-malnourished cases in relation to age (54.9 ± 20.4 vs. 52.9 ± 17.9 years), percentage of white persons (74.4 vs. 64.5%), male gender (76.7 vs. 69.3%) and main diagnoses. Five malnourished (11.6%) and 7 (11.5%) non-malnourished cases had pressure sores (p=0.89). CONCLUSION: Pressure sores were equally common findings in necropsied persons with protein-energy malnutrition, as assessed by body mass index.

Premature thelarche: identification of clinical and laboratory data for the diagnosis of precocious puberty

PURPOSE: Two groups of girls with premature breast development were studied retrospectively. We tried to identify clinical, radiological, and hormonal parameters that could distinguish between a benign, nonprogressive premature thelarche and a true precocious puberty. METHODS: The clinical outcome of 88 girls with breast enlargement before 6.1 years of age was analyzed. Taking into account the progression of their sexual maturation, we allocated the children into 2 groups: "Isolated Premature Thelarche" (n = 63) and "Precocious Puberty" (n = 25) groups. Chronological and bone ages, height and growth velocity centiles, computerized tomography of hypothalamus-pituitary area, pelvic ultrasonography, gonadotropin response to luteinizing hormone-releasing hormone stimulation as well as basal levels of luteinizing hormone, follicle-stimulating hormone, estradiol, and prolactin were studied in both groups. Statistical analysis were performed using the Student t test to compare the sample means. Fisher's exact test and chi² test were used to analyze the nonparametric variables. RESULTS: Isolated premature thelarche most frequently affected girls younger than 2 years who presented exaggerated follicle-stimulating hormone response to luteinizing hormone-releasing hormone stimulation test. The precocious puberty group had higher initial stature, accelerated growth rate and bone age, increased uterine and ovarian volumes, high spontaneous luteinizing hormone levels by immunofluorimetric assay, as well as a high luteinizing hormone response and peak luteinizing hormone/follicle-stimulating hormone ratio after luteinizing hormone-releasing hormone stimulation. CONCLUSION: At initial presentation, girls who undergo true precocious puberty present advanced bone age, increased uterine and ovarian volumes in addition to breast enlargement, as well as an luteinizing hormone-predominant response after a luteinizing hormone-releasing hormone stimulation test.

Salivary gland tumors in a Brazilian population: a retrospective study of 124 cases

Salivary gland tumors constitute a highly heterogeneous histopathologic group. There are few epidemiological studies of large series of benign and malignant salivary gland tumors in Brazil. MATERIAL AND METHODS: Hospital records of 124 patients with salivary gland tumors diagnosed from January 1993 to December 1999 were reviewed. The patients were analyzed according to gender, age, size, location, and histopathology of the tumor. RESULTS AND CONCLUSIONS: Patients with benign and malignant tumors presented with a mean age of 47.7 and 48.8 years, respectively. The frequency of benign tumors was 80% (n = 99) and malignant tumors 20% (n = 25). Tumors were localized in the parotid gland 71% (n = 88), in the submandibular gland 24% (n = 30), and in the minor salivary glands 5% (n = 6). The most common benign tumors were pleomorphic adenoma in 84% (n = 84) and Warthin's tumor in 13% (n = 13). Among malignant tumors, mucoepidermoid carcinoma was the most common in 52% (n = 13), adenoid cystic carcinoma occurred in 20% (n = 5), and carcinoma ex pleomorphic adenoma was detected in 12% (n = 3).

Characterization of newborns with nonimmune hydrops fetalis admitted to a neonatal intensive care unit

PURPOSE: To determine the incidence and characteristics of nonimmune hydrops fetalis in the newborn population. METHOD: A retrospective study of the period between 1996 and 2000, including all newborns with a prenatal or early neonatal diagnosis of nonimmune hydrops fetalis, based on clinical history, physical examination, and laboratory evaluation. The following were analyzed: prenatal follow-up, delivery type, gender, birth weight, gestational age, presence of perinatal asphyxia, nutritional classification, etiopathic diagnosis, length of hospital stay, mortality, and age at death. RESULTS: A total of 47 newborns with hydrops fetalis (0.42% of live births), 18 (38.3%) with the immune form and 29 (61.7%) with the nonimmune form, were selected for study. The incidence of nonimmune hydrops fetalis was 1 per 414 neonates. Data was obtained from 21 newborns, with the following characteristics: 19 (90.5%) were suspected from prenatal diagnosis, 18 (85.7%) were born by cesarean delivery, 15 (71.4%) were female, and 10 (47.6%) were asphyxiated. The average weight was 2665.9 g, and the average gestational age was 35 3/7 weeks; 14 (66.6%) were preterm; 18 (85.0 %) appropriate delivery time; and 3 (14.3%) were large for gestational age. The etiopathic diagnosis was determined for 62%, which included cardiovascular (19.0%), infectious (9.5%), placental (4.8%), hematologic (4.7%), genitourinary (4.8%), and tumoral causes (4.8%), and there was a combination of causes in 9.5%. The etiology was classified as idiopathic in 38%. The length of hospital stay was 26.6 ± 23.6 days, and the mortality rate was 52.4%. CONCLUSIONS: The establishment of a suitable etiopathic diagnosis associated with prenatal detection of nonimmune hydrops fetalis can be an important step in reducing the neonatal mortality rate from this condition.

Measuring male infertility: epidemiological aspects

Evidence suggests that human semen quality may have been deteriorating in recent years. Most of the evidence is retrospective, based on analysis of data sets collected for other purposes. Measures of male infertility are needed if we want to monitor the biological capacity for males to reproduce over time or between different populations. We also need these measures in analytical epidemiology if we want to identify risk indicators, risk factors, or even causes of an impaired male fecundity-that is, the male component in the biological ability to reproduce. The most direct evaluation of fecundity is to measure the time it takes to conceive. Since the time of conception may be missed in the case of an early abortion, time to get pregnant is often measured as the time it takes to obtain a conception that survives until a clinically recognized pregnancy or even a pregnancy that ends with a live born child occurs. A prolonged time required to produce pregnancy may therefore be due to a failure to conceive or a failure to maintain a pregnancy until clinical recognition. Studies that focus on quantitative changes in fecundity (that does not cause sterility) should in principle be possible in a pregnancy sample. The most important limitation in fertility studies is that the design requires equal persistency in trying to become pregnant and rather similar fertility desires and family planning methods in the groups to be compared. This design is probably achievable in exposure studies that make comparisons with reasonable comparable groups concerning social conditions and use of contraceptive methods.

Comparison of catheter-related infection risk in two different long-term venous devices in adult hematology-oncology patients

PURPOSE: Infection is the leading complication of long-term central venous catheters, and its incidence may vary according to catheter type. The objective of this study was to compare the frequency and probability of infection between two types of long-term intravenous devices. METHODS: Retrospective study in 96 onco-hematology patients with partially implanted catheters (n = 55) or completely implanted ones (n = 42). Demographic data and catheter care were similar in both groups. Infection incidence and infection-free survival were used for the comparison of the two devices. RESULTS: In a median follow-up time of 210 days, the catheter-related infection incidence was 0.2102/100 catheter-days for the partially implanted devices and 0.0045/100 catheter-days for the completely implanted devices; the infection incidence rate was 46.7 (CI 95% = 6.2 to 348.8). The 1-year first infection-free survival ratio was 45% versus 97%, and the 1-year removal due to infection-free survival ratio was 42% versus 97% for partially and totally implanted catheters, respectively (P <.001 for both comparisons). CONCLUSION: In the present study, the infection risk was lower in completely implanted devices than in partially implanted ones.

Bionomics data for Anopheles (Anopheles) forattinii Wilkerson & Sallum, 1999

Immature and adult stages of Anopheles (Anopheles) forattinii were collected in the Parque Nacional do Jaú, Novo Airão, Amazonas, Brazil. Larvae and pupae were taken from fresh water among floating plant debris inside flooded "igapó" forest. This species may make use of plant debris for passive dispersal throughout its distribution range.

Modelling Amazonian forest eddy covariance data: a comparison of big leaf versus sun/shade models for the C-14 tower at Manaus I. Canopy photosynthesis

In this study, we concentrate on modelling gross primary productivity using two simple approaches to simulate canopy photosynthesis: "big leaf" and "sun/shade" models. Two approaches for calibration are used: scaling up of canopy photosynthetic parameters from the leaf to the canopy level and fitting canopy biochemistry to eddy covariance fluxes. Validation of the models is achieved by using eddy covariance data from the LBA site C14. Comparing the performance of both models we conclude that numerically (in terms of goodness of fit) and qualitatively, (in terms of residual response to different environmental variables) sun/shade does a better job. Compared to the sun/shade model, the big leaf model shows a lower goodness of fit and fails to respond to variations in the diffuse fraction, also having skewed responses to temperature and VPD. The separate treatment of sun and shade leaves in combination with the separation of the incoming light into direct beam and diffuse make sun/shade a strong modelling tool that catches more of the observed variability in canopy fluxes as measured by eddy covariance. In conclusion, the sun/shade approach is a relatively simple and effective tool for modelling photosynthetic carbon uptake that could be easily included in many terrestrial carbon models.