Pearson's Chi-squared Test (pearson + chi-squar_test)

Distribution by Scientific Domains


Selected Abstracts


Microbiological analysis of infected root canals from symptomatic and asymptomatic teeth with periapical periodontitis and the antimicrobial susceptibility of some isolated anaerobic bacteria

MOLECULAR ORAL MICROBIOLOGY, Issue 5 2003
R. C. Jacinto
The purpose of the present study was to investigate the correlation between the composition of the bacterial flora isolated from infected root canals of teeth with apical periodontitis with the presence of clinical signs and symptoms, and to test the antibiotic susceptibility of five anaerobic bacteria mostly commonly found in the root canals of symptomatic teeth against various substances using the E-test. Microbial samples were taken from 48 root canals, 29 symptomatic and 19 asymptomatic, using adequate techniques. A total of 218 cultivable isolates were recovered from 48 different microbial species and 19 different genera. Root canals from symptomatic teeth harbored more obligate anaerobes and a bigger number of bacterial species than the asymptomatic teeth. More than 70% of the bacterial isolates were strict anaerobes. Statistical analysis used a Pearson Chi-squared test or a one-sided Fisher's Exact test as appropriate. Suggested relationships were found between specific microorganisms, especially gram-negative anaerobes, and the presence of spontaneous or previous pain, tenderness to percussion, pain on palpation and swelling amoxicillin, amoxicillin + clavulanate and cephaclor were effective against all the strains tested. The lowest susceptibility rate was presented by Prevotella intermedia/nigrescens against Penicillin G. Our results suggested that specific bacteria are associated with endodontic symptoms of infected teeth with periapical periodontitis and the majority of the anaerobic bacterial species tested were susceptible to all antibiotics studied. [source]


Clinicopathologic profile of normocomplementemic and hypocomplementemic urticarial vasculitis: a study from South India

JOURNAL OF THE EUROPEAN ACADEMY OF DERMATOLOGY & VENEREOLOGY, Issue 7 2008
CVP Dincy
Abstract Background, This study aims to study the clinical and histopathological characteristics of hypocomplementemic and normocomplementemic urticarial vasculitis (HUVS and NUV) among dermatology clinic attendees in a tertiary care hospital in South India. Patients and methods, A prospective study was conducted in the dermatology department from February 2003 to May 2004. Seventy-five patients met the inclusion criteria for UV. Sixty-eight patients in whom complement levels were available were classified into either NUV or HUVS groups. Clinical features, laboratory parameters and histological features were compared, and the significance of differences was established using Pearson's Chi-squared test. Results, There was a female preponderance among patients with HUVS. Wheals > 24 h were seen in 90% of patients, and in 54.4% of patients, the wheals were partially blanching or non-blanching. Angioedema was more prevalent in patients with NUV than HUVS (44.4% vs. 21.4%). Systemic involvement was seen in 64.3% of patients with HUVS and 44.4% of patients with NUV. Fever, ANA positivity and systemic lupus erythematosus (SLE) were significantly associated with HUVS. In most cases of UV, a provoking factor could not be identified. Neutrophilic small vessel vasculitis was seen in 42.9% of patients with HUVS and 16.6% patients with NUV. Direct immunofluorescence test showing immunoreactants at the dermo-epidermal junction were present in 60% of patients with HUVS and 33.3% patients with NUV. Conclusion, The clinical features of Indian patients with UV were similar to those reported from the West. Fever, ANA positivity and SLE were significantly associated with HUVS. [source]


Preparation of parents by teaching of distraction techniques does not reduce child anxiety at anaesthetic induction.

PEDIATRIC ANESTHESIA, Issue 9 2002
A. Watson
Introduction For those children having surgery, induction of anaesthesia is one of the most stressful procedures the child experiences perioperatively. Current work has failed to show a benefit of parental presence at induction of anaesthesia for all children. The reasons for lack of effect may include the high anxiety levels of some parents and also that the role for parents at their child's induction is not delineated. The main aim of this study was to see if parental preparation by teaching of distraction techniques could reduce their child's anxiety during intravenous induction of anaesthesia. Methods After ethics committee approval 40 children aged 2,10 years old, ASA status I or II undergoing daycase surgery under general anaesthesia were enrolled into the study. To avoid possible confounding factors children with a history of previous, surgery, chronic illness or developmental delay were excluded form participation. No children were given sedative premedication. After written informed consent by the parent, each child and parent was randomly assigned to an intervention or control group. Parents in the intervention group received preparation from a play specialist working on the children's surgical ward. It involved preparation for events in the anaesthetic room and instruction on methods of distraction for their child during induction using novel toys, books or blowing bubbles appropriate to the child's age. Preoperative information collected included demographic and baseline data. The temperament of the child was measured using the EASI (Emotionality, Activity, Sociability, Impulsivity) instrument of child temperament(l). In the anaesthetic room all children were planned to have intravenous induction of anaesthesia after prior application of EMLA cream. Anxiety of the child was measured by the modified Yale Preoperative Anxiety Scale (mYPAS)(2) by a blinded independent observer at three time points: entrance to the anaesthetic room, intravenous cannulation and at anaesthesia induction. Cooperation of the child was measured by the Induction Compliance Checklist (ICC) by the same observer (3). Postoperative data collected included parental satisfaction and anxiety scores measured by the Stait Trait Anxiety Inventory (STAI)(4) and at one week the behaviour of the child was measured Using the Posthospitalisation Behavioural Questionnaire (PHBQ)(5). Normally distributed data were analysed by a two-sample t-test, categorical data by Pearson's Chi-squared test and non-parametric data by the Wilcoxon rank-sum test. Results One parent withdrew after enrolment. This left 22 children in the control group and 17 in the intervention group. There were no significant differences in demographic and baseline data of the children between the two groups including ethnic origin, number of siblings, birth order of the child, recent stressful events in the child's life, previous hospital admissions and the temperament of the child. Parent demographics were also similar between groups including parent's age, sex, relationship to child and level of education. There were no significant differences in child anxiety or cooperation during induction measured by mYPAS and ICC between the control and intervention groups. More parents in the preparation group distracted their child than those without preparation but this did not reach significance. Parental anxiety immediately postinduction was similar between groups as was the level of parental satisfaction. The incidence of development of new negative postoperative behaviour of the child at one week was not significantly different between groups. Discussion This study shows that giving an active role for parents in the induction room, particularly by instructing them on distracting techniques for their child, does not reduce their child's anxiety compared to conventional parental presence. We conclude resources should not be directed at this type of parental preparation. Further work should examine the usefulness of distraction by nursing staff or play specialists during anaesthetic induction. [source]


Tests for Trend in Binary Response

BIOMETRICAL JOURNAL, Issue 3 2003
Georgia Salanti
Abstract Tests for trend are important in analyzing data where the binary response in ordered categories is of interest. An example is in toxicology where the response in various dose groups is observed. For testing an association between the dose and the response the approach from Cochran and Armitage is widely used. However the result of this test is highly dependent on the scores assigned to the dose groups. Various dose assignments can lead to different outcomes. As an alternative the isotonic regression, a nonparametric method, is proposed. The outcome of this approach is independent of the quantification of the dose. Both methods (Cochran-Armitage test and isotonic regression) are compared within a simulation study to an isotonic version of the Pearson's Chi-squared test and the Wilcoxon rank sum test. [source]