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Concept: Chi-square test


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


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


In a retrospective multicentre study, the success rate and efficiency of activator treatment were analysed. All patients from two University clinics (Giessen, Germany and Berne, Switzerland) that fulfilled the selection criteria (Class II division 1 malocclusion, activator treatment, no aplasia, no extraction of permanent teeth, no syndromes, no previous orthodontic treatment except transverse maxillary expansion, full available records) were included in the study. The subject material amounted to 222 patients with a mean age of 10.6 years. Patient records, lateral head films, and dental casts were evaluated. Treatment was classified as successful if the molar relationship improved by at least half to three-fourths cusp width depending on whether or not the leeway space was used during treatment. Group comparisons were carried out using Wilcoxon two-sample and Kruskal-Wallis tests. For discrete data, chi-square analysis was used and Fisher’s exact test when the sample size was small. Stepwise logistic regression was also employed. The success rate was 64 per cent in Giessen and 66 per cent in Berne. The only factor that significantly (P¡0:001) influenced treatment success was the level of co-operation. In approximately 27 per cent of the patients at both centres, the post-treatment occlusion was an ideal Class I. In an additional 38 per cent of the patients, marked improvements in occlusal relationships were found. In subjects with Class II division 1 malocclusions, in which orthodontic treatment is performed by means of activators, a marked improvement of the Class II dental arch relationships can be expected in approximately 65% of subjects. Activator treatment is more efficient in the late than in the early mixed dentition.

Concepts: Class II railroad, Non-parametric statistics, Statistical tests, Teeth, Orthodontics, Chi-square test, Fisher's exact test, Malocclusion


To evaluate utricular and saccular function during the acute and resolved phases of BPPV, ocular and cervical vestibular evoked myogenic potentials (VEMPs) were studied in 112 patients with BPPV and 50 normal controls in a referral-based University Hospital. Ocular (oVEMPs) and cervical VEMPs (cVEMPs) were induced using air-conducted sound (1000Hz tone burst, 100dB normal hearing level) at the time of initial diagnosis and 2months after successful repositioning in patients with BPPV, and the results were compared with those of the controls. Abnormalities of cVEMPs and oVEMPs in patients with BPPV were prevalent and significantly higher compare to the healthy control group (p<0.01 in each VEMP by chi-square test). In the patient group, difference between the proportions of abnormal responses of cVEMP and oVEMP was not significant in both affected (p=0.37, chi-squared test) and non-affected (p=1.00) ears. The abnormalities were more likely reduced or absent responses rather than delayed ones; reduced or absent responses are 17.6% in cVEMPs (p=0.04, chi-square) and 21.6% in oVEMPs (p<0.01). The non-affected ear in the BPPV group also showed significantly higher abnormalities of cVEMP and oVEMP when compared to the control group. The follow-up VEMPs after repositioning maneuvers were not significantly different compared to the initial values from both stimulated affected and non-affected ears. Although most patients had unilateral BPPV, bilateral otolithic dysfunction was often shown by persistently reduced or absent cervical and ocular VEMPs, suggesting that BPPV may be caused by significant bilateral damage to the otolith organs.

Concepts: Auditory system, Superior canal dehiscence, Pearson's chi-square test, Chi-square test, Vestibular evoked myogenic potential, Chi-square distribution, Ear, Benign paroxysmal positional vertigo


The clam Meretrix meretrix is a commercially important mollusc species in the coastal areas of South and Southeast Asia. In the present study, large-scale SNPs were genotyped by the Multiplex SNaPshot genotyping method among the stocks of M. meretrix with different Vibrio spp. infection resistance profile. Firstly, the AUTOSNP software was applied to mine SNPs from M. meretrix transcriptome, and 323 SNP loci (including 120 indels) located on 64 contigs were selected based on Uniprot-GO associations. Then, 38 polymorphic SNP loci located on 15 contigs were genotyped successfully in the clam stocks with different resistance to Vibrio parahaemolyticus infection (11-R and 11-S groups). Pearson’s Chi-square test was applied to compare the allele and genotype frequency distributions of the SNPs between the different stocks, and seven SNP markers located on three contigs were found to be associated with V. parahaemolyticus infection resistance trait. Haplotype-association analysis showed that six haplotypes had significantly different frequency distributions in 11-S and 11-R (P < 0.05). With selective genotyping between 09-R and 09-C populations, which had different resistance to Vibrio harveyi infection, four out of the seven selected SNPs had significantly different distributions (P < 0.05) and therefore they were considered to be associated with Vibrio spp. infection resistance. Sequence alignments and annotations indicated that the contigs containing the associated SNPs had high similarity to the immune related genes. All these results would be useful for the future marker-assisted selection of M. meretrix strains with high Vibrio spp. infection resistance.

Concepts: Gene, Genetics, Immune system, Vibrio, Chi-square distribution, Chi-square test, Vibrio parahaemolyticus, Pearson's chi-square test


Smartphones are now owned by most young adults in many countries. Installed applications regularly update while the phone is in standby. If it is kept near the body, this can lead to considerably higher exposure to radiofrequency electromagnetic radiation than occurred without internet access. Very little is known about current smartphone carrying habits of young women. This survey used an online questionnaire to ask about smartphone location under several circumstances to inform the power calculation for a women’s health study. They were also asked about risk perceptions. Data was analysed using Pearson chi square. Three age categories were made: 15-20, 21-30, 31-40. Smartphones were generally kept on standby (96% by day, 83% at night). Of all participants, in the last week the most common locations of the phone when not in use or during passive use was off-body (86%), in the hand (58%), a skirt/trouser pocket (57%), or against the breast (15%). Pocket and near-the-breast storage were significant by age (χ215.04, p = 0.001 and χ210.96, p = 0.04, respectively), both positively influenced by the youngest group. The same influence lay in the association between holding the phone (χ211.082, p = 0.004) and pocket-storage (χ219.971, p<0.001) during passive use. For calls, 36.5% solely used the phone against the head. More than half kept the phone 20-50 cms from their head at night (53%), while 13% kept it closer than 20 cms. Many (36%) thought RF-EMR exposure was related to health problems while 16% did not. There was no relationship between thinking RF-EMR exposure causes health problems in general and carrying the phone against the upper or lower body (p = 0.69 and p = 0.212, respectively). However, calls with the phone against the head were positively related to perception of health risk (χ2 6.695, p = 0.035). Our findings can be used in the power calculation for a case-control study.

Concepts: Sense, Chi-square test, Mobile phone, Electromagnetic spectrum, Chi-square distribution, Pearson's chi-square test, Electromagnetic radiation, Mind


BACKGROUND: The increasing numbers of colonias along the U.S.-Mexico border are characterized by disproportionately poor families of Mexican-origin, limited access to resources and health services, and heightened risk for obesity and diabetes. Despite consistent evidence supporting physical activity (PA) in prevention of chronic diseases, many individuals of Mexican-origin, including children, fail to meet PA recommendations. Environmental influences on PA, founded in ecological and social cognitive perspectives, have not been examined among children living in colonias. The purpose of this study was to identify and better understand (1) household and neighborhood environmental PA resources/supports, (2) perceived barriers to engaging in PA, and (3) PA offerings, locations, and transportation characteristics for Mexican-origin children living in colonias. METHODS: Data for this study were collected by promotora-researchers (indigenous community health workers trained in research methods) using face-to-face interviews conducted in Spanish. The sample consists of 94 mother-child dyads from Texas border colonias in Hidalgo County. Interviews included questionnaire items addressing PA barriers, household and neighborhood environmental support assessments conducted with each dyad, and open-ended questions that were coded to identify availability and locations of PA opportunities and transportation options. Descriptive statistics were calculated and differences between genders, birth countries, and BMI categories of children were determined using chi-square tests. RESULTS: All children were of Mexican-origin. The most frequently reported barriers were unleashed dogs in the street, heat, bad weather, traffic, no streetlights, and no place like a park to exercise. Prominent locations for current PA included schools, home, and parks. Common PA options for children were exercise equipment, running, playing, and sports. Environmental assessments identified exercise equipment (bicycles/tricycles, balls, etc….), paved/good streets, yard/patio space, and social norms as the most frequent household or neighborhood resources within these colonias. Differences in PA barriers, options, and environmental resources for genders, birth countries, and BMI categories were detected. CONCLUSIONS: This study suggests that PA environmental resources, barriers, and opportunities for colonias children are similar to previous studies and distinctively unique. As expected, built resources in these communities are limited and barriers exist; however, knowledge of PA opportunities and available PA resources within colonias households and neighborhoods offers insight to help guide future research, policy, and PA initiatives.

Concepts: Dyadic, Chi-square distribution, Chi-square test, Body mass index, Family, Sociology, Physical exercise, Obesity


Comprehensive interventions including components of stigma and discrimination reduction in schizophrenia in low- and middle-income countries (LMICs) are lacking. We developed a community-based comprehensive intervention to evaluate its effects on clinical symptoms, social functioning, internalized stigma and discrimination among patients with schizophrenia. A randomized controlled trial including an intervention group (n = 169) and a control group (n = 158) was performed. The intervention group received comprehensive intervention (strategies against stigma and discrimination, psycho-education, social skills training and cognitive behavioral therapy) and the control group received face to face interview. Both lasted for nine months. Participants were measured at baseline, 6 months and 9 months using the Internalized Stigma of Mental Illness scale (ISMI), Discrimination and Stigma Scale (DISC-12), Global Assessment of Functioning (GAF), Schizophrenia Quality of Life Scale (SQLS), Self-Esteem Scale (SES), Brief Psychiatric Rating Scale (BPRS) and PANSS negative scale (PANSS-N). Insight and medication compliance were evaluated by senior psychiatrists. Data were analyzed by descriptive statistics, t-test, chi-square test or Fisher’s exact test. Linear Mixed Models were used to show intervention effectiveness on scales. General Linear Mixed Models with multinomial logistic link function were used to assess the effectiveness on medication compliance and insight. We found a significant reduction on anticipated discrimination, BPRS and PANSS-N total scores, and an elevation on overcoming stigma and GAF in the intervention group after 9 months. These suggested the intervention may be effective in reducing anticipated discrimination, increasing skills overcoming stigma as well as improving clinical symptoms and social functioning in Chinese patients with schizophrenia.

Concepts: Positive and Negative Syndrome Scale, Schizophrenia, Sociology, Effectiveness, Statistical tests, Chi-square test, Psychiatry, Fisher's exact test


The low-molecular-weight fraction of 5% human serum albumin (LMWF-5A) is being developed to treat the signs and symptoms of severe osteoarthritis of the knee. This study was a post hoc pooled analysis of 3 randomized placebo-controlled trials of a single intra-articular injection of LMWF-5A, focusing on the subset of patients with severe osteoarthritis of the knee (Kellgren-Lawrence grade 4). Patients were randomized 1:1 to receive a single 4-mL intra-articular knee injection of either LMWF-5A or saline. Safety was assessed as the incidence and severity of adverse events. Efficacy was assessed as the change from baseline to week 12 on the Western Ontario and McMaster Universities Osteoarthritis Index pain (primary outcome), stiffness, and physical function subscores and on patient global assessment scores and was presented as the least squares mean difference and 95% confidence interval. The proportion of responders was defined with the Outcome Measures in Rheumatology-Osteoarthritis Research Society International criteria for scenario D and examined with Pearson’s chi-square test. For 417 patients with severe osteoarthritis of the knee, treatment with LMWF-5A resulted in a significant decrease in pain at 12 weeks compared with saline (mean difference, -0.19; 95% confidence interval, -0.34 to -0.04; P=.016), with improvements in function (mean difference, -0.15; 95% confidence interval, -0.31 to 0.01) and patient global assessment (mean difference, -0.30; 95% confidence interval, -0.49 to -0.12) and higher responder rates (64.25% vs 50.90%, P=.006). No drug-related serious adverse events and no deaths occurred, and the incidence and severity of adverse events were similar across treatment groups. This pooled analysis supports the use of LMWF-5A as a safe therapeutic agent for relief of the signs and symptoms of severe osteoarthritis of the knee. [Orthopedics. 201x; xx(x):xx-xx.].

Concepts: Normal distribution, Osteoarthritis, Joint, Knee, Chi-square distribution, Chi-square test, Pearson's chi-square test


Resective surgery is considered an effective treatment for refractory localization-related epilepsy. Most studies have reported seizure and psychosocial outcomes of 2-5years postsurgery and a few up to 10years. Our study aimed to assess long-term (up to 15years) postsurgical seizure and psychosocial outcomes at our epilepsy center. The Henry Ford Health System Corporate Data Store was accessed to identify patients who had undergone surgical resection for localization-related epilepsy from 1993 to 2011. Demographics including age at epilepsy onset and surgery, seizure frequency before surgery, and pathology were gathered from electronic medical records. Phone surveys were conducted from May 2012 to January 2013 to determine patients' current seizure frequency and psychosocial metrics including driving and employment status and use of antidepressants. Surgical outcomes were based on Engel’s classification (classes I and II=favorable outcomes). McNemar’s tests, chi-square tests, two sample t-tests, and Wilcoxon two sample tests were used to analyze the relationships of psychosocial and surgical outcomes with demographic and surgical characteristics. A total of 470 patients had resective epilepsy surgery, and of those, 50 (11%) had died since surgery. Of the remaining, 253 (60%) were contacted with mean follow-up of 10.6±5.0years (27% of patients had follow-up of 15years or longer). Of the patients surveyed, 32% were seizure-free and 75% had a favorable outcome (classes I and II). Favorable outcomes had significant associations with temporal resection (78% temporal vs 58% extratemporal, p=0.01) and when surgery was performed after scalp EEG only (85% vs 65%, p<0.001). Most importantly, favorable and seizure-free outcome rates remained stable after surgery over long-term follow-up [i.e., <5years (77%, 41%), 5-10years (67%, 29%), 10-15years (78%, 38%), and >15years (78%, 26%)]. Compared to before surgery, patients at the time of the survey were more likely to be driving (51% vs 35%, p<0.001) and using antidepressants (30% vs 22%, p=0.013) but less likely to be working full-time (23% vs 42%, p<0.001). A large majority of patients (92%) considered epilepsy surgery worthwhile regardless of the resection site, and this was associated with favorable outcomes (favorable=98% vs unfavorable=74%, p<0.001). The findings suggest that resective epilepsy surgery yields favorable long-term postoperative seizure and psychosocial outcomes.

Concepts: Chi-square test, Outcome, Surgery, Seizure, Physician, Hospital, Electroencephalography, Epilepsy