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Biomedical subjects

S I Bangdiwala

Publications and source records attributed to S I Bangdiwala.

At least 19 recordsLinked to original sources

Determinants of work injuries in mines - an application of structural equation modelling.

In spite of stringent regulations and much attention towards reducing risks in the physical environment, the mining industry continues to be associated with high levels of accidents, injuries and illnesses. Only engineering solutions to accident prevention are inappropriate unless coupled with focused attention to the attitudes and behaviours of the mineworkers in coping with the inherent physical, technical and situational risks. The present study identified these various risk factors and analysed their influences on work injury in a causal framework. Data were collected from an underground coalmine of India. The pattern and strength of relationships of 16 causal factors with work injuries were assessed through structural equation modelling. The case study results showed that negatively personified individuals are of major concern for safety improvement in the mine studied. They not only fail to avoid work injuries, they are unable to extend safe work behaviours in their work. The variable safety environment is negatively affected by personality, whereas social support has a positive relationship with safety environment. The variable job hazards appeared to have a significant relationship with job involvement, which has a negative relationship with work injury. Elimination of negative behaviours must be focused and committed by the mine safety management. Long term planning through (i) identification of negative individuals, (ii) proper councelling of adverse effects of negative behaviours, and (iii) special training with psychological treatment is highly required. Identification may begin while recruiting new workers through interview. Proper allocation of jobs (right person for right job) may be a judicial solution to this end.

Accidents, Occupational↗

Sexual and physical abuse are not associated with rectal hypersensitivity in patients with irritable bowel syndrome.

BACKGROUND: Patients with irritable bowel syndrome (IBS) have reduced pain thresholds for rectal distension. In addition, the prevalence of sexual/physical abuse in referred IBS patients is high and is associated with greater pain reporting, poorer health status, and poorer outcome. This lead to a hypothesis that abuse history may sensitise patients to report pain at a lower threshold. AIM: To compare rectal pain thresholds in women with IBS who had a history of severe abuse to IBS women with no history of abuse. METHODS: We studied 74 IBS patients with a history of severe physical and/or sexual abuse and 85 patients with no history of abuse. Abuse history was assessed by a previously validated self-report abuse screening questionnaire. Rectal sensory thresholds were assessed using an electronic barostat and determined by the ascending method of limit (AML) and by the tracking technique. RESULTS: IBS patients with a history of severe abuse had significantly higher rectal pain thresholds, as measured by AML (F (1, 111) = 6.06; p = 0.015) and the tracking technique (F (1, 109) = 5.21; p = 0.024). Patients with a history of severe abuse also reported a significantly higher threshold for urgency to defecate (F (1, 113) = 11.23; p =.001). CONCLUSION: Severe sexual/physical abuse is associated with higher urge and pain thresholds for rectal distension in IBS patients. This suggests that the greater pain reporting and poorer health status in IBS patients with abuse history are not related to increased rectal pain sensitivity. Further studies are needed to determine the causes of these findings.

Adult↗

[The use of state of the art statistical methodology in biomedical research: the example of methodology for interim analyses in clinical trials].

BACKGROUND: Clinical research stresses the need for evidence as a basis for setting research agendas. The extent to which current clinical research involves recent advances in biostatistics is not well known. AIM: This manuscript focuses on the use of interim analyses accumulating data in clinical trials. MATERIAL AND METHODS: A PubMed search was conducted for the period 1990-2000. Keywords used included 'interim analysis', 'alpha-spending function', and 'early termination', after subsetting to 'randomised controlled trials (RCT)' that were 'multicenter' since these particular studies are more likely to have external monitoring boards conducting interim analyses. Studies were grouped by clinical discipline and also by journals of high or low impact index. RESULTS: Thirteen thousand two hundred eighty two articles with both 'RCT' and 'multicenter' were found. Of these, the 'interim analysis' keyword yielded 879 articles, of which only 163 (19%) studies reported their methodology. The percentages varied by clinical discipline and by journal type. A 25% random sample of the articles were further reviewed to investigate the appropriateness of the interim analysis methods used. DISCUSSION: Recent articles in the medical literature attempt to make the interim analysis methods more accessible to clinicians. However, further training of statisticians involved in clinical trials is needed as well.

Clinical Trials as Topic↗

Seroprevalence and seroincidence of Norwalk-like virus infection among Brazilian infants and children.

To determine the importance of Norwalk-like viruses (NLVs) as pediatric pathogens in a developing country, the seroprevalence and seroincidence of this group of viruses in a cohort of children less than 4 years of age in an urban shantytown in northeastern Brazil was examined. Serum samples were collected approximately every 6 months from 135 children who were surveyed three times each week for diarrhea and vomiting. NLV IgG was measured by an enzyme immunosorbent assay (EIA) with recombinant Norwalk virus capsid protein. Overall NLV seroprevalence was 71%, and the overall NLV seroconversion rate was 0.7 seroconversions per child-year. The highest age-specific NLV seroconversion rate (0.8 seroconversions per child-year) was observed in the 13-24-month age group. For all study children, the incidence of diarrhea and vomiting was significantly greater (P < 0.01) during time periods spanned by serum pairs that indicated NLV seroconversion compared with time periods without NLV seroconversion. However, NLV seroconversion was not associated with gastrointestinal symptoms during the first year of life.

Brazil↗

Effects of improvement in aerobic power on resting insulin and glucose concentrations in children.

In this study we determined the influence of improving aerobic power (VO(2max)) on basal plasma levels of insulin and glucose of 11- to 14-year-old children, while accounting for body fat, gender, pubertal status, and leisure-time physical activity (LTPA) levels. Blood samples were obtained from 349 children after an overnight fast and analyzed for plasma insulin and glucose. Height, mass, body mass index (BMI), and sum of skinfolds (Sigma triceps + subscapular sites) were measured. LTPA levels and pubertal status were estimated from questionnaires, and VO(2max) was predicted from a cycle ergometry test. Regardless of gender, insulin levels were significantly correlated (P = 0.0001) to BMI, skinfolds, pubertal stage, and predicted VO(2max), but were not related to LTPA levels. Fasting glucose levels were not correlated to measures of adiposity or exercise (LTPA score, VO(2max)) for females; however, BMI and skinfolds were correlated for males (P < 0.006). The children then took part in an 8-week aerobic exercise program. The 60 children whose VO(2max) improved (>/=3 ml x kg(-1) x min(-1)) had a greater reduction in circulating insulin than the 204 children whose VO(2max) did not increase -16 (41) vs -1 (63) pmol x l(-1); P = 0.028. The greatest change occurred in those children with the highest initial resting insulin levels. Plasma glucose levels were slightly reduced only in those children with the highest insulin levels whose VO(2max) improved (P < 0.0506). The results of this study indicate that in children, adiposity has the most significant influence on fasting insulin levels; however, increasing VO(2max) via exercise can lower insulin levels in those children with initially high levels of the hormone. In addition, LTPA does not appear to be associated with fasting insulin status, unless it is sufficient to increase VO(2max).

Adolescent↗

The influence of physical activity, socioeconomic status, and ethnicity on the weight status of adolescents.

OBJECTIVE: This study examined the effects of physical activity, television viewing, video game play, socioeconomic status (SES), and ethnicity on body mass index (BMI). RESEARCH METHODS AND PROCEDURES: The sample was 2389 adolescents, 10 to 16 years of age (12.7 +/- 1.0 years); 1240 (52%) females and 1149 (48%) males; 77% white and 23% African American; from rural (77%) and urban (23%) settings. BMI and skinfolds were directly assessed. All other data were obtained from questionnaires. RESULTS: Watching television on non-school days was related to being overweight (p < 0.005). However, when BMI analyses were adjusted for ethnicity and SES, there were no significant effects of television viewing on BMI (p > 0.061). Increased hours of video game play enhanced the risk of being overweight for both genders when analyses were adjusted for ethnicity and SES (p < 0.019). In males, participation in as little as one high-intensity physical activity 3 to 5 days a week decreased the ethnic- and SES-adjusted relative risk of being overweight (RR = 0.646; CI: 0.427 to 0.977). For females, the ethnic- and SES-adjusted relative risk for being overweight was not significantly altered by physical activity. The logistic analyses further indicated the influence of low SES and African American ethnicity overshadowed any direct effect of television or videos. DISCUSSION: Because weight status of male adolescents appears to be more related to exercise habits than to television or video game habits, increased participation in high-intensity exercise appears to be important. For females, neither videos nor exercise habits appear to be related to risk of being overweight. However, ethnicity and SES may be important factors that can influence body weight status, while television viewing may be of some importance. Thus, programs to reduce obesity in female adolescent should focus their efforts in lower SES communities.

Adolescent↗

What determines severity among patients with painful functional bowel disorders?

OBJECTIVE: For patients with painful functional bowel disorders (FBD), physicians frequently make diagnostic and treatment decisions based on the severity of the pain reported; patients with severe painful complaints may receive extensive diagnostic tests and treatments. Therefore, it would be important to determine what clinical factors contribute to the judgment of severity among patients with FBD. The aim of this study was to identify the psychosocial, behavioral, and physiological (visceral sensitivity) factors that predicted severity in patients with moderate to severe FBD. METHODS: Two hundred eleven female patients with moderate or severe FBD, as determined by the Functional Bowel Disorder Severity Index, entered a multicenter treatment trial at the University of North Carolina and the University of Toronto. Patients filled out diary cards and were given questionnaires and physiological testing (rectal sensitivity using barostat). Analysis of covariance and logistic regression adjusting for demographic factors were performed to determine which factors distinguished patients at study entry with moderate from those with severe FBD. RESULTS: Patients with severe FBD were characterized by greater depression and psychological distress, poorer physical functioning and health-related quality of life, more maladaptive coping strategies, and greater health care utilization. There was a trend for patients with severe FBD to have lower rectal sensation thresholds. Regression analysis indicated that severity was best predicted by behavioral features: poorer daily physical function, difficulties related to eating, more phone calls to the physician, and more days in bed for GI symptoms. CONCLUSIONS: We conclude that patient illness behaviors are best correlated with severity in FBD. The use of psychopharmacological agents (e.g., antidepressants) and psychological treatments to treat psychiatric comorbidity and to improve behavioral coping styles is recommended. Training to help medical physicians identify and respond to psychosocial and behavioral features of these conditions is likely to improve patient satisfaction with their care and the clinical outcome.

Adolescent↗

Further validation of the IBS-QOL: a disease-specific quality-of-life questionnaire.

OBJECTIVE: There has been growing interest in the investigation of health-related quality of life (HRQOL) among patients with gastrointestinal (GI) disorders. We recently reported on the development and preliminary validation of the IBS-QOL, a specific quality-of-life measure for irritable bowel syndrome (IBS). The aim of this study was to determine the longitudinal construct validity (responsiveness) of the IBS-QOL. METHODS: Female patients enrolled in a multicenter treatment trial for functional bowel disorders were studied pre- and posttreatment with the IBS-QOL and other health status measures. Based on the response to treatment for several variables (pain/14-day score, daily function, and days in bed/3 months), patients were stratified into Responders, Partial Responders, and Nonresponders. Change scores in the IBS-QOL were then statistically compared with changes in the other variables to determine their correlation and whether Responders were significantly different from non- and Partial Responders on the IBS-QOL. RESULTS: There was a significant correlation between change scores on the IBS-QOL and the other measures of treatment effect (Pain/14 days, r = 0.25, p < 0.002; Sickness Impact Profile [SIP] Total Score, r = 0.28, p < 0.0004). In addition, the IBS-QOL scores significantly differentiated Responders from Nonresponders for most of the variables tested (regression trend test for Pain/14 days, p < 0.04; SIP Total, p < 0.0001; SIP Physical, p < 0.0001; SIP Psychosocial, p < 0.002, and SIP Eating, p < 0.04). CONCLUSION: The IBS-QOL is responsive to treatment in a referral-based clinical population of patients with functional bowel disorders.

Adult↗

[Categorizing variables in the statistical analysis of data: consequences for interpreting the results].

Frequently during the process of data analysis in epidemiological studies, the scale of one or more continuous variables is changed. The objective of this paper was to assess the consequences of categorizing variables during data analysis. We studied three situations with different scenarios for statistical analysis with regression models. The results show that dichotomizing continuous variables can substantially modify the relationships between dependent and independent variables. Thus, for example, in epidemiological studies trying to evaluate the effect of an exposure on a response, the magnitude and/or the direction of this effect can be biased by dichotomizing a variable. We therefore recommend avoiding, as much as possible, the categorization of variables when doing analyses.

Analysis of Variance↗

[Interim analysis in clinical trials: a methodological guide].

Interim analysis of data accumulated in clinical trials is one aspect of the monitoring of the study progress. It is usually done to assess whether there are significant differences in efficacy between the experimental and control treatment groups, in order to decide whether to stop or no the trial prematurely. Among many reasons for early interruption of a trial is the ethical consideration that subjects should not be exposed to an unsafe, inferior or ineffective treatment. Statistical methods suited for doing interim analysis, that allow to control the probability of incorrectly rejecting the null hypothesis of no treatment differences, are often not well understood by researchers. In this article we present an intuitive, non-mathematical explanation and review of the statistical methods for doing interim analysis in clinical trials along with an illustrative example of the application of the methods on a hypothetical dataset.

Clinical Protocols↗

Cardiovascular disease risk factors and obesity of rural and urban elementary school children.

Previous studies on the influence of a rural/urban setting on the prevalence of cardiovascular disease risk factors in children have not sufficiently controlled for socioeconomic status, race, gender, and perhaps, may not have included a representative sample of rural and urban children. This study compared the cardiovascular disease risk factors and rate of obesity of children living in rural and urban settings. It also determined the magnitude of the effect of the rural/urban setting on cardiovascular disease risk factors and obesity when controlling for race, socioeconomic status, and gender. The subjects were 2,113 third- and fourth-grade children; 962 from an urban setting and 1,151 from a rural setting. Height, weight, skinfolds, resting blood pressure, and total cholesterol levels were measured. Aerobic power (pVO2max) was estimated from cycle ergometry. Physical activity and smoking history were obtained from a questionnaire. Clustering analyses using adjustment for sample error indicated that total cholesterol, blood pressure, smoking, and physical activity levels of rural and urban children were not different (P > 0.10); however, body mass index and sum of skinfolds was greater for rural youth (P < 0.004). Logistic regression indicated that rural children had a 54.7 percent increased risk of obesity (P = 0.0001). This study's results indicate that, in children, a rural setting is associated with obesity, but not with the major risk factors associated with cardiovascular disease.

Cardiovascular Diseases↗

A public health vs a risk-based intervention to improve cardiovascular health in elementary school children: the Cardiovascular Health in Children Study.

OBJECTIVES: This study sought to determine the population effects of both classroom-based and risk-based interventions designed to reduce cardiovascular disease risk factors in children. METHODS: Elementary school children (n = 2109; age range: 7-12 years) were randomized by school to a classroom-based intervention for all third and fourth graders, a risk-based intervention only for those with 1 or more cardiovascular disease risk factors, or a control group. The 8-week interventions involved both knowledge--attitude and physical activity components. RESULTS: School-level analyses showed that physical activity in the risk-based group and posttest knowledge in the classroom-based group were significantly higher than in the control group. With regard to trends shown by individual-level analyses, cholesterol dropped more in the classroom-based than in the control group, and skinfold thickness decreased 2.9% in the classroom-based group and 3.2% in the risk-based group (as compared with a 1.1% increase in the control group). CONCLUSIONS: Both classroom-based and risk-based interventions had positive effects on physical activity and knowledge, with trends toward reduced body fat and cholesterol. However, the classroom-based approach was easier to implement and evidenced stronger results than the risk-based intervention.

Analysis of Variance↗

[The role of the biostatistician in biomedical research].

Medical research projects that involve any aspect of the collection, summarization, analysis and/or interpretation of clinical quantitative information require statistical support. This input may be provided by the clinicians themselves if properly trained, but is most appropriately and commonly achieved by a relationship with a biostatistician. The biostatistician can be an assistant, a consultant, or a colleague co-investigator. The role of the biostatistician in the research endeavor is one that is partially dictated by the nature of this relationship, but also is one that has evolved considerably in the recent past. This paper reviews the role of the biostatistician in terms of the potential contribution to the research, with special attention to the evolution of this role in light of the fast changes in computation and in statistical methodology. Finally, a method for biostatistical critical appraisal of the biomedical literature is proposed.

Biometry↗

Fatal residential fires: who dies and who survives?

CONTEXT: The United States has one of the highest fire fatality rates in the developed world, and three quarters of these deaths are in residential fires. OBJECTIVE: To compare characteristics of those who die and those who survive in the same residential fire. DESIGN: Data on fatal residential fires were collected from the medical examiner and interviews with local fire officials. SETTING: North Carolina. SUBJECTS: Persons in residential fires with at least 1 fatality in a 1-year period. MAIN OUTCOME MEASURE: Dying vs surviving a fatal residential fire that occurred with more than 1 person at home. RESULTS: Of the 190 decedents, 124 (65%) were male, 78 (41%) were home alone, and 69 (53%) of 130 adults who had blood alcohol measured were intoxicated (blood alcohol content >22 mmol/L [100 mg/dL]). Of the 254 persons present during fires in which more than 1 person was at home, 112 died. Individuals more likely to die (high-vulnerability group) were younger than 5 years or 64 years or older, had a physical or cognitive disability, or were impaired by alcohol or other drugs (risk of death for group, odds ratio [OR], 4.01; 95% confidence interval [CI], 2.29-7.03). The presence of an adult with no physical or cognitive disabilities who was unimpaired by alcohol or other drugs (a potential rescuer) reduced the risk of death in the high-vulnerability group (OR, 0.49; 95% CI, 0.24-0.99) but not the low-vulnerability group. Overall, a functioning smoke detector lowered the risk of death (OR, 0.39; 95% CI, 0.18-0.83). CONCLUSIONS: Smoke detectors were equally effective in both low- and high-vulnerability populations. The high-vulnerability group was more likely to survive if, in addition to a smoke detector, a potential rescuer was present. Further research should seek to identify prompts that facilitate speedy egress from a burning structure and that can be incorporated into residential fire alarm systems.

Adolescent↗

The Madurai Intraocular Lens Study. II: Clinical outcomes.

PURPOSE: To evaluate the safety and efficacy of extracapsular cataract extraction with posterior chamber intraocular lens (ECCE/PC-IOL) compared with intracapsular cataract extraction with aphakic glasses (ICCE-AG). METHODS: In a nonmasked randomized controlled clinical trial, 3,400 bilaterally vision-impaired patients aged 40 to 75 years with operable cataract were randomly assigned to receive either ICCE-AG or ECCE/PC-IOL at the Aravind Eye Hospital in India. The surgery was performed by one of four study surgeons. Patients were hospitalized for 5 postoperative days, with follow-up visits at 2, 6, and 12 months after discharge. Postsurgery evaluations were conducted by two independent study ophthalmologists. RESULTS: At any single postoperative follow-up time point, there were no statistically significant differences of clinical relevance between treatment groups for any complication of a serious nature except cystoid macular edema, which was more common with ICCE (4.2% vs 1.6%). In general, whether of a trivial, intermediate, or serious nature, complication rates were low at each evaluation time point. Cumulatively, the incidence of serious complications of all types throughout the 1-year study period was 14.5% for patients in the ICCE-AG group and 7.7% in the ECCE group (P < .001). Best-corrected visual acuity of 20/40 or better at 12 months was attained by 90.7% of ICCE-AG patients and 96.3% of ECCE/PC-IOL patients (P < .001). CONCLUSION: Although both operative procedures are safe and effective for cataract patients with bilateral impairment, ECCE/PC-IOL is superior to ICCE-AG in terms of both visual acuity restoration and safety.

Adult↗

Smoking initiation in youth: the roles of gender, race, socioeconomics, and developmental status.

PURPOSE: To describe smoking initiation, and to investigate factors that predict the early initiation of smoking in schoolchildren using a longitudinal approach. METHODS: A prospective study of smoking habits of children from the third and fourth grades through the eighth and ninth grades. The initial study population was 1970; 79.8% were white and 20.2% were African-American. Children were classified as "nonsmokers," "experimental smokers," or "current smokers" at five time points over 6 years. Multivariate regression models examined relationships of demographic and developmental factors with smoking initiation. RESULTS: Experimental smoking increased from 4% at Grades 3-4 to 42% at Grades 8-9, and current smoking prevalence rose from 0.4% to 9% over the same period. The mean age of initiation of smoking was 12.3 years. Smoking initiation (experimental smoking) was significantly different by racial group, socioeconomic status (SES), and pubertal development. White children and those of low SES were more likely to be experimental smokers, and also started earlier than African-American children and children of high SES. Once they started, white children advanced more rapidly to become current smokers. Boys had a higher prevalence of experimental smoking than girls at all time points. Children in rural areas were more likely than urban children to start smoking after age 12 years. Children who were at a higher pubertal stage than their peers were also more likely to experiment with smoking. CONCLUSIONS: Race, SES, and pubertal stage are important predictors of initiation of smoking in schoolchildren. This study indicates a need for smoking prevention classes in elementary and middle school, especially in areas with large numbers of white and low-SES youth. Also, smoking cessation programs, as well as smoking prevention classes, would be useful for middle school and high school students.

Child↗

Children who prosper in unfavorable environments: the relationship to social capital.

OBJECTIVE: Social capital describes the benefits that are derived from personal social relationships (within families and communities) and social affiliations. This investigation examined the extent to which social capital is associated with positive developmental and behavioral outcomes in high-risk preschool children. DESIGN: A cross-sectional case-control analysis of young children "doing well" and "not doing well" at baseline in four coordinated longitudinal studies. PARTICIPANTS: A total of 667 2- to 5-year-old children (mean age, 4.4 years) and their maternal caregivers who are participating in the Longitudinal Studies of Child Abuse and Neglect Consortium. At recruitment, all children were characterized by unfavorable social or economic circumstances that contributed to the identification of the children as high risk. MEASURES: Social capital was defined as benefits that accrue from social relationships within communities and families. A social capital index was created by assigning one point to each of the following indicators: 1) two parents or parent-figures in the home; 2) social support of the maternal caregiver; 3) no more than two children in the family; 4) neighborhood support; and 5) regular church attendance. Outcomes were measured with the Child Behavior Checklist, a widely used measure of behavioral/emotional problems, and with the Battelle Developmental Inventory Screening Test, a standardized test that identifies developmental deficits. Children were classified as doing well if their scores on these instruments indicated neither behavioral nor developmental problems. RESULTS: Only 13% of the children were classified as doing well. The individual indicators that best discriminated between levels of child functioning were the most direct measures of social capital-church affiliation, perception of personal social support, and support within the neighborhood. The social capital index was strongly associated with child well-being, more so than any single indicator. The presence of any social capital indicator increased the odds of doing well by 29%; adding any two increased the odds of doing well by 66%. CONCLUSIONS: Our findings suggest that social capital may have an impact on children's well-being as early as the preschool years. In these years it seems to be the parents' social capital that confers benefits on their offspring, just as children benefit from their parents' financial and human capital. Social capital may be most crucial for families who have fewer financial and educational resources. Our findings suggest that those interested in the healthy development of children, particularly children most at risk for poor developmental outcomes, must search for new and creative ways of supporting interpersonal relationships and strengthening the communities in which families carry out the daily activities of their lives.

Case-Control Studies↗

School-based interventions improve heart health in children with multiple cardiovascular disease risk factors.

OBJECTIVE: To determine the immediate effects of two types of elementary school-based interventions on children with multiple cardiovascular disease (CVD) risk factors. DESIGN: Randomized, controlled field trial. SETTING: Conducted in 18 randomly selected elementary schools across North Carolina. STUDY PARTICIPANTS: Four hundred twenty-two children age 9 +/- 0.8 years with at least two risk factors at baseline: low aerobic power and either high serum cholesterol or obesity. INTERVENTION: Both 8-week interventions consisted of a knowledge and attitude program and an adaptation of physical education. The classroom-based intervention was given by regular teachers to all children in the 3rd and 4th grades. The risk-based intervention was given in small groups only to children with identified risk factors. Children in the control group received usual teaching and physical education. OUTCOME MEASURES: The primary outcome measure was cholesterol; additional measures were blood pressure, body mass index, body fat, eating and activity habits, and health knowledge. RESULTS: Both interventions produced large reductions in cholesterol (-10.1 mg/dL and -11.7 mg/dL) compared with a small drop (-2.3 mg/dL) in the controls. There was a trend for systolic blood pressure to increase less in both intervention groups than in the controls. Both intervention groups had a small reduction in body fat and higher health knowledge than the control group. CONCLUSIONS: Both brief interventions can improve the CVD risk profile of children with multiple risk factors. The classroom-based approach was easier to implement and used fewer resources. This population approach should be considered as one means of early primary prevention of CVD.

Cardiovascular Diseases↗