25 resultados para Univariate Analysis box-jenkins methodology
Resumo:
Previous research has shown an association between mental health status and cigarette smoking. This study examined four specific mental health predictors and the outcome variable any smoking, defined as smoking one or more cigarettes in the past 30 days. The population included active duty military members serving in the United States Army, Air Force, Navy and Marine Corps. The data was collected during the 2005 Department of Defense Survey of Health Related Behaviors Among Active Duty Military Personnel, a component of the Defense Lifestyle Assessment Program. The sample size included 13,603 subjects. This cross sectional prevalence study consisted of descriptive statistics, univariate analysis, and multivariate logistic regression analysis of the four mental health predictors and the any smoking outcome variable. Multivariate adjustment showed an association between the four mental health predictors and any smoking. This association is consistent with previous literature and can help guide public health officials in the development of smoking prevention and cessation programs.^
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The recent hurricanes of Katrina, Rita, and Dolly have brought to light the precarious situation populations place themselves in when they are unprepared to face a storm, or do not follow official orders to evacuate when a destructive hurricane is poised to hit the area. Three counties in southern Texas lie within 60 miles of the Gulf of Mexico, and along the Mexican border. Determining the barriers to hurricane evacuation in this distinct and highly impoverished area of the United States would help aid local, state, and federal agencies to respond more effectively to persons living here.^ The aim of this study was to examine intention to comply with mandatory hurricane evacuation orders among persons living in three counties in South Texas by gender, income, education, acculturation and county of residence. A questionnaire was administered to 3,088 households across the three counties using a two-stage cluster sampling strategy, stratified by all three counties. The door-to-door survey was a 73-item instrument that included demographics, reasons for and against evacuation, and preparedness for a hurricane. Weighted data were used for the analyses.^ Chi-square tests were run to determine whether differences between observed and expected frequencies were statistically significant. A logistic regression model was developed based on that univariate analysis. Results from the logistic regression estimated odds ratios and their 95 percent confidence intervals for the independent variables.^ Logistic regression results indicate that females were less likely than men to follow an evacuation order. Having a higher education meant more likelihood of evacuating. Those respondents with a higher affiliation with Spanish than English were more likely to follow the evacuation orders. Hidalgo County residents were less likely to evacuate than Cameron or Willacy Counties' residents. Local officials need to implement communication efforts specifically tailored for females, residents with less of an affiliation with Spanish, and Hidalgo County residents to ensure their successful evacuation prior to a strong hurricane's landfall.^
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Identifying accurate numbers of soldiers determined to be medically not ready after completing soldier readiness processing may help inform Army leadership about ongoing pressures on the military involved in long conflict with regular deployment. In Army soldiers screened using the SRP checklist for deployment, what is the prevalence of soldiers determined to be medically not ready? Study group. 15,289 soldiers screened at all 25 Army deployment platform sites with the eSRP checklist over a 4-month period (June 20, 2009 to October 20, 2009). The data included for analysis included age, rank, component, gender and final deployment medical readiness status from MEDPROS database. Methods.^ This information was compiled and univariate analysis using chi-square was conducted for each of the key variables by medical readiness status. Results. Descriptive epidemiology Of the total sample 1548 (9.7%) were female and 14319 (90.2%) were male. Enlisted soldiers made up 13,543 (88.6%) of the sample and officers 1,746 (11.4%). In the sample, 1533 (10.0%) were soldiers over the age of 40 and 13756 (90.0%) were age 18-40. Reserve, National Guard and Active Duty made up 1,931 (12.6%), 2,942 (19.2%) and 10,416 (68.1%) respectively. Univariate analysis. Overall 1226 (8.0%) of the soldiers screened were determined to be medically not ready for deployment. Biggest predictive factor was female gender OR (2.8; 2.57-3.28) p<0.001. Followed by enlisted rank OR (2.01; 1.60-2.53) p<0.001. Reserve component OR (1.33; 1.16-1.53) p<0.001 and Guard OR (0.37; 0.30-0.46) p<0.001. For age > 40 demonstrated OR (1.2; 1.09-1.50) p<0.003. Overall the results underscore there may be key demographic groups relating to medical readiness that can be targeted with programs and funding to improve overall military medical readiness.^
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This cross-sectional study examined by questionnaire the prevalence of bulimia nervosa and bulimic behaviors in a sample of 1175 undergraduate students enrolled in two state-supported universities in Texas. In one university, the student population was predominantly white; in the other, it was predominantly black. Fifty-nine percent of the respondents were female and 41% were male. Information regarding age, sex, ethnicity, college major, college year, marital status, housing arrangements, religion, socioeconomic status, height, weight, dieting behaviors, and family history of alcoholism, drug abuse, and depression was collected. Bulimia status was assessed using the Revised Bulimia Test (BULIT-R), which is based on the DSM-III-R criteria for bulimia nervosa. Only 1.3% of the females and 0.4% of the males were classified as having bulimia nervosa. The prevalence of bulimic behaviors was considerably higher; 6.4% of the females and 3.6% of the males were classified as having bulimic behaviors. Univariate analysis showed the following factors to be significantly associated with bulimic behaviors: female gender, single marital status, high BMI, a family history of alcoholism, drug abuse, or depression, and certain dieting behaviors. In the present study, ethnicity did not prove to be a significant factor associated with bulimia nervosa or bulimic behaviors. Multivariate analysis showed that, in comparison to normal/underweight individuals, the odds of having bulimic behaviors for severely overweight subjects were 2.23 (95% CI: 1.43, 3.50). Students who were dieting at the time of the study were 3.22 times (95% CI: 2.05, 5.06) as likely to have bulimic behaviors as were students who had never dieted. This study concludes there is a need to distinguish between bulimia nervosa and bulimic behaviors when estimating prevalence of a population. ^
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This cross-sectional study examines the prevalence of selected potential risk factors by stage of diabetic retinopathy (DR) among Black American women with non-insulin-dependent diabetes mellitus (NIDDM) followed at a university diabetes clinic. DR was assessed by ophthalmoscopy and five-field retinography, and graded on counts of microaneurysms, hemorrhages and/or exudates, and presence of proliferative DR. Prevalence of other vascular diseases was assessed from medical records. Potential risk factors included age, known duration of diabetes, type of hypoglycemic treatment, concentrations of random capillary blood glucose, glycosylated hemoglobin, urine protein and fibrinogen, body mass index, and blood pressure. Prevalence of these risk factors is reported for three categories: No DR, mild background DR, severe background or proliferative DR (including surgically treated DR). Duration, age at diagnosis and treatment of diabetes, concentration of urine protein and average blood glucose, hypertension and cardiovascular disease were significantly associated with DR in univariate analysis. The covariance analysis employed stratification on duration, age at diagnosis and therapy of diabetes. The highest DR scores were calculated for those diagnosed before age 45, regardless of duration, therapy, or average blood glucose. Only individuals diagnosed before age 45 had high blood glucose concentrations in all categories of duration. These findings suggest that in this clinic population of Black women, those diagnosed with NIDDm before age 45 who eventually required insulin treatment were at the greatest risk of developing DR and that longterm poor glucose control is a contributing factor. These results suggest that greater emphasis be placed on this subgroup in allocating the limited resources available to improve the quality of glucose regulation, particularly through measures affecting compliance behavior.^ Findings concerning the association of DR with concentration of blood glucose and urine protein, blood pressure/hypertension and weight were compared with those reported from American Indian and Mexican American populations of the Southwestern United States where prevalence of NIDDM, hypertension and obesity is also high. Additional comparative analyses are outlined to substantiate the preliminary finding that there are systematic differences between these ethnic populations. ^
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Background. End-stage liver disease (ESLD) is an irreversible condition that leads to the imminent complete failure of the liver. Orthotopic liver transplantation (OLT) has been well accepted as the best curative option for patients with ESLD. Despite the progress in liver transplantation, the major limitation nowadays is the discrepancy between donor supply and organ demand. In an effort to alleviate this situation, mismatched donor and recipient gender or race livers are being used. However, the simultaneous impact of donor and recipient gender and race mismatching on patient survival after OLT remains unclear and relatively challenging to surgeons. ^ Objective. To examine the impact of donor and recipient gender and race mismatching on patient survival after OLT using the United Network for Organ Sharing (UNOS) database. ^ Methods. A total of 40,644 recipients who underwent OLT between 2002 and 2011 were included. Kaplan-Meier survival curves and the log-rank tests were used to compare the survival rates among different donor-recipient gender and race combinations. Univariate Cox regression analysis was used to assess the association of donor-recipient gender and race mismatching with patient survival after OLT. Multivariable Cox regression analysis was used to model the simultaneous impact of donor-recipient gender and race mismatching on patient survival after OLT adjusting for a list of other risk factors. Multivariable Cox regression analysis stratifying on recipient hepatitis C virus (HCV) status was also conducted to identify the variables that were differentially associated with patient survival in HCV + and HCV − recipients. ^ Results. In the univariate analysis, compared to male donors to male recipients, female donors to male recipients had a higher risk of patient mortality (HR, 1.122; 95% CI, 1.065–1.183), while in the multivariable analysis, male donors to female recipients experienced an increased mortality rates (adjusted HR, 1.114; 95% CI, 1.048–1.184). Compared to white donors to white recipients, Hispanic donors to black recipients had a higher risk of patient mortality (HR, 1.527; 95% CI, 1.293–1.804) in the univariate analysis, and similar result (adjusted HR, 1.553; 95% CI, 1.314–1.836) was noted in multivariable analysis. After the stratification on recipient HCV status in the multivariable analysis, HCV + mismatched recipients appeared to be at greater risk of mortality than HCV − mismatched recipients. Female donors to female HCV − recipients (adjusted HR, 0.843; 95% CI, 0.769–0.923), and Hispanic HCV + recipients receiving livers from black donors (adjusted HR, 0.758; 95% CI, 0.598–0.960) had a protective effect on patient survival after OLT. ^ Conclusion. Donor-recipient gender and race mismatching adversely affect patient survival after OLT, both independently and after the adjustment for other risk factors. Female recipient HCV status is an important effect modifier in the association between donor-recipient gender combination and patient survival.^
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Aims: Obesity is a state of chronic inflammation characterized by depressed Th2 immune response. Animal studies have shown decreased IgA levels in obese rats and Leptin an adipose cell origin cytokine have been shown to enhance the activity of Clostridium difficile Toxin A. Hence we hypothesized that obesity is a risk factor for C. difficile infection (CDI) ^ Methods: 33 cases of CDI and 131 controls matched by age and HORNS index were identified from an IRB approved observational study at St. Luke's Episcopal Hospital in Houston. Variables like age, gender, height, weight, chronic antibiotic use, proton pump inhibitor use, diabetes mellitus, myocardial infarction, inflammatory bowel disease, diverticulitis, transfer from nursing home, hospital or home, nasogastric tube use and use of hemodialysis were provided in the dataset. Height and weight of the patient were used to calculate the BMI, based on which the study subjects were classified as obese and non-obese. Using STATA these variables were analyzed using test, chi square test followed by conditional logistic regression. ^ Results: On univariate analysis and conditional logistic regression, no significant increase in risk was associated with obesity (OR: 1.24; 95% CI: 0.46 - 3.36; p = 0.67) or BMI (OR: 0.98; CI: 0.92 - 1.04; p = 0.92). Hence, we cannot reject our hypothesis and conclude that "obesity is a risk factor associated with higher incidence of CDI in hospitalized patients. On univariate analysis using hemodialysis, nursing home transfer, home transfer, PPI and chronic antibiotics were found to be significantly different (p<0.05) in the cases and controls. On conditional logistic regression home (OR: 3.4; 95% CI: 1.15 - 9.61) and hemodialysis (OR: 4.1; 95% CI: 1.14 - 15.57) were found to be significantly different (p<0.05) between the case and control groups. ^ Conclusion: Our results show that obesity is not a significant risk factor for CDI. Our sample size was small and hence this may need conformation with a larger study. Patients transferred from home to the hospital and patients on hemodialysis had significantly higher incidence of CDI.^
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BACKGROUND. The development of interferon-gamma release assays (IGRA) has introduced powerful tools in diagnosing latent tuberculosis infection (LTBI) and may play a critical role in the future of tuberculosis diagnosis. However, there have been reports of high indeterminate results in young patient populations (0-18 years). This study investigated results of the QunatiFERON-TB Gold In-Tube (QFT-GIT) IGRA in a population of children (0-18 years) at Texas Children's Hospital in association with specimen collection procedures using surrogate variables. ^ METHODS. A retrospective case-control study design was used for this investigation. Cases were defined as having QFT-GIT indeterminate results. Controls were defined as having either positive or negative results (determinates). Patients' admission status, staff performing specimen collection, and specific nurse performing specimen collection were used as surrogates to measure specimen collection procedures. ^ To minimize potential confounding, abstraction of patients' electronic medical records was performed. Abstracted data included patients' medications and evaluation at the time of QFT-GIT specimen collection in addition to their medical history. QFT-GIT related data was also abstracted. Cases and controls were characterized using chi-squared tests or Fisher's exact tests across categorical variables. Continuous variables were analyzed using one-way ANOVA and t-tests for continuous variables. A multivariate model was constructed by backward stepwise removal of statistically significant variables from univariate analysis. ^ RESULTS. Patient data was abstracted from 182 individuals aged 0-18 years from July 2010 to August 2011 at Texas Children's Hospital. 56 cases (indeterminates) and 126 controls (determinates) were enrolled. Cancer was found to be an effect modifier with subsequent stratification resulting in a cancer patient population too small to analyze (n=13). Subsequent analyses excluded these patients. ^ The exclusion of cancer patients resulted in a population of 169 patients with 49 indeterminates (28.99%) and 120 determinates (71.01%), with mean ages of 9.73 (95% CI: 8.03, 11.43) years and 11.66 (95% CI: 10.75, 12.56) years (p = 0.033), respectively. Median age of patients who were indeterminates and determinates were 12.37 and 12.87 years, respectively. Lack of data for our specific nurse surrogate (QFTNurse) resulted in its exclusion from analysis. The final model included only our remaining surrogate variables (QFTStaff and QFTInpatientOutpatient). The staff collecting surrogate (QFTStaff) was found to be modestly associated with indeterminates when nurses collected the specimen (OR = 1.54, 95% CI: 0.51, 4.64, p = 0.439) in the final model. Inpatients were found to have a strong and statistically significant association with indeterminates (OR = 11.65, 95% CI: 3.89, 34.9, p < 0.001) in the final model. ^ CONCLUSION. Inpatient status was used as a surrogate for indication of nurse drawn blood specimens. Nurses have had little to no training regarding shaking of tubes versus phlebotomists regarding QFT-GIT testing procedures. This was also measured by two other surrogates; specifically a medical note stating whether a nurse or phlebotomist collected the specimen (QFTStaff) and the name and title of the specific nurse if collection was performed by a nurse (QFTNurse). Results indicated that inpatient status was a strong and statistically significant factor for indeterminates, however, nurse collected specimens and indeterminate results had no statistically significant association in non-cancer patients. The lack of data denoting the specific nurse performing specimen collection excluded the QFTNurse surrogate in our analysis. ^ Findings suggests training of staff personnel in specimen procedures may have little effect on the number of indeterminates while inpatient status and thus possibly illness severity may be the most important factor for indeterminate results in this population. The lack of congruence between our surrogate measures may imply that our inpatient surrogate gauged illness severity rather than collection procedures as intended. ^ Despite the lack of clear findings, our analysis indicated that more than half of indeterminates were found in specimens drawn by nurses and as such staff training may be explored. Future studies may explore methods in measuring modifiable variables during pre-analytical QFT-GIT procedures that can be discerned and controlled. Identification of such measures may provide insight into ways to lowering indeterminate QFT-GIT rates in children.^
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Software for use with patient records is challenging to design and difficult to evaluate because of the tremendous variability of patient circumstances. A method was devised by the authors to overcome a number of difficulties. The method evaluates and compares objectively various software products for use in emergency departments and compares software to conventional methods like dictation and templated chart forms. The technique utilizes oral case simulation and video recording for analysis. The methodology and experiences of executing a study using this case simulation are discussed in this presentation.
Resumo:
The role of clinical chemistry has traditionally been to evaluate acutely ill or hospitalized patients. Traditional statistical methods have serious drawbacks in that they use univariate techniques. To demonstrate alternative methodology, a multivariate analysis of covariance model was developed and applied to the data from the Cooperative Study of Sickle Cell Disease.^ The purpose of developing the model for the laboratory data from the CSSCD was to evaluate the comparability of the results from the different clinics. Several variables were incorporated into the model in order to control for possible differences among the clinics that might confound any real laboratory differences.^ Differences for LDH, alkaline phosphatase and SGOT were identified which will necessitate adjustments by clinic whenever these data are used. In addition, aberrant clinic values for LDH, creatinine and BUN were also identified.^ The use of any statistical technique including multivariate analysis without thoughtful consideration may lead to spurious conclusions that may not be corrected for some time, if ever. However, the advantages of multivariate analysis far outweigh its potential problems. If its use increases as it should, the applicability to the analysis of laboratory data in prospective patient monitoring, quality control programs, and interpretation of data from cooperative studies could well have a major impact on the health and well being of a large number of individuals. ^