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Relative Risk Ratio (relative + risk_ratio)

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Medical Sciences	62%

Selected Abstracts

Stratified case sampling and the use of family controls

GENETIC EPIDEMIOLOGY, Issue 3 2001
Kimberly D. Siegmund
Abstract We compare the asymptotic relative efficiency (ARE) of different study designs for estimating gene and gene-environment interaction effects using matched case-control data. In the sampling schemes considered, cases are selected differentially based on their family history of disease. Controls are selected either from unrelated subjects or from among the case's unaffected siblings and cousins. Parameters are estimated using weighted conditional logistic regression, where the likelihood contributions for each subject are weighted by the fraction of cases sampled sharing the same family history. Results showed that compared to random sampling, over-sampling cases with a positive family history increased the efficiency for estimating the main effect of a gene for sib-control designs (103,254% ARE) and decreased efficiency for cousin-control and population-control designs (68,94% ARE and 67,84% ARE, respectively). Population controls and random sampling of cases were most efficient for a recessive gene or a dominant gene with an relative risk less than 9. For estimating gene-environment interactions, over-sampling positive-family-history cases again led to increased efficiency using sib controls (111,180% ARE) and decreased efficiency using population controls (68,87% ARE). Using case-cousin pairs, the results differed based on the genetic model and the size of the interaction effect; biased sampling was only slightly more efficient than random sampling for large interaction effects under a dominant gene model (relative risk ratio = 8, 106% ARE). Overall, the most efficient study design for studying gene-environment interaction was the case-sib-control design with over-sampling of positive-family-history-cases. Genet. Epidemiol. 20:316,327, 2001. © 2001 Wiley-Liss, Inc. [source]

Hazardous drinking is associated with an elevated aspartate aminotransferase to platelet ratio index in an urban HIV-infected clinical cohort

HIV MEDICINE, Issue 3 2009
AA Chaudhry
Objectives The aim of the study was to determine the relationship between alcohol consumption and liver fibrosis as assessed by aspartate aminotransferase to platelet ratio index (APRI) in HIV-infected adults and to explore the relative contributions of alcohol and hepatitis C virus (HCV) to APRI among HIV/HCV-coinfected adults. Methods We performed a cross-sectional analysis of data from an observational clinical cohort. Alcohol consumption was categorized according to National Institute on Alcohol Abuse and Alcoholism guidelines. We defined significant liver disease as APRI>1.5, and used multinomial logistic regression to identify correlates of increased APRI. Results Among 1358 participants, 10.4% reported hazardous drinking. It was found that 11.6% had APRI>1.5, indicating liver fibrosis. Hazardous drinking was associated with increased APRI [adjusted relative risk ratio (RRR) 2.30; 95% confidence interval (CI) 1.26,4.17]. Other factors associated with increased APRI were male gender, viral hepatitis, and HIV transmission category of injecting drug use. Among coinfected individuals, 18.3% had APRI>1.5, and hazardous drinking was not associated with APRI. Among non-HCV-infected individuals, 5.3% had APRI>1.5 and hazardous drinking was associated with increased APRI (adjusted RRR 3.72; 95% CI 1.40,9.87). Conclusions Hazardous drinking is an important modifiable risk factor for liver fibrosis, particularly among non-HCV-infected patients. Clinicians and researchers must address alcohol use as the burden of liver disease increases among HIV-positive individuals. [source]

The role of selective digestive decontamination for reducing infection in patients undergoing liver transplantation: A systematic review and meta-analysis,

LIVER TRANSPLANTATION, Issue 7 2004
Nasia Safdar
Selective digestive decontamination (SDD) refers to the use of antimicrobials to reduce the burden of aerobic gram-negative bacteria and/or yeast in the intestinal tract to prevent infections caused by these organisms. Liver transplant patients are highly vulnerable to bacterial infection particularly with gram-negative organisms within the first month after transplantation, and SDD has been proposed as a potential measure to prevent these infections. However, the benefit of this procedure remains controversial. We undertook a systematic review and meta-analysis to determine whether SDD is beneficial in reducing infections overall and those caused by gram-negative bacteria in patients following liver transplantation. All studies that evaluated the efficacy of SDD in liver transplant patients were included. Randomized trials that included liver transplant patients given SDD versus either placebo or no treatment or minimal treatment (e.g., oral nystatin alone), and that provided adequate data to calculate a relative risk ratio, were included in the meta-analysis. Our review shows that most studies found SDD to be effective in reducing gram-negative infection. The nonrandomized and uncontrolled trials also showed benefit with SDD in reducing overall infection; however, the effect on overall infection was limited in the 4 randomized trials, in which the pooled relative risk was 0.88 (95% CI, 0.7-1.1), indicating no statistically significant reduction in infection with the use of SDD. The summary risk ratio for the association between SDD and gram-negative infection was 0.16 (95% CI, 0.07-0.37), indicating an 84% relative risk reduction in the incidence of infection caused by gram-negative bacteria in patients receiving SDD in randomized trials. In conclusion, the available literature supports a beneficial effect of SDD on gram-negative infection following liver transplantation; however, the risk of antimicrobial resistance must be considered. Larger multicenter randomized trials in this patient population to assess the effect of SDD in reducing infection and mortality, while assessing the risk of antimicrobial resistance, are needed. (Liver Transpl 2004;10:817,827.) [source]

The socio-economic burden of asthma is substantial in Europe

ALLERGY, Issue 1 2008
S. Accordini
Background: Few data are available on the asthma burden in the general population. We evaluated the level and the factors associated with the asthma burden in Europe. Methods: In 1999,2002, 1152 adult asthmatics were identified in the European Community Respiratory Health Survey (ECRHS)-II and the socio-economic burden (reduced activity days and hospital services utilization in the past 12 months) was assessed. Results: The asthmatics with a light burden (only a few reduced activity days) were 13.2% (95% CI: 11.4,15.3%), whereas those with a heavy burden (many reduced activity days and/or hospital services utilization) were 14.0% (95% CI: 12.1,16.1%). The burden was strongly associated with disease severity and a lower quality of life. Obese asthmatics had a significantly increased risk of a light [relative risk ratio (RRR) = 2.17; 95% CI: 1.18,4.00] or a heavy burden (RRR = 2.77; 95% CI: 1.52,5.05) compared with normal/underweight subjects. The asthmatics with frequent respiratory symptoms showed a threefold (RRR = 2.74; 95% CI: 1.63,4.61) and sixfold (RRR = 5.76; 95% CI: 3.25,10.20) increased risk of a light or a heavy burden compared with asymptomatic asthmatics, respectively. Moreover, the lower the forced expiratory volume in 1 s % predicted, the higher the risk of a heavy burden. The coexistence with chronic cough/phlegm only increased the risk of a heavy burden (RRR = 1.88; 95% CI: 1.16,3.06). An interaction was found between gender and IgE sensitization, with nonatopic asthmatic females showing the highest risk of a heavy burden (21.6%; 95% CI: 16.9,27.1%). Conclusions: The asthma burden is substantial in Europe. A heavy burden is more common in asthmatics with obesity, frequent respiratory symptoms, low lung function, chronic cough/phlegm and in nonatopic females. [source]

Psychological abuse between parents: associations with child maltreatment from a population-based sample

CHILD: CARE, HEALTH AND DEVELOPMENT, Issue 6 2008
Richard Reading
Psychological abuse between parents: associations with child maltreatment from a population-based sample ChangJ. J., TheodoreA. D., MartinS. L. & RunyanD. K. ( 2008 ) Child Abuse & Neglect , 32 , 819 , 829 . Objective This study examined the association between partner psychological abuse and child maltreatment perpetration. Methods This cross-sectional study examined a population-based sample of mothers with children aged 0,17 years in North and South Carolina (n = 1149). Mothers were asked about the occurrence of potentially neglectful or abusive behaviours towards their children by either themselves or their husband/partner in the past year. Partner psychological abuse was categorized as no psychological abuse (reference), husband perpetrates, wife perpetrates or both perpetrates. Outcome measures for psychological and physical abuse of the child had four categories: no abuse (reference), mother perpetrates, father/father-figure perpetrates or both parents perpetrates, whereas child neglect was binary. Adjusted relative risk ratios (aRRRs), adjusted odds ratios and 95% confidence intervals (CIs) were estimated with regression models. A relative risk ratio was the ratio of odds ratios derived from multinomial logistic regression. Results Children were at the greatest risk of maltreatment when parents psychologically abused each other versus no abuse: the aRRR for child psychological abuse by the mother only was 16.13 (95% CI 5.11, 50.92) compared with no abuse, controlling for child age, gender, Medicaid welfare and mother's level of education. Both parents psychologically abuse each other versus no abuse also results in an aRRR of 14.57 (95% CI 3.85, 55.16) for child physical abuse by both parents compared with no abuse. When only the husband perpetrates towards the wife, the odds of child neglect was 5.29 times as much as families with no psychological abuse (95% CI 1.36, 20.62). Conclusions Partner psychological abuse was strongly related to child maltreatment. Children experienced a substantially increased risk of maltreatment when partner psychological abuse was present in the homes. Practice implications This study observed that intimate partner psychological abuse significantly increased risk of child maltreatment. Increased public awareness of partner psychological abuse is warranted. Primary prevention should include education about the seriousness of partner psychological abuse in families. Domestic violence and child welfare agencies must recognize the link between partner psychological abuse and child maltreatment and work together to develop effective screening for each of these problems. [source]

The Accuracy of Predicting Cardiac Arrest by Emergency Medical Services Dispatchers: The Calling Party Effect

ACADEMIC EMERGENCY MEDICINE, Issue 9 2003
Alex G. Garza MD
Abstract Objectives: To analyze the accuracy of paramedic emergency medical services (EMS) dispatchers in predicting cardiac arrest and to assess the effect of the caller party on dispatcher accuracy in an advanced life support, public utility model EMS system, with greater than 90,000 calls and greater than 60,000 transports per year. Methods: This was a retrospective analysis from January 1, 2000, through June 30, 2000, of 911 calls with dispatcher-assigned presumptive patient condition (PPC) or field diagnosis of cardiac arrest. Sensitivity and positive predictive value (PPV) of the PPC code for cardiac arrest by calling parties were calculated. Homogeneity of sensitivity and PPV of the PPC code for cardiac arrest by calling parties was studied with chi-square analysis. Relevant proportions, relative risk ratios, and associated 95% confidence intervals (95% CIs) were calculated. Student's t-test was used to compare quality assurance scores between calling parties. Results: There were 506 patients included in the study. Overall sensitivity for dispatcher-assigned PPC of cardiac arrest was 68.3% (95% CI = 63.3% to 73.0%) with a PPV of 65.0% (95% CI = 60.0% to 69.7%). There was a significant difference in the PPV for the EMS dispatcher diagnosis of cardiac arrest depending on the type of caller (,2= 17.34, p < 0.001). Conclusions: A higher level of medical training may improve dispatch accuracy for predicting cardiac arrest. The type of calling party influenced the PPV of dispatcher-assigned condition. [source]

Occurrence and risk indicators of increased probing depth in an adult Brazilian population

JOURNAL OF CLINICAL PERIODONTOLOGY, Issue 2 2005
Cristiano Susin
Abstract Background/Aims: There is little information about the occurrence and risk indicators for periodontal diseases in Latin America. The present study describes the prevalence, extent and severity of periodontal probing depth (PPD) and assesses the association between demographic, behavioural and environmental risk indicators and the extent and severity of PPD in this population. Materials and Methods: The target population was urban adults aged 30 years in Rio Grande do Sul state in South Brazil. A representative sample was selected using a multi-stage, probability, cluster sampling strategy and included 853 dentate subjects 30,103 years of age. A full-mouth clinical examination was carried out at six sites per tooth on all permanent teeth, excluding third molars, and was conducted in a mobile examination centre. Results: Approximately 65% and 25% of the subjects and 19% and 5% teeth per subject had PPD 5 and 7 mm, respectively. 31.6%, 33.7% and 34.7% subjects had generalized, localized or no PPD 5 mm, respectively. Probing depth increased in prevalence with increasing age, and leveled off at around 50 years of age and beyond. PPD 5 mm was significantly higher in males than in females, and in non-Whites than in Whites. Cigarette smokers had a significantly higher occurrence of PPD 5 mm than non-smokers, and this relationship was dose dependent. A multivariate model showed that generalized PPD 5 mm was associated with subjects aged 40 years, males, non-Whites and moderate or heavy cigarette smokers (relative risk ratios: 2.0, 2.0, 2.2, 2.4 and 6.8, respectively). Conclusion: Moderate and deep probing depth was a common finding in this urban adult Brazilian population. Older age, male gender, non-White race and moderate and heavy cigarette smoking were significant risk indicators of increased PPD, and these may be useful indicators of periodontal disease high-risk groups. [source]