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Matched Case (matched + case)
Selected AbstractsAnalysis of Matched Case,Control Data in Presence of Nonignorable Missing ExposureBIOMETRICS, Issue 1 2008Samiran Sinha Summary. The present article deals with informative missing (IM) exposure data in matched case,control studies. When the missingness mechanism depends on the unobserved exposure values, modeling the missing data mechanism is inevitable. Therefore, a full likelihood-based approach for handling IM data has been proposed by positing a model for selection probability, and a parametric model for the partially missing exposure variable among the control population along with a disease risk model. We develop an EM algorithm to estimate the model parameters. Three special cases: (a) binary exposure variable, (b) normally distributed exposure variable, and (c) lognormally distributed exposure variable are discussed in detail. The method is illustrated by analyzing a real matched case,control data with missing exposure variable. The performance of the proposed method is evaluated through simulation studies, and the robustness of the proposed method for violation of different types of model assumptions has been considered. [source] Nonignorable Missingness in Matched Case,Control Data AnalysesBIOMETRICS, Issue 2 2004Myunghee Cho Paik Summary. Matched case,control data analysis is often challenged by a missing covariate problem, the mishandling of which could cause bias or inefficiency. Satten and Carroll (2000, Biometrics56, 384,388) and other authors have proposed methods to handle missing covariates when the probability of missingness depends on the observed data, i.e., when data are missing at random. In this article, we propose a conditional likelihood method to handle the case when the probability of missingness depends on the unobserved covariate, i.e., when data are nonignorably missing. When the missing covariate is binary, the proposed method can be implemented using standard software. Using the Northern Manhattan Stroke Study data, we illustrate the method and discuss how sensitivity analysis can be conducted. [source] Characterization of the polysensitized patient: a matched case,control studyCONTACT DERMATITIS, Issue 1 2009Berit Christina Carlsen Background: Polysensitization ( , 3 contact allergies) may be regarded as a special entity in patients with contact allergies. However, this group of polysensitized patients is poorly characterized. Filaggrin mutations are associated with atopic eczema and lead to impaired skin barrier which may predispose to contact allergy. Therefore, it is of interest to consider atopic eczema and contact allergies, especially in patients with multiple allergies. Objective: To characterize polysensitized patients regarding occurrence, duration and course of dermatitis, and examine potential risk factors for polysensitization, including atopic eczema. Methods: A questionnaire case,control study of 562 polysensitized and 1124 single/double-sensitized individuals was performed. Results: The results show that 45% of polysensitized and 31% of single/double-sensitized patients had or had had atopic eczema, and atopic eczema was identified as a risk factor for polysensitization. Patients with leg ulcer constituted only a minor part of the polysensitized group and leg ulcers were not identified as a risk factor for polysensitization in this study. The influence of contact allergies on duration and course of disease diverged between the group of patients with atopic eczema and the group without atopic eczema. Conclusion: Patients with atopic eczema were overrepresented in the group of polysensitized patients and polysensitized patients should be viewed in the light of occurrence or lack of atopic eczema. [source] Diagnostic performance of clinical motor and non-motor tests of Parkinson disease: a matched case,control studyEUROPEAN JOURNAL OF NEUROLOGY, Issue 7 2008N. I. Bohnen Background and purpose:, The diagnosis of Parkinson disease (PD) is made typically on the basis of motor abnormalities. PD is now recognized to have both motor and non-motor manifestations, indicating a need for the development of reliable non-motor diagnostic tests for PD. The aim of the present study was to compare the accuracy of various clinical motor and non-motor tests for the diagnosis of PD. Methods:, Forty-five PD patients (Hoehn and Yahr stages 1,3; mean age 59.5 ± 10.0 years) and 45 healthy controls matched for gender and age completed a clinimetric motor test battery to assess limb bradykinesia, tremor and balance. Non-motor tests consisted of depression, anxiety and smell identification ratings. Area under the receiver operator characteristic curve (AUC) analysis was used. Results:, We found that smell identification was the most accurate predictor of the presence of PD within the overall group of patients and matched control subjects (AUC = 0.886) and also in the subgroups of mild severity (Hoehn and Yahr stages 1,1.5; AUC = 0.923), young-onset (AUC = 0.888) and female PD patients (AUC = 0.797). The second best diagnostic test was the grooved pegboard test for the clinically most affected body side. Conclusions:, We conclude that olfactory function is the most accurate diagnostic predictor within a heterogeneous sample of patients with PD. [source] Matched case,control study to evaluate risk factors for hyperlactataemia in HIV patients on antiretroviral therapyHIV MEDICINE, Issue 4 2003D Datta Background Lactic acidosis is a life-threatening event during antiretroviral therapy (ART). Hyperlactataemia may be a prelude to acidosis. Our database study suggested that female gender, intercurrent illness and didanosine (ddI)-based regimens may increase risk of lactic acidosis. The aim of this matched case,control study was to identify risk factors for hyperlactataemia requiring screening. Methods Cases were defined as patients with two consecutive lactate samples ,3.5 mmol/L taken more than 1 week apart. Cases were matched to two controls on gender, use of ddI and total duration of therapy using a 6-month window on either side. Controls never had raised lactate >2.5 mmol/L. A conditional logistic regression analysis using the PHREG procedure in SAS (SAS Institute Inc, Cary, NC) was performed with a discreet logistic model stratified by matching variables. Results Twenty-one cases were matched to 42 controls. In the univariate model, current use of stavudine (d4T), total cholesterol >5.3 mmol/L and glucose levels ,5.2 mmol/L gave increased likelihood of persistent hyperlactataemia. The multivariate model showed current use of d4T to be a significant independent predictor of persistent hyperlactataemia. Conclusions The results of this case,control study indicate that, when controlling for ddI use, d4T use is an additional risk factor for hyperlactataemia. [source] Simultaneous triple organ specific autoantibody profiling in adult patients with type 1 diabetes mellitus and their first-degree relatives,INTERNATIONAL JOURNAL OF CLINICAL PRACTICE, Issue 3 2009S. Dagdelen Summary Aims:, We aimed to document prevalence and clinical presentations of seropositivities for glutamate decarboxylase (GAD)-antibody, celiac's disease (CD) and autoimmune thyroiditis (AIT) in adult patients with type 1 diabetes mellitus (T1DM), and their first-degree relatives. Methods:, Sixty-five patients with T1DM, 124 first-degree relatives and 65 healthy controls were screened for GAD-antibody, anti-thyroid peroxidase (ATPO), anti-thyroid stimulating hormone receptor (TSHR), anti-tissue transglutaminase and anti-gliadin antibodies in a matched case,control study. Results:, Prevalence of more than one seropositivity for CD-associated antibodies in T1DM-group is 6.0 times increased, compared with controls (p < 0.05). ATPO seropositivity is 5.3 times increased in T1DM group (p < 0.05), but TSHR antibody is comparable with controls (p > 0.05). Seropositivities for T1DM, AIT and CD are 4.3, 1.9 and 2.4 times more prevalent among first-degree relatives respectively, compared with controls (p < 0.05). Pathologically confirmed cases with CD among first-degree relatives were all identified at screening. In contrast, all of pathologically confirmed cases with CD in T1DM group, were either previously diagnosed or symptomatic at time of screening. In the group of patients with T1DM, 31% of seropositive cases for anti-ATPO were clinically latent for AIT, and 74% of ATPO (+) cases were identified at current screening study. Sixty-four per cent of ATPO (+) first-degree relatives were clinically latent for AIT, and 54% were identified at screening. Conclusion:, Type 1 diabetes mellitus, CD and AIT represent a significant overlap in an adult population with already-diagnosed T1DM and their first-degree relatives. With regard to clinical presentations, CD was less likely to be clinically silent than AIT among patients with T1DM. [source] Non-fatal major bleeding during treatment with vitamin K antagonists: influence of soluble thrombomodulin and mutations in the propeptide of coagulation factor IXJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 7 2004J. F. Van Der Heijden Summary., Background and objectives : The key complication of treatment with vitamin K antagonists (VKAs) is bleeding. The major determinant of VKA-induced bleeding is the intensity of anticoagulation. Individual patient characteristics may also influence bleeding risk. In addition, soluble thrombomodulin (s-TM) levels and mutations in the propeptide of factor (F)IX are important candidate risk factors in this respect. Patients and methods : A matched case,control study was designed to search for risk factors that predict bleeding during VKA treatment. We selected cases that had experienced major bleeding during treatment with VKA and matched controls without bleeding complications from the databases of two Thrombosis Services. The controls were matched for indication of treatment, age, gender, type of anticoagulant used and whether or not treatment with VKA was stopped. DNA and plasma were stored of all cases and controls. Results and conclusions : In total 110 patients and 220 controls consented to participate. The results indicate that s-TM levels, measured by ELISA, may be a risk indicator for bleeding [crude odds ratio 3.25 for the highest quartile vs. the lowest quartile (95% confidence interval 1.40, 7.51)]. Three novel mutations, determined by direct sequencing, in the gene portion encoding the propeptide of FIX were identified that do not seem to play an important role in bleeding risk during treatment with VKAs. [source] Serum gastrin and pepsinogens do not correlate with the different grades of severity of gastro-oesophageal reflux disease: a matched case,control studyALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 4 2008K. MONKEMULLER Summary Background, Gastrin and pepsinogens reflect the functional state of the gastric mucosa. Aim, To evaluate whether serum gastrin and pepsinogens correlate with the different grades of severity of gastro-oesophageal reflux disease (GERD). Methods, In all, 388 patients with heartburn not taking any form of acid suppressive therapy were matched-controlled for age and gender and sub-classified into four groups: group 1 non-erosive reflux disease (NERD); group 2, erosive reflux disease (ERD) Los Angeles (LA) A and B, group 3, ERD LA C and D; group 4 Barrett's oesophagus (BO). Fasting serum was analysed for gastrin 17, pepsinogen I, pepsinogen II und Helicobacter pylori using specific EIA tests (GastroPanel; Biohit, Plc). Statistics: Kruskal,Wallis test and analysis of variance. Results, There was a significant difference among the four groups with respect for pepsinogen I, but not for pepsinogen II, the pepsinogen I pepsinogen II ratio, H. pylori serology and gastrin levels. Pepsinogen I was the lowest in NERD and the highest in BO (median 91.6, mean ± standard deviation 106.2 ± 51.6 vs. median 114.7, mean ± standard deviation 130.4 ± 70.6; P = 0.046). Pepsinogen I levels were higher in H. pylori positive subjects. After adjusting for H. pylori status, the differences in pepsinogen I across patient groups were no longer statistically significant (P = 0.298). Conclusions, Serum gastrin and pepsinogen I and II do not correlate with the different grades of severity of GERD. The non-invasive GastroPanel is not useful for the differentiation of the various forms of GERD. [source] Is the hepatitis C virus epidemic over in Egypt?LIVER INTERNATIONAL, Issue 4 2010Incidence, risk factors of new hepatitis C virus infections Abstract Objectives: To estimate hepatitis C virus (HCV) incidence rates and identify risk factors for current HCV transmission with emphasis on the role of living with infected household family members in rural Egypt. Methods: A 4-year population-based, cohort study of seronegative villagers was conducted to identify incident HCV seroconversion cases. A risk factor questionnaire and blood samples for anti-HCV EIA-3 and HCV RNA polymerase chain reaction testing were collected at two rounds of follow-up. Incidence rates, relative risks and 95% confidence interval (CI) were calculated based on a Poisson distribution. A matched case,control analysis to explore specific behavioural predictors of infection was conducted and odds ratios were obtained by conditional logistic regression. Results: Twenty-five participants (11 females) seroconverted in 10 578 person years of follow-up (PY), (incidence rate of 2.4/1000 PY; 95% CI: 1.6,3.5). The median age at seroconversion was 26 years [interquartile range (IQR) 19,35] among males and 20 years (IQR 13,24) among females. The only significant risk factor identified for these cases was receiving injections [adjusted odds ratio (ORadj)=3.3; 95% CI: 1.1,9.8]. Two of the 17 viraemic seroconvertors were infected with the same strain as at least one of their family members. Conclusion: This study identified the important role of injections in spreading HCV infection in this rural community. National healthcare awareness and infection control programmes should be strengthened to prevent further transmission. Screening of families of infected HCV subjects should be an essential part of case management for early detection and management. [source] Relationships between air pollution and preterm birth in CaliforniaPAEDIATRIC & PERINATAL EPIDEMIOLOGY, Issue 6 2006Mary Huynh Summary Air pollution from vehicular emissions and other combustion sources is related to cardiovascular and respiratory outcomes. However, few studies have investigated the relationship between air pollution and preterm birth, a primary cause of infant mortality and morbidity. This analysis examined the effect of fine particulate matter (PM2.5) and carbon monoxide (CO) on preterm birth in a matched case,control study. PM2.5 and CO monitoring data from the California Air Resources Board were linked to California birth certificate data for singletons born in 1999,2000. Each birth was mapped to the closest PM monitor within 5 miles of the home address. County-level CO measures were utilised to increase sample size and maintain a representative population. After exclusion of implausible birthweight,gestation combinations, preterm birth was defined as birth occurring between 24 and 36 weeks' gestation. Each of the 10 673 preterm cases was matched to three controls of term (39,44 weeks) gestation with a similar date of last menstrual period. Based on the case's gestational age, CO and PM2.5 exposures were calculated for total pregnancy, first month of pregnancy, and last 2 weeks of pregnancy. Exposures were divided into quartiles; the lowest quartile was the reference. Because of the matched design, conditional logistic regression was used to adjust for maternal race/ethnicity, age, parity, marital status and education. High total pregnancy PM2.5 exposure was associated with a small effect on preterm birth, after adjustment for maternal factors (adjusted odds ratio [AOR] = 1.15, [95% CI 1.07, 1.24]). The odds ratio did not change after adjustment for CO. Results were similar for PM2.5 exposure during the first month of pregnancy (AOR = 1.21, 95% CI [1.12, 1.30]) and the last 2 weeks of pregnancy (AOR = 1.17, 95% CI [1.09, 1.27]). Conversely, CO exposure at any time during pregnancy was not associated with preterm birth (AORs from 0.95 to 1.00). Maternal exposure to PM2.5, but not CO, is associated with preterm birth. This analysis did not show differences by timing of exposure, although more detailed examination may be needed. [source] Prenatal and intrapartum events and sudden infant death syndromePAEDIATRIC & PERINATAL EPIDEMIOLOGY, Issue 1 2002Hillary S. Klonoff-Cohen Summary The purpose of this study was to evaluate specific pregnancy and labour and delivery events that may increase the risk of sudden infant death syndrome (SIDS). A matched case,control study was conducted in five counties in southern California, using California death certificate records. The sample consisted of 239 Caucasian, African,American, Hispanic and Asian mothers of SIDS infants and 239 mothers of control infants matched on sex, race, birth hospital and date of birth. Mothers participated in a detailed telephone interview and provided access to obstetric and paediatric records. More case than control mothers reported a family history of anaemia (OR = 2.12, P < 0.001). Placental abruptions were strongly associated with SIDS (unadjusted OR = 7.94, [95% CI 1.34,47.12]). There was an increased risk of SIDS death associated with maternal anaemia during pregnancy (OR = 2.51, [95% CI 1.25,5.03]), while simultaneously adjusting for maternal smoking during pregnancy, maternal years of education and age, parity, infant birthweight, gestational age, medical conditions at birth, infant sleep position and post-natal smoking. Interactions of anaemia and prenatal smoking as well as anaemia and post-natal smoking were not statistically significant. There were no other statistically significant differences between case and control mothers for pregnancy conditions, labour and delivery events (e.g. caesarean sections, anaesthesia, forceps) or newborn complications (e.g. nuchal cord, meconium aspiration). Anaemia and placental abruptions were significantly associated with an increased risk of SIDS; both are circumstances in which a fetus may become hypoxic, thereby compromising the subsequent growth, development and ultimate survival of the infant. [source] ORIGINAL ARTICLE: Activating Killer Cell Immunoglobulin-Like Receptor Genes' Association with Recurrent MiscarriageAMERICAN JOURNAL OF REPRODUCTIVE IMMUNOLOGY, Issue 1 2009Rafael Gustavo Vargas Problem, Natural killer (NK) cells are regulated through NK cell receptors such as killer cell immunoglobulin-like receptors (KIRs). KIRs are suspected of being involved in the causes of recurrent miscarriage (RM) as a higher proportion of activated NK cells were observed in women with RM when compared with that in controls. The aim of this study was to investigate if KIR genes coding for receptors known to have as ligands HLA class I molecules are correlated with RM. Method of study A matched case,control study was carried out in 68 south Brazilian Caucasian patient couples with RM and 68 control fertile couples. KIR genes were typed by PCR-Reverse SSO method. Results The rate of possession of an elevated number of activating KIR genes (positive for five or six activating KIR genes out of six different activating KIR genes analyzed) in RM patient women was significantly higher (P = 0.0201) when compared with that in control fertile women. These data suggest that women carrying a high content of activating KIR genes have about threefold increased probability to develop RM [OR = 2.71; 95% CI (1.23,6.01)]. Conclusion Our results indicate that RM could be associated with NK cell activation mediated by a profile rich in activating KIR genes. [source] Maternal periodontal disease and perinatal mortalityAUSTRALIAN AND NEW ZEALAND JOURNAL OF OBSTETRICS AND GYNAECOLOGY, Issue 2 2009Alexis SHUB Background: Periodontal disease has been associated with increased perinatal mortality. Aims: To examine the association between maternal periodontal disease and perinatal mortality. Methods: We performed a retrospective and prospective matched case,control study of women with unexplained perinatal mortality at more than 20 weeks gestational age. Women were matched for socioeconomic status, smoking status and time since delivery. All women underwent a detailed periodontal examination and completed a questionnaire describing oral health symptoms. No intervention took place. Results: Fifty-three women who had experienced a perinatal death and 111 controls completed the study. Thirty-two women were recruited retrospectively and 21 women were recruited prospectively. Twenty-three (43.4%) women who had experienced a perinatal death and 27 (24.3%) controls had periodontal disease. There were no differences in oral health behaviours or symptoms between cases and controls. Perinatal death was associated with periodontal disease (odds ratio (OR) 2.34, 95% confidence interval (CI) 1.05, 5.47). Periodontal disease was more strongly associated with perinatal mortality due to extreme prematurity (OR 3.60, 95% CI 1.20, 12.04). Multivariate analysis showed this relationship to be consistent after inclusion of higher parity, country of birth, advanced maternal age and maternal obesity in the model (OR 4.56, 95% CI 1.25, 21.27). Conclusions: Maternal periodontal disease may contribute to perinatal mortality, especially that caused by extreme prematurity. [source] Analysis of Matched Case,Control Data in Presence of Nonignorable Missing ExposureBIOMETRICS, Issue 1 2008Samiran Sinha Summary. The present article deals with informative missing (IM) exposure data in matched case,control studies. When the missingness mechanism depends on the unobserved exposure values, modeling the missing data mechanism is inevitable. Therefore, a full likelihood-based approach for handling IM data has been proposed by positing a model for selection probability, and a parametric model for the partially missing exposure variable among the control population along with a disease risk model. We develop an EM algorithm to estimate the model parameters. Three special cases: (a) binary exposure variable, (b) normally distributed exposure variable, and (c) lognormally distributed exposure variable are discussed in detail. The method is illustrated by analyzing a real matched case,control data with missing exposure variable. The performance of the proposed method is evaluated through simulation studies, and the robustness of the proposed method for violation of different types of model assumptions has been considered. [source] Conditional Likelihood Methods for Haplotype-Based Association Analysis Using Matched Case,Control DataBIOMETRICS, Issue 4 2007Jinbo Chen Summary Genetic epidemiologists routinely assess disease susceptibility in relation to haplotypes, that is, combinations of alleles on a single chromosome. We study statistical methods for inferring haplotype-related disease risk using single nucleotide polymorphism (SNP) genotype data from matched case,control studies, where controls are individually matched to cases on some selected factors. Assuming a logistic regression model for haplotype-disease association, we propose two conditional likelihood approaches that address the issue that haplotypes cannot be inferred with certainty from SNP genotype data (phase ambiguity). One approach is based on the likelihood of disease status conditioned on the total number of cases, genotypes, and other covariates within each matching stratum, and the other is based on the joint likelihood of disease status and genotypes conditioned only on the total number of cases and other covariates. The joint-likelihood approach is generally more efficient, particularly for assessing haplotype-environment interactions. Simulation studies demonstrated that the first approach was more robust to model assumptions on the diplotype distribution conditioned on environmental risk variables and matching factors in the control population. We applied the two methods to analyze a matched case,control study of prostate cancer. [source] Matched Case,Control Data Analysis with Selection BiasBIOMETRICS, Issue 4 2001I-Feng Lin Summary. Case-control studies offer a rapid and efficient way to evaluate hypotheses. On the other hand, proper selection of the controls is challenging, and the potential for selection bias is a major weakness. Valid inferences about parameters of interest cannot be drawn if selection bias exists. Furthermore, the selection bias is difficult to evaluate. Even in situations where selection bias can be estimated, few methods are available. In the matched case-control Northern Manhattan Stroke Study (NOMASS), stroke-free controls are sampled in two stages. First, a telephone survey ascertains demographic and exposure status from a large random sample. Then, in an in-person interview, detailed information is collected for the selected controls to be used in a matched case,control study. The telephone survey data provides information about the selection probability and the potential selection bias. In this article, we propose bias-corrected estimators in a case-control study using a joint estimating equation approach. The proposed bias-corrected estimate and its standard error can be easily obtained by standard statistical software. [source] Acute treatment outcomes in patients with bipolar I disorder and co-morbid borderline personality disorder receiving medication and psychotherapyBIPOLAR DISORDERS, Issue 2 2005Holly A Swartz Objective:, Patients suffering from both bipolar I disorder and borderline personality disorder (BPD) pose unique treatment challenges. The purpose of this matched case,control study was to compare acute treatment outcomes of a sample of patients who met standardized diagnostic criteria for both bipolar I disorder and BPD (n = 12) to those who met criteria for bipolar I disorder only (n = 58). Method:, Subjects meeting criteria for an acute affective episode were treated with a combination of algorithm-driven pharmacotherapy and weekly psychotherapy until stabilization (defined as four consecutive weeks with a calculated average of the 17-item version of the Hamilton Rating Scale for Depression and Bech-Rafaelsen Mania scale totaling ,7). Results:, Only three of 12 (25%) bipolar-BPD patients achieved stabilization, compared with 43 of 58 (74%) bipolar-only patients. Two of the three bipolar-BPD patients who did stabilize took over 95 weeks to do so, compared with a median time-to-stabilization of 35 weeks in the bipolar-only group. The bipolar-BPD group received significantly more atypical mood-stabilizing medications per year than the bipolar-only group (Z = 4.3, p < 0.0001). Dropout rates in the comorbid group were high. Conclusions:, This quasi-experimental study suggests that treatment course may be longer in patients suffering from both bipolar I disorder and BPD. Some patients improved substantially with pharmacotherapy and psychotherapy, suggesting that this approach is worthy of further investigation. [source] Antenatal pulmonary embolism: risk factors, management and outcomesBJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 4 2008M Knight Objectives, To estimate the incidence of antenatal pulmonary embolism and describe the risk factors, management and outcomes. Design, A national matched case,control study using the UK Obstetric Surveillance System (UKOSS). Setting, All hospitals with consultant-led maternity units in the UK. Participants, A total of 143 women who had an antenatal pulmonary embolism between February 2005 and August 2006. Two hundred and fifty nine matched control women. Methods, Prospective case and control identification through the UKOSS monthly mailing. Main outcome measures, Incidence and case fatality rates with 95% CIs. Adjusted odds ratio estimates. Results, One hundred per cent of UK consultant-led obstetric units contributed data to UKOSS. A total of 143 antenatal pulmonary embolisms were reported, representing an estimated incidence of 1.3 per 10 000 maternities (95% CI 1.1,1.5). Seventy per cent of women had identifiable classical risk factors for thromboembolic disease. The main risk factors for pulmonary embolism were multiparity (adjusted odds ratio [aOR] 4.03, 95% CI 1.60,9.84) and body mass index , 30 kg/m2 (aOR 2.65, 95% CI 1.09,6.45). Nine women who had a pulmonary embolism should have received antenatal thromboprophylaxis with low-molecular-weight heparin (LMWH) according to national guidelines; only three (33%) of them did. Six women (4%) had a pulmonary embolism following antenatal prophylaxis with LMWH; three of these women (50%) were receiving lower than recommended doses. Two women had recurrent pulmonary emboli (1.4%, 95% CI 0.2,5.1%). Five women died (case fatality 3.5%, 95% CI 1.1,8.0%). Conclusions, Significant severe morbidity from thromboembolic disease underlies the maternal deaths from pulmonary embolism in the UK. This study has shown some cases where thromboprophylaxis was not provided according to national guidelines, and there may be scope for further work on guideline implementation. [source] The AmRo study: pregnancy outcome in HIV-1-infected women under effective highly active antiretroviral therapy and a policy of vaginal deliveryBJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 2 2007K Boer Objective, To explore pregnancy outcome in HIV-1-positive and HIV-negative women, and mother-to-child transmission (MTCT) according to mode of delivery under effective highly active antiretroviral therapy (HAART). Design, Cohort of 143 pregnant HIV-1-infected women including a matched case,control study in a 2:1 ratio of controls to cases (n = 98). Setting, Academic Medical Center in Amsterdam and Erasmus Medical Center in Rotterdam, the Netherlands. Population, Consecutive referred HIV-1 infected pregnant women treated with HAART and matched control not infected pregnant women. Main outcome measures, MTCT, preterm delivery, low birthweight, pre-eclampsia. Results, MTCT was 0% (95% CI 0,2.1%). Seventy-eight percent of HIV-1-infected women commenced and 62% completed vaginal delivery. The calculated number of caesarean sections needed to prevent a single MTCT was 131 or more. Preterm delivery rates were 18% (95% CI 11,27) in women infected with HIV-1 and 9% (95% CI 5,13) in controls (P = 0.03). HAART used at <13 weeks of gestation was associated with a 44% preterm delivery rate compared with 21% when HAART was started at or after 13 weeks and 14% in controls. (Very) low birthweight and incidence of pre-eclampsia were not different between HIV-1 and controls. Conclusions, We have not demonstrated any MTCT after vaginal delivery in women effectively treated by HAART. The HAART-associated increase in preterm delivery rate is mainly seen after first trimester HAART use. [source] Derivation of a Triage Algorithm for Chest Radiography of Community-acquired Pneumonia Patients in the Emergency DepartmentACADEMIC EMERGENCY MEDICINE, Issue 1 2008Demetrios N. Kyriacou MD Abstract Background:, Community-acquired pneumonia (CAP) accounts for 1.5 million emergency department (ED) patient visits in the United States each year. Objectives:, To derive an algorithm for the ED triage setting that facilitates rapid and accurate ordering of chest radiography (CXR) for CAP. Methods:, The authors conducted an ED-based retrospective matched case,control study using 100 radiographic confirmed CAP cases and 100 radiographic confirmed influenzalike illness (ILI) controls. Sensitivities and specificities of characteristics assessed in the triage setting were measured to discriminate CAP from ILI. The authors then used classification tree analysis to derive an algorithm that maximizes sensitivity and specificity for detecting patients with CAP in the ED triage setting. Results:, Temperature greater than 100.4°F (likelihood ratio = 4.39, 95% confidence interval [CI] = 2.04 to 9.45), heart rate greater than 110 beats/minute (likelihood ratio = 3.59, 95% CI = 1.82 to 7.10), and pulse oximetry less than 96% (likelihood ratio = 2.36, 95% CI = 1.32 to 4.20) were the strongest predictors of CAP. However, no single characteristic was adequately sensitive and specific to accurately discriminate CAP from ILI. A three-step algorithm (using optimum cut points for elevated temperature, tachycardia, and hypoxemia on room air pulse oximetry) was derived that is 70.8% sensitive (95% CI = 60.7% to 79.7%) and 79.1% specific (95% CI = 69.3% to 86.9%). Conclusions:, No single characteristic adequately discriminates CAP from ILI, but a derived clinical algorithm may detect most radiographic confirmed CAP patients in the triage setting. Prospective assessment of this algorithm will be needed to determine its effects on the care of ED patients with suspected pneumonia. [source] Vitamin D status and acute lower respiratory infection in early childhood in Sylhet, BangladeshACTA PAEDIATRICA, Issue 3 2010DE Roth Abstract Aim: Acute lower respiratory tract infection (ALRI) is the most important global cause of childhood death. Micronutrient deficiencies may increase the risk of ALRI. A case,control study was conducted to assess the association between vitamin D status and ALRI in rural Bangladesh. Methods: Children aged 1,18 months hospitalized with ALRI (cases) were individually matched to controls on age, sex, and village (N = 25 pairs). The mean serum 25-hydroxyvitamin D concentration [25(OH)D] in cases and controls was compared using paired t -test. The unadjusted and adjusted odds of ALRI were assessed by multivariate conditional logistic regression. Results: Mean [25(OH)D] was significantly lower among ALRI cases than controls (29.1 nmol/L vs. 39.1 nmol/L; p = 0.015). The unadjusted odds of ALRI was halved for each 10 nmol/L increase in [25(OH)D] (OR 0.53, 95% CI 0.30,0.96). Adjustment for confounders increased the magnitude of the association. Conclusion: Vitamin D status was associated with early childhood ALRI in a matched case,control study in rural Bangladesh. Randomized trials may establish whether interventions to improve vitamin D status can reduce the burden of ALRI in early childhood. [source] Interaction between a chromosome 10 RET enhancer and chromosome 21 in the Down syndrome,Hirschsprung disease association,HUMAN MUTATION, Issue 5 2009Stacey Arnold Abstract Individuals with Down syndrome (DS) display a 40-fold greater risk of Hirschsprung disease (HSCR) than the general population of newborns implicating chromosome 21 in HSCR etiology. Here we demonstrate that the RET enhancer polymorphism RET+9.7 (rs2435357:C>T) at chromosome 10q11.2 is associated with HSCR in DS individuals both by transmission disequilibrium (P=0.0015) and case,control (P=0.0115) analysis of matched cases. Interestingly, the RET+9.7 T allele frequency is significantly different between individuals with DS alone (0.26±0.04), HSCR alone (0.61±0.04), and those with HSCR and DS (0.41±0.04), demonstrating an association and interaction between RET and chromosome 21 gene dosage. This is the first report of a genetic interaction between a common functional variant (rs2435357) and a not infrequent copy number error (chromosome 21 dosage) in two human developmental disorders. Hum Mutat 30:1,5, 2009. © 2009 Wiley-Liss, Inc. [source] Validation study of the Victorian Birth Defects RegisterJOURNAL OF PAEDIATRICS AND CHILD HEALTH, Issue 9-10 2004M Riley Objective: To determine whether there has been an improvement in ascertainment of birth defects cases (,case validity') by the Victorian Birth Defects Register (BDR) since an earlier study (conducted in 1993), to ascertain the accuracy of registered data (,item validity') and to investigate another possible source of notification. Methods: The medical records were reviewed of 500 children born after 1 January 1993 who were consecutively admitted after 1 January 1999 to two paediatric teaching hospitals in Victoria. In addition, records of 200 children referred to a clinical genetics service were reviewed for children born after 1 January 1993 and who were seen in two periods: 2 months after 1 January 2001 and 2 months after 1 January 2002. The records from the hospitals and clinical genetics service were reviewed separately to determine whether children recorded as having a birth defect had previously been notified to the BDR. Results: Twenty percent of the hospital records related to a child with a birth defect, as did 70% of the clinical genetics service records. Overall case validity for birth defect cases from the hospitals was 88%. There was 100% ascertainment for three of five categories. Sixty per cent of birth defects cases from the clinical genetics service had been notified to the BDR. When all diagnoses in matched cases were considered, item validity was 54%, however, if only primary diagnoses were included then 92% of cases had the same diagnosis. Conclusions: Overall case validity from the two paediatric teaching hospitals has significantly improved since our previous study. The addition of an extra data source from a clinical genetics service would identify new cases, particularly genetic disorders and developmental delay, as well as adding new diagnoses to existing ones. This study has highlighted the need to improve item validity, perhaps through routine education for all coders and notifiers on the inclusion and exclusion of specific associated conditions when notifying major birth defects. [source] Temporal arteritis and Chlamydia pneumoniae: Failure to detect the organism by polymerase chain reaction in ninety cases and ninety controlsARTHRITIS & RHEUMATISM, Issue 4 2002Michael J. Regan Objective To examine the reported correlation between the presence of Chlamydia pneumoniae in temporal artery biopsy specimens and the diagnosis of temporal arteritis (TA). Methods Among 90 possible cases of TA identified at our institution between 1968 and 2000, 79 of the positive biopsy specimens (88%) demonstrated giant cells and the other 11 cases (12%) had other histopathologic features compatible with TA; by chart review, all 90 patients were confirmed to have met the American College of Rheumatology classification criteria for TA. Controls had negative temporal artery biopsy specimens during the same 32-year time period and their postbiopsy disease courses were not compatible with TA. Controls were matched with each case by sex, year of biopsy, and age within 10 years. The biopsy specimens from all cases and controls were reevaluated and readings were confirmed in a masked manner by an experienced eye pathologist. Polymerase chain reaction (PCR) analyses for C pneumoniae were performed on the 180 samples using 2 different sets of PCR primers (which target 2 different genes). A primer set targeting the ompA gene (CP1-CP2/CPC-CPD) was used to perform a nested PCR, followed by confirmation of the findings with primers targeting the 16S ribosomal RNA (rRNA) gene (Cpn90/Cpn91) in a touchdown-enzyme time-release PCR. We used positive and negative controls, as well as controls made from infected and noninfected HEp-2 cells, suspended in a formalin-fixed, paraffin-embedded matrix. Results Seventy-six percent of the 180 cases and controls were women. The mean age of the cases was 72.0 years (range 53,90), and that of the controls was 70.4 years (range 51,86). Eighty percent of the control samples were obtained by temporal artery biopsy performed within 1 year of the biopsies performed on the matched cases. Using the CP1-CP2/CPC-CPD primer set, only 1 TA case sample (1% of all case samples) was positive for the ompA gene. One control sample was also positive using these primers. With the Cpn90/Cpn91 primers, none of the cases and none of the controls were positive for the 16S rRNA gene. Conclusion The results of this study using sensitive and specific PCR analyses do not support a role for C pneumoniae in the pathogenesis of TA. [source] | ||||||||||||||||||||||