Angela Reitsma

McMaster University, Hamilton, Ontario, Canada

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Publications (10)16.35 Total impact

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    ABSTRACT: Clustering of outcomes at centers involved in multicenter trials is a type of center effect. The Consolidated Standards of Reporting Trials Statement recommends that multicenter randomized controlled trials (RCTs) should account for center effects in their analysis, however most do not. The Early External Cephalic Version (EECV) trials published in 2003 and 2011 stratified by center at randomization, but did not account for center in the analyses, and due to the nature of the intervention and number of centers, may have been prone to center effects. Using data from the EECV trials, we undertook an empirical study to compare various statistical approaches to account for center effect while estimating the impact of external cephalic version timing (early or delayed) on the outcomes of cesarean section, preterm birth, and non-cephalic presentation at the time of birth. The data from the EECV pilot trial and the EECV2 trial were merged into one dataset. Fisher’s exact method was used to test the overall effect of external cephalic version timing unadjusted for center effects. Seven statistical models that accounted for center effects were applied to the data. The models included: i) the Mantel-Haenszel test, ii) logistic regression with fixed center effect and fixed treatment effect, iii) center-size weighted and iv) un-weighted logistic regression with fixed center effect and fixed treatment-by-center interaction, iv) logistic regression with random center effect and fixed treatment effect, v) logistic regression with random center effect and random treatment-by-center interaction, and vi) generalized estimating equations. For each of the three outcomes of interest approaches to account for center effect did not alter the overall findings of the trial. The results were similar for the majority of the methods used to adjust for center, illustrating the robustness of the findings. Despite literature that suggests center effect can change the estimate of effect in multicenter trials, this empirical study does not show a difference in the outcomes of the EECV trials when accounting for center effect. Trial registration The EECV2 trial was registered on 30 July 30 2005 with Current Controlled Trials: ISRCTN 56498577.
    Trials 09/2014; 15(1):377. DOI:10.1186/1745-6215-15-377 · 2.12 Impact Factor
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    ABSTRACT: Background There has been a renewed interest in the place of birth, including intended home birth, for low risk women. In the absence of adequately-sized randomised controlled trials, a recent Cochrane review recommended that a systematic review and meta-analysis, including observational studies, be undertaken to inform this topic. The objective of this review is to determine if women intending at the onset of labour to give birth at home are more or less likely to experience a foetal or neonatal loss compared to a cohort of women who are comparable to the home birth cohort on the absence of risk factors but who intend to give birth in a hospital setting. Methods We will search using Embase, MEDLINE, CINAHL, AMED and the Cochrane Library to find studies published since 1990 that compare foetal, neonatal and maternal outcomes for women who intended at the onset of labour to give birth at home to a comparison cohort of low risk women who intended at the onset of labour to give birth in hospital. We will obtain pooled estimates of effect using Review Manager. Because of the likelihood of differences in outcomes in settings where home birth is integrated into the health care system, we will stratify our results according to jurisdictions that have a health care system that integrates home birth and those where home birth is provided outside the usual health care system. Since parity is known to be associated with birth outcomes, only studies that take parity into account will be included in the meta-analyses. We will provide results by parity to the extent possible. Systematic Review Registration This protocol was registered with PROSPERO at http://www.crd.york.ac.uk/Prospero/ (Registration number: CRD42013004046).
    05/2014; 3(1):55. DOI:10.1186/2046-4053-3-55
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    ABSTRACT: The international, multicenter External Cephalic Version 2 (ECV2) Trial compared early external cephalic version at 34(0/7) to 35(6/7) weeks with that at greater than 37 weeks. A total of 1,543 women were randomized from 68 centers in 21 countries. The goal of this component of the trial was to understand women's views about participation in a research trial and timing of external cephalic version. A postpartum questionnaire was completed containing a 5-point Likert scale examining contact and availability of staff, choice of timing of external cephalic version, preference of randomization, convenience of participating, and overall satisfaction. Participants also completed two open-ended questions related to timing of external cephalic version and satisfaction with the trial. Descriptive statistics and content analysis were used to analyze data. A total of 1,458 women completed the questionnaire, of whom 86 percent said "yes"-they would participate in the trial again. Themes influencing decisions about participating were perceptions of the external cephalic version experience, preferred mode of delivery, preferred timing of external cephalic version, and perceptions of the effectiveness of external cephalic version and of the trial environment. Many participants preferred the early timing of the procedure offered through the trial because of perceived advantages of a smaller baby being easier to turn and the opportunity for repeat procedures. Women were positive about their participation in the trial. Early external cephalic version was preferred over the traditional timing as it was perceived to afford both physiologic and practical advantages.
    Birth 03/2012; 39(1):30-8. DOI:10.1111/j.1523-536X.2011.00510.x · 2.05 Impact Factor
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    ABSTRACT: Pregnant women with chronic kidney disease (CKD) are at risk of adverse maternal and fetal outcomes. We conducted a systematic review of observational studies that described this risk. We searched several databases from their date of inception through June 2010 for eligible articles published in any language. We included any study that reported maternal or fetal outcomes in at least five pregnant women in each group with or without CKD. We excluded pregnant women with a history of transplantation or maintenance dialysis. We identified 13 studies. Adverse maternal events including gestational hypertension, pre-eclampsia, eclampsia, and maternal mortality were reported in 12 studies. There were 312 adverse maternal events among 2682 pregnancies in women with CKD (weighted average of 11.5%) compared with 500 events in 26,149 pregnancies in normal healthy women (weighted average of 2%). One or more adverse fetal outcomes such as premature births, intrauterine growth restriction, small for gestational age, neonatal mortality, stillbirths, and low birth weight were reported in nine of the included studies. Overall, the risk of developing an adverse fetal outcome was at least two times higher among women with CKD compared with those without. This review summarizes current available evidence to guide physicians in their decision-making, advice, and care for pregnant women with CKD. Additional studies are needed to better characterize the risks.
    Clinical Journal of the American Society of Nephrology 09/2011; 6(11):2587-98. DOI:10.2215/CJN.10841210 · 5.25 Impact Factor
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    Eileen K. Hutton · Angela H. Reitsma · Karyn Kaufman
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    ABSTRACT: Background: Midwives in Ontario, Canada, provide care in the home and hospital and are required to submit data for all births to the Ontario Ministry of Health database. The purpose of this study was to compare maternal and perinatal/neonatal mortality and morbidity and intrapartum intervention rates for women attended by Ontario midwives who planned a home birth compared with similar low-risk women who planned a hospital birth between 2003 and 2006. Methods: The database provided outcomes for all women planning a home birth at the onset of labor (n = 6, 692) and for a cohort, stratified by parity, of similar low-risk women planning a hospital birth. Results: The rate of perinatal and neonatal mortality was very low (1/1,000) for both groups, and no difference was shown between groups in perinatal and neonatal mortality or serious morbidity (2.4% vs 2.8%; relative risk (RR), 95% confidence intervals (CI): 0.84 (0.68-1.03)). No maternal deaths were reported. All measures of serious maternal morbidity were lower in the planned home birth group as were rates for all interventions including cesarean section (5.2% vs 8.1%; RR (95% CI): 0.64 (0.56, 0.73)). Nulliparas were less likely to deliver at home, and had higher rates of ambulance transport from home to hospital than multiparas planning home birth and had rates of intervention and outcomes similar to, or lower than, nulliparas planning hospital births. Conclusions: Midwives who were integrated into the health care system with good access to emergency services, consultation, and transfer of care provided care resulting in favorable outcomes for women planning both home or hospital births. (BIRTH 36:3 September 2009)
    Obstetric Anesthesia Digest 01/2010; 30(3):176-177. DOI:10.1097/01.aoa.0000386843.88868.af
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    Obstetric Anesthesia Digest 01/2010; 30(3):180-181. DOI:10.1097/01.aoa.0000386847.67783.a5
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    Eileen K Hutton · Angela H Reitsma · Karyn Kaufman
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    ABSTRACT: Midwives in Ontario, Canada, provide care in the home and hospital and are required to submit data for all births to the Ontario Ministry of Health database. The purpose of this study was to compare maternal and perinatal/neonatal mortality and morbidity and intrapartum intervention rates for women attended by Ontario midwives who planned a home birth compared with similar low-risk women who planned a hospital birth between 2003 and 2006. The database provided outcomes for all women planning a home birth at the onset of labor (n = 6,692) and for a cohort, stratified by parity, of similar low-risk women planning a hospital birth. The rate of perinatal and neonatal mortality was very low (1/1,000) for both groups, and no difference was shown between groups in perinatal and neonatal mortality or serious morbidity (2.4% vs 2.8%; relative risk [RR], 95% confidence intervals [CI]: 0.84 [0.68-1.03]). No maternal deaths were reported. All measures of serious maternal morbidity were lower in the planned home birth group as were rates for all interventions including cesarean section (5.2% vs 8.1%; RR [95% CI]: 0.64 [0.56, 0.73]). Nulliparas were less likely to deliver at home, and had higher rates of ambulance transport from home to hospital than multiparas planning home birth and had rates of intervention and outcomes similar to, or lower than, nulliparas planning hospital births. Midwives who were integrated into the health care system with good access to emergency services, consultation, and transfer of care provided care resulting in favorable outcomes for women planning both home or hospital births.
    Birth 09/2009; 36(3):180-9. DOI:10.1111/j.1523-536X.2009.00322.x · 2.05 Impact Factor
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    E K Hutton · M Kasperink · M Rutten · A Reitsma · B Wainman
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    ABSTRACT: Up to one-third of labouring women will experience painful 'back labour'. Sterile water injected lateral to the lumbosacral spine is a simple and well-researched approach to this pain. To determine if sterile water injection for low back pain compared to placebo or alternative therapy increased or decreased the rate of Caesarean section. We performed a literature search with no language restriction in four databases: the Cochrane library, EMBASE (1980-2009), Ovid Medline (1950-2009) and CINAHL (1982-2009). We included all randomised controlled trials (RCTs) of sterile water injection for labour pain that included outcomes of interest and original data. We compared Caesarean section rates among women who received sterile water injection in labour with those who received either placebo treatment or another non-pharmacological treatment modality. Other outcomes included pain scores, use of regional analgesia and women's assessment of treatment. We used Revman 5 for the meta-analysis. Data were entered by one reviewer and independently cross-checked. Pooled outcomes were reported as Relative Risk (RR) or Weighted Mean Difference using Mantel-Haenszel fixed-effects model except when the I2 value >50% indicated significant heterogeneity in which case random-effects model was used. We included eight RCTs. The Caesarean section rate was 4.6% in the sterile water injection group and 9.9% in the comparison group (n = 828) (RR 0.51, 95% CI: 0.30, 0.87). We believe that a large RCT should be mounted to validate our findings regarding the impact of sterile water injections on mode of delivery.
    BJOG An International Journal of Obstetrics & Gynaecology 06/2009; 116(9):1158-66. DOI:10.1111/j.1471-0528.2009.02221.x · 3.86 Impact Factor
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    Eileen K Hutton · Angela H Reitsma
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    ABSTRACT: External cephalic version (ECV) is an approach to turning a fetus from the breech presentation by external maneuvering of the fetus through the maternal abdominal wall into a cephalic presentation. We conducted a systematic search of the current literature on ECV to provide a comprehensive overview of the procedure and associated success rates, risks, and alternatives to ECV. Tocolytics can improve ECV success, but none of the tocolytics shown to be effective for ECV are currently available in Canada. The factors that can best predict ECV success are low uterine tone (associated with parity or tocolytics), easy palpation of the fetal head, and an unengaged breech. The most common side effect of ECV is transient fetal bradycardia with an incidence of one to six percent of all ECV procedures. The risk of requiring an emergency caesarean section because of ECV appears to be around 0.5% or one in 200 ECV procedures performed. Our review suggested no significant risk of fetal/neonatal mortality or serious morbidity associated with ECV. Few alternative approaches to turning a fetus in the breech presentation have been adequately studied. ECV should be considered for all women with a fetus in the breech presentation at term in the absence of any contraindications to the procedure. RÉSUMÉ La version céphalique externe (VCE) est une approche pour tourner un foetus en présentation de siège par une manipulation externe du foetus à travers la paroi abdominale maternelle, et ce, pour le mettre en présentation céphalique. Nous avons effectué une recension systématique des écrits courants portant sur la VCE afin de fournir une vue d'ensemble de ce procédé, du taux de réussite, des risques et des alternatives. Les produits tocolytiques peuvent améliorer la réussite de la VCE, mais aucun des produits tocolytiques qui ont fait preuve d'efficacité pour la VCE ne sont disponible au Canada. Les facteurs qui peuvent le mieux prédire la réussite de la VCE sont le tonus utérin faible (associé à la parité et aux produits tocolytiques), une bonne palpation de la tête foetale ainsi qu'un siège non-engagé. L'effet secondaire le plus commun de la VCE est une bradycardie foetale transitoire avec une incidence d'un à six pour cent de tous les procédés de VCE. Le risque d'avoir recours à une césarienne d'urgence à cause d'une VCE est de 0.5% ou d'une pour 200 procédés de VCE effectués. Notre recension ne démontrait aucune augmentation du risque de mortalité foetale/néonatale, ni de morbidité sévère associée avec la VCE. Peu d'approches alternatives pour tourner un foetus en présentation de siège ont été étudiées de façon adéquate. La VCE devrait être considérée pour toutes les femmes avec un foetus en présentation de siège rendu à terme lorsqu'il n'y a pas de contre-indications à ce procédé. 5 Introduction ECV into midwifery practice are discussed and Among term births, three to four percent of neonates alternative approaches to turning fetuses in the present in the breech presentation, and this is breech presentation are reviewed.
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    Angela H Reitsma · Steve Manske
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    ABSTRACT: Studies in other countries have shown that school tobacco control policy has potential to prevent smoking uptake in adolescents. Since no Canadian research has studied this association, we assessed the statistical link between school tobacco policy and smoking status in Ontario elementary and secondary schools. We conducted secondary analysis of data collected using the School Smoking Profile, a cross-sectional, self-report questionnaire. School policy variables were formed from five survey items concerning students' perceptions of school tobacco control policy. Smoking status was determined through self-report measures which had been validated by carbon monoxide testing. Logistic regression models used school policy variables to explain smoking status in elementary and secondary schools, controlling for school location, school size, and student's grade level. The smoking policy variables, rules and enforcement, explained smoking status after controlling for other variables. In elementary schools, perceptions of stronger enforcement reduced the odds of being a smoker (OR = 0.39, CI99 = 0.34-0.44). In secondary schools, enforcement lost its protective effect (OR = 1.05, CI99 = 1.00-1.10). In addition, student perceptions that rules were strong were indicative of increased smoking in secondary schools (OR = 1.32, CI99 = 1.27-1.37). Strong enforcement of school tobacco control policy appears to be effective in elementary schools but is not as helpful in secondary schools. Secondary school policymakers should consider modifying their sanctions to avoid alienating smokers.
    Canadian journal of public health. Revue canadienne de santé publique 95(3):214-8. · 1.02 Impact Factor