Khalid S. Khan

WHO analysis of causes of maternal death: a systematic review

BACKGROUND The reduction of maternal deaths is a key international development goal. Evidence-based health policies and programmes aiming to reduce maternal deaths need reliable and valid information. We undertook a systematic review to determine the distribution of causes of maternal deaths. METHODS We selected datasets using prespecified criteria, and recorded dataset characteristics, methodological features, and causes of maternal deaths. All analyses were restricted to datasets representative of populations. We analysed joint causes of maternal deaths from datasets reporting at least four major causes (haemorrhage, hypertensive disorders, sepsis, abortion, obstructed labour, ectopic pregnancy, embolism). We examined datasets reporting individual causes of death to investigate the heterogeneity due to methodological features and geographical region and the contribution of haemorrhage, hypertensive disorders, abortion, and sepsis as causes of maternal death at the country level. FINDINGS 34 datasets (35,197 maternal deaths) were included in the primary analysis. We recorded wide regional variation in the causes of maternal deaths. Haemorrhage was the leading cause of death in Africa (point estimate 33.9%, range 13.3-43.6; eight datasets, 4508 deaths) and in Asia (30.8%, 5.9-48.5; 11,16 089). In Latin America and the Caribbean, hypertensive disorders were responsible for the most deaths (25.7%, 7.9-52.4; ten, 11,777). Abortion deaths were the highest in Latin America and the Caribbean (12%), which can be as high as 30% of all deaths in some countries in this region. Deaths due to sepsis were higher in Africa (odds ratio 2.71), Asia (1.91), and Latin America and the Caribbean (2.06) than in developed countries. INTERPRETATION Haemorrhage and hypertensive disorders are major contributors to maternal deaths in developing countries. These data should inform evidence-based reproductive health-care policies and programmes at regional and national levels. Capacity-strengthening efforts to improve the quality of burden-of-disease studies will further validate future estimates.

What is the evidence that postgraduate teaching in evidence based medicine changes anything? A systematic review

Abstract Objective To evaluate the effects of standalone versus clinically integrated teaching in evidence based medicine on various outcomes in postgraduates. Design Systematic review of randomised and non-randomised controlled trials and before and after comparison studies. Data sources Medline, Embase, ERIC, Cochrane Library, DARE, HTA database, Best Evidence, BEME, and SCI. Study selection 23 studies: four randomised trials, seven non-randomised controlled studies, and 12 before and after comparison studies. 18 studies (including two randomised trials) evaluated a standalone teaching method, and five studies (including two randomised trials) evaluated a clinically integrated teaching method. Main outcome measures Knowledge, critical appraisal skills, attitudes, and behaviour. Results Standalone teaching improved knowledge but not skills, attitudes, or behaviour. Clinically integrated teaching improved knowledge, skills, attitudes, and behaviour. Conclusion Teaching of evidence based medicine should be moved from classrooms to clinical practice to achieve improvements in substantial outcomes.

Comparison of treatment effects between animal experiments and clinical trials: systematic review

Objective To examine concordance between treatment effects in animal experiments and clinical trials. Study design Systematic review. Data sources Medline, Embase, SIGLE, NTIS, Science Citation Index, CAB, BIOSIS. Study selection Animal studies for interventions with unambiguous evidence of a treatment effect (benefit or harm) in clinical trials: head injury, antifibrinolytics in haemorrhage, thrombolysis in acute ischaemic stroke, tirilazad in acute ischaemic stroke, antenatal corticosteroids to prevent neonatal respiratory distress syndrome, and bisphosphonates to treat osteoporosis. Review methods Data were extracted on study design, allocation concealment, number of randomised animals, type of model, intervention, and outcome. Results Corticosteroids did not show any benefit in clinical trials of treatment for head injury but did show a benefit in animal models (pooled odds ratio for adverse functional outcome 0.58, 95% confidence interval 0.41 to 0.83). Antifibrinolytics reduced bleeding in clinical trials but the data were inconclusive in animal models. Thrombolysis improved outcome in patients with ischaemic stroke. In animal models, tissue plasminogen activator reduced infarct volume by 24% (95% confidence interval 20% to 28%) and improved neurobehavioural scores by 23% (17% to 29%). Tirilazad was associated with a worse outcome in patients with ischaemic stroke. In animal models, tirilazad reduced infarct volume by 29% (21% to 37%) and improved neurobehavioural scores by 48% (29% to 67%). Antenatal corticosteroids reduced respiratory distress and mortality in neonates whereas in animal models respiratory distress was reduced but the effect on mortality was inconclusive (odds ratio 4.2, 95% confidence interval 0.85 to 20.9). Bisphosphonates increased bone mineral density in patients with osteoporosis. In animal models the bisphosphonate alendronate increased bone mineral density compared with placebo by 11.0% (95% confidence interval 9.2% to 12.9%) in the combined results for the hip region. The corresponding treatment effect in the lumbar spine was 8.5% (5.8% to 11.2%) and in the combined results for the forearms (baboons only) was 1.7% (−1.4% to 4.7%). Conclusions Discordance between animal and human studies may be due to bias or to the failure of animal models to mimic clinical disease adequately.

Effects of interventions in pregnancy on maternal weight and obstetric outcomes: meta-analysis of randomised evidence

Objective To evaluate the effects of dietary and lifestyle interventions in pregnancy on maternal and fetal weight and to quantify the effects of these interventions on obstetric outcomes. Design Systematic review and meta-analysis. Data sources Major databases from inception to January 2012 without language restrictions. Study selection Randomised controlled trials that evaluated any dietary or lifestyle interventions with potential to influence maternal weight during pregnancy and outcomes of pregnancy. Data synthesis Results summarised as relative risks for dichotomous data and mean differences for continuous data. Results We identified 44 relevant randomised controlled trials (7278 women) evaluating three categories of interventions: diet, physical activity, and a mixed approach. Overall, there was 1.42 kg reduction (95% confidence interval 0.95 to 1.89 kg) in gestational weight gain with any intervention compared with control. With all interventions combined, there were no significant differences in birth weight (mean difference −50 g, −100 to 0 g) and the incidence of large for gestational age (relative risk 0.85, 0.66 to 1.09) or small for gestational age (1.00, 0.78 to 1.28) babies between the groups, though by itself physical activity was associated with reduced birth weight (mean difference −60 g, −120 to −10 g). Interventions were associated with a reduced the risk of pre-eclampsia (0.74, 0.60 to 0.92) and shoulder dystocia (0.39, 0.22 to 0.70), with no significant effect on other critically important outcomes. Dietary intervention resulted in the largest reduction in maternal gestational weight gain (3.84 kg, 2.45 to 5.22 kg), with improved pregnancy outcomes compared with other interventions. The overall evidence rating was low to very low for important outcomes such as pre-eclampsia, gestational diabetes, gestational hypertension, and preterm delivery. Conclusions Dietary and lifestyle interventions in pregnancy can reduce maternal gestational weight gain and improve outcomes for both mother and baby. Among the interventions, those based on diet are the most effective and are associated with reductions in maternal gestational weight gain and improved obstetric outcomes.

Use of uterine artery Doppler ultrasonography to predict pre-eclampsia and intrauterine growth restriction: a systematic review and bivariable meta-analysis

Background: Alterations in waveforms in the uterine artery are associated with the development of pre-eclampsia and intrauterine growth restriction. We investigated the predictive accuracy of all uterine artery Doppler indices for both conditions in the first and second trimesters. Methods: We identified relevant studies through searches of MEDLINE, EMBASE, the Cochrane Library and Medion databases (all records to April 2006) and by checking bibliographies of identified studies and consulting with experts. Four of us independently selected studies, extracted data and assessed study validity. We performed a bivariable meta-analysis of sensitivity and specificity and calculated likelihood ratios. Results: We identified 74 studies of pre-eclampsia (total 79 547 patients) and 61 studies of intrauterine growth restriction (total 41 131 patients). Uterine artery Doppler ultrasonography provided a more accurate prediction when performed in the second trimester than in the first-trimester. Most Doppler indices had poor predictive characteristics, but this varied with patient risk and outcome severity. An increased pulsatility index with notching was the best predictor of pre-eclampsia (positive likelihood ratio 21.0 among high-risk patients and 7.5 among low-risk patients). It was also the best predictor of overall (positive likelihood ratio 9.1) and severe (positive likelihood ratio 14.6) intrauterine growth restriction among low-risk patients. Interpretation: Abnormal uterine artery waveforms are a better predictor of pre-eclampsia than of intrauterine growth restriction. A pulsatility index, alone or combined with notching, is the most predictive Doppler index. These indices should be used in clinical practice. Future research should also concentrate on combining uterine artery Doppler ultrasonography with other tests.

Factors predisposing women to chronic pelvic pain: systematic review

Abstract Objective To evaluate factors predisposing women to chronic and recurrent pelvic pain. Design, data sources, and methods Systematic review of relevant studies without language restrictions identified through Medline, Embase, PsycINFO, Cochrane Library. SCISEARCH, conference papers, and bibliographies of retrieved primary and review articles. Two reviewers independently extracted data on study characteristics, quality, and results. Exposure to risk factors was compared between women with and without pelvic pain. Results were pooled within subgroups defined by type of pain and risk factors. Results There were 122 studies (in 111 articles) of which 63 (in 64 286 women) evaluated 54 risk factors for dysmenorrhoea, 19 (in 18 601 women) evaluated 14 risk factors for dyspareunia, and 40 (in 12 040 women) evaluated 48 factors for non-cyclical pelvic pain. Age < 30 years, low body mass index, smoking, earlier menarche (< 12 years), longer cycles, heavy menstrual flow, nulliparity, premenstrual syndrome, sterilisation, clinically suspected pelvic inflammatory disease, sexual abuse, and psychological symptoms were associated with dysmenorrhoea. Younger age at first childbirth, exercise, and oral contraceptives were negatively associated with dysmenorrhoea. Menopause, pelvic inflammatory disease, sexual abuse, anxiety, and depression were associated with dyspareunia. Drug or alcohol abuse, miscarriage, heavy menstrual flow, pelvic inflammatory disease, previous caesarean section, pelvic pathology, abuse, and psychological comorbidity were associated with an increased risk of non-cyclical pelvic pain. Conclusion Several gynaecological and psychosocial factors are strongly associated with chronic pelvic pain. Randomised controlled trials of interventions targeting these potentially modifiable factors are needed to assess their clinical relevance in chronic pelvic pain.

The educational effects of portfolios on undergraduate student learning: A Best Evidence Medical Education (BEME) systematic review. BEME Guide No. 11

Introduction: In recent years, the use of portfolios as learning and assessment tools has become more widespread across the range of health professions. Whilst a growing body of literature has accompanied these trends, there is no clear collated summary of the evidence for the educational effects of the use of portfolios in undergraduate education. This systematic review is the result of our work to provide such a summary. Methods: We developed a protocol based on the recommendations of the Best Evidence Medical Education (BEME) collaboration. Citations retrieved by electronic searches of 10 databases were assessed against pre-defined inclusion/exclusion criteria by two independent reviewers and full texts of potentially relevant articles were obtained. Studies were identified for inclusion in the review by examination of full text articles by two independent reviewers. At all stages, discrepancies were resolved by consensus. Data relating to characteristics of the student population, intervention, outcome measures, study design and outcomes were collected using a piloted data extraction form. Each study was assessed against 11 quality indicators designed to provide information about how well it was designed and conducted; and against the Kirkpatrick hierarchy as modified for educational settings. Comparisons between different groups were carried out using the Kruskal–Wallis test (non-parametric ANOVA) or the Mann–Whitney U test as appropriate. Results: Electronic searches yielded 2,348 citations. A further 23 citations were obtained by hand searching of reference lists. Five hundred and fifty four full articles were retrieved and assessed against our inclusion criteria. Of the 69 studies included in our review, 18 were from medicine, 32 from nursing and 19 from other allied health professions, including dentistry, physiotherapy and radiography. In all professional groups, portfolios were used mainly in the clinical setting, completion was mostly compulsory, reflection required and assessment (either formative, summative or a combination of both) the norm. Three studies used electronic portfolios. Whilst many studies used a combination of data collection methods, over half of all included studies used questionnaires, a third used focus group interviews and another third used direct assessment of portfolios. Most studies assessed student or tutor perceptions of the effect of the use of portfolios on their learning. Five studies used a comparative design, one of which was a randomized controlled trial. Studies were most likely to meet the quality indicators relating to appropriateness of study subjects, clarity of research question and completeness of data. However, in many studies, methods were not reported in sufficient detail to allow a judgement to be made. Nineteen of the 69 included studies (27%) met seven or more quality indicators. Across all professions, such ‘higher quality’ studies were more likely to have been published recently. The median ‘quality score’ (number of indicators met) rose from two for studies published in 2000 or earlier to seven for studies published in 2005 or later. Significant differences were observed between the quality scores for studies published in or before 2000 and those published between 2001 and 2004 (p = 0.027), those published in or before 2000 and those published in 2005 or later (p = 0.002) and between all studies (p = 0.004). Similar trends were seen in all professional groups. Fifty nine (85%) of the included studies were assessed at level 1 of the modified Kirkpatrick hierarchy (i.e. ‘participation’ effects, including ‘post hoc’ evaluations of student perceptions of the effects of keeping a portfolio on their learning). Nine (13%) of the studies reported direct measurement of changes in student skills or attitudes and one study reported a change in student behaviour. The main effects of portfolio use identified by the included studies were: Improvement in student knowledge and understanding (28 studies, six at Kirkpatrick level 2 or above), greater self-awareness and encouragement of reflection (44 studies, seven at Kirkpatrick level 2 or above) and the ability to learn independently (10 studies, one at Kirkpatrick level 2). The findings of higher quality studies also identified benefits in these areas. They reported improved student knowledge and understanding, particularly the ability to integrate theory with practice, although a correlation with improved scores in other assessments was not always apparent. Greater self-awareness and engagement in reflection were also noted, although some studies questioned the quality of the reflection undertaken. Higher quality studies also suggest that use of portfolios improves feedback to students and gives tutors a greater awareness of students’ needs, may help students to cope with uncertain or emotionally demanding situations and prepares students for postgraduate settings in which reflective practice is required. Time commitment required to collate a portfolio was the major drawback identified. In two of the studies, this was found to detract from other clinical learning. Conclusions: At present, the strength and extent of the evidence base for the educational effects of portfolios in the undergraduate setting is limited. However, there is evidence of an improving trend in the quality of reported studies. ‘Higher quality’ papers identify improvements in knowledge and understanding, increased self-awareness and engagement in reflection and improved student–tutor relationships as the main benefits of portfolio use. However, they also suggest that whilst portfolios encourage students to engage in reflection, the quality of those reflections cannot be assumed and that the time commitment required for portfolio completion may detract from other learning or deter students from engaging with the process unless required to do so by the demands of assessment. Further work is needed to strengthen the evidence base for portfolio use, particularly comparative studies which observe changes in student knowledge and abilities directly, rather than reporting on their perceptions once a portfolio has been completed.

How useful is uterine artery Doppler flow velocimetry in the prediction of pre-eclampsia, intrauterine growth retardation and perinatal death? An overview.

Objective To evaluate the clinical usefulness of Doppler analysis of the uterine artery velocity waveform in the prediction of pre‐eclampsia and its associated complications of intrauterine growth retardation and perinatal death.

Accuracy of information on apparently credible websites: survey of five common health topics

The internet provides an easily accessible forum to disseminate both accurate and inaccurate health information—so it has the potential to facilitate but also to jeopardise healthcare provision. 1 2 Many criteria have been alleged to capture the quality of health websites, 3 4 but the validity of these criteria needs to be examined.5 The source, currency, and hierarchy of the evidence posted on a website may be used to judge its credibility—that is, the power of inspiring belief. If these criteria were fulfilled, the contents of the website would be expected to be accurate. We determined whether websites that seem to be credible provide accurate health information. We determined the relation between credibility features and accuracy of contents of 121 websites that provided information on five common health topics: chronic obstructive pulmonary disease …

Pulse oximetry screening for critical congenital heart defects in asymptomatic newborn babies: a systematic review and meta-analysis

BACKGROUND Screening for critical congenital heart defects in newborn babies can aid in early recognition, with the prospect of improved outcome. We assessed the performance of pulse oximetry as a screening method for the detection of critical congenital heart defects in asymptomatic newborn babies. METHODS In this systematic review, we searched Medline (1951-2011), Embase (1974-2011), Cochrane Library (2011), and Scisearch (1974-2011) for relevant citations with no language restriction. We selected studies that assessed the accuracy of pulse oximetry for the detection of critical congenital heart defects in asymptomatic newborn babies. Two reviewers selected studies that met the predefined criteria for population, tests, and outcomes. We calculated sensitivity, specificity, and corresponding 95% CIs for individual studies. A hierarchical receiver operating characteristic curve was fitted to generate summary estimates of sensitivity and specificity with a random effects model. FINDINGS We screened 552 studies and identified 13 eligible studies with data for 229,421 newborn babies. The overall sensitivity of pulse oximetry for detection of critical congenital heart defects was 76·5% (95% CI 67·7-83·5). The specificity was 99·9% (99·7-99·9), with a false-positive rate of 0·14% (0·06-0·33). The false-positive rate for detection of critical congenital heart defects was particularly low when newborn pulse oximetry was done after 24 h from birth than when it was done before 24 h (0·05% [0·02-0·12] vs 0·50 [0·29-0·86]; p=0·0017). INTERPRETATION Pulse oximetry is highly specific for detection of critical congenital heart defects with moderate sensitivity, that meets criteria for universal screening. FUNDING None.