K S Khan

Queen Mary, University of London, Londinium, England, United Kingdom

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Publications (175)607.26 Total impact

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    ABSTRACT: OBJECTIVE: To determine the accuracy, acceptability and cost-effectiveness of polymerase chain reaction (PCR) and optical immunoassay (OIA) rapid tests for maternal group B streptococcal (GBS) colonisation at labour. DESIGN: A test accuracy study was used to determine the accuracy of rapid tests for GBS colonisation of women in labour. Acceptability of testing to participants was evaluated through a questionnaire administered after delivery, and acceptability to staff through focus groups. A decision-analytic model was constructed to assess the cost-effectiveness of various screening strategies. SETTING: Two large obstetric units in the UK. PARTICIPANTS: Women booked for delivery at the participating units other than those electing for a Caesarean delivery. INTERVENTIONS: Vaginal and rectal swabs were obtained at the onset of labour and the results of vaginal and rectal PCR and OIA (index) tests were compared with the reference standard of enriched culture of combined vaginal and rectal swabs. MAIN OUTCOME MEASURES: The accuracy of the index tests, the relative accuracies of tests on vaginal and rectal swabs and whether test accuracy varied according to the presence or absence of maternal risk factors. RESULTS: PCR was significantly more accurate than OIA for the detection of maternal GBS colonisation. Combined vaginal or rectal swab index tests were more sensitive than either test considered individually [combined swab sensitivity for PCR 84% (95% CI 79-88%); vaginal swab 58% (52-64%); rectal swab 71% (66-76%)]. The highest sensitivity for PCR came at the cost of lower specificity [combined specificity 87% (95% CI 85-89%); vaginal swab 92% (90-94%); rectal swab 92% (90-93%)]. The sensitivity and specificity of rapid tests varied according to the presence or absence of maternal risk factors, but not consistently. PCR results were determinants of neonatal GBS colonisation, but maternal risk factors were not. Overall levels of acceptability for rapid testing amongst participants were high. Vaginal swabs were more acceptable than rectal swabs. South Asian women were least likely to have participated in the study and were less happy with the sampling procedure and with the prospect of rapid testing as part of routine care. Midwives were generally positive towards rapid testing but had concerns that it might lead to overtreatment and unnecessary interference in births. Modelling analysis revealed that the most cost-effective strategy was to provide routine intravenous antibiotic prophylaxis (IAP) to all women without screening. Removing this strategy, which is unlikely to be acceptable to most women and midwives, resulted in screening, based on a culture test at 35-37 weeks' gestation, with the provision of antibiotics to all women who screened positive being most cost-effective, assuming that all women in premature labour would receive IAP. The results were sensitive to very small increases in costs and changes in other assumptions. Screening using a rapid test was not cost-effective based on its current sensitivity, specificity and cost. CONCLUSIONS: Neither rapid test was sufficiently accurate to recommend it for routine use in clinical practice. IAP directed by screening with enriched culture at 35-37 weeks' gestation is likely to be the most acceptable cost-effective strategy, although it is premature to suggest the implementation of this strategy at present.
    09/2009;
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    ABSTRACT: Several authors have described the close correlation between 24-hour protein excretion and the protein/creatinine ratio in a random sample of urine. All studies to date are limited by a small sample size and many describe correlations rather than predictive values of the test. Literature from 1970 to 2002 was identified. Studies were selected if the accuracy of protein/creatinine ratio measurement in predicting total protein excretion was estimated and compared to a reference standard. Study selection, quality assessment and data abstraction, as 2 × 2 tables comparing the diagnostic test with the reference standard was performed independently and in duplicate. Test accuracy was expressed as likelihood ratio (LR). From 1543 citations, 31 were selected and 11 studies were included in the review (seven for dipstick urinalysis and four for protein/creatinine ratio). The studies evaluating protein/creatinine ratios produced a pooled LR+ of 4.87 (95%b CI 3.84–6.17) and an LR− of 0.24 (95% CI 0.19–0.31) for predicting 300 mg/24-hour proteinuria at the 1+ threshold. The studies evaluating visual dipsticks, produced a pooled LR+ of 2.4 (95% CI 2.05–2.81) and an LR− of 0.57 (95% CI 0.51–0.64) for predicting 300 mg/24-hour proteinuria at the 1+ threshold.
    07/2009; 23(s1):S51-S52.
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    ABSTRACT: To determine the accuracy with which various types of tests for bacterial vaginosis (BV) predict spontaneous preterm birth in pregnant women, studies were identified, without language restrictions, through nine different databases and manual searching of bibliographies of known primary and review articles. There are four different BV testing methods: Gram-staining test using either Nugent's or Spiegel's criteria, gas liquid chromatography and clinical criteria. Two reviewers selected studies independently and extracted data on their characteristics, quality and accuracy with spontaneous preterm birth as the reference standard. Data on asymptomatic women and women with symptoms of threatened preterm labour were analysed separately. Data were pooled to produce summary estimates of likelihood ratios for positive (LR+) and negative (LR−) test results for the various types of tests. There were 18 primary articles, involving a total of 17 868 women. Meta-analysis of studies testing asymptomatic women in the second trimester showed that clinical criteria had an LR+ of 5.14 (95% confidence interval 4.44–6.15) and an LR− of 0.48 (0.42–0.55), Gram-staining (Nugent's criteria) had an LR+ of 1.64 (1.44–1.87) and an LR− of 0.88 (0.84–0.92), and Gram-staining (Spiegel's criteria) had an LR+ of 2.44 (1.36–4.98) and an LR− of 0.81 (0.64 to 1.01). Among symptomatic women, Gram-staining (Spiegel's criteria) had an LR+ of 1.29 (1.03–1.62) and an LR− of 0.85 (0.73–1.00).
    BJOG An International Journal of Obstetrics & Gynaecology 07/2009; 23(s1):S34-S34. · 3.76 Impact Factor
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    ABSTRACT: Summary Summary Residual bladder volumes in 216 women, following spontaneous vertex delivery, were measured by ultrasound. Of these cases, 39 women had asymptomatic residual bladder volumes exceeding 50 ml on the first or second postpartum day. The factors associated with significant residual bladder volume were evaluated using multiple logistic regression analysis. Maternal age. height, parity, gestation, duration of first stage of labour, fetal macrosomia, and the presence or absence of perineal trauma did not contribute significantly to the logistic model. A longer duration of second stage of labour increased the odds of having residual volume > 50 ml (odds ratio = 2–63; 95 per cent confidence interval = 1-19-5-85; P = 0–017) after adjustment for confounding due to intrapartum epidural analgesia. The effect of epidural analgesia was not significant (odds ratio = 1–90; 95 per cent confidence interval = 0-90-4-02; P = 0–092). Avoidance of prolonged maternal pushing during the second stage of labour by active management of labour may result in a reduction in the incidence of significant residual bladder volume postnatally.
    07/2009; 16(3):146-150.
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    ABSTRACT: Haemorrhage, a leading cause of maternal morbidity and mortality, is frequently associated with caesarean section. Allogeneic blood is an increasingly rare and scare resource. Intraoperative Cell Salvage (IOCS) offers the possibility of improving outcome and reducing allogeneic blood transfusion in cases of haemorrhage at caesarean section. The available literature on the use of IOCS in obstetrics demonstrates that there is limited evidence to support or refute the use of IOCS at caesarean section. However, this procedure has been introduced into obstetric practice. Before opinions about its use become solidified, there is a window of opportunity to launch a large multicentre randomised controlled trial to address the current equipoise.
    BJOG An International Journal of Obstetrics & Gynaecology 06/2009; 116(6):743-7. · 3.76 Impact Factor
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    A Raza, P F W Chien, K S Khan
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    ABSTRACT: To assess the trend in multicentre randomised controlled trials (RCTs), a database of 670 RCTs was assembled from four generic obstetric and gynaecological journals (Acta Obstetricia et Gynecologica Scandinavica, British Journal of Obstetrics & Gynaecology, Obstetrics & Gynecology and American Journal of Obstetrics & Gynecology) for 1975, 1980, 1985, 1990, 1995, 2000 and 2005. During this period, there was an inflationary trend with the proportion of published multicentre RCTs (from 12.9% in 1975 of all RCTs to 23.8% in 2005; P = 0.008). Multicentre RCTs had multiauthored publications (OR = 2.90; 95% CI 1.99-4.22) and more often received external funding (OR = 2.41; 95% CI 1.70-3.48) than single centre RCTs. The inflationary trend in multicentre RCTs requiring funding and collaboration represents the increasing complexity of medical research necessary to underpin evidence-based practice.
    BJOG An International Journal of Obstetrics & Gynaecology 06/2009; 116(8):1130-4. · 3.76 Impact Factor
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    ABSTRACT: Congenital urinary tract obstruction can lead to perinatal mortality and morbidity. Assessing antenatal ultrasound features may help identify fetuses likely to suffer complications. To evaluate the accuracy of antenatal ultrasound in the prediction of postnatal renal function in cases of congenital lower urinary tract obstruction (LUTO). We conducted electronic searches in MEDLINE, EMBASE, the Cochrane Library, MEDION, SIGLE, SCISEARCH Index of scientific and technical proceedings, National Research Register (database inception - 2008) and Medical Conferences register and searched reference lists. Two reviewers independently selected articles in which the accuracy of fetal ultrasound features were evaluated to predict postnatal renal function with no language restrictions. Data were extracted on study characteristics, quality and results to construct 2 x 2 tables. Likelihood ratios for positive (LR+) and negative (LR-) test results, sensitivity and specificity were generated for the different ultrasound parameters and reference standards. Thirteen articles that met the selection criteria, including 215 women and 33 2 x 2 tables. Meta-analysis was performed using clinically similar subgroups to minimise clinical heterogeneity. The ultrasound parameter that showed the best predictive value for postnatal renal function in survivors was renal cortical appearance, sensitivity 0.57 (95% CI 0.37-0.76) and specificity 0.84 (95% CI 0.71-0.94), area under the curve 0.78. Measurement of amniotic fluid volume and the appearance of the renal cortex at diagnosis of LUTO show promising predictive accuracy for poor postnatal renal function.
    BJOG An International Journal of Obstetrics & Gynaecology 06/2009; 116(10):1290-9. · 3.76 Impact Factor
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    ABSTRACT: To assess the effectiveness of an antenatal service using community based breastfeeding peer support workers on initiation of breast feeding. Cluster randomised controlled trial. Community antenatal clinics in one primary care trust in a multiethnic, deprived population. 66 antenatal clinics with 2511 pregnant women: 33 clinics including 1140 women were randomised to receive the peer support worker service and 33 clinics including 1371 women were randomised to receive standard care. An antenatal peer support worker service planned to comprise a minimum of two contacts with women to provide advice, information, and support from approximately 24 weeks' gestation within the antenatal clinic or at home. The trained peer support workers were of similar ethnic and sociodemographic backgrounds to their clinic population. Initiation of breast feeding obtained from computerised maternity records of the hospitals where women from the primary care trust delivered. The sample was multiethnic, with only 9.4% of women being white British, and 70% were in the lowest 10th for deprivation. Most of the contacts with peer support workers took place in the antenatal clinics. Data on initiation of breast feeding were obtained for 2398 of 2511 (95.5%) women (1083/1140 intervention and 1315/1371 controls). The groups did not differ for initiation of breast feeding: 69.0% (747/1083) in the intervention group and 68.1% (896/1315) in the control groups; cluster adjusted odds ratio 1.11 (95% confidence interval 0.87 to 1.43). Ethnicity, parity, and mode of delivery independently predicted initiation of breast feeding, but randomisation to the peer support worker service did not. A universal service for initiation of breast feeding using peer support workers provided within antenatal clinics serving a multiethnic, deprived population was ineffective in increasing initiation rates. Current Controlled Trials ISRCTN16126175.
    BMJ (online) 02/2009; 338:b131. · 17.22 Impact Factor
  • Raza A, Chein P, Khan KS
    British Journal of Obstetrics and Gynaecology 01/2009; 116(8-116):1130-4.
  • A. Raza, Y. Afifi, K. Khan
    International Journal of Gynecology & Obstetrics - INT J GYNECOL OBSTET. 01/2009; 107.
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    ABSTRACT: To investigate prognosis of the fetus with isolated gastroschisis and bowel dilatation from a systematic review of the literature. We aimed to compare the incidence of (a) intrauterine death, (b) death within 4 weeks of delivery, (c) bowel resection, (d) length of time to oral feeds and (e) time as inpatient in fetuses with gastroschisis with and without evidence of bowel dilatation. Literature was identified by searching two bibliographical databases between 1980 and 2007. Studies were assessed for quality and stratified according to the definition of bowel dilatation. The data extracted were inspected for clinical and methodological heterogeneity. The search strategy yielded 1335 potentially relevant citations. Full manuscripts were retrieved for 92 citations. 10 studies (273 patients) were finally included in the systematic review. No difference was found between groups for death within 4 weeks of delivery (OR = 0.62 (95% CI 0.11 to 3.32); heterogeneity p = 0.39) or bowel resection (OR = 3.35 (95% CI 0.82 to 13.74); heterogeneity p = 0.39). There were insufficient data to compare the risk of intrauterine death and length of time to oral feeds. The mean inpatient stay was not significantly different between groups (OR = 16.63 (95% CI 0.98 to 32.28); heterogeneity p = 0.23). Current available evidence suggests that fetuses with isolated gastroschisis and bowel dilatation are not at increased risk of adverse perinatal outcome compared to those without bowel dilatation. However, there is a paucity of studies, and a randomised controlled trial is urgently needed.
    Archives of Disease in Childhood - Fetal and Neonatal Edition 12/2008; 94(4):F268-74. · 3.45 Impact Factor
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    ABSTRACT: Assessing in undergraduate medical education the educational effectiveness of a short computer-based session, integrating a lecturer's video with a standardized structure, for evidence based medicine (EBM) teaching, compared to a lecture-based teaching session of similar structure and duration. A concealed, randomized controlled trial of computer based session versus lecture of equal duration (40 minutes) and identical content in EBM and systematic reviews. The study was based at the Medical School, University of Birmingham, UK involving one hundred and seventynine year one medical students. The main outcome measures were change from pre to post-intervention score measured using a validated questionnaire assessing knowledge (primary outcome) and attitudes (secondary outcome). Participants' improvement in knowledge in the computer based group was equivalent to the lecture based group (gain in score: 0.8 [S.D = 3.2] versus 1.3 [S.D = 2.4]; p = 0.24). Attitudinal gains were similar in both groups. Computer based teaching and typical lecture sessions have similar educational gains.
    Medical Teacher 06/2008; 30(3):302-7. · 1.82 Impact Factor
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    ABSTRACT: The randomized controlled trial (RCT) is the least biased measure of the effectiveness of interventions, including surgical interventions. The aim was to review the available evidence base in gynaecologic surgery, to assess what progress has been made and to determine gaps in the evidence for clinical decision-making. Systematic reviews involving gynaecological surgery interventions were extracted from the Cochrane Database of Systematic Reviews (Issue 2, 2007) and data were extracted for key primary outcomes from each of the randomized trials in the reviews. The reviews were categorized as to whether they had provided evidence of effectiveness for pre-defined outcomes of most relevance to patients. Of 371 reviews or protocols published on the Cochrane Database of Systematic Reviews (Issue 2, 2007), only 30 were completed reviews assessing surgical interventions. Seven reviews concluded there was evidence of a significant effect (whether beneficial or harmful) of the interventions studied for pre-defined primary outcomes; 11 reviews concluded there was some evidence of significant effects for primary outcomes along with some gaps for primary outcomes; 12 reviews concluded insufficient evidence of effectiveness. Common themes of unique methodological challenges and pitfalls with trials of surgical interventions were apparent. Cochrane reviews have gone a long way to establishing a sound evidence base in gynaecologic surgery: some gaps in the evidence have been eliminated and others highlighted. In general, gynaecology has been a specialty where surgical interventions have been well exposed to the scrutiny of RCTs compared with other surgical specialties.
    Human Reproduction 05/2008; 23(4):832-9. · 4.67 Impact Factor
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    ABSTRACT: Lymph node status is the key to determining the prognosis and treatment of cervical cancer. However, it cannot be assessed clinically, and testing for nodal metastasis is controversial. We sought to systematically review the diagnostic accuracy literature on sentinel node biopsy, positron emission tomography, magnetic resonance imaging and computed tomography to evaluate the accuracy of each index test in determining lymph node status in patients with cervical cancer. We searched MEDLINE (1966-2006), EMBASE (1980-2006), Medion (1980-2006) and the Cochrane library (Issue 2, 2006) for relevant articles. We also manually searched the reference lists from primary articles and reviews, and we contacted experts in the field for conference abstracts and unpublished studies. We performed random-effects meta-analysis of accuracy indices, and we performed meta-regression analysis to test the effect of study quality on diagnostic accuracy and to identify other sources of heterogeneity. We included 72 relevant primary studies, involving a total of 5042 women, in our analysis. We found that, in determining lymph node status, sentinel node biopsy had a pooled positive likelihood ratio of 40.8 (95% confidence interval [CI] 24.6-67.6) and a pooled negative likelihood ratio of 0.18 (95% CI 0.14-0.24). The pooled positive likelihood ratios (and 95% CI) were 15.3 (7.9-29.6) for positron emission tomography, 6.4 (4.9-8.3) for magnetic resonance imaging and 4.3 (3.0-6.2) for computed tomography. The pooled negative likelihood ratios (and 95% CIs) were 0.27 (0.11-0.66) for positron emission tomography, 0.50 (0.39-0.64) for magnetic resonance imaging and 0.58 (0.48-0.70) for computed tomography. Using a 27% pretest probability of lymph node metastasis among all cases (regardless of stage), we found that a positive sentinel node biopsy result increased post-test probability to 94% (95% CI 90%-96%), whereas a positive finding on positron emission tomography increased it to 85% (75%-92%). Sentinel node biopsy has greater accuracy in determining lymph node status among women with primary cervical cancer than current commonly used imaging methods.
    Canadian Medical Association Journal 04/2008; 178(7):855-62. · 6.47 Impact Factor
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    ABSTRACT: To investigate the accuracy of predictive tests for pre-eclampsia and the effectiveness of preventative interventions for pre-eclampsia. Also to assess the cost-effectiveness of strategies (test-intervention combinations) to predict and prevent pre-eclampsia. Major electronic databases were searched to January 2005 at least. Systematic reviews were carried out for test accuracy and effectiveness. Quality assessment was carried out using standard tools. For test accuracy, meta-analyses used a bivariate approach. Effectiveness reviews were conducted under the auspices of the Cochrane Pregnancy and Childbirth Group and used standard Cochrane review methods. The economic evaluation was from an NHS perspective and used a decision tree model. For the 27 tests reviewed, the quality of included studies was generally poor. Some tests appeared to have high specificity, but at the expense of compromised sensitivity. Tests that reached specificities above 90% were body mass index greater than 34, alpha-foetoprotein and uterine artery Doppler (bilateral notching). The only Doppler test with a sensitivity of over 60% was resistance index and combinations of indices. A few tests not commonly found in routine practice, such as kallikreinuria and SDS-PAGE proteinuria, seemed to offer the promise of high sensitivity, without compromising specificity, but these would require further investigation. For the 16 effectiveness reviews, the quality of included studies was variable. The largest review was of antiplatelet agents, primarily low-dose aspirin, and included 51 trials (36,500 women). This was the only review where the intervention was shown to prevent both pre-eclampsia and its consequences for the baby. Calcium supplementation also reduced the risk of pre-eclampsia, but with some uncertainty about the impact on outcomes for the baby. The only other intervention associated with a reduction in RR of pre-eclampsia was rest at home, with or without a nutritional supplement, for women with normal blood pressure. However, this review included just two small trials and its results should be interpreted with caution. The cost of most of the tests was modest, ranging from 5 pounds for blood tests such as serum uric acid to approximately 20 pounds for Doppler tests. Similarly, the cost of most interventions was also modest. In contrast, the best estimate of additional average cost associated with an average case of pre-eclampsia was high at approximately 9000 pounds. The results of the modelling revealed that prior testing with the test accuracy sensitivities and specificities identified appeared to offer little as a way of improving cost-effectiveness. Based on the evidence reviewed, none of the tests appeared sufficiently accurate to be clinically useful and the results of the model favoured no-test/treat-all strategies. Rest at home without any initial testing appeared to be the most cost-effective 'test-treatment' combination. Calcium supplementation to all women, without any initial testing, appeared to be the second most cost-effective. The economic model provided little support that any form of Doppler test has sufficiently high sensitivity and specificity to be cost-effective for the early identification of pre-eclampsia. It also suggested that the pattern of cost-effectiveness was no different in high-risk mothers than the low-risk mothers considered in the base case. The tests evaluated are not sufficiently accurate, in our opinion, to suggest their routine use in clinical practice. Calcium and antiplatelet agents, primarily low-dose aspirin, were the interventions shown to prevent pre-eclampsia. The most cost-effective approach to reducing pre-eclampsia is likely to be the provision of an effective, affordable and safe intervention applied to all mothers without prior testing to assess levels of risk. It is probably premature to suggest the implementation of a treat-all intervention strategy at present, however the feasibility and acceptability of this to women could be explored. Rigorous evaluation is needed of tests with modest cost whose initial assessments suggest that they may have high levels of both sensitivity and specificity. Similarly, there is a need for high-quality, adequately powered randomised controlled trials to investigate whether interventions such as advice to rest are indeed effective in reducing pre-eclampsia. In future, an economic model should be developed that considers not just pre-eclampsia, but other related outcomes, particularly those relevant to the infant such as perinatal death, preterm birth and small for gestational age. Such a modelling project should make provision for primary data collection on the safety of interventions and their associated costs.
    Health technology assessment (Winchester, England) 04/2008; 12(6):iii-iv, 1-270. · 4.03 Impact Factor
  • P M Latthe, R Foon, K Khan
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    ABSTRACT: The guidance on SUI has not been rigorously assessed using GRADE system. To determine if the quality and results of existing systematic reviews on conservative treatment of stress urinary incontinence (SUI) can underpin evidence-based recommendations for practice. Review of systematic reviews. Data sources Electronic search in PubMed, Medline (OVID 1966-version), CINAHL, Biomed, Psychinfo, the Cochrane library, National Library for Health, the National Research Register and hand search of reference lists. Two reviewers independently selected systematic review articles in which a publicly available database was searched for randomised trials on conservative treatment of SUI and assessed them for quality of methods and results (OR and 95% CIs). The extracted information was used to classify strength of evidence as per the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) system. There were 13 reviews of variable quality. Quality assessment of studies included in the reviews and their findings were adequately tabulated in all but four reviews. Meta-analysis of data was carried out in six reviews. Pelvic floor muscle training (PFMT) and other physical treatments, estrogens and duloxetine were better than no treatment in SUI. Based on the assessment as per GRADE system, only 2/13 (15.4%) reviews were deemed to be of high quality, 8/13 (61.5%) of moderate quality and 3/13 (23.1%) of low quality. The case for recommendation of PFMT and duloxetine was strong. Systematic reviews of conservative treatments of SUI are not always suitable to generate robust recommendations for practice as they are weak in methodological quality or lack power to produce reliable results.
    BJOG An International Journal of Obstetrics & Gynaecology 04/2008; 115(4):435-44. · 3.76 Impact Factor
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    ABSTRACT: To assess if mode of delivery is associated with increased symptoms of anal incontinence following childbirth. Systematic review of all relevant studies in English. Medline, Embase, Cochrane Library, bibliographies of retrieved primary articles and consultation with experts. Data were extracted on study characteristics, quality and results. Exposure to risk factors was compared between women with and without anal incontinence. Categorical data in 2 x 2 contingency tables were used to generate odds ratios. Eighteen studies met the inclusion criteria with 12,237 participants. Women having any type of vaginal delivery compared with a caesarean section have an increased risk of developing symptoms of solid, liquid or flatus anal incontinence. The risk varies with the mode of delivery ranging from a doubled risk with a forceps delivery (OR 2.01, 95% CI 1.47-2.74, P < 0.0001) to a third increased risk for a spontaneous vaginal delivery (OR 1.32, 95% CI 1.04-1.68, P = 0.02). Instrumental deliveries also resulted in more symptoms of anal incontinence when compared with spontaneous vaginal delivery (OR 1.47, 95% CI 1.22-1.78). This was statistically significant for forceps deliveries alone (OR 1.5, 95% CI 1.19-1.89, P = 0.0006) but not for ventouse deliveries (OR 1.31, 95% CI 0.97-1.77, P = 0.08). When symptoms of solid and liquid anal incontinence alone were assessed, these trends persisted but were no longer statistically significant. Symptoms of anal incontinence in the first year postpartum are associated with mode of delivery.
    BJOG An International Journal of Obstetrics & Gynaecology 03/2008; 115(4):421-34. · 3.76 Impact Factor
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    ABSTRACT: The importance of antenatal care (ANC) for improving perinatal outcomes is well established. However access to ANC in Kenya has hardly changed in the past 20 years. This study aims to identify the determinants of attending ANC and the association between attendance and behavioural and perinatal outcomes (live births and healthy birthweight) for women in the Kwale region of Kenya. A Cohort survey of 1,562 perinatal outcomes (response rate 100%) during 2004-05 in the catchment areas for five Ministry of Health dispensaries in two divisions of the Kwale region. The associations between background and behavioural decisions on ANC attendance and perinatal outcomes were explored using univariate analysis and multivariate logistic regression models with backwards-stepwise elimination. The outputs from these analyses were reported as odds ratios (OR) with 95% confidence intervals (CI). Only 32% (506/1,562) of women reported having any ANC. Women with secondary education or above (adjusted OR 1.83; 95% CI 1.06-3.15) were more likely to attend for ANC, while those living further than 5 km from a dispensary were less likely to attend (OR 0.29; 95% CI 0.22-0.39). Paradoxically, however, the number of ANC visits increased with distance from the dispensary (OR 1.46; 95% CI 1.33-1.60). Women attending ANC at least twice were more likely to have a live birth (vs. stillbirth) in both multivariate models. Women attending for two ANC visits (but not more than two) were more likely to have a healthy weight baby (OR 4.39; 95% CI 1.36-14.15). The low attendance for ANC, combined with a positive relationship between attendance and perinatal outcomes for the women in the Kwale region highlight the need for further research to understand reasons for attendance and non-attendance and also for strategies to be put in place to improve attendance for ANC.
    BMC Pregnancy and Childbirth 02/2008; 8:2. · 2.52 Impact Factor
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    ABSTRACT: To generate a classification of methods to evaluate medical tests when there is no gold standard. Multiple search strategies were employed to obtain an overview of the different methods described in the literature, including searches of electronic databases, contacting experts for papers in personal archives, exploring databases from previous methodological projects and cross-checking of reference lists of useful papers already identified. All methods available were classified into four main groups. The first method group, impute or adjust for missing data on reference standard, needs careful attention to the pattern and fraction of missing values. The second group, correct imperfect reference standard, can be useful if there is reliable information about the degree of imperfection of the reference standard and about the correlation of the errors between the index test and the reference standard. The third group of methods, construct reference standard, have in common that they combine multiple test results to construct a reference standard outcome including deterministic predefined rules, consensus procedures and statistical modelling (latent class analysis). In the final group, validate index test results, the diagnostic test accuracy paradigm is abandoned and research examines, using a number of different methods, whether the results of an index test are meaningful in practice, for example by relating index test results to relevant other clinical characteristics and future clinical events. The majority of methods try to impute, adjust or construct a reference standard in an effort to obtain the familiar diagnostic accuracy statistics, such as sensitivity and specificity. In situations that deviate only marginally from the classical diagnostic accuracy paradigm, these are valuable methods. However, in situations where an acceptable reference standard does not exist, applying the concept of clinical test validation can provide a significant methodological advance. All methods summarised in this report need further development. Some methods, such as the construction of a reference standard using panel consensus methods and validation of tests outwith the accuracy paradigm, are particularly promising but are lacking in methodological research. These methods deserve particular attention in future research.
    Health technology assessment (Winchester, England) 01/2008; 11(50):iii, ix-51. · 4.03 Impact Factor
  • Obstetric Anesthesia Digest 01/2008; 28(3).

Publication Stats

3k Citations
607.26 Total Impact Points

Institutions

  • 2011–2014
    • Queen Mary, University of London
      • Centre for Primary Care and Public Health
      Londinium, England, United Kingdom
  • 1998–2013
    • University of Birmingham
      • • Department of Public Health, Epidemiology and Biostatistics
      • • School of Clinical and Experimental Medicine
      • • School of Health and Population Sciences
      • • Group of Reproduction, Genes and Development
      Birmingham, ENG, United Kingdom
  • 2012
    • The Bracton Centre, Oxleas NHS Trust
      Дартфорде, England, United Kingdom
  • 1998–2012
    • Birmingham Women's NHS Foundation Trust
      Birmingham, England, United Kingdom
  • 2006–2010
    • University Hospitals Birmingham NHS Foundation Trust
      Birmingham, England, United Kingdom
    • University Hospital Of North Staffordshire NHS Trust
      Stoke-upon-Trent, England, United Kingdom
  • 2009
    • Chelsea and Westminster Hospital NHS Foundation Trust
      Londinium, England, United Kingdom
  • 1997–2009
    • Ninewells Hospital
      Dundee, Scotland, United Kingdom
  • 2008
    • The University of Manchester
      Manchester, England, United Kingdom
  • 2007–2008
    • Academisch Medisch Centrum Universiteit van Amsterdam
      • • Department of General Practice
      • • Department of Obstetrics & Gynecology
      Amsterdam, North Holland, Netherlands
    • University of Auckland
      • Department of Obstetrics and Gynaecology
      Auckland, Auckland, New Zealand
    • Auckland City Hospital
      Окленд, Auckland, New Zealand
  • 2005
    • Sandwell and West Birmingham Hospitals NHS Trust
      Birmingham, England, United Kingdom
  • 2004
    • Birmingham Community Healthcare NHS Trust
      Birmingham, England, United Kingdom
  • 2000–2004
    • The University of York
      • Centre for Reviews and Dissemination
      York, England, United Kingdom
  • 2001
    • CUNY Graduate Center
      New York City, New York, United States
  • 1993–1998
    • Aga Khan University Hospital, Karachi
      • Department of Obstetrics and Gynaecology
      Karachi, Sindh, Pakistan