Browsing by Author "Jia, Xueli"

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64-slice computed tomography angiography in the diagnosis and assessment of coronary artery disease : systematic review and meta-analysis
(BMJ, 2008) Mowatt, Graham; Cook, Jonathan Alistair; Hillis, Graham Scott; Walker, Shonagh Mary; Fraser, Cynthia Mary; Jia, Xueli; Waugh, Norman Robert; University of Aberdeen, School of Medicine & Dentistry, Division of Applied Health Sciences
Objective To assess whether 64-slice computed tomography (CT) angiography might replace some coronary angiography (CA) for diagnosis and assessment of coronary artery disease (CAD). Methods We searched electronic databases, conference proceedings and scanned reference lists of included studies. Eligible studies compared 64-slice CT with a reference standard of CA in adults with suspected/known CAD, reporting sensitivity and specificity or true and false positives and negatives. Data were pooled using the hierarchical summary receiver operating characteristic model. Results Forty studies were included; 28 provided sufficient data for inclusion in the meta-analyses, all using a cutoff of ≥ 50% stenosis to define significant CAD. In patient-based detection (n=1286) 64-slice CT pooled sensitivity was 99% (95% credible interval (CrI) 97 to 99%), specificity 89% (95% CrI 83 to 94%), median positive predictive value (PPV) across studies 93% (range 64 to 100%) and negative predictive value (NPV) 100% (range 86 to 100%). In segment-based detection (n=14,199) 64-slice CT pooled sensitivity was 90% (95% CrI 85 to 94%), specificity 97% (95% CrI 95 to 98%), median positive predictive value (PPV) across studies 76% (range 44 to 93%) and negative predictive value (NPV) 99% (range 95 to 100%). Conclusions 64-slice CT is highly sensitive for patient-based detection of CAD and has high NPV. An ability to rule out significant CAD means that it may have a role in the assessment of chest pain, particularly when the diagnosis remains uncertain despite clinical evaluation and simple non-invasive testing.
Efficacy and safety of using mesh or grafts in surgery for anterior and/or posterior vaginal wall prolapse: systematic review and meta-analysis.
(Elsevier Science, 2008) Jia, Xueli; Glazener, Cathryn Margaret Anne; Mowatt, Graham; MacLennan, Graeme Stewart; Fraser, Cynthia Mary; Bain, Christine; Burr, Jennifer Margaret
Background The efficacy and safety of mesh/graft in surgery for anterior or posterior pelvic organ prolapse is uncertain. Objectives To systematically review the efficacy and safety of mesh/graft for anterior or posterior vaginal wall prolapse surgery. Search strategy Electronic databases and conference proceedings were searched, experts and manufacturers contacted and reference lists of retrieved papers scanned. Selection criteria Randomised controlled trials (RCTs), non-randomised comparative studies, registries, case series involving at least 50 women, and RCTs published as conference abstracts from 2005 onwards. Data collection and analysis One reviewer screened titles/abstracts, undertook data extraction, and assessed study quality. Data analysis was conducted for three subgroups: anterior, posterior, and anterior and/or posterior repair (not reported separately). Results Forty-nine studies involving 4569 women treated with mesh/graft were included. Study quality was generally high. Median follow up was 13 months (range 1 to 51). In anterior repair, there was short-term evidence that mesh/graft (any type) significantly reduced objective prolapse recurrence rates compared with no mesh/graft (relative risk 0.48, 95% CI 0.32-0.72). Non-absorbable synthetic mesh had a significantly lower objective prolapse recurrence rate (8.8%, 48/548) than absorbable synthetic mesh (23.1%, 63/273) and biological graft (17.9%, 186/1041), but a higher erosion rate (10.2%, 68/666) than synthetic mesh (0.7%, 1/147) and biological graft (6.0%, 35/581). There was insufficient information to compare any of the other outcomes regardless of prolapse type. Conclusion Evidence for most outcomes was too sparse to provide meaningful conclusions. Rigorous long-term RCTs are required to determine the comparative efficacy of using mesh/graft.
Eltrombopag for the treatment of chronic idiopathic (immune) thrombocytopenic purpura (ITP) : a single technology appraisal
(2011-05) Boyers, Dwayne; Jia, Xueli; Crowther, Mark; Jenkinson, David; Fraser, Cynthia; Mowatt, Graham; University of Aberdeen.Other Applied Health Sciences
Eltrombopag for the treatment of chronic idiopathic (immune) thrombocytopenic purpura : A Single Technology Appraisal
(NIHR Health Technology Assessment programme, 2008-12) Boyers, Dwayne; Jia, Xueli; Crowther, M; Jenkinson, David James; Fraser, Cynthia Mary; Mowatt, Graham; University of Aberdeen.Other Applied Health Sciences
Relative effectiveness of robot-assisted and standard laparoscopic prostatectomy as alternatives to open radical prostatectomy for treatment of localised prostate cancer : a systematic review and mixed treatment comparison meta-analysis
(2013-10) Robertson, Clare; Close, Andrew; Fraser, Cynthia; Gurung, Tara; Jia, Xueli; Sharma, Pawana; Vale, Luke; Ramsay, Craig; Pickard, Robert; University of Aberdeen.Other Applied Health Sciences; University of Aberdeen.Institute of Applied Health Sciences
Repeatability and validity of a food frequency questionnaire in free-living older people in relation to cognitive function
(Editions Serdi, 2008) Jia, Xueli; Craig, Leone CA; Aucott, Lorna S; Milne, Anne C; McNeill, Geraldine
Objectives: To determine the repeatability and validity of a self-administered, 175-item food frequency questionnaire (FFQ) in free-living older people and to assess whether these are influenced by cognitive function. Participants and setting: 189 free-living people aged 64-80y were recruited from participants in a previous study. Design: To assess repeatability, 102 (52M, 50F) participants completed the FFQ on two occasions three months apart. To assess validity, another 87 participants (44 M, 43 F) completed the FFQ and a four-day weighed diet record three months later. 25 nutrients were studied. Results: For repeatability, Spearman rank correlation coefficients were above 0.35 (p<0.05) for all nutrients. Cohen’s weighted Kappa was above 0.4 for all nutrients except starch, riboflavin, retinol, β-carotene, and calcium. There were no substantial differences in correlation coefficients between sub-groups divided by short-term memory test score. There was no clear pattern for correlation coefficients in sub-groups divided by executive function test score. For validity, the Spearman rank correlation coefficients were above 0.2 (p<0.05) for all nutrients except fat, mono-unsaturated fatty acids, niacin equivalents and vitamin D, and Cohen’s weighted kappa was above 0.4 for alcohol and was above 0.2 for 13 other nutrients. Participants in the lowest-score groups of short-term memory and executive function had the lowest median Spearman correlation coefficient. Conclusions: The FFQ had reasonable repeatability and validity in ranking nutrient intakes in this population though the results varied between nutrients. Poor short-term memory or executive function may affect FFQ validity in ranking nutrient intakes.
Romiplostim for the treatment of chronic immune or idiopathic thrombocytopenic purpura
(2009-09) Mowatt, Graham; Boachie, Charles; Crowther, Mark; Fraser, Cynthia Mary; Hernandez, Rodolfo Andres; Jia, Xueli; Ternent, Laura; University of Aberdeen.Other Applied Health Sciences; University of Aberdeen.Health Economics Research Unit
Systematic review of the clinical effectiveness and cost-effectiveness of 64-slice or higher computed tomography angiography as an alternative to invasive coronary angiography in the investigation of coronary artery disease
(Gray Publishing, 2008-05) Mowatt, Graham; Cummins, E.; Waugh, N.; Walker, S.; Cook, Jonathan Alistair; Jia, Xueli; Hillis, Graham S.; Fraser, Cynthia Mary
Objectives: To assess the clinical effectiveness and cost-effectiveness, in different patient groups, of the use of 64-slice or higher computed tomography (CT) angiography, instead of invasive coronary angiography (CA), for diagnosing people with suspected coronary artery disease (CAD) and assessing people with known CAD. Data sources: Electronic databases were searched from 2002 to December 2006. Review methods: Included studies were tabulated and sensitivity, specificity, positive and negative predictive values calculated. Meta-analysis models were fitted using hierarchical summary receiver operating characteristic curves. Summary sensitivity, specificity, positive and negative likelihood ratios and diagnostic odds ratios for each model were reported as a median and 95% credible interval (CrI). Searches were also carried out for studies on the cost-effectiveness of 64-slice CT in the assessment of CAD. Results: The diagnostic accuracy and prognostic studies enrolled over 2500 and 1700 people, respectively. The overall quality of the studies was reasonably good. In the pooled estimates, 64-slice CT angiography was highly sensitive (99%, 95% CrI 97 to 99%) for patientbased detection of significant CAD (defined as 50% or more stenosis), while across studies the negative predictive value (NPV) was very high (median 100%, range 86 to 100%). In segment-level analysis compared with patient-based detection, sensitivity was lower (90%, 95% CrI 85 to 94%, versus 99%, 95% CrI 97 to 99%) and specificity higher (97%, 95% CrI 95 to 98%, versus 89%, 95% CrI 83 to 94%), while across studies the median NPV was similar (99%, range 95 to 100%, versus 100%, range 86 to 100%). At individual coronary artery level the pooled estimates for sensitivity ranged from 85% for the left circumflex (LCX) artery to 95% for the left main artery, specificity ranged from 96% for both the left anterior descending (LAD) artery and LCX to 100% for the left main artery, while across studies the positive predictive value (PPV) ranged from 81% for the LCX to 100% for the left main artery and NPV was very high, ranging from 98% for the LAD (range 95 to 100%), LCX (range 93 to 100%) and right coronary artery (RCA) (range 94 to 100%) to 100% for the left main artery. The pooled estimates for bypass graft analysis were 99% (95% CrI 95 to 100%) sensitivity, 96% (95% CrI 86 to 99%) specificity, with median PPV and NPV values across studies of 93% (range 90 to 95%) and 99% (range 98 to 100%), respectively. This compares with, for stent analysis, a pooled sensitivity of 89% (95% CrI 68 to 97%), specificity 94% (95% CrI 83 to 98%), and median PPV and NPV values across studies of 77% (range 33 to 100%) and 96% (range 71 to 100%), respectively. Sixty-four-slice CT is almost as good as invasive CA in terms of detecting true positives. However, it is somewhat poorer in its rate of false positives. It seems likely that diagnostic strategies involving 64-slice CT will still require invasive CA for CT test positives, partly to identify CT false positives, but also because CA provides other information that CT currently does not, notably details of insertion site and distal run-off for possible coronary artery bypass graft (CABG). The high sensitivity of 64-slice CT avoids the costs of unnecessary CA in those referred for investigation but who do not have CAD. Given the possible, although small, associated death rate, avoiding these unnecessary CAs through the use of 64-slice CT may also confer a small immediate survival advantage. This in itself may be sufficient to outweigh the very marginally inferior rates of detection of true positives by strategies involving 64-slice CT. The avoidance of unnecessary CA through the use of 64-slice CT also appears likely to result in overall cost savings in the diagnostic pathway. Only if both the cost of CA is relatively low and the prevalence of CAD in the presenting population is relatively high (so that most patients will go on to CA) will the use of 64-slice CT be likely to result in a higher overall diagnostic cost per patient. Conclusions: The main value of 64-slice CT may at present be to rule out significant CAD. It is unlikely to replace CA in assessment for revascularisation of patients, particularly as angiography and angioplasty are often done on the same occasion. Further research is needed into the marginal advantages and costs of 256-slice machines compared with 64-sliceCT, the usefulness of 64-slice CT in people with suspected acute coronary syndrome, the potential of multislice computed tomography to examine plaque morphology, the role of CT in identifying patients suitable for CABG, and the concerns raised about repetitive use, or use of 64-slice or higher CT angiography in younger individuals or women of childbearing age.
Systematic review of the efficacy and safety of using mesh in surgery for uterine or vaginal vault prolapse
(2010-11-01) Jia, Xueli; Glazener, Cathryn M A; Mowatt, Graham; Jenkinson, David; Fraser, Cynthia; Bain, Christine; Burr, Jennifer; University of Aberdeen.Other Applied Health Sciences; University of Aberdeen.Aberdeen Centre for Evaluation