Systematic Review and Meta-Analysis of Diagnostic Accuracy of Serum Refractometry and Brix Refractometry for the Diagnosis of Inadequate Transfer of Passive Immunity in Calves.

BACKGROUND: Transfer of passive immunity in calves can be assessed by direct measurement of immunoglobulin G (IgG) by methods such as radial immunodiffusion (RID) or turbidimetric immunoassay (TIA). IgG can also be measured indirectly by methods such as serum refractometry (REF) or Brix refractometry (BRIX). OBJECTIVES: To determine the accuracy of REF and BRIX for assessment of inadequate transfer of passive immunity (ITPI) in calves. DESIGN: Systematic review and meta-analysis of diagnostic accuracy studies. METHODS: Databases (PubMed and CAB Abstract, Searchable Proceedings of Animal Science) and Google Scholar were searched for relevant studies. Studies were eligible if the accuracy (sensitivity and specificity) of REF or BRIX was determined using direct measurement of IgG by RID or turbidimetry as the reference standard. The study population included calves <14 days old that were fed with natural colostrum (colostrum replacement products were excluded). Quality assessment was performed by the QUADAS-2 tool. Hierarchical models were used for meta-analysis. RESULTS: From 1,291 references identified, 13 studies of 3,788 calves were included. Of these, 11 studies evaluated REF and 5 studies evaluated BRIX. The median (range) prevalence of ITPI (defined as calves with IgG <10 g/L by RID or TIA) was 21% (1.3-56%). Risk of bias and applicability concerns were generally low or unclear. For REF, summary estimates were obtained for 2 different cutoffs: 5.2 g/dL (6 studies) and 5.5 g/dL (5 studies). For the 5.2 g/dL cutoff, the summary sensitivity (95% CI) and specificity (95% CI) were 76.1% (63.8-85.2%) and 89.3% (82.3-93.7%), and 88.2% (80.2-93.3%) and 77.9% (74.5-81.0%) for the 5.5 g/dL cutoff. Due to the low number of studies using the same cutoffs, summary estimates could not be obtained for BRIX. CONCLUSIONS AND CLINICAL IMPORTANCE: Despite their widespread use on dairy farms, evidence about the optimal strategy for using refractometry, including the optimal cutoff, are sparse (especially for BRIX). When using REF to rule out ITPI in herds, the 5.5 g/dL cutoff may be used whereas for ruling in ITPI, the 5.2 g/dL cutoff may be used.

Antenatal magnetic resonance imaging versus ultrasound for predicting neonatal macrosomia: a systematic review and meta-analysis.

BACKGROUND: Fetal macrosomia is associated with an increased risk of adverse maternal and neonatal outcomes. OBJECTIVES: To compare the accuracy of antenatal two-dimensional (2D) ultrasound, three-dimensional (3D) ultrasound, and magnetic resonance imaging (MRI) in predicting fetal macrosomia at birth. SEARCH STRATEGY: Medline (1966-2013), Embase, the Cochrane Library and Web of Knowledge. SELECTION CRITERIA: Cohort or diagnostic accuracy studies of women with a singleton pregnancy, who had third-trimester imaging to predict macrosomia (>4000 g, >4500 g or >90th or >95th centile). DATA COLLECTION AND ANALYSIS: Two reviewers screened studies, performed data extraction and assessed methodological quality. The bivariate model was used to obtain summary sensitivities, specificities and likelihood ratios. MAIN RESULTS: Fifty-eight studies (34 367 pregnant women) were included. Most were poorly reported. Only one study assessed 3D ultrasound volumetry. For predicting birthweight >4000 g or >90th centile, the summary sensitivity for 2D ultrasound (Hadlock) estimated fetal weight (EFW) >90th centile or >4000 g (29 studies) was 0.56 (95% CI 0.49-0.61), 2D ultrasound abdominal circumference (AC) >35 cm (four studies) was 0.80 (95% confidence interval [95% CI] 0.69-0.87) and MRI EFW (three studies) was 0.93 (95% CI 0.76-0.98). The summary specificities were 0.92 (95% CI 0.90-0.94), 0.86 (95% CI 0.74-0.93) and 0.95 (95% CI 0.92-0.97), respectively. CONCLUSION: There is insufficient evidence to conclude that MRI EFW is more sensitive than 2D ultrasound AC (which is more sensitive than 2D EFW); although it was more specific. Further primary research is required before recommending MRI EFW for use in clinical practice. TWEETABLE ABSTRACT: Systematic review of antenatal imaging to predict macrosomia. MRI EFW is more sensitive than ultrasound EFW.

The diagnosis of food allergy: a systematic review and meta-analysis.

BACKGROUND: We investigated the accuracy of tests used to diagnose food allergy. METHODS: Skin prick tests (SPT), specific-IgE (sIgE), component-resolved diagnosis and the atopy patch test (APT) were compared with the reference standard of double-blind placebo-controlled food challenge. Seven databases were searched and international experts were contacted. Two reviewers independently identified studies, extracted data, and used QUADAS-2 to assess risk of bias. Where possible, meta-analysis was undertaken. RESULTS: Twenty-four (2831 participants) studies were included. For cows' milk allergy, the pooled sensitivities were 53% (95% CI 33-72), 88% (95 % CI 76-94), and 87% (95% CI 75-94), and specificities were 88% (95% CI 76-95), 68% (95% CI 56-77), and 48% (95% CI 36-59) for APT, SPT, and sIgE, respectively. For egg, pooled sensitivities were 92% (95% CI 80-97) and 93% (95% CI 82-98), and specificities were 58% (95% CI 49-67) and 49% (40-58%) for skin prick tests and specific-IgE. For wheat, pooled sensitivities were 73% (95% CI 56-85) and 83% (95% CI 69-92), and specificities were 73% (95% CI 48-89) and 43% (95% CI 20-69%) for SPT and sIgE. For soy, pooled sensitivities were 55% (95% CI 33-75) and 83% (95% CI 64-93), and specificities were 68% (95% CI 52-80) and 38% (95% CI 24-54) for SPT and sIgE. For peanut, pooled sensitivities were 95% (95% CI 88-98) and 96% (95% CI 92-98), and specificities were 61% (95% CI 47-74), and 59% (95% CI 45-72) for SPT and sIgE. CONCLUSIONS: The evidence base is limited and weak and is therefore difficult to interpret. Overall, SPT and sIgE appear sensitive although not specific for diagnosing IgE-mediated food allergy.

Surveillance for ocular hypertension: an evidence synthesis and economic evaluation.

OBJECTIVES: To determine effective and efficient monitoring criteria for ocular hypertension [raised intraocular pressure (IOP)] through (i) identification and validation of glaucoma risk prediction models; and (ii) development of models to determine optimal surveillance pathways. DESIGN: A discrete event simulation economic modelling evaluation. Data from systematic reviews of risk prediction models and agreement between tonometers, secondary analyses of existing datasets (to validate identified risk models and determine optimal monitoring criteria) and public preferences were used to structure and populate the economic model. SETTING: Primary and secondary care. PARTICIPANTS: Adults with ocular hypertension (IOP > 21 mmHg) and the public (surveillance preferences). INTERVENTIONS: We compared five pathways: two based on National Institute for Health and Clinical Excellence (NICE) guidelines with monitoring interval and treatment depending on initial risk stratification, 'NICE intensive' (4-monthly to annual monitoring) and 'NICE conservative' (6-monthly to biennial monitoring); two pathways, differing in location (hospital and community), with monitoring biennially and treatment initiated for a ≥ 6% 5-year glaucoma risk; and a 'treat all' pathway involving treatment with a prostaglandin analogue if IOP > 21 mmHg and IOP measured annually in the community. MAIN OUTCOME MEASURES: Glaucoma cases detected; tonometer agreement; public preferences; costs; willingness to pay and quality-adjusted life-years (QALYs). RESULTS: The best available glaucoma risk prediction model estimated the 5-year risk based on age and ocular predictors (IOP, central corneal thickness, optic nerve damage and index of visual field status). Taking the average of two IOP readings, by tonometry, true change was detected at two years. Sizeable measurement variability was noted between tonometers. There was a general public preference for monitoring; good communication and understanding of the process predicted service value. 'Treat all' was the least costly and 'NICE intensive' the most costly pathway. Biennial monitoring reduced the number of cases of glaucoma conversion compared with a 'treat all' pathway and provided more QALYs, but the incremental cost-effectiveness ratio (ICER) was considerably more than £30,000. The 'NICE intensive' pathway also avoided glaucoma conversion, but NICE-based pathways were either dominated (more costly and less effective) by biennial hospital monitoring or had a ICERs > £30,000. Results were not sensitive to the risk threshold for initiating surveillance but were sensitive to the risk threshold for initiating treatment, NHS costs and treatment adherence. LIMITATIONS: Optimal monitoring intervals were based on IOP data. There were insufficient data to determine the optimal frequency of measurement of the visual field or optic nerve head for identification of glaucoma. The economic modelling took a 20-year time horizon which may be insufficient to capture long-term benefits. Sensitivity analyses may not fully capture the uncertainty surrounding parameter estimates. CONCLUSIONS: For confirmed ocular hypertension, findings suggest that there is no clear benefit from intensive monitoring. Consideration of the patient experience is important. A cohort study is recommended to provide data to refine the glaucoma risk prediction model, determine the optimum type and frequency of serial glaucoma tests and estimate costs and patient preferences for monitoring and treatment. FUNDING: The National Institute for Health Research Health Technology Assessment Programme.

A systematic review of positron emission tomography (PET) and positron emission tomography/computed tomography (PET/CT) for the diagnosis of breast cancer recurrence.

BACKGROUND: Breast cancer (BC) accounts for one-third of all cases of cancer in women in the UK. Current strategies for the detection of BC recurrence include computed tomography (CT), magnetic resonance imaging (MRI) and bone scintigraphy. Positron emission tomography (PET) and, more recently, positron emission tomography/computed tomography (PET/CT) are technologies that have been shown to have increasing relevance in the detection and management of BC recurrence. OBJECTIVE: To review the accuracy of PET and PET/CT for the diagnosis of BC recurrence by assessing their value compared with current practice and compared with each other. DATA SOURCES: MEDLINE and EMBASE were searched from inception to May 2009. STUDY SELECTION: Studies were included if investigations used PET or PET/CT to diagnose BC recurrence in patients with a history of BC and if the reference standard used to define the true disease status was histological diagnosis and/or long-term clinical follow-up. Studies were excluded if a non-standard PET or PET/CT technology was used, investigations were conducted for screening or staging of primary breast cancer, there was an inadequate or undefined reference standard, or raw data for calculation of diagnostic accuracy were not available. STUDY APPRAISAL: Quality assessment and data extraction were performed independently by two reviewers. Direct and indirect comparisons were made between PET and PET/CT and between these technologies and methods of conventional imaging, and meta-analyses were carried out. Analysis was conducted separately on patient- and lesion-based data. Subgroup analysis was conducted to investigate variation in the accuracy of PET in certain populations or contexts and sensitivity analysis was conducted to examine the reliability of the primary outcome measures. RESULTS: Of the 28 studies included in the review, 25 presented patient-based data and 7 presented lesion-based data for PET and 5 presented patient-based data and 1 presented patient- and lesion-based data for PET/CT; 16 studies conducted direct comparisons with 12 comparing the accuracy of PET or PET/CT with conventional diagnostic tests and 4 with MRI. For patient-based data (direct comparison) PET had significantly higher sensitivity [89%, 95% confidence interval (CI) 83% to 93% vs 79%, 95% CI 72% to 85%, relative sensitivity 1.12, 95% CI 1.04 to 1.21, p = 0.005] and significantly higher specificity (93%, 95% CI 83% to 97% vs 83%, 95% CI 67% to 92%, relative specificity 1.12, 95% CI 1.01 to 1.24, p = 0.036) compared with conventional imaging tests (CITs)--test performance did not appear to vary according to the type of CIT tested. For patient-based data (direct comparison) PET/CT had significantly higher sensitivity compared with CT (95%, 95% CI 88% to 98% vs 80%, 95% CI 65% to 90%, relative sensitivity 1.19, 95% CI 1.03 to 1.37, p = 0.015), but the increase in specificity was not significant (89%, 95% CI 69% to 97% vs 77%, 95% CI 50% to 92%, relative specificity 1.15, 95% CI 0.95 to 1.41, p = 0.157). For patient-based data (direct comparison) PET/CT had significantly higher sensitivity compared with PET (96%, 95% CI 90% to 98% vs 85%, 95% CI 77% to 91%, relative sensitivity 1.11, 95% CI 1.03 to 1.18, p = 0.006), but the increase in specificity was not significant (89%, 95% CI 74% to 96% vs 82%, 95% CI 64% to 92%, relative specificity 1.08, 95% CI 0.94 to 1.20, p = 0.267). For patient-based data there were no significant differences in the sensitivity or specificity of PET when compared with MRI, and, in the one lesion based study, there was no significant differences in the sensitivity or specificity of PET/CT when compared with MRI. LIMITATIONS: Studies reviewed were generally small and retrospective and this may have limited the generalisability of findings. Subgroup analysis was conducted on the whole set of studies investigating PET and was not restricted to comparative studies. Conventional imaging studies that were not compared with PET or PET/CT were excluded from the review. CONCLUSIONS: Available evidence suggests that for the detection of BC recurrence PET, in addition to conventional imaging techniques, may generally offer improved diagnostic accuracy compared with current standard practice. However, uncertainty remains around its use as a replacement for, rather than an add-on to, existing imaging technologies. In addition, PET/CT appeared to show clear advantage over CT and PET alone for the diagnosis of BC recurrence. FUTURE WORK: Future research should include: prospective studies with patient populations clearly defined with regard to their clinical presentation; a study of diagnostic accuracy of PET/CT compared with conventional imaging techniques; a study of PET/CT compared with whole-body MRI; studies investigating the possibility of using PET/CT as a replacement for rather than an addition to CITs; and using modelling of the impact of PET/CT on patient outcomes to inform the possibility of conducting large-scale intervention trials.

Tri-adcortyl ointment ear dressing in myringoplasty: an analysis of outcome.

In a retrospective study of patients who had undergone myringoplasty at our department within a 12-month period, we assessed the graft take rate using tri-adcortyl ointment (TAO) as ear dressing. Data including age, site and size of perforation, grade of surgeon, surgical approach, use of postoperative ear dressings, complications and audiometric outcome was collected from the patient notes and analysed. The overall success rate of the operation (with success being defined as an intact tympanic membrane at 6 months) was noted. Seventy-seven patients were operated, but data were complete on 64 patients and these constituted the study population. TAO was used in 95% of the patients and BIPP gauze pack in the remaining 5%. Age ranged from 8 to 63 years (mean 34 years). Mean follow-up period was 13 months. Most of the operations (72.88%) were carried out by consultants with a success rate of 89% and the remaining patients were operated by trainees with a success rate of 88% (P = 1.000). The overall success rate was 89, 90.16% for TAO and 66.66% (2 out of 3) for BIPP (P = 0.298), 95% for small and 86% for subtotal perforations (P = 0.573), 85% for anterior and 100% for posterior perforations (P = 0.240), 91% for adult patients and 88% for children (P = 1.000). TAO is a suitable ear dressing in myringoplasty. Routine use of TAO did not affect the success rate of myringoplasty at our centre.

Effect of post-operative analgesia duration on post-tonsillectomy readmission rate: comparison of five-day and 14-day regime.

OBJECTIVES: To determine whether the introduction of a 14-day post-tonsillectomy analgesic regime would be associated with a statistically significant decrease in readmission rate. METHOD: A comparative study of tonsillectomy patients over two study periods. A retrospective review was undertaken of 342 patients (group one, five-day analgesic regime) who had undergone tonsillectomy. A prospective study was undertaken of 228 patients (group two, 14-day analgesic regime). The readmission rates for the two study periods were compared. RESULTS: The median age of group one patients was 8.1 years (range, zero to 43 years). In this group, 'cold steel' dissection was performed in 177 patients (52 per cent) and bipolar dissection in 165 patients (48 per cent); seven patients suffered reactionary haemorrhage, all from the cold steel dissection group. The median age of group two patients was 8.0 years (range, one to 47 years). In this group, cold steel dissection was performed in 103 patients (45 per cent) and bipolar dissection in 125 patients (55 per cent); there were no cases of reactionary haemorrhage. The readmission rate for group one was 9.9 per cent (34 patients), with 2.1 per cent (seven patients) returning to the operating theatre for control of haemorrhage. In group two, 8.8 per cent (20 patients) were readmitted and 1.3 per cent (three patients) returned to the operating theatre. The main reason for readmission was secondary haemorrhage: 9.1 per cent from group one and 8.3 per cent from group two. No significant difference in readmission was found between the 5-day analgesia and the 14-day analgesia groups (p=0.443). However, there was a significant difference between the diathermy and cold steel dissection groups (p<0.001). Patients undergoing bipolar diathermy were almost six times more likely to be readmitted than those undergoing cold steel dissection (odds ratio 5.78). The average time to readmission after tonsillectomy did not significantly differ between the two groups. CONCLUSION: The post-tonsillectomy readmission rate was not affected by the duration of post-operative analgesia; however, operating technique did have an effect.

Myringoplasty: a comparison of bismuth iodoform paraffin paste gauze pack and tri-adcortyl ointment ear dressing.

OBJECTIVES: To assess the myringoplasty graft take rate, comparing two methods of post-operative ear packing: bismuth iodoform paraffin paste (BIPP) gauze versus tri-adcortyl ointment (TAO). METHODS: A retrospective study of patients who had undergone myringoplasty at our department within a three-year period was undertaken. Data, including age, site and size of perforation, grade of surgeon, surgical approach, use of post-operative ear dressings, complications, and audiometric outcome, were collected from the patient notes and analysed. The overall success rate of the operation (with success being defined as an intact tympanic membrane at six months) was noted. RESULTS: One hundred and seventy myringoplasties were performed over the study period, but data were complete on 154 patients and these constituted the study population. Age ranged from nine to 71 years (mean age 34 years) and the mean follow-up period was seven months. Consultants performed 62 per cent of the operations, with an 85 per cent success rate, whereas trainees performed the remaining 38 per cent, with a success rate of 73 per cent (p=0.059). The overall success rate was 80 per cent; 79 per cent for BIPP and 83 per cent for TAO (p=0.55), and 87 per cent for small perforations and 75 per cent for subtotal perforations (p=0.22). There was audiometric improvement in 74 per cent of cases. CONCLUSION: We found no significant difference in outcome between patients packed with TAO and BIPP. Packing with TAO is therefore a suitable alternative to BIPP gauze ear dressing following myringoplasty.

Rigid endoscopy in globus pharyngeus: how valuable is it?

The aim of this study was to assess the value of rigid endoscopy in patients presenting with globus symptoms. We conducted a retrospective analysis of 250 patients who underwent rigid endoscopy for globus symptoms over a 12-month period. In 217 patients (86.8 per cent) the examination of the larynx, pharynx and upper oesophagus was entirely normal. Abnormal findings included cricopharyngeal spasm in 12 patients (4.8 per cent), reflux in 11 (4.4 per cent), pharyngitis in two (0.8 per cent), web in two (0.8 per cent), and retention cyst in three (1.2 per cent). The 95 per cent confidence interval (CI) for the mean number of persons with malignancy based on the Poisson distribution is 0 and 3.7 (0 and 14.8 as rates per 1000). The relationship between the clinical diagnosis and endoscopic findings was examined using the chi-square test, with a p value of 0.0001. These results suggest that patients presenting with globus sensation are unlikely to harbour neoplastic lesions and therefore rigid endoscopy may well be an inappropriate investigation in this group. The risks, costs and discomfort associated with this intervention can often be avoided.

Wegener's granulomatosis: an analysis of 33 patients seen over a 10-year period.

This retrospective study examined 33 patients with Wegener's granuloma seen between 1990 and 1999 in the Ayrshire and Arran region of Scotland. There was an estimated annual incidence of 10/million/year. The diagnosis in this series was based on the presence of one or more of the following: a positive histology, a positive c-ANCA or a typical clinical course. Twenty-eight patients were diagnosed based on either a positive histology and/or c-ANCA, whereas the remaining five were diagnosed based on the clinical course. c-ANCA was positive in 79.3% but correlated poorly with disease activity. Nasal biopsies were positive in 40%, whereas 94% of renal biopsies were positive, thereby making nasal biopsies unreliable in the diagnosis. Significantly elevated levels of erythrocyte sedimentation rate (ESR) averaging 77 mm/h were found in 32 patients at diagnosis. This showed fluctuation with disease activity. Thirteen patients died, 12 within 5 years. The best prognostic indicator statistically was age.

Fractured tracheostomy tubes in the tracheobronchial tree of a child.

Fractured tracheostomy tube presenting as foreign bodies in the tracheobronchial tree is rare. Only four previous episodes in children have been reported in literature and most of these in developing countries. We report an unusual case of fractured tracheostomy tubes in the tracheobronchial tree of a child and review the literature.