Prognostic indices for early mortality in ischaemic stroke - meta-analysis.

OBJECTIVES: Several models have been developed to predict mortality in ischaemic stroke. We aimed to evaluate systematically the performance of published stroke prognostic scores. METHODS: We searched MEDLINE and EMBASE in February 2014 for prognostic models (published between 2003 and 2014) used in predicting early mortality (<6 months) after ischaemic stroke. We evaluated discriminant ability of the tools through meta-analysis of the area under the curve receiver operating characteristic curve (AUROC) or c-statistic. We evaluated the following components of study validity: collection of prognostic variables, neuroimaging, treatment pathways and missing data. RESULTS: We identified 18 articles (involving 163 240 patients) reporting on the performance of prognostic models for mortality in ischaemic stroke, with 15 articles providing AUC for meta-analysis. Most studies were either retrospective, or post hoc analyses of prospectively collected data; all but three reported validation data. The iSCORE had the largest number of validation cohorts (five) within our systematic review and showed good performance in four different countries, pooled AUC 0.84 (95% CI 0.82-0.87). We identified other potentially useful prognostic tools that have yet to be as extensively validated as iSCORE - these include SOAR (2 studies, pooled AUC 0.79, 95% CI 0.78-0.80), GWTG (2 studies, pooled AUC 0.72, 95% CI 0.72-0.72) and PLAN (1 study, pooled AUC 0.85, 95% CI 0.84-0.87). CONCLUSIONS: Our meta-analysis has identified and summarized the performance of several prognostic scores with modest to good predictive accuracy for early mortality in ischaemic stroke, with the iSCORE having the broadest evidence base.

Habitual chocolate consumption and the risk of incident heart failure among healthy men and women.

BACKGROUND: We aimed to examine the association between chocolate intake and the risk of incident heart failure in a UK general population. We conducted a systematic review and meta-analysis to quantify this association. METHODS AND RESULTS: We used data from a prospective population-based study, the European Prospective Investigation into Cancer (EPIC)-Norfolk cohort. Chocolate intake was quantified based on a food frequency questionnaire obtained at baseline (1993-1997) and incident heart failure was ascertained up to March 2009. We supplemented the primary data with a systematic review and meta-analysis of studies which evaluated risk of incident heart failure with chocolate consumption. A total of 20,922 participants (53% women; mean age 58 ± 9 years) were included of whom 1101 developed heart failure during the follow up (mean 12.5 ± 2.7 years, total person years 262,291 years). After adjusting for lifestyle and dietary factors, we found 19% relative reduction in heart failure incidence in the top (up to 100 g/d) compared to the bottom quintile of chocolate consumption (HR 0.81 95%CI 0.66-0.98) but the results were no longer significant after controlling for comorbidities (HR 0.87 95%CI 0.71-1.06). Additional adjustment for potential mediators did not attenuate the results further. We identified five relevant studies including the current study (N = 75,408). The pooled results showed non-significant 19% relative risk reduction of heart failure incidence with higher chocolate consumption (HR 0.81 95%CI 0.66-1.01). CONCLUSIONS: Our results suggest that higher chocolate intake is not associated with subsequent incident heart failure.

Soft drinks and sweetened beverages and the risk of cardiovascular disease and mortality: a systematic review and meta-analysis.

BACKGROUND: Soft drink consumption is associated with adverse health behaviours that predispose to adverse cardiovascular risk factor profiles; however, it is unclear whether their intake independently leads to an increased risk of cardiovascular events and mortality. We conducted a systematic review and meta-analysis to evaluate this. METHODS: Medline and EMBASE were searched in July 2015 for studies that considered soft drink intake and risk of mortality, myocardial infarction (MI) or stroke. Pooled risk ratios (RRs) for adverse outcomes were calculated using inverse variance with a random effects model, and heterogeneity was assessed using the I2 statistic. RESULTS: A total of seven prospective cohort studies with 308,420 participants (age range 34-75 years) were included in the review. The pooled results suggest a greater risk of stroke (RR 1.13, 95% CI 1.02-1.24), and MI (RR 1.22, 95% CI 1.14-1.30), but not vascular events with incremental increase in sugar-sweetened beverage (SSB) consumption. With incremental increase in artificially sweetened beverage (ASB) consumption, there was a greater risk of stroke (RR 1.08, 95% CI 1.03-1.14), but not vascular events or MI. In the evaluation of high vs. low SSB, there was a greater risk of MI (RR 1.19, 95% CI 1.09-1.31) but not stroke, vascular events or mortality. For ASB, there was a significantly greater risk of stroke (RR 1.14, 95% CI 1.04-1.26) and vascular events (RR 1.44, 95% CI 1.02-2.03) but not MI or mortality. CONCLUSIONS: Our results suggest an association between consumption of sugar-sweetened and ASBs and cardiovascular risk, although consumption may be a surrogate for adverse health behaviours.

Influenza, influenza-like symptoms and their association with cardiovascular risks: a systematic review and meta-analysis of observational studies.

AIMS: To synthesise the evidence relating influenza and influenza-like symptoms to the risks of myocardial infarction (MI), heart failure (HF) and stroke. METHODS: We conducted a systematic review and meta-analysis of the evidence relating influenza and influenza-like symptoms to the risks of MI, HF and stroke. We systematically searched all MEDLINE and EMBASE entries up to August 2014 for studies of influenza vs. the cardiovascular outcomes above. We conducted random effects meta-analysis using inverse variance method for pooled odds ratios (OR) and evaluated statistical heterogeneity using the I(2) statistic. RESULTS: We identified 12 studies with a total of 84,003 participants. The pooled OR for risk of MI vs. influenza (serologically confirmed) was 1.27 (95% CI, confidence interval 0.54-2.95), I(2)  = 47%, which was significant for the only study that adjusted for confounders (OR 5.50, 95% CI 1.31-23.13). The pooled OR for risk of MI vs. influenza-like symptoms was 2.17 (95% CI 1.68-2.80), I(2)  = 0%, which was significant for both unadjusted (OR 2.23, 95% CI 1.65-3.01, five studies) and adjusted studies (OR 2.01, 95% CI 1.24-3.27, two studies). We found one study that evaluated stroke risk, one study in patients with HF, and one that evaluated mortality from MI - all of these studies suggested increased risks of events with influenza-like symptoms. CONCLUSIONS: There is an association between influenza-like illness and cardiovascular events, but the relationship is less clear with serologically diagnosed influenza. We recommend renewed efforts to apply current clinical guidelines and maximise the uptake of annual influenza immunisation among patients with cardiovascular diseases, to decrease their risks of MI and stroke.

The SOAR stroke score predicts hospital length of stay in acute stroke: an external validation study.

AIMS: The objective of this study is to externally validate the SOAR stroke score (Stroke subtype, Oxfordshire Community Stroke Project Classification, Age and prestroke modified Rankin score) in predicting hospital length of stay (LOS) following an admission for acute stroke. METHODS: We conducted a multi-centre observational study in eight National Health Service hospital trusts in the Anglia Stroke & Heart Clinical Network between September 2008 and April 2011. The usefulness of the SOAR stroke score in predicting hospital LOS in the acute settings was examined for all stroke and then stratified by discharge status (discharged alive or died during the admission). RESULTS: A total of 3596 patients (mean age 77 years) with first-ever or recurrent stroke (92% ischaemic) were included. Increasing LOS was observed with increasing SOAR stroke score (p < 0.001 for both mean and median) and the SOAR stroke score of 0 had the shortest mean LOS (12 ± 20 days) while the SOAR stroke score of 6 had the longest mean LOS (26 ± 28 days). Among patients who were discharged alive, increasing SOAR stroke score had a significantly higher mean and median LOS (p < 0.001 for both mean and median) and the LOS peaked among patients with score value of 6 [mean (SD) 35 ± 31 days, median (IQR) 23 (14-48) days]. For patients who died as in-patient, there was no significant difference in mean or median LOS with increasing SOAR stroke score (p = 0.68 and p = 0.79, respectively). CONCLUSION: This external validation study confirms the usefulness of the SOAR stroke score in predicting LOS in patients with acute stroke especially in those who are likely to survive to discharge. This provides a simple prognostic score useful for clinicians, patients and service providers.

TIA, stroke and orthostatic hypotension: a disease spectrum related to ageing vasculature?

AIMS: We sought to identify the determinants of orthostatic hypotension (OH) among patients referred to the transient ischaemic attack (TIA) clinic. METHODS: We conducted a retrospective analysis of prospectively collected data on patients who attended the TIA clinic in a UK hospital between January 2006 and September 2009. Each patient had their supine and standing or sitting blood pressure measured. Logistic regression was used to estimate the univariate and multivariate odds of OH for the subgroups of patients based on their diagnosis. A 10% significance level for the univariate analysis was used to identify variables in the multivariate model. RESULTS: A total of 3222 patients were studied of whom 1131 had a TIA, 665 a stroke and 1426 had other diagnoses. The prevalence of either systolic or diastolic OH in the TIA, stroke and patients with other diagnoses was similar being 22% (n = 251), 24% (n = 162) and 20% (n = 292), respectively. Multivariate analyses showed age, prior history of TIA, and diabetes were independently significantly associated with systolic OH alone or diastolic OH alone or either systolic or diastolic OH [ORs 1.03 (1.02-1.05); 1.56 (1.05-2.31); 1.65 (1.10-2.47), respectively]. Among the patients with the diagnosis of stroke, peripheral vascular disease (PVD) was significantly associated with increased odds of OH (3.56, 1.53-8.31), whereas male gender had a significantly lower odds of OH (0.61, 0.42-0.88). In patients with other diagnoses, age (1.04, 1.02-1.05) and diabetes (1.47, 1.04-2.09) were associated with OH, whereas male gender was (0.76, 0.58-1.00) not associated with OH. CONCLUSION: Orthostatic hypotension is prevalent among patients presenting to TIA clinic. Previous history of vascular disease (prior TIA/stroke/PVD) appears to be a significant associate of OH in this patient population.

Chronic obstructive pulmonary disease and mortality from pneumonia: meta-analysis.

BACKGROUND: We aimed to determine whether patients with concomitant community-acquired pneumonia (CAP) and chronic obstructive pulmonary disease (COPD) are at greater risk of death when compared with those with CAP or acute COPD exacerbation alone. We also assessed the effect of inhaled corticosteroids (ICS) on pneumonia mortality in COPD. METHODS: We searched MEDLINE and EMBASE from inception to March 2012 for studies reporting on mortality in patients with COPD and CAP. We assessed ascertainment of disease, mortality, drug exposure and adjustment for confounders. Data were pooled using random effects meta-analysis, and heterogeneity was estimated using I². RESULTS: We identified 24 eligible articles overall. Evaluation of 13 studies revealed considerable heterogeneity and a non-significant mortality risk associated with concomitant COPD and CAP as compared with CAP in five studies that reported adjusted or severity-matched data, pooled RR 1.44 (95% CI 0.97-2.16, I² = 50%). There was also considerable inconsistency amongst the effect estimates from five studies that reported on the associated mortality with concomitant CAP and COPD as compared with acute COPD exacerbations alone. Evaluation of six datasets found that ICS use in COPD was not consistently associated with lower mortality in CAP. Reports of reduced mortality with prior ICS use stemmed from three studies that enrolled participants from the same healthcare database. CONCLUSIONS: Evidence on associated mortality risk with concomitant CAP and COPD (as opposed to CAP alone, or COPD exacerbation alone) is weak and heterogeneous. ICS use was not consistently associated with reduced mortality from pneumonia.

Efficacy of topical treatments for cutaneous warts: a meta-analysis and pooled analysis of randomized controlled trials.

Many topical treatments for cutaneous warts exist and previous reviews of trials did not follow intention-to-treat (ITT) principles for analysis. We aimed to perform a meta-analysis and pooled analysis of randomized controlled trials (RCTs) of topical treatment for cutaneous warts using ITT principles. Systematic electronic searches (Cochrane library, Medline, Embase, Clinical trial registers) were conducted in May 2009. Included trials reported completed cure of warts and data were extracted from these trials. We performed random-effects meta-analysis and assessed heterogeneity using the I(2) statistic and conducted a pooled analysis of each treatment. We found 77 relevant studies of which the majority were of low methodological quality. Salicylic acid (SA) was superior to placebo with a risk ratio (RR) for cure of 1·60 [95% confidence interval (CI) 1·15-2·24]. Cryotherapy was not statistically better than placebo, RR 0·89 (95% CI 0·27-2·92), but aggressive cryotherapy was significantly better than gentle cryotherapy with a RR of 2·06 (95% 1·20-3·52). Combined therapy of SA and cryotherapy had a higher cure rate than either SA or cryotherapy alone. The results of the pooled analysis found a cure rate of 23% (5-73%) in placebo trials, 52% (0-87%) in SA trials, 49% (0-69%) in cryotherapy trials, 54% (45-75%) in aggressive cryotherapy trials and 58% (38-78%) in the combined cryotherapy and SA trials. Aside from the use of SA and aggressive cryotherapy there is insufficient evidence from RCTs to support the use of other therapies. Higher quality evidence is needed to evaluate other therapies.

Cerebral microbleeds: histopathological correlation of neuroimaging.

BACKGROUND: In recent years, there has been a growing interest in cerebral microbleeds (CMBs) and their role in cerebrovascular disease. A few studies have investigated the histopathological correlation between CMBs and neuroimaging findings. We conducted a systematic review in an attempt to characterize the pathological and radiological correlation. METHODS: A systematic literature search was conducted for studies in which CMBs were characterized histopathologically and correlated with MRI findings. RESULTS: Five studies met the inclusion criteria, with a total of 18 patients. Hemosiderin deposition was reported in 42 CMBs (49%), while 16 CMBs (19%) were described as old hematomas which stained for iron, 13 (15%) had no associated specific pathology, 11 (13%) contained intact erythrocytes, 1 (1%) was due to vascular pseudocalcification, 1 (1%) was a microaneurysm and 1 (1%) was a distended dissected vessel. Lipofibrohyalinosis was the most prominent associated vascular finding. Amyloid angiopathy was present primarily in patients with dementia. CONCLUSIONS: Although histopathological associations have been observed using MRI in patients with CMBs, the findings have yet to be validated and further research is warranted.

Dabigatran and rivaroxaban for prevention of venous thromboembolism--systematic review and adjusted indirect comparison.

WHAT IS KNOWN AND OBJECTIVE: Dabigatran and rivaroxaban are new oral anticoagulants for thromboprophylaxis after elective orthopaedic surgery. We aimed to systematically compare their relative benefits and harms through meta-analysis, and adjusted indirect comparison. METHODS: We searched PubMed, EMBASE, trial registries and regulatory documents through May 2009 for randomized controlled trials (RCTs) of dabigatran (150 and 220 mg daily) and rivaroxaban (10 mg daily) compared with enoxaparin (40-60 mg daily) in elective orthopaedic surgery. We used random effects meta-analysis to calculate pooled relative risks (RRs) and 95% confidence intervals (95% CI) for the outcomes of total venous thromboembolism, VTE (deep venous thrombosis, non-fatal pulmonary embolism and all-cause mortality), and haemorrhagic adverse events (major and clinically relevant non-major bleeds). Adjusted indirect comparison was used for the pooled RRs of dabigatran and rivaroxaban with enoxaparin as the common control. RESULTS: Rivaroxaban was superior to enoxaparin for the prevention of venous thromoboembolism (RR 0.56, 95% CI 0.43-0.73, P<0.0001), with a trend for increased haemorrhage (RR 1.26, 95% CI 0.94-1.69, P=0.13). Dabigatran was not superior to enoxaparin for prevention of VTE (RR 1.12, 95% 0.97-1.29, P=0.12), and did not reduce haemorrhage risk (RR 1.10, 95% 0.90-1.35, P=0.32). Adjusted indirect comparison showed that rivaroxaban was superior to dabigatran in preventing VTE, RR 0.50 (95% CI 0.37-0.68), but with a slight trend towards increased haemorrhage RR 1.14 (95% CI 0.80-1.64). WHAT IS NEW AND CONCLUSION: Rivaroxaban may be more effective than dabigatran for prevention of VTE after elective orthopaedic surgery but might also slightly increase the risk of haemorrhage.

Risk of myocardial infarction and cardiovascular death associated with inhaled corticosteroids in COPD.

The effect of long-term inhaled corticosteroid (ICS) use on myocardial infarction (MI) and cardiovascular (CV) death in chronic obstructive pulmonary disease (COPD) remains uncertain. We conducted a systematic search of MEDLINE, EMBASE, ISI, regulatory documents and manufacturers' trial registries for long-term (>24 weeks duration) randomised controlled trials (RCTs) or controlled observational studies reporting on CV outcomes or death with ICS use in COPD. A fixed effects model was used to calculate the relative risks (RRs) and 95% CIs. 23 RCTs with 24-160 weeks of follow-up were included. In the RCTs, ICS were not associated with a significantly reduced risk of MI (RR 0.95, 95% CI 0.73-1.23; p = 0.68, I(2) = 0%), CV death (RR 1.02; 95% CI 0.81-1.27; p = 0.89, I(2) = 0%), or mortality (RR 0.96, 95% CI 0.86-1.07; p = 0.43, I(2) = 0%). In the observational studies, ICS use was associated with a significant reduction in CV death (two studies: RR 0.79, 95% CI 0.72-0, 86; p <0.0001, I(2) = 44%) and mortality (11 studies: RR 0.78, 95% CI 0.75-0.80; p<0.001, I(2) = 33%). Publication bias via funnel plot asymmetry was noted for mortality in the observational studies (Egger test, p = 0.05). We conclude that while observational studies suggest that ICS may potentially confer CV or mortality benefit, RCTs failed to show any significant effect of ICS therapy on MI or CV death. These conflicting findings need to be clarified through further research.

Mode of presentation and mortality amongst patients hospitalized with heart failure? A report from the First Euro Heart Failure Survey.

BACKGROUND: Heart failure is heterogeneous in aetiology, pathophysiology, and presentation. Despite this diversity, clinical trials of patients hospitalized for HF deal with this problem as a single entity, which may be one reason for repeated failures. METHODS: The first EuroHeart Failure Survey screened consecutive deaths and discharges of patients with suspected heart failure during 2000-2001. Patients were sorted into seven mutually exclusive hierarchical presentations: (1) with cardiac arrest/ventricular arrhythmia; (2) with acute coronary syndrome; (3) with rapid atrial fibrillation; (4) with acute breathlessness; (5) with other symptoms/signs such as peripheral oedema; (6) with stable symptoms; and (7) others in whom the contribution of HF to admission was not clear. RESULTS: The 10,701 patients enrolled were classified into the above seven presentations as follows: 260 (2%), 560 (5%), 799 (8%), 2479 (24%), 1040 (10%), 703 (7%), and 4691 (45%) for which index-admission mortality was 26%, 20%, 10%, 8%, 6%, 6%, and 4%, respectively. Compared to those in group 7, the hazard ratios for death during the index admission were 4.9 (p ≤ 0.001), 4.0 (p < 0.001), 2.2 (p < 0.001), 2.1 (p < 0.001), 1.4 (p < 0.04) and 1.4 (p = 0.04), respectively. These differences were no longer statistically significant by 12 weeks. CONCLUSION: There is great diversity in the presentation of heart failure that is associated with very different short-term outcomes. Only a minority of hospitalizations associated with suspected heart failure are associated with acute breathlessness. This should be taken into account in the design of future clinical trials.

Application of high-resolution radiochromic film dosimetry in verifying a small-field stereotactic radiosurgery plan.

A high-resolution radiochromic film dosimetry (Hr-RCFD) method has been applied to verify a small-field stereotactic radiosurgery (SRS) plan. This was done by exposing a RCF in a Perspex head phantom undergoing the same treatment plan as the patient. The dose distribution obtained by the Hr-RCFD was verified against that calculated by the stereotactic treatment planning system and the result was satisfactory. The Hr-RCFD method has been found to be an accurate and practical tool in verifying small-field SRS plans.

Mathematical model of simultaneous diffusion and binding of antitumor antibodies in multicellular human tumor spheroids.

Multicellular tumor spheroids are widely used as in vitro models of poorly vascularized tumor nodules in vivo. The uptake kinetics of tumor-associated antibodies in multicellular tumor spheroids is assumed to be governed by passive diffusion and irreversible binding of the antibodies with binding sites on the cell surface. By further assuming that the spheroids are homogeneous with respect to diffusion and binding, a mathematical model has been developed which permits the extraction of the macroscopic diffusion constant D and the macroscopic binding rate k from empirical studies. The model was applied to uptake kinetics data obtained (a) with a melanoma-associated monoclonal antibody 96.5 (isotype IgG2a)-human multicellular melanoma spheroid system exhibiting strong antibody to cell binding and (b) with the same monoclonal antibody-human multicellular colon adenocarcinoma HT29 spheroid system exhibiting nonspecific binding. The spheroids had approximately 300 microns diameter. The constants D and k were estimated to be 0.45 micron2 s-1 and 2.0 x 10(-3) s-1, respectively, for the system with specific binding. Saturation of binding sites occurred. In the nonspecific binding system, D and k were found to be 0.10 micron2 s-1 and 1.0 x 10(-5) s-1. No saturation of binding sites occurred. D and k were also estimated to be, respectively, 0.52 micron2 s-1 and 6.4 x 10(-5) s-1 for another melanoma-associated monoclonal antibody 140.240 (same isotype as 96.5) in the melanoma spheroid system exhibiting moderate cell binding with the antibody. The mathematical model describes well the system exhibiting nonspecific binding, but requires modifications and further development for the systems exhibiting moderate to strong binding.

Uptake kinetics of monoclonal antibodies by human malignant melanoma multicell spheroids.

Detailed uptake kinetics by multicell spheroids of three tumor associated monoclonal antibodies was investigated. The spheroids were established from a human melanoma cell line and the human colon adenocarcinoma cell line HT29 as in vitro models of poorly vascularized micrometastases in vivo. The selected antibodies 96.5, 140.240, and OST15 showed a wide range of reactivity against the melanoma cell but they all had negligible binding with the colon cancer cell. Uptake of the antibodies by small spheroids (about 300 micron diameter) was generally sigmoidal in shape with respect to incubation time, and amount of uptake followed the same trend of immunoreactivity of the antibodies with single cells. The correlation was weaker for spheroids with diameter greater than 500 micron presumably due to the increasing size of the necrotic core. By varying the concentration of the antibodies in the incubation medium from tracer dose (0.2 microgram/ml) to a higher dose (3 micrograms/ml), negligible changes in the amount of antibodies bound with their target spheroids were observed. Nonspecific binding between antibodies and spheroids, however, resulted in proportional increase in uptake.

Optimization of radioimmunotherapy using human malignant melanoma multicell spheroids as a model.

In vitro multicell spheroids from a human melanoma cell line and the human colon cancer cell line HT29, used as control, have been established as a model of poorly vascularized micrometastases in vivo. The antimelanoma monoclonal antibody 96.5 was radiolabeled with 131I at specific radioactivities from 1.85 to 3.96 GBq/mg. Cytotoxicity of 131I-96.5 to the spheroids, at an initial size of 300 microns in diameter, was investigated as a function of concentration of 131I-96.5 in the incubation medium, specific radioactivity, and treatment time. Spheroid growth delay and clonogenic survival of cells disaggregated from the spheroids at various times after treatment were used as end points. Therapeutic effects increased with the concentration of 131I-96.5 within the range 0.2 to 2 mg/liter (0.34 to 3.4 GBq/liter) at a fixed specific radioactivity. The effects increased with specific radioactivity at a fixed concentration of 131I-96.5. Difference in therapeutic effect was also observed between treatment times of 8 and 24 h. Radiation doses to the melanoma spheroids varied from 10 to 16 Gy. Unlabeled 96.5 at 2 mg/liter or 131I-iodide at 1.7 GBq/liter did not affect the growth of the melanoma spheroids. The HT29 spheroids, however, only suffered slight cytotoxicity at 1 or 2 mg/liter of 131I-96.5 and for a treatment time of 24 h despite comparable radiosensitivity of HT29 cells and melanoma cells to high-dose-rate radiation. Similar cytotoxicity was observed in the HT29 group treated with 131I-iodide at 1.7 GBq/liter. Present findings therefore demonstrate preferential and adequate killing of the melanoma spheroids by 131I-96.5 at 0.5 mg/liter and 3.96 GBq/mg in 8 h.

General paediatric surgery for patients aged under 5 years: a 5-year experience at a district general hospital.

Introduction The gradual shift of general paediatric surgery (GPS) provision from district general hospitals (DGH) to specialised units is well recognised in the UK. The consequences of centralisation include a reduction in exposure to GPS for current surgical trainees. The GPS practice of a DGH is examined here. Methods All operations performed on children aged under 5 years over a 5-year period were identified using the local electronic operation database. Electronic hospital records and clinic letters were accessed to collect data on demographics, operations performed and outcome measures. Results 472 GPS operations were performed on children between the age of 22 days and 5 years between 2009 and 2014, of which 43 were on an emergency basis and 105 were performed on patients aged less than 1 year. Three patients were admitted following day case surgery. Six patients were readmitted within 30 days. Complication rates for all procedures and the four most common procedures were similar to those found in published literature. Conclusions GPS for patients aged less than 5 years is comparatively safe in the DGH setting. The training opportunities available at DGHs are invaluable to surgical trainees and vital for sustaining the future provision of GPS by such hospitals.

Dual-peak dose measurement for radiochromic films by a newly developed spectral microdensitometer.

Radiochromic film (RCF) dosimetry is usually based on densitometric methods which use an analyzing light source of a fixed or a broad spectrum of wavelengths. These methods have not exploited the sensitivity of the dose response of the RCF otherwise attainable by using a light source with wavelengths peaked at the two absorption peaks in the absorption spectrum of the RCF. A new algorithm of dual-peak dose measurement for the RCF has been proposed in this paper to make use of these dual absorption peaks to achieve the maximum attainable sensitivity. This technique relies on the measurement of the transmittance of the RCF at the wavelength of the major and minor absorption peaks, respectively. The dual-peak dose measurement is accomplished with the aid of a novel spectral microdensitometer developed in our Institute. The microdensitometer utilizes a monochromator to provide a light source of which the wavelength can be matched precisely to the wavelength of the absorption peaks of the RCF. The doses obtained at these wavelengths are fed into a weighted objective function and an optimum dose is searched by minimizing the objective function to give the best estimate of the dose deposited on the film. An initial test shows that there is a good agreement between the estimated and actual dose deposited; and the maximum discrepancy was found to be less than 1%.