Improved individual and population-level HbA1c estimation using CGM data and patient characteristics.

Machine learning and linear regression models using CGM and participant data reduced HbA1c estimation error by up to 26% compared to the GMI formula, and exhibit superior performance in estimating the median of HbA1c at the cohort level, potentially of value for remote clinical trials interrupted by COVID-19.

Impact of managing affected results in haemolysed samples of an infant-maternity hospital using an unconventional approach.

BACKGROUND: The management of affected results in haemolysed samples (HS) is debated. In an infant-maternity setting, for reporting interfered test results, we provided the result itself, the degree of haemolysis (as free haemoglobin concentration), and a warning recommending sample recollection. We investigated the impact of this approach on sample quality and clinicians' decision-making. METHODS: Free haemoglobin was measured on Beckman Coulter AU680 as haemolytic index. We estimated the total HS number, the clinical wards more affected by HS, the most interfered analytes, and the retesting rate of interfered tests, by comparing data from Apr-Dec 2017, the period just after the introduction of the new policy, vs. Apr-Dec 2018. RESULTS: One year after the new report introduction, a significant HS decrease (5.8% vs. 7.8%, P < 0.001) was detected, together with a reduction of the frequency by which haemolysis affected results. The most affected wards, i.e., Paediatric and Neonatal Intensive Care Units, showed an improvement in sample quality (HS rate, 30.6% to 16.1%, P < 0.001, and 25.2% to 20.9%, P = 0.048, respectively). We noted a significant decrease in retesting after an alerted result for aspartate aminotransferase, magnesium, potassium, conjugated bilirubin, and lactate dehydrogenase. CONCLUSIONS: Our approach led to a HS decrease, suggesting that the provided report could be a driving force for improvement of phlebotomy quality, also helping clinicians in deciding if retesting is essential or not.

Turkish pediatric residents' knowledge, perceptions, and practices of blood culture sampling.

INTRODUCTION: Pediatrics is one of the medical specialties in which blood cultures for bloodstream infections are performed very frequently. This study aimed to evaluate pediatric residents' knowledge and perceptions of blood culture sampling. MATERIAL AND METHODS: Between June 2019 and September 2019, a questionnaire comprising 20 questions about blood culture sampling was sent via email to participants who were pediatric residents at five different hospitals in Turkey. There were 11 true/false and nine multiple-choice questions that assessed three aspects of culture sampling: indications, sampling practice and knowledge, and contamination. The percentage of correct answers was used to calculate an overall score and subsection scores. RESULTS: A total of 132 pediatric residents [102 (77%) female] with a mean age of 28.3±2.8 years completed the questionnaire. Forty-five (35%) were in their 1st year of residency. Sixty (46%) participants reported that they had not performed blood culture sampling in the last week. There was a negative relationship between years in training and the number of cultures performed (Kendal's tau-b=-0.297, p<0.001). The overall median score was 65 (range, 35-90) and it seemed to increase with years of training. The lowest median score was in the contamination subscale and only one (0.76%) participant correctly answered all questions concerning contamination. CONCLUSION: Residents who obtained the majority of blood cultures had the lowest knowledge levels. Therefore, it is evident that the knowledge levels of pediatric residents must be increased in order to improve blood culture sampling practices in centers where they perform blood culture sampling.

Preanalytical Sample Handling Conditions and Their Effects on the Human Serum Metabolome in Epidemiologic Studies.

Many epidemiologic studies use metabolomics for discovery-based research. The degree to which sample handling may influence findings, however, is poorly understood. In 2016, serum samples from 13 volunteers from the US Department of Agriculture's Beltsville Human Nutrition Research Center were subjected to different clotting (30 minutes/120 minutes) and refrigeration (0 minutes/24 hours) conditions, as well as different numbers (0/1/4) and temperatures (ice/refrigerator/room temperature) of thaws. The median absolute percent difference (APD) between metabolite levels and correlations between levels across conditions were estimated for 628 metabolites. The potential for handling artifacts to induce false-positive associations was estimated using variable hypothetical scenarios in which 1%-100% of case samples had different handling than control samples. All handling conditions influenced metabolite levels. Across metabolites, the median APD when extending clotting time was 9.08%. When increasing the number of thaws from 0 to 4, the median APD was 10.05% for ice and 5.54% for room temperature. Metabolite levels were correlated highly across conditions (all r's ≥ 0.84), indicating that relative ranks were preserved. However, if handling varied even modestly by case status, our hypotheticals showed that results can be biased and can result in false-positive findings. Sample handling affects levels of metabolites, and special care should be taken to minimize effects. Shorter room-temperature thaws should be preferred over longer ice thaws, and handling should be meticulously matched by case status.

Adrenal Venous Sampling-Guided Adrenalectomy Rates in Primary Aldosteronism: Results of an International Cohort (AVSTAT).

CONTEXT: Adrenal venous sampling (AVS) is the current criterion standard lateralization technique in primary aldosteronism (PA). Japanese registry data found that 30% of patients with unilateral PA did not undergo adrenalectomy, but the reasons for this and whether the same pattern is seen internationally are unknown. OBJECTIVE: To assess the rate of AVS-guided adrenalectomy across an international cohort and identify factors that resulted in adrenalectomy not being performed in otherwise eligible patients. DESIGN, SETTING, AND PARTICIPANTS: Retrospective, multinational, multicenter questionnaire-based survey of management of PA patients from 16 centers between 2006 and 2018. MAIN OUTCOME MEASURES: Rates of AVS implementation, AVS success rate, diagnosis of unilateral PA, adrenalectomy rate, and reasons why adrenalectomy was not undertaken in patients with unilateral PA. RESULTS: Rates of AVS implementation, successful AVS, and unilateral disease were 66.3%, 89.3% and 36.9% respectively in 4818 patients with PA. Unilateral PA and adrenalectomy rate in unilateral PA were lower in Japanese than in European centers (24.0% vs 47.6% and 78.2% vs 91.4% respectively). The clinical reasoning for not performing adrenalectomy in unilateral PA were more likely to be physician-derived in Japan and patient-derived in Europe. Physician-derived factors included non-AVS factors, such as good blood pressure control, normokalemia, and the absence of adrenal lesions on imaging, which were present before AVS. CONCLUSION: Considering the various unfavorable aspects of AVS, stricter implementation and consideration of surgical candidacy prior to AVS will increase its diagnostic efficiency and utility.

Prediction of hyperaldosteronism subtypes when adrenal vein sampling is unilaterally successful.

OBJECTIVE: Adrenal venous sampling (AVS) is the gold standard to discriminate patients with unilateral primary aldosteronism (UPA) from bilateral disease (BPA). AVS is technically demanding and in cases of unsuccessful cannulation of adrenal veins, the results may not always be interpreted. The aim of our study was to develop diagnostic models to distinguish UPA from BPA, in cases of unilateral successful AVS and the presence of contralateral suppression of aldosterone secretion. DESIGN: Retrospective evaluation of 158 patients referred to a tertiary hypertension unit who underwent AVS. We randomly assigned 110 patients to a training cohort and 48 patients to a validation cohort to develop and test the diagnostic models. METHODS: Supervised machine learning algorithms and regression models were used to develop and validate two prediction models and a simple 19-point score system to stratify patients according to their subtype diagnosis. RESULTS: Aldosterone levels at screening and after confirmatory testing, lowest potassium, ipsilateral and contralateral imaging findings at CT scanning, and contralateral ratio at AVS, were associated with a diagnosis of UPA and were included in the diagnostic models. Machine learning algorithms correctly classified the majority of patients both at training and validation (accuracy: 82.9-95.7%). The score system displayed a sensitivity/specificity of 95.2/96.9%, with an AUC of 0.971. A flow-chart integrating our score correctly managed all patients except 3 (98.1% accuracy), avoiding the potential repetition of 77.2% of AVS procedures. CONCLUSIONS: Our score could be integrated in clinical practice and guide surgical decision-making in patients with unilateral successful AVS and contralateral suppression.

Prediction of Daily Blood Sampling Room Visits Based on ARIMA and SES Model.

This paper is aimed at establishing a combined prediction model to predict the demand for medical care in terms of daily visits in an outpatient blood sampling room, which provides a basis for rational arrangement of human resources and planning. On the basis of analyzing the comprehensive characteristics of the randomness, periodicity, trend, and day-of-the-week effects of the daily number of blood collections in the hospital, we firstly established an autoregressive integrated moving average model (ARIMA) model to capture the periodicity, volatility, and trend, and secondly, we constructed a simple exponential smoothing (SES) model considering the day-of-the-week effect. Finally, a combined prediction model of the residual correction is established based on the prediction results of the two models. The models are applied to data from 60 weeks of daily visits in the outpatient blood sampling room of a large hospital in Chengdu, for forecasting the daily number of blood collections about 1 week ahead. The result shows that the MAPE of the combined model is the smallest overall, of which the improvement during the weekend is obvious, indicating that the prediction error of extreme value is significantly reduced. The ARIMA model can extract the seasonal and nonseasonal components of the time series, and the SES model can capture the overall trend and the influence of regular changes in the time series, while the combined prediction model, taking into account the comprehensive characteristics of the time series data, has better fitting prediction accuracy than a single model. The new model can well realize the short-to-medium-term prediction of the daily number of blood collections one week in advance.

The impact of pre-analytical variations on biochemical analytes stability: A systematic review.

OBJECTIVE: A common problem in clinical laboratories is maintaining the stability of analytes during pre-analytical processes. The aim of this study was to systematically summarize the results of a set of studies about the biochemical analytes stability. METHODS: A literature search was performed on the Advanced search field of PubMed using the keywords: "(stability) AND (analytes OR laboratory analytes OR laboratory tests OR biochemical analytes OR biochemical tests OR biochemical laboratory tests)." A total of 56 entries were obtained. After applying the selection criteria, 20 articles were included in the study. RESULTS: In the 20 included references, up to 123 different analytes were assessed. The 34 analytes in order of the most frequently studied analytes were evaluated: Alanine aminotransferase, aspartate aminotransferase, potassium, triglyceride, alkaline phosphatase, creatinine, total cholesterol, albumin, lactate dehydrogenase, sodium, calcium, γ-glutamyltransferase, total bilirubin, urea, creatine kinase, inorganic phosphate, total protein, uric acid, amylase, chloride, high-density lipoprotein, magnesium, glucose, C-reactive protein, bicarbonate, ferritin, iron, lipase, transferrin, cobalamin, cortisol, folate, free thyroxine, and thyroid-stimulating hormone. Stable test results could be varied between 2 hours and 1 week according to the type of samples and/or type of blood collection tubes on a basic classification set as refrigerated or room temperature. CONCLUSIONS: Biochemical analytes stability could be improved if the best pre-analytical approaches are used.

Evaluation of Adrenal Vein Sampling Use and Outcomes in Patients With Primary Aldosteronism.

BACKGROUND: Primary aldosteronism (PA) occurs in 10%-20% of patients with resistant hypertension. Guidelines recommend adrenal vein sampling (AVS) to identify patients for surgical management. We evaluate the use of AVS in managing PA to better understand the selection and outcomes of medical versus surgical treatment. METHODS: A retrospective review was performed, and patients were divided into those who did (AVS) and did not have AVS (non-AVS). Demographics, aldosterone and renin levels, blood pressure, comorbidities, and antihypertensive medications were recorded. Reasons to defer AVS and medical versus surgical decision-making were examined and groups were compared. RESULTS: We included 113 patients; 39.8% (45/113) had AVS, whereas 60.2% (68/113) did not. Groups were similar in age, body mass index, and initial systolic blood pressure (SBP). In patients who underwent AVS, 31 of 45 (68.9%) had unilateral secretion and were referred for surgery, whereas 13 of 45 (28.9%) had bilateral secretion. Of the 31 referred for surgery, 26 underwent laparoscopic adrenalectomy, all cured; four refused surgery; and one counseled toward medical management by their physician. In 68 non-AVS patients, 6 (8.8%) underwent adrenalectomy without sampling and 2 with no clinical improvement. The remaining deferrals were because of normal or bilateral adrenal nodules on imaging (8/68, 11.8%); medical management due to poor surgical candidacy (12/68, 17.6%); patient refusal of intervention (13/68, 19.1%); or reasons not stated (28/68, 41.1%). At the follow-up, patients who underwent AVS had lower median SBP (135.4 mmHg versus 144.7 mmHg, P = 0.0241) and shorter follow-up (17.7 mo versus 54.0 mo, P < 0.0001). Surgically managed patients had biochemical resolution of PA with normalization of potassium levels (3.6 to 4.7mEq/L, P < 0.00001). CONCLUSIONS: AVS correctly selects patients for surgical management avoiding unnecessary surgery. However, despite guidelines, AVS is not always pursued as part of PA treatment, potentially excluding surgical candidates.

Applying Queuing Theory and Mixed Integer Programming to Blood Center Nursing Schedules of a Large Hospital in China.

Blood centers in large hospitals in China are facing serious problems, including complex patient queues and inflexible nursing schedules. This study is aimed at developing a flexible scheduling method for blood center nurses. By systematically analyzing the constraints that affect scheduling, a flexible scheduling model is established based on queuing theory and mixed integer programming. This combined model can reasonably determine the number of nurses required during a given working period and flexibly arrange nursing schedules while ensuring sufficient rest periods for individual nurses. Results of numerical studies conducted using data from a large hospital in China show a significant improvement in patient waiting time performance metrics over the hospital's current practice. In addition, the nurses' workloads and rest periods are well balanced, indicating that the proposed method can effectively and flexibly arrange nursing shifts in blood centers.

Utility of Plasmodium falciparum DNA from rapid diagnostic test kits for molecular analysis and whole genome amplification.

BACKGROUND: Rapid diagnostic tests (RDTs) have become the most common diagnostic tool for detection of Plasmodium falciparum malaria, in particular in remote areas. RDT blood spots provide a source of parasite DNA for molecular analysis. In this study, the utility of RDTs for molecular analysis and the performance of different methods for whole genome amplification were investigated. METHODS: Positive P. falciparum RDTs were collected from Kayin, Myanmar from August 2014 to January 2016. The RDT samples were stored for 6 months, 9 months, 20 months, 21 months, and 32 months before DNA extraction and subsequent molecular analysis of P. falciparum kelch 13 (pfkelch13) mutations, P. falciparum multidrug resistance 1 (pfmdr1), and P. falciparum plasmepsin 2 (pfplasmepsin2) gene amplification. In addition, performance of four whole genome amplification (WGA) kits were compared, including REPLI-g®, MALBACTM, PicoPLEX®, and GenomePlex®, for which DNA quantity and quality were compared between original DNA and post-WGA products. RESULTS: The proportion of successful amplification of the different molecular markers was similar between blood spots analysed from RDTs stored for 6, 9, 20, 21, or 32 months. Successful amplification was dependent on the molecular markers fragment length (p value < 0.05): 18% for a 1245 bp fragment of pfkelch13, 71% for 364 bp of pfkelch13, 81% for 87 bp of pfmdr1, 81% for 108 bp of pfplasmepsin2. Comparison of the four WGA assay kits showed that REPLI-g®, MALBACTM, and PicoPLEX® increased the quantity of DNA 60 to 750-fold, whereas the ratio of parasite DNA amplification over human DNA was most favourable for MALBAC®. Sequencing results of pfkelch13, P. falciparum chloroquine resistance transporter (pfcrt), P. falciparum dihydrofolate reductase (pfdhfr) and six microsatellite markers assessed from the post-WGA product was the same as from the original DNA. CONCLUSIONS: Blood spots from RDTs are a good source for molecular analysis of P. falciparum, even after storage up to 32 months. WGA of RDT-derived parasite DNA reliably increase DNA quantity with sufficient quality for molecular analysis of resistance markers.

Most noninvasive prenatal screens failing due to inadequate fetal cell free DNA are negative for trisomy when repeated.

OBJECTIVE: We aimed to test for an association between the amount of circulating fetal cell-free DNA and trisomy, and whether NIPS failure due to low fetal fraction indicates trisomy risk. METHOD: Maternal BMI, maternal age, fetal sex, gestational age, fetal cfDNA fraction, and NIPS results was collected on 2374 pregnancies. Additional clinical information was available for 1180 research consented patients. We investigated associations between fetal fraction and available variables and determined the success rate of repeat NIPS testing. RESULTS: Fetal trisomy was marginally associated with decreased fetal fraction (P = .067). However, the proportions of trisomy events were not significantly increased in women who had failed NIPS due to low fetal fraction (<4%) (OR = 1.37 [0.3-7.4]; P = .714). 66% of repeated NIPS after a second blood draw were successful. CONCLUSION: Failure to meet the clinical cutoff of 4% fetal fraction established for NIPS accuracy did not suggest increased risk for trisomy in our cohort. Because repeat testing was successful in the majority of cases and most failures were explained by high BMI and low gestational age, a redraw may be an appropriate next step before invasive screening due to concerns for trisomic pregnancies.

Financial analysis of large-volume delayed sampling to reduce bacterial contamination of platelets.

BACKGROUND: Effective and financially viable mitigation approaches are needed to reduce bacterial contamination of platelets in the US. Expected costs of large-volume delayed sampling (LVDS), which would be performed by a blood center prior to shipment to a hospital, were compared to those of pathogen reduction (PR), point-of-release testing (PORt), and secondary bacterial culture (SBC). METHODS: Using a Markov-based decision-tree model, the financial and clinical impact of implementing all variants of LVDS, PR, PORt, and SBC described in FDA guidance were evaluated from a hospital perspective. Hospitals were assumed to acquire leukoreduced apheresis platelets, with LVDS adding $30 per unit. Monte Carlo simulations were run to estimate the direct medical costs for platelet acquisition, testing, transfusion, and possible complications associated with each approach. Input parameters, including test sensitivity and specificity, were drawn from existing literature and costs (2018US$) were based on a hospital perspective. A one-way sensitivity analysis varied the assumed additional cost of LVDS. RESULTS: Under an approach of LVDS (7-day), the total cost per transfused unit is $735.78, which falls between estimates for SBC (7-day) and PORt. Assuming 20,000 transfusions each year, LVDS would cost $14.72 million annually. Per-unit LVDS costs would need to be less than $22.32 to be cheaper per transfusion than all other strategies, less than $32.02 to be cheaper than SBC (7-day), and less than $196.19 to be cheaper than PR (5-day). CONCLUSIONS: LVDS is an effective and cost-competitive approach, assuming additional costs to blood centers and associated charges to hospitals are modest.

Three groups of suspects in police reported rape cases: First-time suspects, recidivists and unidentified suspects. A comparative study.

BACKGROUND: Previous studies show that reported suspects in adult rape cases often have a criminal record, and that many are rape recidivists. Annual numbers of police reported rapes have dramatically increased but the proportion of rapes being prosecuted and numbers of convictions are low. To increase knowledge about the suspects in cases of police reported rapes; whether they have committed the crime before or not may inform preventive measures. AIMS: To compare suspect, victim, and assault related characteristics among different groups of police-reported rape suspects (first-time suspects, recidivist suspects and unidentified suspects). METHODS: Retrospective, descriptive study of suspects in cases of rape or attempted rape reported by women ≥16 years of age in the Sør-Trøndelag police district, Norway, from 2003 to 2010. RESULTS: Among the 356 suspects included, 207 (58%) were first-time suspects, 75 (21%) were recidivists and 74 (21%) were unidentified. Being a first-time suspect was significantly associated with victim being <18 years, recidivist suspect was significantly associated with victim being a partner, both suspect- and victim unemployment, and suspect reporting intake of other drugs than alcohol. When suspects were unidentified, victims were more likely to have consumed alcohol prior to assault, and reporting the suspect being of non-Western origin. Also, the reporting of a public venue was more frequent when unidentified suspect. CONCLUSIONS: The study shows different patterns in groups of suspects as to victim and assault characteristics. Detection and description of such differences can provide valuable information for future prevention programs, police investigation methods and health care guidelines.

Historical changes and between-facility differences in adrenal venous sampling for primary aldosteronism in Japan.

Primary aldosteronism (PA) is a common curable cause of hypertension. Adrenal venous sampling (AVS) is recommended for subtype diagnosis but is a difficult procedure. Recently, an increased prevalence of PA was reported, creating a greater demand for treatment of the condition in clinical facilities. The aim of the present study was to identify the historical changes over time and the differences between facilities in the success rate and subtype diagnosis of PA. The database of the PA registry developed by the Japan PA Study (JPAS) was used. A total of 2599 patients with PA who underwent AVS were evaluated. The overall success rate of AVS was 88%. The bilateral subtype was the dominant subtype, comprising 69% of cases. During the period 2004-2011 to 2011-2017, there were significant changes in the total number of AVS procedures (from 562 to 1732), ratio of ACTH administration with AVS (75 to 97%), success rate (79 to 90%), and proportion with bilateral subtype diagnosis (53 to 72%). There were also significant inter-facility differences in the number of AVS procedures (6 to 322), success rate (59 to 97%), and proportion with the bilateral subtype (44 to 86%). The principal enrolled department was Endocrinology (86%), and the ratio of unilateral PA was significantly higher in this department than in others (32% vs. 25%). In conclusion, the number of AVS procedures performed, the success rate, and the proportion with the bilateral subtype increased over time after normalizing the centre difference. Significant differences were observed between the centres.

Postpartum hypertensive disorders in the Emergency Department - A retrospective review of local practice in Calgary, Alberta.

Hypertensive disorders of pregnancy (HDP) commonly occur postpartum and are associated with preventable maternal morbidity and mortality. HDP is the most common reason for presentation to the Emergency Department (ED) after delivery. However, given the broad range of non-specific symptoms, recognition and management of postpartum HDP may be delayed leading to serious adverse clinical outcomes. OBJECTIVES: To describe: (1) the clinical presentation; (2) ED physician's diagnosis; and (3) current ED management of women with HDP in Calgary ED's. METHODS: A retrospective review of postpartum women (within 42 days of delivery) attending three Calgary EDs between 2011 and 2012 was performed. Administrative data was used to randomly select 119 women; 44 with diagnostic codes for any HDP (labeled "HDP") and 75 with diagnostic codes for related diagnoses (e.g., abdominal pain, headache) (labeled "non-HDP"). Charts were reviewed for: maternal demographics; obstetrical history; and ED clinical findings, investigations and management. RESULTS: Maternal characteristics were similar between groups. There was considerable overlap in clinical presentation between groups, with no significant difference for any presenting symptom. Only 52.3% (CI 40.0-64.3%) of women in the "HDP" group had HDP investigations (bloodwork and urinalysis) vs. 30.4% (CI 18.7-58.5%) of "non-HDP" (p = 0.072). HDP was diagnosed by the ED team in 42.9% (CI 31.1-55.5%) of the HDP group of whom only 40.3% (CI 28.7-53.1) received antihypertensive therapy. CONCLUSIONS: Postpartum HDP is commonly under-recognized and under-treated in the ED, highlighting opportunities for interventions to improve the recognition and management of postpartum HDP.

Lack of effect of a poster-based intervention to reduce the number of blood culture samples collected.

OBJECTIVE: To reduce the number of blood culture samples collected. PATIENTS AND METHOD: We performed a cluster randomized controlled trial in adult acute care, and subacute care and rehabilitation wards in a university hospital in France. A poster associating an image of eyes looking at the reader with a summary of blood culture sampling guidelines was displayed in hospital wards in the intervention group. The incidence rate of blood cultures per 1000 days during pre- and post-intervention periods was calculated. RESULTS: Thirty-one wards participated in the study. The median difference in blood cultures/1000 days between periods was -1.863 [-11.941; 1.007] in the intervention group and -5.824 [-14.763; -2.217] in the control group (P=0.27). CONCLUSION: The intervention did not show the expected effect, possibly due to the choice of blood cultures as a target of good practice, but also to confounding factors such as the stringent policy of decreasing unnecessary costly testing.

"Rainbow Draws" in the Emergency Department: Clinical Utility and Staff Perceptions.

BACKGROUND: Collecting a predefined set of blood tubes (the "rainbow draw") is a common but controversial practice in many emergency departments (EDs), with limited data to support it. We determined the actual utilization of rainbow draw tubes at a single facility and evaluated the perceptions of ED staff regarding the utility of rainbow draws. METHODS: We analyzed 2 weeks of ED visits (1326 visits by 1240 unique patients) to determine blood tube utilization for initial and add-on testing, as well as the incidence of additional venipunctures. We also surveyed ED staff regarding aspects of ED phlebotomy and test ordering. Utilization data analysis was structured to satisfy specific concerns addressed in the ED staff survey. RESULTS: Observed tube utilization data showed that fluoride/oxalate, citrate, and serum separator tubes were frequently discarded unused, and that the actual utility of the rainbow draw for add-on testing and avoiding additional venipunctures was low. ED staff perceived that the rainbow draw was highly valuable, both to expedite add-on testing and to avoid additional venipunctures. Contrasting the objective (utilization data) and subjective (survey results) to drive changes in the standard ED blood collection reduced the estimated waste blood by 175 L/year. CONCLUSIONS: Comparison of perceptions and objective utilization data drove process changes that were mutually agreeable to ED and laboratory staff. Although specifics of ED and laboratory work flows vary between institutions, the principles and strategy of this study are widely applicable.

The Chinese National Twin Registry: a 'gold mine' for scientific research.

The Chinese National Twin Registry (CNTR) currently includes data from 61 566 twin pair from 11 provinces or cities in China. Of these, 31 705, 15 060 and 13 531 pairs are monozygotic, same-sex dizygotic and opposite-sex dizygotic pairs, respectively, determined by opposite sex or intrapair similarity. Since its establishment in 2001, the CNTR has provided an important resource for analysing genetic and environmental influences on chronic diseases especially cardiovascular diseases. Recently, the CNTR has focused on collecting biologic specimens from disease-concordant or disease-discordant twin pairs or from twin pairs reared apart. More than 8000 pairs of these twins have been registered, and blood samples have been collected from more than 1500 pairs. In this review, we summarize the main findings from univariate and multivariate genetic effects analyses, gene-environment interaction studies, omics studies exploring DNA methylation and metabolomic markers associated with phenotypes. There remains further scope for CNTR research and data mining. The plan for future development of the CNTR is described. The CNTR welcomes worldwide collaboration.