Quantifying the added value of a diagnostic test or marker

The American Society for Microbiology collaboration with the CDC Laboratory Medicine Best Practices initiative for evidence-based laboratory medicine

SUMMARYClinical medicine has embraced the use of evidence for patient treatment decisions; however, the evaluation strategy for evidence in laboratory medicine practices has lagged. It was not until the end of the 20th century that the Institute of Medicine (IOM), now the National Academy of Medicine, and the Centers for Disease Control and Prevention, Division of Laboratory Systems (CDC DLS), focused on laboratory tests and how testing processes can be designed to benefit patient care. In collaboration with CDC DLS, the American Society for Microbiology (ASM) used an evidence review method developed by the CDC DLS to develop a program for creating laboratory testing guidelines and practices. The CDC DLS method is called the Laboratory Medicine Best Practices (LMBP) initiative and uses the A-6 cycle method. Adaptations made by ASM are called Evidence-based Laboratory Medicine Practice Guidelines (EBLMPG). This review details how the ASM Systematic Review (SR) Processes were developed and executed collaboratively with CDC's DLS. The review also describes the ASM transition from LMBP to the organization's current EBLMPG, maintaining a commitment to working with agencies in the U.S. Department of Health and Human Services and other partners to ensure that EBLMPG evidence is readily understood and consistently used.

Integrating polygenic risk scores in the prediction of gestational diabetes risk in China

Background

Polygenic risk scores (PRS) serve as valuable tools for connecting initial genetic discoveries with clinical applications in disease risk estimation. However, limited studies have explored the association between PRS and gestational diabetes mellitus (GDM), particularly in predicting GDM risk among Chinese populations.

Aim

To evaluate the relationship between PRS and GDM and explore the predictive capability of PRS for GDM risk in a Chinese population.

Methods

A prospective cohort study was conducted, which included 283 GDM and 2,258 non-GDM cases based on demographic information on pregnancies. GDM was diagnosed using the oral glucose tolerance test (OGTT) at 24-28 weeks. The strength of the association between PRS and GDM odds was assessed employing odds ratios (ORs) with 95% confidence intervals (CIs) derived from logistic regression. Receiver operating characteristic curves, net reclassification improvement (NRI), and integrated discrimination improvement (IDI) were employed to evaluate the improvement in prediction achieved by the new model.

Results

Women who developed GDM exhibited significantly higher PRS compared to control individuals (OR = 2.01, 95% CI = 1.33-3.07). The PRS value remained positively associated with fasting plasma glucose (FPG), 1-hour post-glucose load (1-h OGTT), and 2-hour post-glucose load (2-h OGTT) (all p < 0.05). The incorporation of PRS led to a statistically significant improvement in the area under the curve (0.71, 95% CI: 0.66-0.75, p = 0.024) and improved discrimination and classification (IDI: 0.007, 95% CI: 0.003-0.012, p < 0.001; NRI: 0.258, 95% CI: 0.135-0.382, p < 0.001).

Conclusions

This study highlights the increased odds of GDM associated with higher PRS values and modest improvements in predictive capability for GDM.

Diagnostic accuracy and cellular origin of pleural fluid CXCR3 ligands for tuberculous pleural effusion

BACKGROUND

Pleural biomarkers represent potential diagnostic tools for tuberculous pleural effusion (TPE) due to their advantages of low cost, short turnaround time, and less invasiveness. This study evaluated the diagnostic accuracy of two CXCR3 ligands, C-X-C motif chemokine ligand 9 (CXCL9) and CXCL11, for TPE. In addition, we investigated the cellular origins and biological roles of CXCL9 and CXCL11 in the development of TPE.

METHODS

This double-blind study prospectively enrolled patients with undiagnosed pleural effusion from two centers (Hohhot and Changshu) in China. Pleural fluid on admission was obtained and levels of CXCL9 and CXCL11 were measured by an enzyme-linked immunosorbent assay (ELISA). The receiver operating characteristic (ROC) curve and the decision curve analysis (DCA) were used to evaluate their diagnostic accuracy and net benefit, respectively. THP-1 cell-derived macrophages were treated with Bacillus Calmette-Guérin (BCG), and quantitative real-time PCR (qRT-PCR) and ELISA were used to determine the mRNA and protein levels of CXCL9 and CXCL11. The chemoattractant activities of CXCL9 and CXCL11 for T helper (Th) cells were analyzed by a transwell assay.

RESULTS

One hundred and fifty-three (20 TPEs and 133 non-TPEs) patients were enrolled in the Hohhot Center, and 58 (13 TPEs and 45 non-TPEs) were enrolled in the Changshu Center. In both centers, we observed increased CXCL9 and CXCL11 in TPE patients. The areas under the ROC curves (AUCs) of pleural CXCL9 and CXCL11 in the Hohhot Center were 0.70 (95 % CI: 0.55-0.85) and 0.68 (95 % CI: 0.52-0.84), respectively. In the Changshu Center, the AUCs of CXCL9 and CXCL11 were 0.96 (95 % CI: 0.92-1.00) and 0.97 (95 % CI: 0.94-1.00), respectively. The AUCs of CXCL9 and CXCL11 decreased with the advancement of age. The decision curves of CXCL9 and CXCL11 showed net benefits in both centers. CXCL9 and CXCL11 were upregulated in BCG-treated macrophages. Pleural fluid from TPE and conditioned medium from BCG-treated macrophages were chemotactic for Th cells. Anti-CXCL9 or CXCL11 neutralizing antibodies could partly block the chemotactic activity.

CONCLUSIONS

Pleural CXCL9 and CXCL11 are potential diagnostic markers for TPE, but their diagnostic accuracy is compromised in elderly patients. CXCL9 and CXCL11 can promote the migration of peripheral Th cells, thus representing a therapeutic target for the treatment of TPE.

Left ventricular concentric hypertrophy with cardiac magnetic resonance imaging improves risk stratification in patients with Duchenne muscular dystrophy: a prospective cohort study

BACKGROUND

The development of left ventricular (LV) remodeling has been associated with an increased cardiovascular risk and cardiogenic death, and different patterns of remodeling result in varying levels of prognosis.

OBJECTIVE

To investigate the association between different patterns of LV remodeling and clinical outcomes in the preclinical stage of patients with Duchenne muscular dystrophy (DMD).

MATERIALS AND METHODS

A total of 148 patients with DMD and 43 sex- and age-matched healthy participants were enrolled. We used the four-quadrant analysis method to investigate LV remodeling based on cardiac magnetic resonance (MR) imaging. Kaplan-Meier curves were generated to illustrate the event-free survival probability stratified by the LV remodeling pattern. Cox regression models were constructed and compared to evaluate the incremental predictive value of the LV remodeling pattern.

RESULTS

During the median follow-up period of 2.2 years, all-cause death, cardiomyopathy, and ventricular arrhythmia occurred in 5, 35, and 7 patients, respectively. LV concentric hypertrophy (hazard ratio 2.91, 95% confidence interval 1.47-5.75, P=0.002) was an independent predictor of composite endpoint events. Compared to the model without LV concentric hypertrophy, the model with LV concentric hypertrophy had significant incremental predictive value (chi-square value 33.5 vs. 25.2, P=0.004).

CONCLUSION

Age and late gadolinium enhancement positivity were positively correlated with clinical outcomes according to the prediction models. LV concentric hypertrophy was also an independent predictor for risk stratification and provided incremental value for predicting clinical outcomes in the preclinical stage of patients with DMD.

An efficient strategy for evaluating new non-invasive screening tests for colorectal cancer: the guiding principles

OBJECTIVE

New screening tests for colorectal cancer (CRC) are rapidly emerging. Conducting trials with mortality reduction as the end point supporting their adoption is challenging. We re-examined the principles underlying evaluation of new non-invasive tests in view of technological developments and identification of new biomarkers.

DESIGN

A formal consensus approach involving a multidisciplinary expert panel revised eight previously established principles.

RESULTS

Twelve newly stated principles emerged. Effectiveness of a new test can be evaluated by comparison with a proven comparator non-invasive test. The faecal immunochemical test is now considered the appropriate comparator, while colonoscopy remains the diagnostic standard. For a new test to be able to meet differing screening goals and regulatory requirements, flexibility to adjust its positivity threshold is desirable. A rigorous and efficient four-phased approach is proposed, commencing with small studies assessing the test's ability to discriminate between CRC and non-cancer states (phase I), followed by prospective estimation of accuracy across the continuum of neoplastic lesions in neoplasia-enriched populations (phase II). If these show promise, a provisional test positivity threshold is set before evaluation in typical screening populations. Phase III prospective studies determine single round intention-to-screen programme outcomes and confirm the test positivity threshold. Phase IV studies involve evaluation over repeated screening rounds with monitoring for missed lesions. Phases III and IV findings will provide the real-world data required to model test impact on CRC mortality and incidence.

CONCLUSION

New non-invasive tests can be efficiently evaluated by a rigorous phased comparative approach, generating data from unbiased populations that inform predictions of their health impact.

Association of remnant cholesterol with intracranial atherosclerosis in community-based population: The ARIC study

OBJECTIVE

To evaluate the association between remnant cholesterol (remnant-C) and intracranial atherosclerotic disease (ICAD) in the Atherosclerosis Risk in Communities Neurocognitive Study (ARIC-NCS).

METHODS

We studied 1,564 participants with data on lipid profiles and high-resolution vessel wall MRI (VWMRI) from the ARIC-NCS. Remnant-C was computed as total cholesterol minus high-density lipoprotein cholesterol minus low-density lipoprotein cholesterol (LDL-C). The primary outcomes were the presence of intracranial plaques and luminal stenosis. Contributors were separated into four different groups based on remnant-C (22 mg/dL) and LDL-C (100 mg/dL) levels to investigate the function of remnant-C vs. LDL-C on ICAD. Multivariable logistic regression models were utilized to estimate the correlation among the discordant/concordant remnant-C and LDL-C, and ICAD.

RESULTS

A total of 1,564 participants were included (age 76.2 ± 5.3). After multivariable adjustment, log remnant-C was correlated with greater ICAD risk [odds ratio (OR) 1.36, 95% confidence interval (CI) 1.01 to 1.83]. The lower remnant-C/higher LDL-C group and the higher remnant-C/lower LDL-C group manifested a 1.53-fold (95% CI 1.06 to 2.20) and 1.52-fold (95% CI 1.08 to 2.14) greater risk of ICAD, relative to those having lower remnant-C/low LDL-C. Additionally, remnant-C ≥ 22 mg/dL distinguished participants at a greater risk of the presence of any stenosis compared to those at lower levels, even in participants with optimal levels of LDL-C.

CONCLUSIONS

Elevated levels of remnant-C were connected to ICAD independent of LDL-C and traditional risk factors. The mechanisms of remnant-C association with ICAD probably offer insight into preventive risk-factor of ischemic stroke.

Pleural fluid adenosine deaminase to serum C-reactive protein ratio for diagnosing tuberculous pleural effusion

BACKGROUND

Tuberculous pleural effusion (TPE) and malignant pleural effusion (MPE) may occasionally show similar cytological and biochemical picture including ADA. In such cases, differentiating TPE and MPE is challenging and needs histopathology of pleural tissue which may involve invasive procedures. The present study aims to evaluate the diagnostic accuracy of pleural fluid ADA to serum CRP (ADA/CRP) ratio to discriminate between tuberculous and malignant pleural effusion. In addition, we investigated whether the ratio ADA/CRP adds diagnostic value to ADA.

METHODS

This cross-sectional study was conducted in the National Institute of Diseases of the Chest and Hospital (NIDCH), Mohakhali, Dhaka, from July 2021 to February 2022 on diagnosed patients of TPE and malignant pleural effusion MPE. A receiver operating characteristic curve (ROC) was constructed for identifying TPE. The added value of the ADA/CRP ratio to ADA was evaluated using the net reclassification improvement (NRI) and integrated discrimination improvement (IDI). A value of p < 0.05 was considered statistically significant for all tests.

RESULTS

Fifty-nine patients were enrolled in this study, of which 31 had TPE, and 28 had MPE. Pleural fluid ADA to serum CRP ratio and pleural fluid ADA level was significantly higher in patients with TPE, but there was no significant difference in serum CRP levels between patients with TPE and MPE. At cut off value of > 1.25, pleural fluid ADA to serum CRP ratio had a sensitivity of 93.8%, specificity of 85.2%, and positive and negative predictive values were 88.2% and 92% respectively, in the diagnosis of TPE and area under ROC curve (AUC) was 0.94. The NRI and IDI analyses revealed added diagnostic value of ADA/CRP to ADA.

CONCLUSION

This study shows that the ADA/CRP ratio improves the diagnostic usefulness of ADA for TPE.

Review of Statistical and Methodological Issues in the Forensic Prediction of Malingering from Validity Tests: Part I: Statistical Issues

Forensic neuropsychological examinations with determination of malingering have tremendous social, legal, and economic consequences. Thousands of studies have been published aimed at developing and validating methods to diagnose malingering in forensic settings, based largely on approximately 50 validity tests, including embedded and stand-alone performance validity tests. This is the first part of a two-part review. Part I explores three statistical issues related to the validation of validity tests as predictors of malingering, including (a) the need to report a complete set of classification accuracy statistics, (b) how to detect and handle collinearity among validity tests, and (c) how to assess the classification accuracy of algorithms for aggregating information from multiple validity tests. In the Part II companion paper, three closely related research methodological issues will be examined. Statistical issues are explored through conceptual analysis, statistical simulations, and through reanalysis of findings from prior validation studies. Findings suggest extant neuropsychological validity tests are collinear and contribute redundant information to the prediction of malingering among forensic examinees. Findings further suggest that existing diagnostic algorithms may miss diagnostic accuracy targets under most realistic conditions. The review makes several recommendations to address these concerns, including (a) reporting of full confusion table statistics with 95% confidence intervals in diagnostic trials, (b) the use of logistic regression, and (c) adoption of the consensus model on the "transparent reporting of multivariate prediction models for individual prognosis or diagnosis" (TRIPOD) in the malingering literature.

Age affects the diagnostic accuracy of the cancer ratio for malignant pleural effusion

BACKGROUND AND OBJECTIVE

Cancer ratio (CR), which is defined as serum lactate dehydrogenase (LDH) to pleural fluid adenosine deaminase (ADA) ratio, has been reported to be a useful diagnostic marker for malignant pleural effusion (MPE). Whether its diagnostic accuracy is affected by age remains unknown. This study aimed to investigate the effects of age on the diagnostic accuracy of CR.

METHODS

The participants in this study were from a prospective cohort (SIMPLE cohort, n = 199) and a retrospective cohort (BUFF cohort, n = 158). All participants were patients with undiagnosed pleural effusion (PE). We used receiver operating characteristic (ROC) curves to evaluate the diagnostic accuracy of CR. The effect of age on the diagnostic accuracy of CR was investigated by adjusting the upper limit of age for participant enrolment.

RESULTS

Eighty-eight MPE patients were verified in the SIMPLE cohort, and thirty-five MPE patients were verified in the BUFF cohort. The AUCs of CR in the SIMPLE and BUFF cohorts were 0.60 (95% CI: 0.52-0.68) and 0.63 (95% CI: 0.54-0.71), respectively. In both cohorts, the AUCs of CR decreased with the advancement of age.

CONCLUSION

Age can affect the diagnostic accuracy of CR for MPE. CR has limited diagnostic value in older patients.

KEY MESSAGE

Cancer ratio is a promising diagnostic marker for malignant pleural effusion. This study revealed that its diagnostic accuracy decreased in older patients. Its diagnostic accuracy is overestimated by previous studies using tuberculosis and pneumonia patients as controls.

Incremental predictive value of platelet parameters for preeclampsia: results from a large prospective cohort study

BACKGROUND

Platelet parameters during pregnancy were associated with the risk of preeclampsia (PE), but the predictive value of these parameters for PE remained unclear. Our aim was to clarify the individual and incremental predictive value of platelet parameters, including platelet count (PC), mean platelet volume (MPV), plateletcrit (PCT), and platelet distribution width (PDW) for PE.

METHODS

This study was based on the Born in Guangzhou Cohort Study in China. Data on platelet parameters were extracted from medical records of routine prenatal examinations. Receiver operating characteristic (ROC) curve was performed to analyze the predictive ability of platelet parameters for PE. Maternal characteristic factors proposed by NICE and ACOG were used to develop the base model. Detection rate (DR), integrated discrimination improvement (IDI) and continuous net reclassification improvement (NRI) were calculated compared with the base model to assess the incremental predictive value of platelet parameters.

RESULTS

A total of 30,401 pregnancies were included in this study, of which 376 (1.24%) were diagnosed with PE. Higher levels of PC and PCT were observed at 12-19 gestational weeks in women who developed PE later. However, no platelet parameters before 20 weeks of gestation reliably distinguished between PE complicated pregnancy and non-PE complicated pregnancy, with all values of the areas under the ROC curves (AUC) below 0.70. The addition of platelet parameters at 16-19 gestational weeks to the base model increased the DR for preterm PE from 22.9 to 31.4% at a fixed false positive rate of 5%, improved the AUC from 0.775 to 0.849 (p = 0.015), and yielded a NRI of 0.793 (p < 0.001), and an IDI of 0.0069 (p = 0.035). Less but significant improvement in prediction performance was also observed for term PE and total PE when all the four platelet parameters were added to the base model.

CONCLUSIONS

Although no single platelet parameter at the early stage of pregnancy identified PE with high accuracy, the addition of platelet parameters to known independent risk factors could improve the prediction of PE.

Genetic Risk Scores and Missing Heritability in Ovarian Cancer

Ovarian cancers are curable by surgical resection when discovered early. Unfortunately, most ovarian cancers are diagnosed in the later stages. One strategy to identify early ovarian tumors is to screen women who have the highest risk. This opinion article summarizes the accuracy of different methods used to assess the risk of developing ovarian cancer, including family history, BRCA genetic tests, and polygenic risk scores. The accuracy of these is compared to the maximum theoretical accuracy, revealing a substantial gap. We suggest that this gap, or missing heritability, could be caused by epistatic interactions between genes. An alternative approach to computing genetic risk scores, using chromosomal-scale length variation should incorporate epistatic interactions. Future research in this area should focus on this and other alternative methods of characterizing genomes.

The Value of Handgrip Strength and Self-Rated Squat Ability in Predicting Mild Cognitive Impairment: Development and Validation of a Prediction Model

Early identification of individuals with mild cognitive impairment (MCI) is essential to combat worldwide dementia threats. Physical function indicators might be low-cost early markers for cognitive decline. To establish an early identification tool for MCI by combining physical function indicators (upper and lower limb function) via a clinical prediction modeling strategy. A total of 5393 participants aged 60 or older were included in the model. The variables selected for the model included sociodemographic characteristics, behavioral factors, mental status and chronic conditions, upper limb function (handgrip strength), and lower limb function (self-rated squat ability). Two models were developed to test the predictive value of handgrip strength (Model 1) or self-rated squat ability (Model 2) separately, and Model 3 was developed by combining handgrip strength and self-rated squat ability. The 3 models all yielded good discrimination performance (area under the curve values ranged from 0.719 to 0.732). The estimated net reclassification improvement values were 0.3279 and 0.1862 in Model 3 when comparing Model 3 to Model 1 and Model 2, respectively. The integrated discrimination improvement values were estimated as 0.0139 and 0.0128 when comparing Model 3 with Model 1 and Model 2, respectively. The model that contains both upper and lower limb function has better performance in predicting MCI. The final prediction model is expected to assist health workers in early identification of MCI, thus supporting early interventions to reduce future risk of AD, particularly in socioeconomically deprived communities.

Diagnostic accuracy of pleural fluid to serum carcinoembryonic antigen ratio and delta value for malignant pleural effusion: findings from two cohorts

BACKGROUND

Pleural fluid (PF) carcinoembryonic antigen (CEA) is a widely used diagnostic marker for malignant pleural effusion (MPE). Recent studies revealed that PF to serum CEA was also a promising diagnostic parameter for MPE.

OBJECTIVE

We aimed to investigate whether PF to serum CEA ratio and delta CEA (PF minus serum CEA) provided added value to PF CEA in diagnosing MPE.

METHODS

Patients with pleural effusion in a retrospective cohort (BUFF) and a prospective cohort (SIMPLE) were included. The clinical characteristics of the patients were extracted from their medical records. The diagnostic value of CEA ratio and delta CEA was estimated by a receiver operating characteristics (ROC) curve, net reclassification improvement (NRI), and integrated discrimination improvement (IDI).

RESULTS

A total of 148 patients in the BUFF cohort and 164 patients in the SIMPLE cohort were enrolled. The BUFF cohort had 46 MPE patients and 102 benign pleural effusion (BPE) patients, and the SIMPLE cohort had 85 MPE patients and 79 BPE patients. In both cohorts, MPE patients had significantly higher PF CEA, serum CEA, CEA ratio, and delta CEA. The area under ROC curves (AUCs) of PF CEA, CEA ratio, and delta CEA were 0.78 (95% CI: 0.67-0.88), 0.80 (95% CI: 0.72-0.89) and 0.83 (95% CI: 0.75-0.91) in the BUFF cohort, and 0.89 (95% CI: 0.83-0.94), 0.86 (95% CI: 0.80-0.92), and 0.84 (95% CI: 0.78-0.91) in the SIMPLE cohort. The differences between the AUCs of PF CEA, CEA ratio, and delta CEA did not reach statistical significance. The continuous NRI and IDI of CEA ratio and delta CEA were <0.

CONCLUSION

CEA ratio and delta value cannot provide added diagnostic value to PF CEA. The simultaneous determination of serum and PF CEA should not be adopted in clinical practice.

Diagnostic accuracy of pleural fluid lactate dehydrogenase to adenosine deaminase ratio for tuberculous pleural effusion: an analysis of two cohorts

Background

This study aimed to evaluate the diagnostic accuracy of pleural fluid (PF) lactate dehydrogenase (LDH) to adenosine deaminase (ADA) (LDH/ADA) ratio for tuberculous pleural effusion (TPE). Especially to explore whether the LDH/ADA ratio provides added diagnostic value to ADA.

Methods

The diagnostic accuracy of PF LDH/ADA ratio and ADA for TPE was evaluated in two cohorts, named the BUFF (Biomarkers for patients with Undiagnosed pleural eFFusion) cohort (62 with TPE and 194 with non-TPE) and the SIMPLE (a Study Investigating Markers in PLeural Effusion) cohort (33 with TPE and 177 with non-TPE). Receiver operating characteristic (ROC) curve and decision curve were used to measure the diagnostic accuracy of the PF LDH/ADA ratio. The added diagnostic value of the LDH/ADA ratio to ADA was evaluated with net reclassification improvement (NRI) and integrated discrimination improvement (IDI).

Results

The area under the ROC curves (AUCs) of PF ADA and LDH/ADA ratio in the BUFF cohort were 0.76 and 0.74, respectively. In the SIMPLE cohort, the AUCs of PF ADA and LDH/ADA ratio were 0.80 and 0.85, respectively. The decision curves of PF LDH/ADA and ADA were close in both the BUFF and SIMPLE cohorts. The NRI and IDI analyses did not reveal any added diagnostic value of LDH/ADA to ADA.

Conclusions

PF LDH/ADA ratio has moderate diagnostic accuracy for TPE. It does not provide added diagnostic value beyond ADA. The current evidence does not support LDH/ADA ratio for diagnosing TPE.

Utility of Investigations, History, and Physical Examination in "Medical Clearance" of Psychiatric Patients: A Meta-Analysis

OBJECTIVE

Few reviews and no meta-analyses have explored the utility of investigations, such as laboratory tests, among patients presenting with psychiatric symptoms, and none has explored the yield of history and physical examination. A meta-analysis of studies exploring the utility of "medical clearance" among adult psychiatric patients was conducted.

METHODS

PubMed, PsycInfo, and Web of Science were systematically searched from inception until February 15, 2021. Primary outcome was detection by investigations (e.g., bloodwork and imaging), history, or physical examination of an illness that caused or aggravated psychiatric symptoms or was comorbid and that resulted in change in the patient's diagnosis or management ("yield"). A mixed-effects meta-analysis with inverse-variance weighting was used to pool results.

RESULTS

Twenty-five cross-sectional studies were included. Pooled yield of investigations was 1.1% (95% confidence interval [CI]=0.5%-2.2%), although yield was relatively higher among disoriented, agitated, or older patients. Yield was higher in the inpatient setting, compared with the emergency room, with similar results by approach (protocolized versus nonprotocolized). Compared with investigations, yield of history and physical examination was higher (15.6%, 95% CI=9.1%-25.6%, and 14.9%, 95% CI=8.1%-25.9%, respectively), with nonsignificant differences by evaluator (psychiatrist versus nonpsychiatrist) for physical examination.

CONCLUSIONS

Investigations were of relatively low yield, especially when weighed against cost and potential harm, and they should not be routinely conducted for patients presenting with primarily psychiatric complaints, although certain subgroups may benefit. History and physical examination, by contrast, should be undertaken for all patients, ideally with participation of the consulting psychiatrist.

Performance of a Multianalyte 'Rule-Out' Assay in Pregnant Individuals With Suspected Preeclampsia

BACKGROUND

The ability to diagnose preeclampsia clinically is suboptimal. Our objective was to validate a novel multianalyte assay and characterize its performance, when intended for use as an aid to rule-out preeclampsia.

METHODS

Prospective, multicenter cohort study of pregnant individuals presenting between 280/7 and 366/7 weeks' with preeclampsia-associated signs and symptoms. Individuals not diagnosed with preeclampsia after baseline evaluation were enrolled in the study cohort, with those who later developed preeclampsia, classified as cases and compared with a negative control group who did not develop preeclampsia. Individuals with assay values at time of enrollment ≥0.0325, determined using a previously developed algorithm, considered at risk. The primary analysis was the time to develop preeclampsia assessed using a multivariate Cox regression model.

RESULTS

One thousand thirty-six pregnant individuals were enrolled in the study cohort with an incidence of preeclampsia of 30.3% (27.6%-33.2%). The time to develop preeclampsia was shorter for those with an at-risk compared with negative assay result (log-rank P<0.0001; adjusted hazard ratio of 4.81 [3.69-6.27, P<0.0001]). The performance metrics for the assay to rule-out preeclampsia within 7 days of enrollment showed a sensitivity 76.4% (67.5%-83.5%), negative predictive value 95.0% (92.8%-96.6%), and negative likelihood ratio 0.46 (0.32-0.65). Assay performance improved if delivery occurred <37 weeks and for individuals enrolled between 28 and 35 weeks.

CONCLUSIONS

We confirmed that a novel multianalyte assay was associated with the time to develop preeclampsia and has a moderate sensitivity and negative likelihood ratio but high negative predictive value when assessed as an aid to rule out preeclampsia within 7 days of enrollment.

REGISTRATION

The study was registered on Clinicaltrials.gov (Identifier NCT02780414).

Association of inflammatory markers with cerebral small vessel disease in community-based population

Background

This study investigated the relationships of neutrophil count (NC), neutrophil-to-lymphocyte ratio (NLR) and systemic immune-inflammation index (SII) with cerebral small vessel disease (CSVD).

Methods

A total of 3052 community-dwelling residents from the Poly-vasculaR Evaluation for Cognitive Impairment and vaScular Events (PRECISE) study were involved in this cross-sectional study. CSVD burden and imaging markers, including white matter hyperintensity (WMH), lacunes, cerebral microbleeds (CMBs) and enlarged perivascular spaces in basal ganglia (BG-EPVS), were assessed according to total CSVD burden score. The associations of NC, NLR and SII with CSVD and imaging markers were evaluated using logistic regression models. Furthermore, two-sample Mendelian randomization (MR) analysis was performed to investigate the genetically predicted effect of NC on CSVD. The prognostic performances of NC, NLR and SII for the presence of CSVD were assessed.

Results

At baseline, the mean age was 61.2 ± 6.7 years, and 53.5% of the participants were female. Higher NC was suggestively associated with increased total CSVD burden and modified total CSVD burden (Q4 vs. Q1: common odds ratio (cOR) 1.33, 95% CI 1.05–1.70; cOR 1.28, 95% CI 1.02–1.60) and marginally correlated with the presence of CSVD (OR 1.29, 95% CI 1.00–1.66). Furthermore, elevated NC was linked to a higher risk of lacune (OR 2.13, 95% CI 1.25–3.62) and moderate-to-severe BG-EPVS (OR 1.67, 95% CI 1.14–2.44). A greater NLR was related to moderate-to-severe BG-EPVS (OR 1.68, 95% CI 1.16–2.45). Individuals with a higher SII had an increased risk of modified WMH burden (OR 1.35, 95% CI 1.08–1.69) and moderate-to-severe BG-EPVS (OR 1.70, 95% CI 1.20–2.41). MR analysis showed that genetically predicted higher NC was associated with an increased risk of lacunar stroke (OR 1.20, 95% CI 1.04–1.39) and small vessel stroke (OR 1.21, 95% CI 1.06–1.38). The addition of NC to the basic model with traditional risk factors improved the predictive ability for the presence of CSVD, as validated by the net reclassification index and integrated discrimination index (all p < 0.05).

Conclusions

This community-based population study found a suggestive association between NC and CSVD, especially for BG-EPVS and lacune, and provided evidence supporting the prognostic significance of NC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12974-022-02468-0.

Performance metric curve analysis framework to assess impact of the decision variable threshold, disease prevalence, and dataset variability in two-class classification

Purpose: The aim of this study is to (1) demonstrate a graphical method and interpretation framework to extend performance evaluation beyond receiver operating characteristic curve analysis and (2) assess the impact of disease prevalence and variability in training and testing sets, particularly when a specific operating point is used. Approach: The proposed performance metric curves (PMCs) simultaneously assess sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV), and the 95% confidence intervals thereof, as a function of the threshold for the decision variable. We investigated the utility of PMCs using six example operating points associated with commonly used methods to select operating points (including the Youden index and maximum mutual information). As an example, we applied PMCs to the task of distinguishing between malignant and benign breast lesions using human-engineered radiomic features extracted from dynamic contrast-enhanced magnetic resonance images. The dataset had 1885 lesions, with the images acquired in 2015 and 2016 serving as the training set (1450 lesions) and those acquired in 2017 as the test set (435 lesions). Our study used this dataset in two ways: (1) the clinical dataset itself and (2) simulated datasets with features based on the clinical set but with five different disease prevalences. The median and 95% CI of the number of type I (false positive) and type II (false negative) errors were determined for each operating point of interest. Results: PMCs from both the clinical and simulated datasets demonstrated that PMCs could support interpretation of the impact of decision threshold choice on type I and type II errors of classification, particularly relevant to prevalence. Conclusion: PMCs allow simultaneous evaluation of the four performance metrics of sensitivity, specificity, PPV, and NPV as a function of the decision threshold. This may create a better understanding of two-class classifier performance in machine learning.

The diagnostic process from primary care to child and adolescent mental healthcare services: the incremental value of information conveyed through referral letters, screening questionnaires and structured multi-informant assessment

BACKGROUND

A variety of information sources are used in the best-evidence diagnostic procedure in child and adolescent mental healthcare, including evaluation by referrers and structured assessment questionnaires for parents. However, the incremental value of these information sources is still poorly examined.

AIMS

To quantify the added and unique predictive value of referral letters, screening, multi-informant assessment and clinicians' remote evaluations in predicting mental health disorders.

METHOD

Routine medical record data on 1259 referred children and adolescents were retrospectively extracted. Their referral letters, responses to the Strengths and Difficulties Questionnaire (SDQ), results on closed-ended questions from the Development and Well-Being Assessment (DAWBA) and its clinician-rated version were linked to classifications made after face-to-face intake in psychiatry. Following multiple imputations of missing data, logistic regression analyses were performed with the above four nodes of assessment as predictors and the five childhood disorders common in mental healthcare (anxiety, depression, autism spectrum disorders, attention-deficit hyperactivity disorder, behavioural disorders) as outcomes. Likelihood ratio tests and diagnostic odds ratios were computed.

RESULTS

Each assessment tool significantly predicted the classified outcome. Successive addition of the assessment instruments improved the prediction models, with the exception of behavioural disorder prediction by the clinician-rated DAWBA. With the exception of the SDQ for depressive and behavioural disorders, all instruments showed unique predictive value.

CONCLUSIONS

Structured acquisition and integrated use of diverse sources of information supports evidence-based diagnosis in clinical practice. The clinical value of structured assessment at the primary-secondary care interface should now be quantified in prospective studies.

Can periodontal measures assist in the identification of adults with undiagnosed hyperglycaemia? A systematic review

AIM

The aim of this review was to answer the following question: Can periodontal measures be used to identify dental patients with undiagnosed hyperglycaemia?

MATERIALS AND METHODS

Systematic searches of electronic databases and the grey literature were carried out to identify studies developing and/or validating prediction models, based on any periodontal measure, to screen adults for undiagnosed hyperglycaemia (pre-diabetes and diabetes). Risk of bias was evaluated using the PRediction mOdel risk-of-Bias ASsessment Tool (PROBAST).

RESULTS

Ten studies were identified, of which eight were model development studies. The remaining two studies reported the external validation of one existing prediction model. The periodontal prediction model with some evidence of external validation showed moderate diagnostic performance in the development sample but lower performance in the external validation samples. According to PROBAST, all studies had high risk of bias mainly due to methodological limitations in data analysis, but also in the recruitment of participants, choice and measurement of periodontal predictors and diabetes.

CONCLUSIONS

There is a need for more robust external validation studies of existing prediction models adhering to current recommendations. Dental professionals who see patients at risk of diabetes and routinely collect periodontal measures have an important role to play in their identification and referral.

Ceramides and phospholipids in plasma extracellular vesicles are associated with high risk of major cardiovascular events after carotid endarterectomy

Ceramides and phosphatidylcholines (PCs) are bioactive lipids and lipid bilayer membrane components. Distinct ceramides/PCs (ratios) predict cardiovascular outcome in patients with coronary artery disease. Extracellular vesicles (EVs) are proposed biomarkers for cardiovascular disease and contain ceramides/PCs. Ceramides/PCs have not been studied in patients undergoing carotid endarterectomy (CEA) nor in EVs. We therefore investigated whether levels of ceramides/PCs in plasma and EVs are associated with postoperative risk of major adverse cardiovascular events (MACE) following CEA. In 873 patients undergoing CEA of the Athero-Express biobank, we quantitatively measured seven ceramides/PCs in preoperative blood samples: Cer(d18:1/16:0), Cer(d18:1/18:0), Cer(d18:1/24:0), Cer(d18:1/24:1), PC(14:0/22:6), PC(16:0/16:0) and PC(16:0/22:5) in plasma and two plasma EV-subfractions (LDL and TEX). We analyzed the association of ceramides, PCs and their predefined ratios with the three-year postoperative risk of MACE (including stroke, myocardial infarction and cardiovascular death). A total of 138 patients (16%) developed MACE during the three-year follow-up. In the LDL-EV subfraction, higher levels of Cer(d18:1/24:1) and Cer(d18:1/16:0)/PC(16:0/22:5) ratio were significantly associated with an increased risk of MACE (adjusted HR per SD [95% CI] 1.24 [1.01–1.53] and 1.26 [1.04–1.52], respectively). In the TEX-EV subfraction, three ratios Cer(d18:1/16:0)/Cer(d18:1/24:0), Cer(d18:1/18:0)/Cer(d18:1/24:0) and Cer(d18:1/24:1)/Cer(d18:1/24:0) were positively associated with MACE (adjusted HR per SD 1.34 [1.06–1.70], 1.24 [1.01–1.51] and 1.31 [1.08–1.58], respectively). In conclusion, distinct ceramides and PCs in plasma EVs determined in preoperative blood were independently associated with an increased 3-year risk of MACE after CEA. These lipids are therefore potential markers to identify high-risk CEA patients qualifying for secondary preventive add-on therapy.

Predictive Added Value of Selected Plasma Lipids to a Re-estimated Minimal Risk Tool

Background: Lipidomics is emerging for biomarker discovery in cardiovascular disease, and circulating lipids are increasingly incorporated in risk models to predict cardiovascular events. Moreover, specific classes of lipids, such as sphingomyelins, ceramides, and triglycerides, have been related to coronary artery disease (CAD) severity and plaque characteristics. To avoid unnecessary testing, it is important to identify individuals at low CAD risk. The only pretest model available so far to rule out the presence of coronary atherosclerosis in patients with chest pain, but normal coronary arteries, is the minimal risk tool (MRT).

Aim: Using state-of-the-art statistical methods, we aim to verify the additive predictive value of a set of lipids, derived from targeted plasma lipidomics of suspected CAD patients, to a re-estimated version of the MRT for ruling out the presence of coronary atherosclerosis assessed by coronary CT angiography (CCTA).

Methods: Two hundred and fifty-six subjects with suspected stable CAD recruited from five European countries within H2020-SMARTool, undergoing CCTA and blood sampling for clinical biochemistry and lipidomics, were selected. The MRT was validated by regression methods and then re-estimated (reMRT). The reMRT was used as a baseline model in a likelihood ratio test approach to assess the added predictive value of each lipid from 13 among ceramides, triglycerides, and sphingomyelins. Except for one lipid, the analysis was carried out on more than 240 subjects for each lipid. A sensitivity analysis was carried out by considering two alternative models developed on the cohort as baseline models.

Results: In 205 subjects, coronary atherosclerosis ranged from minimal lesions to overt obstructive CAD, while in 51 subjects (19.9%) the coronary arteries were intact. Four triglycerides and seven sphingomyelins were significantly (p < 0.05) and differentially expressed in the two groups and, at a lesser extent, one ceramide (p = 0.067). The probability of being at minimal risk was significantly better estimated by adding either Cer(d18:1/16:0) (p = 0.01), SM(40:2) (p = 0.04), or SM(41:1) at a lesser extent (p = 0.052) to reMRT than by applying the reMRT alone. The sensitivity analysis confirmed the relevance of these lipids. Furthermore, the addition of SM(34:1), SM(38:2), SM(41:2), and SM(42:4) improved the predictive performance of at least one of the other baseline models. None of the selected triglycerides was found to provide an added value.

Conclusions: Plasma lipidomics can be a promising source of diagnostic and prognostic biomarkers in cardiovascular disease, exploitable not only to assess the risk of adverse events but also to identify subjects without coronary atherosclerosis, thus reducing unnecessary further testing in normal subjects.

The journey is just as important as the destination-Digital neuropsychological assessment provides performance stability measures in patients with acquired brain injury

BACKGROUND

Cognitive performances on neuropsychological paper-and-pencil tests are generally evaluated quantitatively by examining a final score (e.g., total duration). Digital tests allow for a quantitative evaluation of "how" a patient attained a final score, which opens the possibility to assess more subtle cognitive impairment even when final scores are evaluated as normal. We assessed performance stability (i.e., the number of fluctuations in test performance) to investigate (1) differences in performance stability between patients with acquired brain injury (ABI) and healthy controls; (2) the added value of performance stability measures in patients with ABI; and (3) the relation between performance stability and cognitive complaints in daily life in patients with ABI.

METHODS

We administered three digital neuropsychological tests (Rey Auditory Verbal Learning Test, Trail Making Test, Stroop Colour and Word Test) and the Cognitive Complaints-Participation (CoCo-P) inventory in patients with ABI (n = 161) and healthy controls (n = 91).

RESULTS

Patients with ABI fluctuated more in their performance on all tests, when compared to healthy controls. Furthermore, 4-15% of patients who performed inside normal range on the conventional final scores were outside normal range on the performance stability measures. The performance stability measures, nor the conventional final scores, were associated with cognitive complaints in daily life.

CONCLUSIONS

Stability in test performance of patients was clearly dissociable from healthy controls, and may assess additional cognitive weaknesses which might not be observed or objectified with paper-and-pencil tests. More research is needed for developing measures better associated with cognitive complaints.

Tumour markers with clinically controlled cut-offs for suspected cancer

BACKGROUND

Due to insufficient scientific evidence, panels of tumour markers (TMs) are currently not recommended for use in suspected cancer. However, recent well-designed studies have revealed a potential clinical value in lung cancer. We analysed the diagnostic accuracy of a panel of 11 circulating TMs with clinically controlled thresholds in the differentiation of cancer from nonmalignant diseases.

METHODS

We prospectively recruited 4776 consecutive patients presenting with focal or nonspecific symptoms suggestive of cancer who underwent testing for 11 serum TMs before diagnosis was known. The study abided by 2015 STARD guidelines. Tumour markers included, among others, carbohydrate antigen 19-9, carcinoembryonic antigen, alpha-fetoprotein, squamous cell carcinoma-associated antigen, prostate-specific antigen (males), neuron-specific enolase, progastrin-releasing peptide and carbohydrate antigen 125. Thresholds were adjusted for the presence of kidney failure, liver disease, effusions and dermatological disorders. Results showing ≥1 TMs with concentrations above threshold were considered positive.

RESULTS

Benign diseases were diagnosed in 3281 (68.7%) patients and cancer in 1495 (31.3%), with epithelial cancers in 1214 (77% at stage IV). When applying criteria for controlled thresholds, overall specificity was 98%. Overall sensitivity of the panel in epithelial cancers was 72.2%, positive predictive value 93% and negative predictive value 90.5%. The area under the receiver operating characteristic curve was 0.920 (95% confidence interval, 0.902-0.924).

CONCLUSIONS

By using clinically controlled cut-offs, the combined panel demonstrated an excellent ability to discriminate epithelial cancers from nonmalignant diseases. However, its use in clinical practice would need formal validation through a multicentre controlled trial assessing a panel-guided strategy vs. standard diagnosis.

Added value of clinical prediction rules for bacteremia in hemodialysis patients: An external validation study

Introduction

Having developed a clinical prediction rule (CPR) for bacteremia among hemodialysis (HD) outpatients (BAC-HD score), we performed external validation.

Materials & methods

Data were collected on maintenance HD patients at two Japanese tertiary-care hospitals from January 2013 to December 2015. We enrolled 429 consecutive patients (aged ≥ 18 y) on maintenance HD who had had two sets of blood cultures drawn on admission to assess for bacteremia. We validated the predictive ability of the CPR using two validation cohorts. Index tests were the BAC-HD score and a CPR developed by Shapiro et al. The outcome was bacteremia, based on the results of the admission blood cultures. For added value, we also measured changes in the area under the receiver operating characteristic curve (AUC) using logistic regression and Net Reclassification Improvement (NRI), in which each CPR was added to the basic model.

Results

In Validation cohort 1 (360 subjects), compared to a Model 1 (Basic Model) AUC of 0.69 (95% confidence interval [95% CI]: 0.59–0.80), the AUC of Model 2 (Basic model + BAC-HD score) and Model 3 (Basic model + Shapiro’s score) increased to 0.8 (95% CI: 0.71–0.88) and 0.73 (95% CI: 0.63–0.83), respectively. In validation cohort 2 (96 subjects), compared to a Model 1 AUC of 0.81 (95% CI: 0.68–0.94), the AUCs of Model 2 and Model 3 increased to 0.83 (95% CI: 0.72–0.95) and 0.85 (95% CI: 0.76–0.94), respectively. NRIs on addition of the BAC-HD score and Shapiro’s score were 0.3 and 0.06 in Validation cohort 1, and 0.27 and 0.13, respectively, in Validation cohort 2.

Conclusion

Either the BAC-HD score or Shapiro’s score may improve the ability to diagnose bacteremia in HD patients. Reclassification was better with the BAC-HD score.

Evaluation of Diagnostic Tests

As technology advances, diagnostic tests continue to improve and each year, we are presented with new alternatives to standard procedures. Given the plethora of diagnostic alternatives, diagnostic tests must be evaluated to determine their place in the diagnostic armamentarium. The first step involves determining the accuracy of the test, including the sensitivity and specificity, positive and negative predictive values, likelihood ratios for positive and negative tests, and receiver operating characteristic (ROC) curves. The role of the test in a diagnostic pathway has then to be determined, following which the effect on patient outcome should be examined.

Panel of novel urine biomarkers for incident microalbuminuria in people with type 2 diabetes mellitus

AIM

The need to identify novel biomarkers for early diagnosis and treatment of diabetic nephropathy is widely recognized. However, only a few studies have investigated the association between biomarkers and the onset of albuminuria. In this study, we aimed to investigate a panel of biomarkers suitable for predicting microalbuminuria.

METHODS

Some 346 Japanese people with type 2 diabetes exhibiting normoalbuminuria were studied. The endpoint was defined as the onset of microalbuminuria. Thirty biomarkers were selected from among urinary biomarkers described in previous studies. A panel of biomarkers was selected using least absolute shrinkage and selection operator (LASSO). The prognostic performance of the developed panel was evaluated.

RESULTS

During a mean follow-up of 6.2 years, 45 people progressed to microalbuminuria. A composite panel of six biomarkers (monocyte chemoattractant protein-1, osteopontin, soluble human tumour necrosis factor receptor-1, tenascin C, vascular endothelial growth factor-A and kidney injury molecule-1) was developed using LASSO. Compared with the basal model comprising estimated GFR and urinary albumin-to-creatinine ratio, addition of these six biomarkers significantly increased the overall C index from 0.773 to 0.824 (P = 0.019). Net reclassification improvement and integrated discrimination improvement were estimated to be 0.412 (P = 0.049) and 0.040 (P = 0.040), respectively. Decision curve analysis also showed that the model with the six novel biomarkers had a better prognostic value for predicting the onset of microalbuminuria. The optimism was moderate or negligible according to measures.

CONCLUSIONS

The panel consisting of six novel urinary biomarkers effectively predicted incident microalbuminuria in people with type 2 diabetes.

Translating Laboratory Tests into Clinical Practice: A Conceptual Framework

The use of laboratory biomarkers in clinical practice is rapidly increasing. Laboratory tests are, however, rarely evaluated adequately before implementation, and the utility of many tests is essentially unclear. An important reason for this knowledge gap is that a comprehensive and generally accepted methodological framework supporting evaluation studies is essentially lacking. Researchers, clinicians, and decision-makers are often not aware of the methodological tools available and face problems with the appraisal of a test's utility. With the present article, I aim to summarize current concepts and methodological tools and propose a framework for a phased approach that could be used in future evaluation projects. Future research will refine this suggested framework by identifying problems in current evaluation projects, specifying methodological criteria for all phases, as well as developing advanced methodological tools.

Valid cardiac biomarkers. Part I

Biomarkers are widely used for the diagnosing of diseases, evaluation of their severity, prediction of outcomes, and for monitoring the effectiveness and safety of targeted therapy. This review describes specific cardiac biomarkers approved by FDA (Food and Drug AdministrationбUSA). The list of described biomarkers is not exhaustive. In addition to the general concepts of biomarkers, definitions and classification, this Part I of the review contains data on diagnostic and prognostic biomarkers of cardiovascular diseases associated with atherosclerosis.

The added value of periodontal measurements for identification of diabetes among Saudi adults

BACKGROUND

The aims of this study were to develop a prediction model for identification of individuals with diabetes based on clinical and perceived periodontal measurements; and to evaluate its added value when combined with standard diabetes screening tools.

METHODS

The study was carried out among 250 adults attending primary care clinics in Riyadh (Saudi Arabia). The study adopted a case-control approach, where diabetes status was first ascertained, and the Finnish Diabetes Risk Score (FINDRISC), Canadian Diabetes Risk questionnaire (CANRISK), and periodontal examinations were carried out afterward.

RESULTS

A periodontal prediction model (PPM) including three periodontal indicators (missing teeth, percentage of sites with pocket probing depth ≥6 mm, and mean pocket probing depth) had an area under the curve (AUC) of 0.694 (95% Confidence Interval: 0.612-0.776) and classified correctly 62.4% of participants. The FINDRISC and CANRISK tools had AUCs of 0.766 (95% CI: 0.690-0.843) and 0.821 (95% CI: 0.763-0.879), respectively. The addition of the PPM significantly improved the AUC of FINDRISC (P = 0.048) but not of CANRISK (P = 0.144), with 26.8% and 9.8% of participants correctly reclassified, respectively. Finally, decision curve analysis showed that adding the PPM to both tools would result in net benefits among patients with probability scores lower than 70%.

CONCLUSIONS

This study showed that periodontal measurements could play a role in identifying individuals with diabetes, and that addition of clinical periodontal measurements improved the performance of FINDRISC and CANRISK.

Preventing overuse of laboratory diagnostics: a case study into diagnosing anaemia in Dutch general practice

Background

More information is often thought to improve medical decision-making, which may lead to test overuse. This study assesses which out of 15 laboratory tests contribute to diagnosing the underlying cause of anaemia by general practitioners (GPs) and determines a potentially more efficient subset of tests for setting the correct diagnosis.

Methods

Logistic regression was performed to determine the impact of individual tests on the (correct) diagnosis. The statistically optimal test subset for diagnosing a (correct) underlying cause of anaemia by GPs was determined using data from a previous survey including cases of real-world anaemia patients.

Results

Only 9 (60%) of the laboratory tests, and patient age, contributed significantly to the GPs’ ability to diagnose an underlying cause of anaemia (CRP, ESR, ferritin, folic acid, haemoglobin, leukocytes, eGFR/MDRD, reticulocytes and serum iron). Diagnosing the correct underlying cause may require just five (33%) tests (CRP, ferritin, folic acid, MCV and transferrin), and patient age.

Conclusions

In diagnosing the underlying cause of anaemia a subset of five tests has most added value. The real-world impact of using only this subset should be further investigated. As illustrated in this case study, a statistical approach to assessing the added value of tests may reduce test overuse.

Monocyte Distribution Width: A Novel Indicator of Sepsis-2 and Sepsis-3 in High-Risk Emergency Department Patients

Supplemental Digital Content is available in the text.

Objectives:

Most septic patients are initially encountered in the emergency department where sepsis recognition is often delayed, in part due to the lack of effective biomarkers. This study evaluated the diagnostic accuracy of peripheral blood monocyte distribution width alone and in combination with WBC count for early sepsis detection in the emergency department.

Design:

An Institutional Review Board approved, blinded, observational, prospective cohort study conducted between April 2017 and January 2018.

Setting:

Subjects were enrolled from emergency departments at three U.S. academic centers.

Patients:

Adult patients, 18–89 years, with complete blood count performed upon presentation to the emergency department, and who remained hospitalized for at least 12 hours. A total of 2,212 patients were screened, of whom 2,158 subjects were enrolled and categorized per Sepsis-2 criteria, such as controls (n = 1,088), systemic inflammatory response syndrome (n = 441), infection (n = 244), and sepsis (n = 385), and Sepsis-3 criteria, such as control (n = 1,529), infection (n = 386), and sepsis (n = 243).

Interventions:

The primary outcome determined whether an monocyte distribution width of greater than 20.0 U, alone or in combination with WBC, improves early sepsis detection by Sepsis-2 criteria. Secondary endpoints determined monocyte distribution width performance for Sepsis-3 detection.

Measurements and Main Results:

Monocyte distribution width greater than 20.0 U distinguished sepsis from all other conditions based on either Sepsis-2 criteria (area under the curve, 0.79; 95% CI, 0.76–0.82) or Sepsis-3 criteria (area under the curve, 0.73; 95% CI, 0.69–0.76). The negative predictive values for monocyte distribution width less than or equal to 20 U for Sepsis-2 and Sepsis-3 were 93% and 94%, respectively. Monocyte distribution width greater than 20.0 U combined with an abnormal WBC further improved Sepsis-2 detection (area under the curve, 0.85; 95% CI, 0.83–0.88) and as reflected by likelihood ratio and added value analyses. Normal WBC and monocyte distribution width inferred a six-fold lower sepsis probability.

Conclusions:

An monocyte distribution width value of greater than 20.0 U is effective for sepsis detection, based on either Sepsis-2 criteria or Sepsis-3 criteria, during the initial emergency department encounter. In tandem with WBC, monocyte distribution width is further predicted to enhance medical decision making during early sepsis management in the emergency department.

Optimizing Outcome Prediction Scores in Patients Undergoing Endovascular Thrombectomy for Large Vessel Occlusions Using Collateral Grade on Computed Tomography Angiography

BACKGROUND

Although several outcome prediction scores incorporated with pretreatment variables have been developed for acute ischemic stroke (AIS) patients, there is not currently a prediction score that includes pretreatment imaging that can show salvageable brain tissue.

OBJECTIVE

To evaluate whether addition of the collateral grade on computed tomography angiography to previously published prediction scores could increase accuracy of clinical outcome prediction in endovascular thrombectomy (EVT) for AIS.

METHODS

This study used a retrospective multicenter registry for patients undergoing EVT for anterior circulation large vessel occlusion. Three previously published outcome prediction scores (Houston intra-arterial therapy 2, HIAT2; totaled health risks in vascular events, THRIVE; and Pittsburgh response to endovascular therapy, PRE scores) were tested in this study. Using 482 deprivation cohorts, areas under the receiver operating characteristic curves (AUC-ROCs) were compared between prediction scores with/without collateral grades in predicting the poor outcomes (modified Rankin Scale 4-6 at 3-mo follow-up) after EVT. We developed modified prediction scores by adding the collateral grade, and their advancement of outcome prediction was validated using 208 independent validation cohorts.

RESULTS

AUC-ROCs of HIAT2, THRIVE, and PRE scores that incorporated with collateral grade were superior in predicting poor outcomes when compared to that of the unmodified scores (P < 0.001). In modified prediction models, 3, 3, and 10 points were added for poor collateral grade to HIAT2, THRIVE, and PRE score. Modified models outperformed unmodified models in testing of the validation cohorts (P < 0.001).

CONCLUSION

The addition of the collateral grade to outcome prediction scores resulted in better prediction of poor outcome after EVT for AIS compared to the prediction scores alone.

Added value of inflammatory markers to vital signs to predict mortality in patients suspected of severe infection

OBJECTIVE

To evaluate the added value of inflammatory markers to vital signs to predict mortality in patients suspected of severe infection.

METHODS

This study was conducted at an acute care hospital (471-bed capacity). Consecutive adult patients suspected of severe infection who presented to either ambulatory care or the emergency department from April 2015 to March 2017 were retrospectively evaluated. A prognostic model for predicting 30-day in-hospital mortality based on previously established vital signs (systolic blood pressure, respiratory rate, and mental status) was compared with an extended model that also included four inflammatory markers (C-reactive protein, neutrophil-lymphocyte ratio, mean platelet volume, and red cell distribution width). Measures of interest were model fit, discrimination, and the net percentage of correctly reclassified individuals at the pre-specified threshold of 10% risk.

RESULTS

Of the 1015 patients included, 66 (6.5%) died. The extended model including inflammatory markers performed significantly better than the vital sign model (likelihood ratio test: p < 0.001), and the c-index increased from 0.69 (range 0.67-0.70) to 0.76 (range 0.75-0.77) (p = 0.01). All included markers except C-reactive protein showed significant contribution to the model improvement. Among those who died, 9.1% (95% CI -2.8-21.8) were correctly reclassified by the extended model at the 10% threshold.

CONCLUSIONS

The inflammatory markers except C-reactive protein showed added predictive value to vital signs. Future studies should focus on developing and validating prediction models for use in individualized predictions including both vital signs and the significant markers.

A Study Investigating Markers in PLeural Effusion (SIMPLE): a prospective and double-blind diagnostic study

INTRODUCTION

Serum and fluid laboratory markers are valuable for exploring the aetiologies of pleural effusion (PE) because of their relative non-invasiveness, low cost, objective result and short turnaround time. The diagnostic accuracy of these potential markers needs to be rigorously evaluated before their widespread application in clinical practice. Here, we plan to perform a Study Investigating Markers in PLeural Effusion (SIMPLE).

METHODS AND ANALYSIS

This is a prospective and double-blind clinical trial which is being performed at the Affiliated Hospital of Inner Mongolia Medical University, China. Adult patients admitted for the evaluation of aetiology of PE from September 2018 to July 2021 will be enrolled after informed consent. Pleural fluid and serum specimens will be collected and stored at -80°C for the laboratory analysis. The final diagnosis will be concurred with further imaging, microbiology, cytology and biopsy if needed. The results of investigated laboratory markers will be unknown to the clinicians who will make diagnosis and the clinical diagnoses will be unknown to the laboratory technicians who will determine markers. The diagnostic accuracy of investigated markers will be assessed using receiver operating characteristics (ROC) curve analysis, multivariable logistic regression model, decision curve analysis (DCA), net reclassification index (NRI) and integrated discriminatory index (IDI).

ETHICS AND DISSEMINATION

The study is approved by the Ethic Committee of the Affiliated Hospital of Inner Mongolia Medical University (NO: 2018011). The results of SIMPLE will be submitted to international scientific peer-reviewed journals or conferences in laboratory medicine or respiratory medicine, thoracic diseases.

TRIAL REGISTRATION NUMBER

Chinese Clinical Trial Registry (ChiCTR1800017449); Pre-results.

Handheld flow meter improves COPD detectability regardless of using a conventional questionnaire: A split-sample validation study

BACKGROUND AND OBJECTIVE

Improved detectability of chronic obstructive pulmonary disease (COPD) using a handheld flow meter (HFM) with symptom-based questionnaires has not been sufficiently evaluated. This study aimed to identify the benefit of using an HFM in COPD screening.

METHODS

A total of 2008 participants, who were ≥ 40 years of age, from Isumi City, Japan, were recruited. We developed two novel point systems for detecting COPD, one incorporated score of HFM alone (sHFM) and the other incorporated the score of International Primary Care Airway Group questionnaire (IPAG) and HFM (sIPAG + HFM). Validation using random sample allocation (split-sample validation) was carried out to assess the predictive performance of these models.

RESULTS

Participants were assigned to a data set for model creation (n = 1007) or a data set for model assessment (n = 1001) to perform split-sample validation. Decision curve analysis showed that the net benefits of sHFM and sIPAG + HFM were higher than that of the IPAG score (sIPAG) and specificity of the former two were also significantly higher than that of sIPAG. However, the curves of sHFM and sIPAG + HFM were crossing and practically the same with no significant difference in sensitivity and specificity.

CONCLUSION

This study confirms that HFM is significantly advantageous in detecting COPD despite the use of a conventional questionnaire.

Understanding and Improving Diagnostic Tests: The Clinician Perspective

Recent advances in molecular and mass screening technologies have paved the way for discovery of novel diagnostic tests and/or biomarkers for accurate identification of specific diseases and organ injuries. However, new diagnostic tests/biomarkers should be subjected to thorough evaluation before introduction into routine clinical practice. This review focuses on the up-to-date methodology in designing and evaluating diagnostic tests/biomarkers, and assessing their clinical utilities for improving health care efficiency, cost-effectiveness and outcomes. In addition to improved diagnostic utilities, future diagnostic tests should be developed in collaboration with our industrial partners and be applicable at the bedside for disease surveillance.

Cancer biomarker discovery and translation: proteomics and beyond

INTRODUCTION

Cancer is often diagnosed at late stages when the chance of cure is relatively low and although research initiatives in oncology discover many potential cancer biomarkers, few transition to clinical applications. This review addresses the current landscape of cancer biomarker discovery and translation with a focus on proteomics and beyond. Areas covered: The review examines proteomic and genomic techniques for cancer biomarker detection and outlines advantages and challenges of integrating multiple omics approaches to achieve optimal sensitivity and address tumor heterogeneity. This discussion is based on a systematic literature review and direct participation in translational studies. Expert commentary: Identifying aggressive cancers early on requires improved sensitivity and implementation of biomarkers representative of tumor heterogeneity. During the last decade of genomic and proteomic research, significant advancements have been made in next generation sequencing and mass spectrometry techniques. This in turn has led to a dramatic increase in identification of potential genomic and proteomic cancer biomarkers. However, limited successes have been shown with translation of these discoveries into clinical practice. We believe that the integration of these omics approaches is the most promising molecular tool for comprehensive cancer evaluation, early detection and transition to Precision Medicine in oncology.

The interpretive contribution of the baseline serum cortisol concentration of the ACTH stimulation test in the diagnosis of pituitary dependent hyperadrenocorticism in dogs

Background

Current recommendation for performing the ACTH stimulation test (ACTHST) for diagnosis of hyperadrenocorticism (HAC) advocates the collection of baseline serum cortisol concentration (BC), but no references for interpretation of its results exist.

Objective

Evaluate the contribution of BC of the ACTHST to the diagnosis of HAC.

Animals

Fifty‐four dogs were evaluated for suspected HAC at a referral hospital.

Methods

Records of dogs that had been evaluated by ACTHST for suspected HAC were reviewed. Receiver operator characteristics (ROC) analyses were used to assess the performance of BC, post‐stimulation serum cortisol concentrations (PC), post‐to‐baseline cortisol concentration difference (DeltaC) and quotient (RatioC) for the diagnosis of HAC by comparing the area under the ROC curve (AUC) of PC to each of the other tests.

Results

The AUC of PC (95% confidence interval [CI]: 0.92; 95% CI, 0.81‐0.98) was significantly higher than AUCs of BC (0.70; 95% CI, 0.56‐0.82; P = .01) and RatioC (0.55; 95% CI, 0.41‐0.69; P < .001), and was not significantly different from AUC of DeltaC (0.86; 95% CI, 0.74‐0.94; P = .09). An optimal cutoff value of 683 nmol/L (24.8 μg/dL) for PC yielded a sensitivity of 86% and a specificity of 94%, respectively, and a cutoff value of 718 nmol/L (26.0 μg/dL) yielded a specificity of 100% with of 81% sensitivity for the diagnosis of pituitary‐dependent HAC.

Conclusion and Clinical Importance

The PC had good discriminatory ability for the diagnosis of HAC. It was comparable to DeltaC, whereas BC and RatioC were ineffective. Current recommendations to collect samples for BC appear redundant.

Simulated driving: The added value of dynamic testing in the assessment of visuo-spatial neglect after stroke

BACKGROUND

Visuo-spatial neglect (VSN) is generally assessed with neuropsychological paper-and-pencil tasks, which are often not sensitive enough to detect mild and/or well-compensated VSN. It is of utmost importance to develop dynamic tasks, resembling the dynamics of daily living.

OBJECTIVE

A simulated driving task was used to assess (1) differences in performance (i.e., position on the road and magnitude of sway) between patients with left- and right-sided VSN, recovered VSN, without VSN, and healthy participants; (2) the relation between average position and VSN severity; and (3) its diagnostic accuracy in relation to traditional tasks.

METHODS

Stroke inpatients were tested with a cancellation task, the Catherine Bergego Scale and the simulated driving task.

RESULTS

Patients with left-sided VSN and recovered VSN deviated more regarding position on the road compared to patients without VSN. The deviation was larger in patients with more severe VSN. Regarding diagnostic accuracy, 29% of recovered VSN patients and 6% of patients without VSN did show abnormal performance on the simulated driving task. The sensitivity was 52% for left-sided VSN. Right-sided VSN was not well detected, probably due to the asymmetric layout.

CONCLUSIONS

Based on these results, the simulated driving task should not be the only task to assess VSN, especially in its current form. Given the heterogenic nature of VSN, the assessment should always consist of several tasks varying in nature and complexity and include a dynamic task to detect mild and/or recovered VSN. A symmetric design should be used when designing novel tasks to assess right-sided VSN.

Risk stratification based on components of the complete blood count in patients with acute coronary syndrome: A classification and regression tree analysis

To develop a risk stratification model based on complete blood count (CBC) components in patients with acute coronary syndrome (ACS) using a classification and regression tree (CART) method. CBC variables and the Global Registry of Acute Coronary Events (GRACE) scores were determined in 2,693 patients with ACS. The CART analysis was performed to classify patients into different homogeneous risk groups and to determine predictors for major adverse cardiovascular events (MACEs) at 1-year follow-up. The CART algorithm identified the white blood cell count, hemoglobin, and mean platelet volume levels as the best combination to predict MACE risk. Patients were stratified into three categories with MACE rates ranging from 3.0% to 29.8%. Kaplan-Meier analysis demonstrated MACE risk increased with the ascending order of the CART risk categories. Multivariate Cox regression analysis showed that the CART risk categories independently predicted MACE risk. The predictive accuracy of the CART risk categories was tested by measuring discrimination and graphically assessing the calibration. Furthermore, the combined use of the CART risk categories and GRACE scores yielded a more accurate predictive value for MACEs. Patients with ACS can be readily stratified into distinct prognostic categories using the CART risk stratification tool on the basis of CBC components.

Human biomarker interpretation: the importance of intra-class correlation coefficients (ICC) and their calculations based on mixed models, ANOVA, and variance estimates

Human biomonitoring is the foundation of environmental toxicology, community public health evaluation, preclinical health effects assessments, pharmacological drug development and testing, and medical diagnostics. Within this framework, the intra-class correlation coefficient (ICC) serves as an important tool for gaining insight into human variability and responses and for developing risk-based assessments in the face of sparse or highly complex measurement data. The analytical procedures that provide data for clinical and public health efforts are continually evolving to expand our knowledge base of the many thousands of environmental and biomarker chemicals that define human systems biology. These chemicals range from the smallest molecules from energy metabolism (i.e., the metabolome), through larger molecules including enzymes, proteins, RNA, DNA, and adducts. In additiona, the human body contains exogenous environmental chemicals and contributions from the microbiome from gastrointestinal, pulmonary, urogenital, naso-pharyngeal, and skin sources. This complex mixture of biomarker chemicals from environmental, human, and microbiotic sources comprise the human exposome and generally accessed through sampling of blood, breath, and urine. One of the most difficult problems in biomarker assessment is assigning probative value to any given set of measurements as there are generally insufficient data to distinguish among sources of chemicals such as environmental, microbiotic, or human metabolism and also deciding which measurements are remarkable from those that are within normal human variability. The implementation of longitudinal (repeat) measurement strategies has provided new statistical approaches for interpreting such complexities, and use of descriptive statistics based upon intra-class correlation coefficients (ICC) has become a powerful tool in these efforts. This review has two parts; the first focuses on the history of repeat measures of human biomarkers starting with occupational toxicology of the early 1950s through modern applications in interpretation of the human exposome and metabolic adverse outcome pathways (AOPs). The second part reviews different methods for calculating the ICC and explores the strategies and applications in light of different data structures.