Stratum-specific Likelihood Ratios Research Articles

Prospective external validation of the FluScore risk score for influenza in outpatients.

Testing for influenza in patients with acute lower respiratory tract infection (LRTI) is common and in some cases is performed for all patients with LRTI. A more selective approach to testing could be more efficient. We used data from two prospective studies in the US primary and urgent care settings that enrolled patients with acute LRTI or influenza-like illness. Data were collected in the 2016, 2019, 2021, and 2022 flu seasons. All patients underwent polymerase chain reaction (PCR) testing for influenza and the FluScore was calculated based on patient-reported symptoms at their initial visit. The probability of influenza in each risk group was reported, as well as stratum-specific likelihood ratios (SSLRs) for each risk level. The prevalence of influenza within risk groups varied based on overall differences in flu seasons and populations. However, the FluScore exhibited consistent performance across various seasons and populations based on the SSLRs. The FluScore had a consistent SSLR range of 0.20 to 0.23 for the low-risk group, 0.63 to 0.99 for the moderate-risk group, and 1.46 to 1.67 for the high-risk group. The diagnostic odds ratio based on the midpoints of these ranges was 7.25. The FluScore could streamline patient categorization, identifying patients who could be exempted from testing, while identifying candidates for rapid influenza tests. This has the potential to be more efficient than a "one size fits all" test strategy, as it strategically targets the use of tests on patients most likely to benefit. It is potentially usable in a telehealth setting.

Develop and Validate a Prognostic Index With Laboratory Tests to Predict Mortality in Middle-Aged and Older Adults Using Machine Learning Models: A Prospective Cohort Study.

Prognostic indices can enhance personalized predictions of health burdens. However, a simple, practical, and reproducible tool is lacking for clinical use. This study aimed to develop a machine learning-based prognostic index for predicting all-cause mortality in community-dwelling older individuals. We utilized the Healthy Aging Longitudinal Study in Taiwan (HALST) cohort, encompassing data from 5663 participants. Over the 5-year follow-up, 447 deaths were confirmed. A machine learning-based routine blood examination prognostic index (MARBE-PI) was developed using common laboratory tests based on machine learning techniques. Participants were grouped into multiple risk categories by stratum-specific likelihood ratio analysis based on their MARBE-PI scores. The MARBE-PI was subsequently externally validated with an independent population-based cohort from Japan. Beyond age, sex, education level, and BMI, 6 laboratory tests (low-density lipoprotein, albumin, aspartate aminotransferase, lymphocyte count, high-sensitivity C-reactive protein, and creatinine) emerged as pivotal predictors via stepwise logistic regression (LR) for 5-year mortality. The area under curves of MARBE-PI constructed by LR were 0.799 (95% confidence interval [95% CI]: 0.778-0.819) and 0.756 (95% CI: 0.694-0.814) for the internal and external validation data sets, and were 0.801 (95% CI: 0.790-0.811) and 0.809 (95% CI: 0.774-0.845) for the extended 10-year mortality in both data sets, respectively. Risk categories stratified by MARBE-PI showed a consistent dose-response association with mortality. The MARBE-PI also performed comparably with indices constructed with clinical health deficits and/or laboratory results. The MARBE-PI is considered the most applicable measure for risk stratification in busy clinical settings. It holds potential to pinpoint older individuals at elevated mortality risk, thereby aiding clinical decision-making.

The Kessler Psychological Distress Scale in Australian adolescents: Analysis of the second Australian Child and Adolescent Survey of Mental Health and Wellbeing.

The 10-item Kessler Psychological Distress Scale (K10) is used to screen adolescents for mental disorders in Australian clinical practice; however, there are no Australian adolescent normative data. Data were drawn from a nationally representative sample (N = 2964) of Australian adolescents (11-17 years). This study had three aims: (1) to examine concurrent validity between the K10 and Strengths and Difficulties Questionnaire (SDQ) emotional symptoms subscale, (2) to establish normative Australian adolescent K10 data and (3) to determine optimal K10 cut-off scores for screening for major depressive disorder (MDD) via receiver operator characteristic curve analysis and stratum-specific likelihood ratios. The K10 and SDQ emotional symptoms scales were moderately correlated (rs = 0.63, p < 0.001). Older female adolescents reported higher total K10 scores compared with younger female adolescents (15-17 years: M = 20.2, standard error [SE] = 0.3; 11-14 years: M = 16.8, SE = 0.3) and male adolescents (11-14 years: M = 16.6, SE = 0.2; 15-17 years: M = 16.0, SE=0.2). K10 scores to optimally discriminate those with and without MDD varied by age and sex and had low specificities. Stratum-specific likelihood ratios indicated adolescents with a K10 score of ≥30 will have a 12.9 (95% confidence interval = [10.2, 16.2]) increased likelihood of MDD. The K10 has utility for assessing psychological distress in health care and epidemiological research in Australian adolescents. Adolescents with K10 scores in the 'very high' range are at increased risk of MDD. Further assessment of these young people is indicated to identify those with or at risk of developing MDD.

Predictive validity of a parental questionnaire for identifying children with developmental language disorders.

The underdiagnosis of developmental language disorder (DLD) in children is a serious problem in developing countries with limited resources. It has long been noted that the concerns parents have about their children's health and development are richly informative, and if this information can be used for diagnosis, it may provide a means to address the problem of underdiagnosis of DLD. This study aimed to quantify the utility of parental linguistic concern questions (PLCQ) on the identification of language disorders in monolingual Spanish-speaking children in Mexico. It also explored whether a combination of biological and environmental conditions questions (BECQ) might improve the performance of a screening test to identify DLD. A total of 680 monolingual Mexican Spanish-speaking children and their parents from urban areas in Mexico participated in the study. The distribution of responses to questions about DLD concerns was compared between 185 children diagnosed with DLD and 495 control subjects, and multiple logistic regression analysis was performed to select questions with high predictivity, based on the Akaike information criterion. The diagnostic utility of the questions was assessed by receiver operating characteristic (ROC) curves, stratum-specific likelihood ratios (SSLRs), and changes in pretest and post-test probabilities of DLD. A similar procedure was used to explore whether adding BECQ would improve the diagnostic utility of questions about DLD concerns using data of 128 children. Four questions regarding parental linguistic concerns were found to be useful in identifying children with DLD. When all four concerns were present, the SSLR was 8.79, while it was only 0.27 when there were no concerns at all. The estimates of DLD probability increased from 0.12 to 0.55 at pretest and post-test. On the other hand, the BECQ did not perform as well as the PLCQ in identifying DLD, and the improvement in diagnostic performance it provided was limited to one question. The parental questionnaire can be used as a screening tool to help in identifying children with DLD. The data presented in this study underscore the importance of considering linguistic parental concerns as part of the screening process. This is a realistic option to provide a solution to the current problem of underdiagnosis of DLD in Mexico.

Assessment of performance of stratum-specific likelihood ratios of the aldosteronoma resolution score for predicting hypertension cure after adrenalectomy for primary aldosteronism: a systematic review and meta-analysis.

The Aldosteronoma Resolution Score (ARS) is the most studied scoring system for predicting the high likelihood of hypertension cure after adrenalectomy for unilateral primary aldosteronism (PA). However, the ARS's accuracy in PA patients worldwide is uncertain. We aimed to perform a meta-analysis of the accuracy, discrimination, and calibration of the ARS using stratum-specific likelihood ratios (SSLR) by organizing available data from cohort studies. We searched PubMed, Embase (Ovid), the Cochrane CENTRAL, Web of Science to November 2021 according to PRISMA statement. The quality assessment used adapted TRIPOD and PROBAST criteria. Thirteen studies comprising 2158 PA patients from North America (43%), Europe (32%), Asia (22%), and other continents, were included. The pooled estimate of the area under the receiver operating characteristic curve for all studies was 0.77 (95% CI: 0.73-0.81), and the ratio of the observed to expected complete resolution of hypertension (CRH) for all studies was 0.9 (95% CI: 0.8-1.0). The summary estimates of the SSLR for all studies were 0.31, 0.89, and 3.1, for the low (ARS 0-1), medium (ARS 2-3), and high-likelihood group (ARS 4-5) of CRH, respectively. However, substantial heterogeneity existed among studies. Follow-up period, and adrenalectomy AVS (adrenal vein sampling)-guided served as potential sources of heterogeneity for quantitative studies, which were measurement and reference standard for qualitative studies selection. In conclusion, in patients with unilateral PA, the ARS is currently an accurate prediction tool, the easiest and cheapest, for identifying long-term high likelihood of CRH after adrenalectomy, particularly when the adrenalectomy is AVS-guided.

DISCRIMINATION, CALIBRATION, AND STRATUM-SPECIFIC LIKELIHOOD RATIOS FOR THE ALDOSTERONOMA RESOLUTION SCORE: A META-ANALYSIS

Objective: The Aldosteronoma Resolution Score (ARS) is the most studied scoring system for predicting the high likelihood of complete resolution of hypertension (CRH) after adrenalectomy for primary aldosteronism (PA). We aimed to perform a meta-analysis of the accuracy, discrimination, and calibration of the ARS using a novel approach to calculation of stratum-specific likelihood ratios (SSLR). Design and method: We searched PubMed, Embase (Ovid), the Cochrane CENTRAL, Web of Science, the Bielefeld Academic Search Engine (BASE) to November 2021 according to the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) statement. The quality assessment used adapted TRIPOD (Transparent Reporting of a multivariable prediction model for Individual Prognosis Or Diagnosis) and PROBAST (Prediction model Risk Of Bias ASsessment Tool) criteria. Results: Thirteen studies comprising 2,158 PA patients from North America (43%), Europe (32%), Asia (22%), and other continents, were included. The pooled estimate of the area under the receiver operating characteristic curve for all studies was 0.77 (95% CI 0.73–0.81), and the ratio of the observed to expected CRH for all studies was 0.9 (95% CI 0.8–1.0). The summary estimates of the SSLR for all studies were 0.3, 0.9, and 3.1, for the low (ARS 0–1), medium (ARS 2–3), and high-likelihood group (ARS 4–5) of CRH, respectively. For studies with a mean follow-up closest to 6, 12, and 36 months, the likelihood ratios were 0.3, 0.8, and 2.6; 0.3, 0.7, and 3.9; and 0.3, 1.8, and 7.0, respectively. When we compared studies that had performed adrenal vein sampling (AVS) in at least 50% of the cohort (mean 77% vs. 38%), the ARS model’s accuracy doubled in the high-likelihood group (ARS 4–5) and tripled in the only study in which all patients were underwent AVS (Figure). Conclusions: In patients with unilateral PA, the ARS is currently the easiest, cheapest, and accurate prediction tool for identifying the long-term high likelihood of CRH after adrenalectomy, particularly when the adrenalectomy is AVS-guided.

A Data-Driven Approach to Defining the Volume-Outcome Relationship in Lung Transplantation

Advances in immunosuppression, bridging therapies, and ex vivo perfusion and ventilation have led to substantial advances in lung transplantation (LTx). Nevertheless, LTx is associated with substantial morbidity and mortality. Better outcomes have been demonstrated in "high volume" lung transplant centers, but the field lacks a definition of high volume. The present study aims to identify meaningful, data-driven volume thresholds predicting improved outcomes for LTx centers. All single and double LTx cases performed on patients over the age of 18 between 2005 and 2015 in the United Network for Organ Sharing (UNOS) database were reviewed. Patients listed for other organs or transplants performed in centers that were active for less than three of the ten years of the study period were excluded. Under 1% of patients were excluded due to lack of follow-up data. Stratum-specific likelihood ratios (SSLR) were calculated to establish volume thresholds predictive of the primary outcome of 1 year mortality. Demographic and outcomes data were compared between volume strata. A total of 20,153 recipients were included in the final cohort. We identified two thresholds based on SSLR analysis at 12 and 28 LTx/year, which yielded three distinct volume strata: low (under 12), intermediate (12-27), and high volume (over 27). The majority of transplants are performed at high volume centers, which have shorter lengths of stay (24 days vs 29 for low-volume) and better 30-day and 1-year patient survival (96.7% and 86%, vs 94.2% and 80.3% for low-volume), despite older recipients, greater ischemic time, and increased use of extended-criteria donors. The results of our study support that high volume centers outperform their low and intermediate volume counterparts and distinguish between the three volume levels. Our study adds to the existing literature by estimating targets for annual lung transplants at which centers may attain improvements in recipient outcomes.

Development and validation of the Japanese version of the problem gambling severity index

BackgroundThe Problem Gambling Severity Index (PGSI) has been the most frequently used instrument for prevalence studies of problem gambling in the 2010s. However, the Japanese version of the PGSI has yet to be developed. ObjectiveTo develop the Japanese version of the PGSI and to investigate its reliability and validity. Materials and methodsWe translated and back-translated the original version of the PGSI into Japanese. The author of the original PGSI confirmed the semantic equivalence between the original PGSI and its Japanese version. We examined the reliability and validity of the Japanese version of the PGSI using data from a nationwide prevalence study of problem gambling conducted in Japan in 2017. ResultsUsable responses were obtained from 5365 residents. The PGSI had excellent internal consistency (Cronbach's alpha coefficient: 0.89) and moderate test-retest reliability after 45–60 days (intraclass coefficient: 0.54). Exploratory factor analysis revealed the unidimensionality of the PGSI. As for criterion validity, using the diagnosis of gambling disorder in DSM-5 as a reference standard, the stratum specific likelihood ratios of the PGSI score of 0 = non-problem; 1–2 = low risk; 3–7 = moderate risk; and 8–27 = problem gambling were 0.00; 0.68 (95% confidence interval: 0.21 to 2.22); 8.71 (5.2 to 14.5); and 67.9 (35.6 to 129.5) respectively. ConclusionsWe recommend including the PGSI in future prevalence studies of problem gambling in Japan.

Meta-analysis of Calibration, Discrimination, and Stratum-Specific Likelihood Ratios for the CRB-65 Score.

The CRB-65 score is recommended as a decision support tool to help identify patients with community-acquired pneumonia (CAP) who can safely be treated as outpatients. To perform an updated meta-analysis of the accuracy, discrimination, and calibration of the CRB-65 score using a novel approach to calculation of stratum-specific likelihood ratios. Meta-analysis of accuracy, discrimination, and calibration. We searched PubMed, Google, previous systematic reviews, and reference lists of included studies. Data was abstracted and quality assessed in parallel by two investigators. The quality assessment used an adaptation of the TRIPOD and PROBAST criteria. Measures of discrimination, calibration, and stratum-specific likelihood ratios are reported. Twenty-nine studies met our inclusion criteria and provided usable data. Most studies were set in Europe, none in North America, and 12 were judged to be at low risk of bias. The pooled estimate of area under the receiver operating characteristic curve was 0.74 (95% CI 0.71-0.77) for all studies. Calibration was good although there was significant heterogeneity; the pooled estimate of the ratio of observed to expected mortality for all studies was 1.04 (95% CI 0.91-1.19). The corresponding values for studies at low risk of bias where patients could be treated as outpatients or inpatients were 0.76 (0.70-0.81) and 0.88 (0.69-1.13). Summary estimates of stratum-specific likelihood ratios for all studies were 0.19 for the low-risk group, 1.1 for the moderate-risk group, and 4.5 for the high-risk group, and 0.13, 1.3, and 5.6 for studies at low risk of bias where patients could be treated as outpatients or inpatients. The CRB-65 is useful for identifying low-risk patients for outpatient therapy. Given a 4% overall mortality risk, patients classified as low risk by the CRB-65 had an outpatient mortality risk of no more than 0.5%.

Performance of the Japanese version of the Patient Health Questionnaire-9 (J-PHQ-9) for depression in primary care.

To assess the performance of the Japanese version of the Patient Health Questionnaire-9 (J-PHQ-9) for depression in primary care. Participants in both phases completed the J-PHQ-9, while patients in the second phase also completed the SF-8 (the short form for the health-related QOL scale SF-36). Subjects (n = 284; male = 107, female = 177) had to return the questionnaires to their health care professional within 48 hours and undergo a diagnostic evaluation interview based on the Japanese version of M.I.N.I-Plus. 93 patients were diagnosed as having major depressive disorder (MDD). In the J-PHQ-9, the optimal cutpoint ≥ 10 had sensitivity of 90.5% and specificity of 76.6%. As for the categorical algorithms, the sensitivity was 80.6%; specificity was 89.5%, and a positive likelihood ratio of 7.7. The Stratum-specific likelihood ratios (SSLRs) of the J-PHQ-9 scores of 0-9, 10-14, 15-19, and 20-27 for major depression were 0.10 (95% CI: 0.05-0.20), 1.67 (95% CI: 1.02-2.76), 5.41 (95% CI: 2.87-10.22), and 11.98 (95% CI: 5.39-26.63), respectively. The relationship between the severity of J-PHQ-9 and the MCS of SF-8 was significant (χ 2 ＝ 85.72, df = 4, P ≤ 0.0001). This study has validated the J-PHQ-9 as a useful tool for the assessment of MDD in primary care in Japan.

Performance characteristics of an automated latex immunoturbidimetric assay [HemosIL® HIT-Ab(PF4-H)] for the diagnosis of immune heparin-induced thrombocytopenia

BackgroundHeparin-induced thrombocytopenia (HIT) is a prothrombotic drug reaction caused by platelet-activating anti-PF4/heparin antibodies. Given time-sensitive treatment considerations, a rapid and accurate laboratory test for HIT antibodies is needed. AimsTo determine operating characteristics for the HemosIL® HIT-Ab(PF4/H), a rapid, on-demand, fully-automated, latex immunoturbidimetric assay (LIA), for diagnosis of HIT. MethodsWe evaluated LIA sensitivity, specificity, negative (NPV) and positive predictive value (PPV), negative (LR−) and positive likelihood ratio (LR+), using citrated-plasma from 429 patients (prospective cohort study of 4Ts scoring; HIT, n=31), and from consecutive HIT patients (n=125), using reference standard serotonin-release assay (SRA). Comparators included two PF4-dependent enzyme-immunoassays (EIAs). We used stratum-specific likelihood ratios (SSLRs) to determine how differing magnitudes of LIA-positivity influenced post-test probability of HIT. ResultsLIA operating characteristics were: sensitivity=97.4% (152/156); specificity=94.0% (374/398); PPV=55.6% (30/54); and NPV=99.7% (374/375). At manufacturers' cutoffs, LIA specificity and PPV were superior to the EIAs. Although a negative LIA pointed strongly against HIT (LR−, 0.034), the post-test probability was ~2% with high 4Ts score. The LIA's LR+ was high (16.0), with SSLRs rising substantially with greater LIA-positivity: 5.7 (1.0–4.9U/mL), 31 (5.0–15.9U/mL), and 128 (≥16U/mL). A LIA-positive result (at 1.0 cutoff) indicated at least 24% HIT probability (low 4Ts score), rising to 90% with high 4Ts score. ConclusionsAlthough approximately 1 in 40 SRA-positive patients tested LIA-negative, the LIA's high NPV and PPV indicate that this rapid assay is useful for the diagnostic evaluation of HIT, including in low pre-test situations.

Evidence supports severe renal insufficiency as a relative contraindication to heart transplantation

This study was conducted to determine whether survival after orthotopic heart transplant (OHT) is associated with pre-transplant estimated glomerular filtration rate (eGFR) and to define ranges of pre-OHT eGFR associated with differences in post-transplant survival. The 2006 International Society for Heart and Lung Transplantation revised listing criteria for OHT stated that chronic kidney disease, defined by an eGFR <40 ml/min is a relative contraindication for OHT alone. The committee noted that this recommendation was supported by consensus opinion of experts and not data derived from a randomized trial or non-randomized studies. The United Network for Organ Sharing provided deidentified patient-level data. The study population included 17,459 OHT recipients aged ≥18 years who received allografts between January 1, 2001, and December 31, 2009. Logistic regression was used to assess the effect of multiple variables on survival after OHT. Receiver operating characteristic curves and stratum-specific likelihood ratios were generated to compare 1-year survival at eGFR thresholds. The primary outcomes measure was actuarial post-transplant survival expressed in years. Regression analysis showed that a lower pre-transplant eGFR is associated with worse post-transplant survival. Threshold analysis demonstrated 3 distinct survival strata: eGFR ≤ 34 ml/min, eGFR 35 to 49 ml/min, and eGFR > 49 ml/min. Graft survival at all times is decreased for patients with eGFR ≤ 34 ml/min. They are also more likely to have in-hospital and long-term complications. eGFR is a strong predictor of post-transplant survival and should be considered when assessing patients for OHT. This analysis supports current International Society for Heart and Lung Transplantation guidelines and suggests that end-stage heart failure patients with an eGFR ≤ 34 ml/min is a relative contraindication for heart transplantation alone.

Using an accumulation of deficits approach to measure frailty in a population of home care users with intellectual and developmental disabilities: an analytical descriptive study.

BackgroundThe aging population of adults with intellectual and developmental disabilities (IDD) is growing. In the general aging population, frailty is commonly used to predict adverse health outcomes, including hospital use, death, and admission to long-term care. However, existing frailty measures are less appropriate for aging persons with IDD, given their pre-existing conditions and limitations. An accumulation of deficits approach, which is now widely used to describe frailty in the general population, may be more suitable for persons with IDD. Frailty measures specific to persons with IDD have not been widely studied.MethodsUsing pre-determined criteria, a frailty index (FI) specific to persons with IDD was developed based on items in the Resident Assessment Instrument - Home Care (RAI-HC), and using the assessments of 7,863 individuals with IDD in Ontario (aged 18–99 years) admitted to home care between April 1st, 2006 and March 31st, 2014. FI scores were derived by dividing deficits present by deficits measured, and categorized into meaningful strata using stratum-specific likelihood ratios. A multinomial logistic regression model identified associations between frailty and individual characteristics.ResultsThe resulting FI is comprised of 42 deficits across five domains (physiological, psychological, cognitive, social and service use). The mean FI score was 0.22 (SD = 0.13), equivalent to 9 deficits. Over half of the cohort was non-frail (FI score < 0.21), while the remaining were either pre-frail (21 %, FI score between 0.21 and 0.30) or frail (27 %, FI score > 0.30). Controlling for individual characteristics, women were more likely to be frail compared to men (OR = 1.39, 95 % CI: 1.23–1.56). Individuals who were frail were significantly more likely to have a caregiver who was unable to continuing caring (OR = 1.86, 95 % CI: 1.55–2.22) or feeling distressed (OR = 1.54, 95 % CI: 1.30–1.83). Living with a family members was significantly protective of frailty (OR = 0.35, 95 % CI: 0.29–0.41), compared to living alone.ConclusionsUsing the FI to identify frailty in adults with IDD is feasible and can be incorporated into existing home care assessments. This could offer case managers assistance in identifying at-risk individuals. Future analyses should evaluate this measure’s ability to predict future adverse outcomes.Electronic supplementary materialThe online version of this article (doi:10.1186/s12877-015-0170-5) contains supplementary material, which is available to authorized users.

Reliability and validity of the new Tanaka B Intelligence Scale scores: a group intelligence test.

ObjectiveThe present study evaluated the reliability and concurrent validity of the new Tanaka B Intelligence Scale, which is an intelligence test that can be administered on groups within a short period of time.MethodsThe new Tanaka B Intelligence Scale and Wechsler Intelligence Scale for Children-Third Edition were administered to 81 subjects (mean age ± SD 15.2±0.7 years) residing in a juvenile detention home; reliability was assessed using Cronbach’s alpha coefficient, and concurrent validity was assessed using the one-way analysis of variance intraclass correlation coefficient. Moreover, receiver operating characteristic analysis for screening for individuals who have a deficit in intellectual function (an FIQ<70) was performed. In addition, stratum-specific likelihood ratios for detection of intellectual disability were calculated.ResultsThe Cronbach’s alpha for the new Tanaka B Intelligence Scale IQ (BIQ) was 0.86, and the intraclass correlation coefficient with FIQ was 0.83. Receiver operating characteristic analysis demonstrated an area under the curve of 0.89 (95% CI: 0.85–0.96). In addition, the stratum-specific likelihood ratio for the BIQ≤65 stratum was 13.8 (95% CI: 3.9–48.9), and the stratum-specific likelihood ratio for the BIQ≥76 stratum was 0.1 (95% CI: 0.03–0.4). Thus, intellectual disability could be ruled out or determined.ConclusionThe present results demonstrated that the new Tanaka B Intelligence Scale score had high reliability and concurrent validity with the Wechsler Intelligence Scale for Children-Third Edition score. Moreover, the post-test probability for the BIQ could be calculated when screening for individuals who have a deficit in intellectual function. The new Tanaka B Intelligence Test is convenient and can be administered within a variety of settings. This enables evaluation of intellectual development even in settings where performing intelligence tests have previously been difficult.

Improving Clinical Interpretation of the Anti-Platelet Factor 4/Heparin Enzyme-Linked Immunosorbent Assay for the Diagnosis of Heparin-Induced Thrombocytopenia Through the Use of Receiver Operating Characteristic Analysis, Stratum-Specific Likelihood Ratios, and Bayes Theorem

Heparin-induced thrombocytopenia (HIT) is diagnosed using clinical criteria and detection of platelet-activating anti-platelet factor 4/heparin (anti-PF4/H) antibodies, usually through a surrogate enzyme-linked immunosorbent assay (ELISA). The high false-positive rate (FPR) of this ELISA prompted us to reexamine its interpretation. We analyzed anti-PF4/H ELISA results from a previously published dataset of 1,958 patients, using clinical suspicion and serotonin-release assay (SRA) to diagnose HIT. We performed receiver operating characteristic (ROC) analysis using stratum-specific likelihood ratios (SSLRs) and used Bayes theorem to construct a clinical decision-support algorithm. The most discriminant single cutoff by anti-PF4/H ELISA for the diagnosis of HIT was found to be 0.8 optical density (OD) units, not 0.4 OD (currently accepted practice). This change reduced the FPR from 31% to 6% (95% CI, 5%-8%). ELISA results were grouped into five strata, which yielded SSLRs ranging from 0.02 (strongly ruling HIT out) to 104.4 (strongly ruling HIT in). Comparison of ROC curves demonstrated that this five-strata approach is statistically more accurate than current accepted practice at discriminating whether patients have HIT or not (area under the ROC curve, 0.97 [95% CI, 0.93-1.00] vs 0.83 [95% CI, 0.80-0.89]). Our decision-support algorithm incorporated clinical assessment into this stratified model and clarified HIT diagnosis with a high degree of certainty and without the need for SRA testing in approximately 90% of patients. Diagnostic accuracy of the anti-PF4/H ELISA can be optimized by using a higher cutoff and a stratified interpretation of the results. Our algorithm should significantly reduce overdiagnosis of HIT and the need for SRA testing.

A Family Psychosocial Risk Questionnaire for Use in Pediatric Practice

The objective of this study is to develop new methods to better identify psychosocial risk such that children with the greatest risk of poor future outcomes receive more intensive preventive health services. Based on structured literature review and secondary data analysis, a 52-item psychosocial risk questionnaire was administered to 2,083 families of children (<36 months). To quantify the questionnaire's construct validity, developmental concern was assessed with the Ages and Stages Questionnaire version II (ASQ) [n = 1,163]. An iterative model selection process was used to produce the most parsimonious predictive model. Model fit was examined using c-statistics, the Hosmer-Lemeshow test, and a heuristic measure of model overfit based on the fitted log-likelihood values and associated number of degrees of freedom. We found 13 items easily obtained from parental report produced a regression model with a c-statistic of 0.70. Using an integer scoring system derived from the regression model, we calculated stratum specific likelihood ratios to revise a given prior probability of ASQ failure. The posterior probability of ASQ failure was 44.9 % for a child in the highest risk group (score >25) on the questionnaire, more than double our observed average failure rate of 19.5 %, while it was less than 7 % for a child with the lowest possible score on the questionnaire. Thirteen parent-reported items can be compiled into a summary psychosocial risk questionnaire that predicts failure on developmental screening among preschool children. With further validation, this questionnaire could conceivably be used by clinicians to tailor pediatric preventive care to children at varying levels of risk.

Performance of the 6-item Kessler scale for measuring serious mental illness in Hong Kong

BackgroundThe 6-item Kessler scale (K6) promises to be a valuable epidemiological tool for assessing serious mental illness (SMI) in communities with limited resources for psychiatric research and treatment. Its performance in Chinese community has not been studied with reference to clinically assessed SMI. MethodFrom a representative telephone-based population survey (n = 3014) that administered the K6, 153 participants were readministered the K6 and, on the same day, interviewed face-to-face by clinicians using the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorder, Fourth Edition, Axis I Disorder. Predictive indicators such as McNemar χ2, area under receiver operating characteristic curve and stratum-specific likelihood ratios were used to investigate the concordance between the K6 and clinical status of SMI, individual-level predicted probabilities of having SMI, and the weighted prevalence of SMI in the community. ResultThe K6 exhibited high internal consistency and test-retest reliability. Factor analysis revealed 2 correlating components composed of depression and anxiety. Matching of K6 caseness and SMI status showed that at the cutoff of 12/13, the area under receiver operating characteristic curve was moderate (0.69). The K6 had high specificity and was a stronger screen-out than screen-in tool for SMI. The weighted prevalence estimate of SMI in Hong Kong was 6.5%. A person scoring 13 or above on the K6 has a probability of at least 22.2% of having SMI. ConclusionThe Chinese K6 is reliable and generates the likelihood of SMI with substantial concordance with face-to-face clinical interviews in Hong Kong. It is a valuable tool for screening SMI, behavioral risk factor surveillance, and community epidemiological surveys.

Kessler Psychological Distress Scale: Normative Data from the 2007 Australian National Survey of Mental Health and Wellbeing

To present Australian normative data on the ten-item Kessler Psychological Distress Scale (K10). Analysis of cross-sectional data from the 2007 Australian National Survey of Mental Health and Wellbeing, a nationally representative household survey of 8841 adults. Mean K10 scores and K10 scores at selected percentiles of the K10 score distribution are presented by sex, age, the presence of mental disorders and the presence of physical conditions. Stratum-specific likelihood ratios were computed to help clinicians and researchers calculate predicted probabilities of mental disorder given scores on the K10. Scores on the K10 were generally higher in women compared to men, in people with a mental disorder compared to without a mental disorder and in people with affective disorders compared to people with substance use disorders. The SSLRs were informative in ruling in a diagnosis of mental disorder, particularly at the high or very high end of the psychological distress spectrum. These data may be helpful for clinicians and researchers alike in understanding the likelihood of mental disorder in a given individual or sample.

Liver stiffness measurement in the risk assessment of hepatocellular carcinoma for patients with chronic hepatitis

[corrected] The risk of hepatocellular carcinoma (HCC) increased with progression of hepatic fibrosis as assessed by liver stiffness measurement (LSM). This study used LSM to assess the risk of HCC presence in patients with chronic hepatitis. The patients with liver tumor or chronic hepatitis indicated for biopsy were prospectively enrolled. LSM was performed on the same day as biopsy. The diagnostic performances of clinical parameters and LSM in predicting HCC presence were compared with the areas under receiver operating characteristics curves (AUROC). The risk of HCC presence was assessed with stratum-specific likelihood ratios (SSLR). The cut-off values and its diagnostic validity were calculated for LSM. A total of 435 patients, including 106 HCC and 329 chronic hepatitis, were enrolled. The AUROC in predicting HCC presence was 0.736, 0.733, 0.594, 0.579 and 0.532 for LSM, alpha-fetoprotein, platelet count, total bilirubin, and aspartate aminotransferase-platelet ratio index, respectively. Multivariate analysis showed liver stiffness was an independent factor for HCC presence (odds ratio 1.07, 95% confidence interval (CI) 1.05-1.09). SSLR for HCC presence by liver stiffness was 0.43 (95% CI 0.32-0.57) in <12 kPa, 1.28 (0.89-1.84) in 12-24 kPa, and 5.94 (3.77-9.35) in >24 kPa. With 12 and 24 kPa as the cut-offs in predicting HCC presence, the sensitivity was 69.8 and 41.5%, respectively. The specificity was 69.6 and 92.7%, respectively. LSM identified the risk group for HCC presence in chronic hepatitis patients and had high specificity in the prediction of HCC with the cut-off of 24 kPa.

Japanese Version of the Delirium Rating Scale, Revised–98 (DRS-R98–J): Reliability and Validity

Delirium is a common neuropsychiatric disorder in medical and surgical inpatients of all ages. It is associated with increased long-term mortality, longer length of hospital stay, poor functional recovery, and increased likelihood of nursing home placement. The aim of this study was to investigate the reliability and the validity of the Japanese translation of the Delirium Rating Scale, Revised–98 (DRS-R–98). Psychiatric-consultation patients were assessed to compare groups of delirium, dementia, and non-delirium. Mean Total and Severity scores significantly distinguished delirium from the other groups. The scale had high interrater reliability and high internal consistency. Mean Severity scores during delirium differed from the posttreatment scores. Stratum-specific likelihood ratios showed that the DRS-R98–J is a reliable diagnostic tool. This study indicates that the Japanese version of the DRS-R-98 has high reliability and validity, and is a useful tool for assessing delirium among Japanese medically ill populations.