Performance of Existing and Novel Symptom- and Antigen Testing-Based COVID-19 Case Definitions in a Community Setting.

Point-of-care antigen tests are an important tool for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) detection, yet are less clinically sensitive than real-time reverse-transcription polymerase chain reaction (RT-PCR), affecting their efficacy as screening procedures. Our goal in this analysis was to see whether we could improve this sensitivity by considering antigen test results in combination with other relevant information, namely exposure status and reported symptoms. In November 2020, we collected 3,419 paired upper respiratory specimens tested by RT-PCR and the Abbott BinaxNOW (Abbott Laboratories, Abbott Park, Illinois) antigen test at 2 community testing sites in Pima County, Arizona. We used symptom, exposure, and antigen-testing data to evaluate the sensitivity and specificity of various symptom definitions in predicting RT-PCR positivity. Our analysis yielded 6 novel multisymptom case definitions with and without antigen test results, the best of which overall achieved a Youden's J index of 0.66, as compared with 0.53 for antigen testing alone. Using a random forest as a guide, we show that this definition, along with our others, does not lose the ability to generalize well to new data despite achieving optimal performance in our sample. Our methodology is broadly applicable, and our code is publicly available to aid public health practitioners in developing or fine-tuning their own case definitions.

A longitudinal assessment of chronic periodontitis in Australian adults.

AIM: The study aimed to estimate the incidence/progression and reversal of chronic periodontitis and to identify factors associated with chronic periodontitis in Australian adults over a 12-year period. MATERIALS AND METHODS: Data were obtained from the longitudinal component of the National Study of Adult Oral Health (NSAOH) in 2004-2006, and repeated data, among the same adults, in 2017-2018. NSAOH 2004-2006 was a population-based study of Australian adults aged 15+ years. The American Academy of Periodontology/European Federation of Periodontology case definitions were used, and then compared with two other case definitions. Multivariable Poisson regression models were used to estimate incidence rate ratios (IRRs) and reversal rate ratio (RRRs) of periodontitis. RESULTS: A total of 775 dentate Australian adults had dental examinations at both times. The proportion of incidence/progression and reversal among Australian adults was 56.4% and 11.0%, respectively. Tobacco smokers presented with more than three times higher incidence (IRR: 3.32, 95% CI: 1.50-7.60) and lower reversals (RRR: 0.94, 95% CI: 0.39-0.98) than those who had never smoked. Cessation of smoking was positively associated with periodontitis reversal. The total incidence/progression was 471.7/10,000 person-years, with reversal being 107.5/10,000 person-years. The average number of teeth lost due to periodontal disease was 1.9 in 2017-2018. Being male and not having periodontal treatment were significant risk markers for the incidence/progression of periodontitis. CONCLUSION: Smoking is a risk factor for periodontitis. Cessation of smoking is an effective means of reducing the incidence and progression of chronic periodontitis, to reduce the risk of tooth loss, and to improve overall periodontal health.

Recommendations for uniform definitions used in newborn screening for severe combined immunodeficiency.

BACKGROUND: Public health newborn screening (NBS) programs continuously evolve, taking advantage of international shared learning. NBS for severe combined immunodeficiency (SCID) has recently been introduced in many countries. However, comparison of screening outcomes has been hampered by use of disparate terminology and imprecise or variable case definitions for non-SCID conditions with T-cell lymphopenia. OBJECTIVES: This study sought to determine whether standardized screening terminology could overcome a Babylonian confusion and whether improved case definitions would promote international exchange of knowledge. METHODS: A systematic literature review highlighted the diverse terminology in SCID NBS programs internationally. While, as expected, individual screening strategies and tests were tailored to each program, we found uniform terminology to be lacking in definitions of disease targets, sensitivity, and specificity required for comparisons across programs. RESULTS: The study's recommendations reflect current evidence from literature and existing guidelines coupled with opinion of experts in public health screening and immunology. Terminologies were aligned. The distinction between actionable and nonactionable T-cell lymphopenia among non-SCID cases was clarified, the former being infants with T-cell lymphopenia who could benefit from interventions such as protection from infections, antibiotic prophylaxis, and live-attenuated vaccine avoidance. CONCLUSIONS: By bringing together the previously unconnected public health screening community and clinical immunology community, these SCID NBS deliberations bridged the gaps in language and perspective between these disciplines. This study proposes that international specialists in each disorder for which NBS is performed join forces to hone their definitions and recommend uniform registration of outcomes of NBS. Standardization of terminology will promote international exchange of knowledge and optimize each phase of NBS and follow-up care, advancing health outcomes for children worldwide.

Diagnostic performance of the AAP/EFP classification and the CDC/AAP case definition among pregnant women and a practical screening tool for maternal periodontal diseases.

BACKGROUND AND OBJECTIVE: There is a limited number of studies on the performance assessment of the 2017 AAP/EFP classification and the CDC/AAP case definition among pregnant females. This study evaluated the agreement between these two systems and explored a practical tool for screening maternal periodontal diseases by general dentists. MATERIALS AND METHODS: Totally, 204 systemically healthy females at different phases of pregnancy underwent a full-mouth periodontal examination. Demographic characteristics, lifestyles, and systemic conditions were recorded. Referring to the CDC/AAP definition, the diagnostic performance of the AAP/EFP classification was evaluated by the area under the ROC curve (AUC) and statistical tests (e.g., Youden's index and kappa coefficient). Additionally, a modified scoring system of the FDI Periodontal Diseases Chairside Guide (FDI-CG) was formulated with the addition of pregnancy for testing accordingly. RESULTS: Overall, there were 22.1% of the participants in early phase of pregnancy (7-13 weeks) and 77.9% in late phase (34-36 weeks). The majority of them were below 35 years and non-smokers without gestational diabetes. Notably, 30.9% of subjects presented with Moderate/Severe periodontitis (CDC/AAP), and 35.8% with Stages II-IV periodontitis (AAP/EFP). Referring to the CDC/AAP definition, the AUC, Youden's index, and κ of the AAP/EFP classification were 0.979, 0.890, and 92.9%, respectively. The modified FDI-CG system improved the AUC (0.815), Youden's index (63.0%), and κ (0.544) with reference to the original one. CONCLUSIONS: This study shows that the AAP/EFP classification is in high agreement with the CDC/AAP definition among the pregnant women. The phases of pregnancy-integrated FDI scoring system may serve as a convenient screening tool for maternal periodontal diseases in general dental practice.

Development and validation of an automated emergency department-based syndromic surveillance system to enhance public health surveillance in Yukon: a lower-resourced and remote setting.

BACKGROUND: Automated Emergency Department syndromic surveillance systems (ED-SyS) are useful tools in routine surveillance activities and during mass gathering events to rapidly detect public health threats. To improve the existing surveillance infrastructure in a lower-resourced rural/remote setting and enhance monitoring during an upcoming mass gathering event, an automated low-cost and low-resources ED-SyS was developed and validated in Yukon, Canada. METHODS: Syndromes of interest were identified in consultation with the local public health authorities. For each syndrome, case definitions were developed using published resources and expert elicitation. Natural language processing algorithms were then written using Stata LP 15.1 (Texas, USA) to detect syndromic cases from three different fields (e.g., triage notes; chief complaint; discharge diagnosis), comprising of free-text and standardized codes. Validation was conducted using data from 19,082 visits between October 1, 2018 to April 30, 2019. The National Ambulatory Care Reporting System (NACRS) records were used as a reference for the inclusion of International Classification of Disease, 10th edition (ICD-10) diagnosis codes. The automatic identification of cases was then manually validated by two raters and results were used to calculate positive predicted values for each syndrome and identify improvements to the detection algorithms. RESULTS: A daily secure file transfer of Yukon's Meditech ED-Tracker system data and an aberration detection plan was set up. A total of six syndromes were originally identified for the syndromic surveillance system (e.g., Gastrointestinal, Influenza-like-Illness, Mumps, Neurological Infections, Rash, Respiratory), with an additional syndrome added to assist in detecting potential cases of COVID-19. The positive predictive value for the automated detection of each syndrome ranged from 48.8-89.5% to 62.5-94.1% after implementing improvements identified during validation. As expected, no records were flagged for COVID-19 from our validation dataset. CONCLUSIONS: The development and validation of automated ED-SyS in lower-resourced settings can be achieved without sophisticated platforms, intensive resources, time or costs. Validation is an important step for measuring the accuracy of syndromic surveillance, and ensuring it performs adequately in a local context. The use of three different fields and integration of both free-text and structured fields improved case detection.

Validation of a case definition for depression in administrative data against primary chart data as a reference standard.

BACKGROUND: Because the collection of mental health information through interviews is expensive and time consuming, interest in using population-based administrative health data to conduct research on depression has increased. However, there is concern that misclassification of disease diagnosis in the underlying data might bias the results. Our objective was to determine the validity of International Classification of Disease (ICD)-9 and ICD-10 administrative health data case definitions for depression using review of family physician (FP) charts as the reference standard. METHODS: Trained chart reviewers reviewed 3362 randomly selected charts from years 2001 and 2004 at 64 FP clinics in Alberta (AB) and British Columbia (BC), Canada. Depression was defined as presence of either: 1) documentation of major depressive episode, or 2) documentation of specific antidepressant medication prescription plus recorded depressed mood. The charts were linked to administrative data (hospital discharge abstracts and physician claims data) using personal health numbers. Validity indices were estimated for six administrative data definitions of depression using three years of administrative data. RESULTS: Depression prevalence by chart review was 15.9-19.2% depending on year, region, and province. An ICD administrative data definition of '2 depression claims with depression ICD codes within a one-year window OR 1 discharge abstract data (DAD) depression diagnosis' had the highest overall validity, with estimates being 61.4% for sensitivity, 94.3% for specificity, 69.7% for positive predictive value, and 92.0% for negative predictive value. Stratification of the validity parameters for this case definition showed that sensitivity was fairly consistent across groups, however the positive predictive value was significantly higher in 2004 data compared to 2001 data (78.8 and 59.6%, respectively), and in AB data compared to BC data (79.8 and 61.7%, respectively). CONCLUSIONS: Sensitivity of the case definition is often moderate, and specificity is often high, possibly due to undercoding of depression. Limitations to this study include the use of FP charts data as the reference standard, given the potential for missed or incorrect depression diagnoses. These results suggest that that administrative data can be used as a source of information for both research and surveillance purposes, while remaining aware of these limitations.

Health worker knowledge of Integrated Disease Surveillance and Response standard case definitions: a cross-sectional survey at rural health facilities in Kenya.

BACKGROUND: The correct knowledge of standard case definition is necessary for frontline health workers to diagnose suspected diseases across Africa. However, surveillance evaluations commonly assume this prerequisite. This study assessed the knowledge of case definitions for health workers and their supervisors for disease surveillance activities in rural Kenya. METHODS: A cross-sectional survey including 131 health workers and their 11 supervisors was undertaken in two counties in Kenya. Descriptive analysis was conducted to classify the correctness of knowledge into four categories for three tracer diseases (dysentery, measles, and dengue). We conducted a univariate and multivariable logistic regression analyses to explore factors influencing knowledge of the case definition for dysentery. RESULTS: Among supervisors, 81.8% knew the correct definition for dysentery, 27.3% for measles, and no correct responses were provided for dengue. Correct knowledge was observed for 50.4% of the health workers for dysentery, only 12.2% for measles, and none for dengue. Of 10 examined factors, the following were significantly associated with health workers' correct knowledge of the case definition for dysentery: health workers' cadre (aOR 2.71; 95% CI 1.20-6.12; p = 0.017), and display of case definition poster (aOR 2.24; 95% CI 1.01-4.98; p = 0.048). Health workers' exposure to the surveillance refresher training, supportive supervision and guidelines were not significantly associated with the knowledge. CONCLUSION: The correct knowledge of standard case definitions was sub-optimal among health workers and their supervisors, which is likely to impact the reliability of routine surveillance reports generated from health facilities.

Operationalizing Substantial Reduction in Functioning Among Young Adults with Chronic Fatigue Syndrome.

PURPOSE: Chronic fatigue syndrome and myalgic encephalomyelitis are fatiguing illnesses that often result in long-term impairment in daily functioning. In reviewing case definitions, Thrope et al. (Fatigue 4(3):175-188, 2016) noted that the vast majority of case definitions used to describe these illnesses list a "substantial reduction" in activities as a required feature for diagnosis. However, there is no consensus on how to best operationalize the criterion of substantial reduction. METHOD: The present study used a series of receiver operating curve (ROC) analyses to explore the use of the Medical Outcomes Study Short-Form-36 Health Survey (SF-36), designed by Ware and Shelbourne for operationalizing the substantial reduction criterion in a young adult population (18-29 years old). We compared the sensitivity and specificity of various cutoff scores for the SF-36 subscales and assessed their usefulness in discriminating between a group of young adults with a known diagnosis of chronic fatigue syndrome or myalgic encephalomyelitis (n = 98) versus those without that diagnosis (n = 272). RESULTS: The four top performing subscales and their associated cutoffs were determined: Physical Functioning ≤ 80, General Health ≤ 47, Role Physical ≤ 25, and Social Functioning ≤ 50. Used in combination, these four cutoff scores were shown to reliably discriminate between the patients and controls in our sample of young adults. CONCLUSION: The implications of these findings for employing the substantial reduction criterion in both clinical and research settings are discussed.

Assessing Sensitivity and Specificity of Surveillance Case Definitions for Zika Virus Disease.

We evaluated performance of 5 case definitions for Zika virus disease surveillance in a human cohort during an outbreak in Singapore, August 26-September 5, 2016. Because laboratory tests are largely inaccessible, use of case definitions that include rash as a required clinical feature are useful in identifying this disease.

Incidence of Multiple Sclerosis in Germany: A Cohort Study Applying Different Case Definitions Based on Claims Data.

BACKGROUND: Data on the incidence of multiple sclerosis (MS) on the national level is scarce. We aimed to estimate the incidence of MS in Germany and to compare different MS case definitions based on claims data. METHODS: We conducted a cohort study with the German Pharmacoepidemiological Research Database in 2012 and calculated age- and gender-standardized incidence rates (sIRs) for 3 case definitions. In addition, the effect of stepwise reduction of the look-back period without MS diagnosis on the incidence rate was evaluated. RESULTS: Our cohort comprised 4,175,877 individuals. The first case definition based on ICD-10 diagnoses yielded an sIR of 21.8 (95% CI 20.2-23.5) per 100,000 person years, whereas the second and third case definitions with additional requirements for drug treatment and diagnostic tests resulted in lower sIRs of 10.1 (9.1-11.3) and 6.6 (5.8-7.6) respectively. We observed a higher incidence for shorter look-back periods. CONCLUSION: The incidence of MS in Germany might be substantially higher than suggested in earlier studies. In addition, our study highlights the importance of a look-back period of at least 36 months to identify incident MS cases based on claims data.

The Impact of Different Case Ascertainment Definitions on the Prevalence of Major Congenital Malformations and their Association with Asthma During Pregnancy.

Objectives To compare the prevalence of major malformations using different case ascertainment definitions and to evaluate their impact on maternal asthma-major malformations association. Methods A cohort of pregnancies with and without asthma between 1990 and 2010 was formed. We used two classification methods: the Two step Congenital Malformation Classification (TCMC) and the Canadian Congenital Anomalies Surveillance System (CCASS). Within each method, three case definitions were compared: (1) ≥1 diagnosis in the hospital database; (2) ≥1 diagnosis in the hospital database or ≥2 in the medical claims; and (3) ≥1 diagnosis in the hospital database or ≥1 in the medical claims. We calculated the prevalence of major malformations and adjusted odds ratios (aORs) for maternal asthma association. Results Of 467,946 pregnancies, 12.3 % were with active asthma. The prevalence estimates were: TCMC 5.10-7.08 % and CCASS 7.03-10.57 %. Asthma-major malformations association was weaker with the CCASS (aOR 1.14-1.20) versus TCMC (aOR 1.22-1.26). Discussion The case ascertainment definitions with ≥1 hospitalization are likely to be the most reliable in similar administrative databases. The case ascertainment definition had a considerable impact on the prevalence of major malformations, but hardly influenced the aORs. Future studies should formally assess the validity of the case ascertainment definitions and allow generalizability to other maternal exposures.

Hepatitis E virus infection in Europe: surveillance and descriptive epidemiology of confirmed cases, 2005 to 2015.

Hepatitis E virus (HEV) is an under-recognised cause of acute hepatitis in high-income countries. The purpose of this study was to provide an overview of testing, diagnosis, surveillance activities, and data on confirmed cases in the European Union/European Economic Area (EU/EEA). A semi-structured survey was developed and sent to 31 EU/EEA countries in February 2016, 30 responded. Twenty of these countries reported that they have specific surveillance systems for HEV infection. Applied specific case definition for HEV infection varied widely across countries. The number of reported cases has increased from 514 cases per year in 2005 to 5,617 in 2015, with most infections being locally acquired. This increase could not be explained by additional countries implementing surveillance for HEV infections over time. Hospitalisations increased from less than 100 in 2005 to more than 1,100 in 2015 and 28 fatal cases were reported over the study period. EU/EEA countries are at different stages in their surveillance, testing schemes and policy response to the emergence of HEV infection in humans. The available data demonstrated a Europe-wide increase in cases. Standardised case definitions and testing policies would allow a better understanding of the epidemiology of HEV as an emerging cause of liver-related morbidity.

Performance of influenza case definitions for influenza community surveillance: based on the French influenza surveillance network GROG, 2009-2014.

International case definitions recommended by the Centers for Disease Control and Prevention (CDC), the European Centre for Disease Prevention and Control (ECDC), and the World Health Organization (WHO) are commonly used for influenza surveillance. We evaluated clinical factors associated with the laboratory-confirmed diagnosis of influenza and the performance of these influenza case definitions by using a complete dataset of 14,994 patients with acute respiratory infection (ARI) from whom a specimen was collected between August 2009 and April 2014 by the Groupes Régionaux d'Observation de la Grippe (GROG), a French national influenza surveillance network. Cough and fever ≥ 39 °C most accurately predicted an influenza infection in all age groups. Several other symptoms were associated with an increased risk of influenza (headache, weakness, myalgia, coryza) or decreased risk (adenopathy, pharyngitis, shortness of breath, otitis/otalgia, bronchitis/ bronchiolitis), but not throughout all age groups. The WHO case definition for influenza-like illness (ILI) had the highest specificity with 21.4%, while the ECDC ILI case definition had the highest sensitivity with 96.1%. The diagnosis among children younger than 5 years remains challenging. The study compared the performance of clinical influenza definitions based on outpatient surveillance and will contribute to improving the comparability of data shared at international level.

Clinical Predictors of Critical Lower Respiratory Tract Illness Due to Respiratory Syncytial Virus in Infants and Children: Data to Inform Case Definitions for Efficacy Trials.

We analyzed data from 524 Argentinean infants hospitalized with lower respiratory tract illness (LRTI) due to respiratory syncytial virus (RSV) to inform selection of clinical end points for RSV vaccine efficacy trials. Cases of LRTI due to RSV that required a mask, continuous or bilevel positive airway pressure, or mechanical ventilation were classified as critical. Oxygen saturation of ≤90%, tachypnea, and tachycardia were each associated with an increased odds of critical LRTI due to RSV (adjusted odds ratios [ORs], 2.30 [95% confidence interval {CI}, 1.26-4.24; P = .007], 2.22 [95% CI, 1.19-4.16; P = .012], and 2.35 [95% CI, 1.22-4.50; P = .010], respectively). The odds of critical LRTI due to RSV increased substantially (OR, 8.57; 95% CI, 2.19-73.5; P = .001) among individuals with ≥2 indicators. Lower chest wall indrawing was not associated with critical disease.

Evaluation of case definitions to detect respiratory syncytial virus infection in hospitalized children below 5 years in Rural Western Kenya, 2009-2013.

BACKGROUND: In order to better understand respiratory syncytial virus (RSV) epidemiology and burden in tropical Africa, optimal case definitions for detection of RSV cases need to be identified. METHODS: We used data collected between September 2009 - August 2013 from children aged <5 years hospitalized with acute respiratory Illness at Siaya County Referral Hospital. We evaluated the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of individual signs, symptoms and standard respiratory disease case definitions (severe acute respiratory illness [SARI]; hospitalized influenza-like illness [hILI]; integrated management of childhood illness [IMCI] pneumonia) to detect laboratory-confirmed RSV infection. We also evaluated an alternative case definition of cough or difficulty breathing plus hypoxia, in-drawing, or wheeze. RESULTS: Among 4714 children hospitalized with ARI, 3810 (81 %) were tested for RSV; and 470 (12 %) were positive. Among individual signs and symptoms, cough alone had the highest sensitivity to detect laboratory-confirmed RSV [96 %, 95 % CI (95-98)]. Hypoxia, wheezing, stridor, nasal flaring and chest wall in-drawing had sensitivities ranging from 8 to 31 %, but had specificities >75 %. Of the standard respiratory case definitions, SARI had the highest sensitivity [83 %, 95 % CI (79-86)] whereas IMCI severe pneumonia had the highest specificity [91 %, 95 % CI (90-92)]. The alternative case definition (cough or difficulty breathing plus hypoxia, in-drawing, or wheeze) had a sensitivity of [55 %, 95 % CI (50-59)] and a specificity of [60 %, 95 % CI (59-62)]. The PPV for all case definitions and individual signs/symptoms ranged from 11 to 20 % while the negative predictive values were >87 %. When we stratified by age <1 year and 1- < 5 years, difficulty breathing, severe pneumonia and the alternative case definition were more sensitive in children aged <1 year [70 % vs. 54 %, p < 0.01], [19 % vs. 11 %, p = 0.01] and [66 % vs. 43 %, p < 0.01] respectively, while non-severe pneumonia was more sensitive [14 % vs. 26 %, p < 0.01] among children aged 1- < 5 years. CONCLUSION: The sensitivity and specificity of different commonly used case definitions for detecting laboratory-confirmed RSV cases varied widely, while the positive predictive value was consistently low. Optimal choice of case definition will depend upon study context and research objectives.

Functional Measures Developed for Clinical Populations Identified Impairment Among Active Workers with Upper Extremity Disorders.

PURPOSE: Few studies have explored measures of function across a range of health outcomes in a general working population. Using four upper extremity (UE) case definitions from the scientific literature, we described the performance of functional measures of work, activities of daily living, and overall health. METHODS: A sample of 573 workers completed several functional measures: modified recall versions of the QuickDASH, Levine Functional Status Scale (FSS), DASH Work module (DASH-W), and standard SF-8 physical component score. We determined case status based on four UE case definitions: (1) UE symptoms, (2) UE musculoskeletal disorders (MSD), (3) carpal tunnel syndrome (CTS), and (4) work limitations due to UE symptoms. We calculated effect sizes for each case definition to show the magnitude of the differences that were detected between cases and non-cases for each case definition on each functional measure. Sensitivity and specificity analyses showed how well each measure identified functional impairments across the UE case definitions. RESULTS: All measures discriminated between cases and non-cases for each case definition with the largest effect sizes for CTS and work limitations, particularly for the modified FSS and DASH-W measures. Specificity was high and sensitivity was low for outcomes of UE symptoms and UE MSD in all measures. Sensitivity was high for CTS and work limitations. CONCLUSIONS: Functional measures developed specifically for use in clinical, treatment-seeking populations may identify mild levels of impairment in relatively healthy, active working populations, but measures performed better among workers with CTS or those reporting limitations at work.

Clinical Case Definitions for Classification of Intrathoracic Tuberculosis in Children: An Update.

Consensus case definitions for childhood tuberculosis have been proposed by an international expert panel, aiming to standardize the reporting of cases in research focusing on the diagnosis of intrathoracic tuberculosis in children. These definitions are intended for tuberculosis diagnostic evaluation studies of symptomatic children with clinical suspicion of intrathoracic tuberculosis, and were not intended to predefine inclusion criteria into such studies. Feedback from researchers suggested that further clarification was required and that these case definitions could be further improved. Particular concerns were the perceived complexity and overlap of some case definitions, as well as the potential exclusion of children with acute onset of symptoms or less severe disease. The updated case definitions proposed here incorporate a number of key changes that aim to reduce complexity and improve research performance, while maintaining the original focus on symptomatic children suspected of having intrathoracic tuberculosis. The changes proposed should enhance harmonized classification for intrathoracic tuberculosis disease in children across studies, resulting in greater comparability and the much-needed ability to pool study results.

Multicenter study comparing case definitions used to identify patients with chronic obstructive pulmonary disease.

RATIONALE: Clinical trials in chronic obstructive pulmonary disease (COPD) usually require evidence of airflow obstruction and clinical risk factors. International Classification of Diseases, Ninth Revision (ICD-9) diagnosis codes or patient-reported physician diagnoses are often used for epidemiologic studies and performance improvement programs. OBJECTIVES: To evaluate agreement between these case definitions for COPD and to assess the comparability of study populations identified as having COPD not using the clinical trial reference standard. METHODS: We recruited patients from the COPD Outcomes-based Network for Clinical Effectiveness and Research Translation multicenter clinical registry in a cross-sectional study. Demographics, clinical, and post-bronchodilator spirometry data were collected at an in-person study visit. The kappa statistic (κ) was used to evaluate agreement. A multivariable logistic regression model was used to identify patient characteristics associated with meeting the trial reference standard. MEASUREMENTS AND MAIN RESULTS: A total of 998 (82.8%) of 1,206 study participants met at least one case definition for COPD (of the 998: 91% using ICD-9 codes, 73% using patient-reported physician diagnosis, 56% using trial reference standard); agreement between case definitions was poor (κ = 0.20-0.26). Lack of airflow obstruction was the principal (89%) reason patients identified as having COPD did not meet the trial reference standard. Patients who were black (vs. white), obese (vs. normal weight), or had depression (vs. not) were less likely to meet the trial reference standard (odds ratio [95% CI], 0.37 [0.26-0.53], 0.51 [0.34-0.75], 0.53 [0.40-0.71], respectively). CONCLUSIONS: Findings highlight concerns about the applicability of findings in clinical trials to patients meeting other case definitions for COPD.

Defining Essential Features of Myalgic Encephalomyelitis and Chronic Fatigue Syndrome.

Considerable debate surrounds the search for the defining features of patients with Myalgic Encephalomyelitis (ME) and chronic fatigue syndrome (CFS). Current case definitions were created through clinical consensus. Failure to operationalize these case definitions has led to considerable variability in the identification of patients. In addition, some case definitions (e.g., Fukuda et al., 1994) do not require cardinal symptoms of this illness, where as other case definitions do require core symptoms of this illness (Carruthers et al., 2003, 2011), and these latter case criteria appear to identify a more impaired group of patients. Criterion variance is most likely to occur when operationally explicit criteria do not exist for diagnostic categories (Spitzer, Endicott, & Robins, 1978), or when there are varying criteria for contrasting case definitions, which is an impediment to the research in this field. To deal with this problem, it is possible to differentiate those that meet more loosely defined criteria from those that are more narrowly and defined, thus differentiating CFS from ME. In order to progress the search for biological markers and effective treatments, essential features need to be operationalized and broadly used in order to increase the probability that individuals included in samples have the same underlying illness.

Identification of patients with systemic lupus erythematosus in administrative healthcare databases.

OBJECTIVE: Our aim was to validate and compare decision rules for the identification of patients with systemic lupus erythematosus (SLE) in administrative healthcare databases. METHODS: A retrospective cohort study was performed using administrative health care data from a population of 1 million people with access to universal healthcare. Information was available on hospital discharges and physician billings over a 10-year period. Each SLE case was matched 4:1 by age and gender to randomly selected controls. Seven case definitions were applied to identify SLE cases and their performance compared with the diagnosis by a rheumatologist. RESULTS: We identified 373 SLE cases and 1492 non-SLE controls, all of whom had been reviewed by a rheumatologist. The overall accuracy of the case definitions for SLE cases varied between 88.2-95.6% with a kappa statistic between 0.53-0.86. The sensitivity varied from 41.0-86.6% and the specificity between 92.4-99.9%. In a total reference population of 1 million the mean estimated annual incidence of SLE was between 29-255 and the mean estimated annual prevalence was between 172-920. CONCLUSION: The accuracy of case definitions for the identification of SLE patients in administrative healthcare databases is variable and this should be considered when comparing results across studies. This variability may also be used to advantage in different study designs depending on the relative importance of sensitivity and specificity for identifying the population of interest to the research question.