Changes In Diagnostic Accuracy Research Articles

The Impact of Intraoperative Glucagon on the Diagnostic Accuracy of Intraoperative Cholangiogram for the Diagnosis of Choledocholithiasis: Experience from a Large Tertiary Care Center.

A proportion of patients who undergo intraoperative cholangiogram (IOC) do not have bile duct stones at the time of endoscopic retrograde cholangiopancreatography (ERCP), either due to the spontaneous passage of stones or a false-positive IOC. Glucagon has been utilized as an inexpensive tool to allow the passage of micro-choledocholithiasis to the duodenum and resolve filling defects caused by stones or air bubbles. The purpose of our study is to understand the change in diagnostic accuracy of IOC to detect choledocholithiasis with intraoperative glucagon. We conducted a retrospective study at a tertiary care center on adult patients who underwent laparoscopic cholecystectomy with IOC. The diagnostic accuracy of IOC was assessed before and after the administration of intravenous glucagon. Of 1455 patients, 374 (25.7%) received intraoperative glucagon, and 103 of these 374 patients (27.5%) showed resolution of the filling defect with the passage of contrast to the duodenum. Pre- and post-glucagon administration comparison showed enhancement in specificity from 78% to 83%, an increase in positive predictive value from 67.3% to 72.4%, and an improvement in the diagnostic accuracy of IOC from 81.5% to 84.3%. Our findings suggest that intraoperative glucagon administration carries the potential to reduce the rate of false-positive IOCs, thereby reducing the performance of unnecessary ERCPs.

Longitudinal Changes in Diagnostic Accuracy of a Differential Diagnosis List Developed by an AI-Based Symptom Checker: Retrospective Observational Study.

Artificial intelligence (AI) symptom checker models should be trained using real-world patient data to improve their diagnostic accuracy. Given that AI-based symptom checkers are currently used in clinical practice, their performance should improve over time. However, longitudinal evaluations of the diagnostic accuracy of these symptom checkers are limited. This study aimed to assess the longitudinal changes in the accuracy of differential diagnosis lists created by an AI-based symptom checker used in the real world. This was a single-center, retrospective, observational study. Patients who visited an outpatient clinic without an appointment between May 1, 2019, and April 30, 2022, and who were admitted to a community hospital in Japan within 30 days of their index visit were considered eligible. We only included patients who underwent an AI-based symptom checkup at the index visit, and the diagnosis was finally confirmed during follow-up. Final diagnoses were categorized as common or uncommon, and all cases were categorized as typical or atypical. The primary outcome measure was the accuracy of the differential diagnosis list created by the AI-based symptom checker, defined as the final diagnosis in a list of 10 differential diagnoses created by the symptom checker. To assess the change in the symptom checker's diagnostic accuracy over 3 years, we used a chi-square test to compare the primary outcome over 3 periods: from May 1, 2019, to April 30, 2020 (first year); from May 1, 2020, to April 30, 2021 (second year); and from May 1, 2021, to April 30, 2022 (third year). A total of 381 patients were included. Common diseases comprised 257 (67.5%) cases, and typical presentations were observed in 298 (78.2%) cases. Overall, the accuracy of the differential diagnosis list created by the AI-based symptom checker was 172 (45.1%), which did not differ across the 3 years (first year: 97/219, 44.3%; second year: 32/72, 44.4%; and third year: 43/90, 47.7%; P=.85). The accuracy of the differential diagnosis list created by the symptom checker was low in those with uncommon diseases (30/124, 24.2%) and atypical presentations (12/83, 14.5%). In the multivariate logistic regression model, common disease (P<.001; odds ratio 4.13, 95% CI 2.50-6.98) and typical presentation (P<.001; odds ratio 6.92, 95% CI 3.62-14.2) were significantly associated with the accuracy of the differential diagnosis list created by the symptom checker. A 3-year longitudinal survey of the diagnostic accuracy of differential diagnosis lists developed by an AI-based symptom checker, which has been implemented in real-world clinical practice settings, showed no improvement over time. Uncommon diseases and atypical presentations were independently associated with a lower diagnostic accuracy. In the future, symptom checkers should be trained to recognize uncommon conditions.

Take a break: should breaks be enforced during digital breast tomosynthesis reading sessions?

ObjectivesDigital breast tomosynthesis (DBT) can improve diagnostic accuracy compared to 2D mammography, but DBT reporting is time-consuming and potentially more fatiguing. Changes in diagnostic accuracy and subjective and objective fatigue were evaluated over a DBT reporting session, and the impact of taking a reporting break was assessed.Materials and methodsForty-five National Health Service (NHS) mammography readers from 6 hospitals read a cancer-enriched set of 40 DBT cases whilst eye tracked in this prospective cohort study, from December 2020 to April 2022. Eye-blink metrics were assessed as objective fatigue measures. Twenty-one readers had a reporting break, 24 did not. Subjective fatigue questionnaires were completed before and after the session. Diagnostic accuracy and subjective and objective fatigue measures were compared between the cohorts using parametric and non-parametric significance testing.ResultsReaders had on average 10 years post-training breast screening experience and took just under 2 h (105.8 min) to report all cases. Readers without a break reported greater levels of subjective fatigue (44% vs. 33%, p = 0.04), which related to greater objective fatigue: an increased average blink duration (296 ms vs. 286 ms, p < 0.001) and a reduced eye-opening velocity (76 mm/s vs. 82 mm/s, p < 0.001). Objective fatigue increased as the trial progressed for the no break cohort only (ps < 0.001). No difference was identified in diagnostic accuracy between the groups (accuracy: 87% vs. 87%, p = 0.92).ConclusionsImplementing a break during a 2-h DBT reporting session resulted in lower levels of subjective and objective fatigue. Breaks did not impact diagnostic accuracy, which may be related to the extensive experience of the readers.Clinical relevance statementDBT is being incorporated into many mammography screening programmes. Recognising that reporting breaks are required when reading large volumes of DBT studies ensures this can be factored in when setting up reading sessions.Trial registrationClinical trials registration number: NCT03733106Key Points• Use of digital breast tomosynthesis (DBT) in breast screening programmes can cause significant reader fatigue.• The effectiveness of incorporating reading breaks into DBT reporting sessions, to reduce mammography reader fatigue, was investigated using eye tracking.• Integrating breaks into DBT reporting sessions reduced reader fatigue; however, diagnostic accuracy was unaffected.

Training dermatology residents in dermatoscopy: A case control lecture series assessment.

Lack of standardized dermatoscopy training limits confidence and accuracy. We assessed the effect of a dermatoscopy lecture series on the diagnostic accuracy of dermatology residents' biopsies. Additionally, we evaluated resident comfort with and knowledge of dermatoscopy before and after the curriculum. Twelve dermatology residents were enrolled in a 5-month dedicated dermatoscopy curriculum. To assess knowledge of and comfort with dermatoscopy, residents were given a 50-question assessment and 21-question survey before and after the curriculum. Change in diagnostic accuracy was assessed by comparing the suspected clinical diagnosis to the final histopathologic diagnosis of lesions biopsied by residents before and after the course. Upon completion of the curriculum, residents felt significantly more comfortable performing dermatoscopy (P=.002) and using dermatoscopy to identify melanocytic nevi (P=.037) and melanomas (invasive and in situ) (P=.012). Postgraduate year 2 residents also showed significantly improved diagnostic accuracy after the training course (odds ratio, 1.33; 95% confidence interval, 1.06-1.67; P=.013). Our study was limited by a small sample size of 12 residents from a single academic institution. A formal dermatoscopy course can effectively improve dermatology residents' knowledge, confidence, and diagnostic accuracy when using dermatoscopy.

Diagnostic agreement and concordance between consultation-liaison psychiatry and non-psychiatric (medical and surgical) doctors: changes within junior doctor's terms.

To investigate whether diagnostic agreement and concordance between non-psychiatric (medical and surgical) doctors and consultation-liaison psychiatry changes within junior doctors' terms. This was a retrospective cohort analysis of referrals from medical and surgical units to a consultation-liaison psychiatry service. Diagnostic agreement was calculated across all diagnoses and expressed as a percentage. Diagnostic concordance (expressed using Cohen's Kappa) was calculated for the two most common diagnoses of depression and delirium. Diagnostic agreement and concordance in the first two weeks (Timepoint A) were compared to those in the last two weeks (Timepoint B) of junior doctors' terms. Around half the referrals (Timepoint A = 48.1%, Timepoint B = 54.0%) were excluded as no diagnosis was listed.Diagnostic agreement over all diagnoses was 31.7% (Timepoint A) and 29.9% (Timepoint B) and was not statistically different. Diagnostic concordance for depression increased from fair to moderate but was not statistically significant. Diagnostic concordance for delirium was substantial for both timepoints and were not statistically different. No statistically significant change in diagnostic accuracy over a junior doctors' term was found in this study.

102 Detection of Acute Coronary Syndrome by Magnetocardiography

To evaluate the use of magnetocardiography (MCG) for early identification or rule out of acute coronary syndromes (ACS) in emergency department (ED) patients with chest pain. Magnetocardiography is a noninvasive imaging method that measures the electromagnetic fields generated by the heart’s activity. MCG is rapid, easy to perform, and provides a radiation-free imaging assessment for patients with suspected ACS. This is a prospective, observational, multicenter trial comparing the accuracy and time to disposition of ED standard of care (SOC) vs. MCG. Patients were enrolled at 3 sites from January to May 2021. Inclusion criteria were ED patients with chest pain, age ≥ 18 years, modified heart score > 2, and signs/symptoms of ACS in the ED. Exclusion criteria were STEMI, unable to fit into the device, non-ambulatory, hemodynamically unstable, and unable to lie supine for up to 5 minutes. Additional exclusion criteria were patients with pacemakers, AICD, other active devices, or any ferromagnetic metal above the costal margins. Patients underwent a MCG scan in addition to ED SOC. MCG was performed within 4 hours of ED triage. We hypothesize that the use of MCG will lead to shorter ED length of stay (LOS), with equal or improved diagnosis of suspected ACS patients. Of 58 scans, 32 were available for evaluation. 26 were unevaluable due to either insufficient data or uninterpretable. Patients with any artifacts were considered unevaluable. With technical improvements, the arttifact on current scans may be decreased which will result in fewer unevaluable scans. Mean age was 51.3 (SD± 1 .9) years, 50% female, 59.4% Black, 37.5% White, 3.1% other. Mean HEART score was 4.2 (SD± 1.1). Mean number of cardiovascular risk factors was 3.0 (SD± 1.6). Mean LOS (minutes) for MCG was 187 (SD ± 122) vs. SOC 812 (SD ± 73) (P < 0.0001 by paired t-test) (95% CI difference: -882.0, - 368.1). Thus, when compared with standard of care evaluation alone, the mean length-of-stay could have been reduced by 10.6 hours without any significant change in diagnostic accuracy. MCG and SOC based on troponins were both negative in 28 patients.There were 2 false positives by SOC (6.2%, 2/32). In these two patients presumed to have ACS by SOC, both went to cardiac catheterization, which revealed no ACS. MCG correctly identified the patients to have no ACS. There were two false negatives by MCG. In these two patients, MCG was positive and SOC rule out by troponins was negative. No stress test or cardiac catheterization was done in these two patients. Eleven patients (34%) were placed in the observation unit (OU). The MCG done in the ED and the rule out in the OU were both negative for ACS. Furthermore, early MCG done in the ED as compared with standard of care evaluation alone, would potentially eliminate overnight observation unit stays in 34% of the study population. Magnetocardiography results in a significantly lower LOS for chest pain in the ED which could lead to decreased ED LOS, improved ED turnaround times and better ED efficiency. MCG may avoid an OU stay with resultant cost savings in about one-third of ED chest pain patients. More importantly, MCG detected patients who were false positive by SOC and could have avoided a cardiac catheterization. MCG had two false positives which were negative by troponins but no cardiac catheterization or stress test were done in these two patients.

Use of a structured approach and virtual simulation practice to improve diagnostic reasoning.

In 2015, the National Academy of Medicine IOM estimated that 12 million patients were misdiagnosed annually. This suggests that despite prolonged training in medical school and residency there remains a need to improve diagnostic reasoning education. This study evaluates a new approach. A total of 285 medical students were enrolled in this 8 center, IRB approved trial. Students were randomized to receive training in either abdominal pain (AP) or loss of consciousness (LOC). Baseline diagnostic accuracy of the two different symptoms was assessed by completing a multiple-choice question (MCQ) examination and virtual patient encounters. Following a structured educational intervention, including a lecture on the diagnostic approach to that symptom and three virtual patient practice cases, each student was re-assessed. The change in diagnostic accuracy on virtual patient encounters was compared between (1) baseline and post intervention and (2) post intervention students trained in the prescribed symptom vs. the alternate symptom (controls). The completeness of the student's differential diagnosis was also compared. Comparison of proportions were conducted using χ2-tests. Mixed-effects regressions were used to examine differences accounting for case and repeated measures. Compared with baseline, both the AP and LOC groups had marked post-intervention improvements in obtaining a correct final diagnosis; a 27% absolute improvement in the AP group (p<0.001) and a 32% absolute improvement in the LOC group (p<0.001). Compared with controls (the groups trained in the alternate symptoms), the rate of correct diagnoses increased by 13% but was not statistically significant (p=0.132). The completeness and efficiency of the differential diagnoses increased by 16% (β=0.37, p<0.001) and 17% respectively (β=0.45, p<0.001). The study showed that a virtual patient platform combined with a diagnostic reasoning framework could be used for education and diagnostic assessment and improved correct diagnosis compared with baseline performance in a simulated platform.

Effects of multiphase versus single-phase CT angiography for the detection of distal cerebral vessel occlusion.

The goal of this study was to determine whether the benefits of multiphase CTA (mCTA) over single-phase CTA (sCTA) for the detection of proximal cerebrovascular occlusions similarly extend to the distal cerebral vasculature. Four attending radiologists, two neuroradiologists and two emergency radiologists, contributed as readers to this retrospective study. For each reader, two sessions were conducted, one using sCTA and one using mCTA. During each session, the reader interpreted the studies of 104 patients who underwent imaging for suspicion of acute ischemic stroke, resulting in a total of 832 interpretations. Changes in diagnostic accuracy, time to render final decision, and reported levels of reader confidence were quantitatively assessed. Further analysis comparing the effects for neuroradiologists versus emergency radiologists was additionally conducted. Using mCTA resulted in a significant 5.0% absolute increase in sensitivity (91.6% vs. 96.6%, p = .004) and an insignificant increase in specificity (99.5% vs. 99.7%, p = .39). A significant reduction in reading time (66.7s vs. 59.6s, p = .001) and an increase in diagnostic confidence (2.26 vs. 2.58, p < .001) were observed. Using sCTA, higher sensitivity was achieved by neuroradiologists than emergency radiologists (96.0% vs. 86.9%, p = .002); using mCTA resulted in an absolute increase in sensitivity of 0.9% (97.4%, p = .44) for neuroradiologists and 9.6% (96.5%, p < .001) for emergency radiologists, eliminating significant differences between the groups (p = 0.57). The use of mCTA results in increased sensitivity and negative predictive value, decreased reading time, increased diagnostic confidence, and the elimination of differences in accuracy between neuroradiologists and emergency radiologists.

Ultra-low-dose computed tomography and its utility in wrist trauma in the emergency department.

The use and frequency of computed tomography (CT) are increasing day by day in emergency departments (ED). This increases the amount of radiation exposed. To evaluate the image quality obtained by ultra-low-dose CT (ULDCT) in patients with suspected wrist fractures in the ED and to investigate whether it is an alternative to standard-dose CT (SDCT). This is a study prospectively examining 336 patients who consulted the ED for wrist trauma. After exclusion criteria were applied, the patients were divided into the study and control groups. Then, SDCT (120 kVp and 100 mAs) and ULDCT (80 kVp and 5 mAs) wrist protocols were applied simultaneously. The images obtained were evaluated for image quality and fracture independently by a radiologist and an emergency medical specialist using a 5-point scale. The effective radiation dose calculated for the control group scans was 41.1 ± 2.1 µSv, whereas the effective radiation dose calculated for the study group scans was 0.5 ± 0.0 µSv. The effective radiation dose of the study group was significantly lower than that of the control group (P < 0.01). The CT images in the study group showed no significant differences in the mean image quality score between observer 1 and observer 2 (3.4 and 4.3, respectively; P = 0.58). Both observers could detect all fractures using the ULDCT images. ULDCT provides high-quality images in wrist traumas while reducing the radiation dose by approximately 98% compared to SDCT without any changes in diagnostic accuracy.

Pediatric Endoscopy During the COVID-19 Pandemic: Implications of Universal Preprocedural Testing for PPE Utilization.

Pediatric Endoscopy During the COVID-19 Pandemic: Implications of Universal Preprocedural Testing for PPE Utilization.

Severe mental illness diagnosis in English general hospitals 2006-2017: A registry linkage study.

The higher mortality rates in people with severe mental illness (SMI) may be partly due to inadequate integration of physical and mental healthcare. Accurate recording of SMI during hospital admissions has the potential to facilitate integrated care including tailoring of treatment to account for comorbidities. We therefore aimed to investigate the sensitivity of SMI recording within general hospitals, changes in diagnostic accuracy over time, and factors associated with accurate recording. We undertook a cohort study of 13,786 adults with SMI diagnosed during 2006-2017, using data from a large secondary mental healthcare database as reference standard, linked to English national records for 45,706 emergency hospital admissions. We examined general hospital record sensitivity across patients' subsequent hospital records, for each subsequent emergency admission, and at different levels of diagnostic precision. We analyzed time trends during the study period and used logistic regression to examine sociodemographic and clinical factors associated with psychiatric recording accuracy, with multiple imputation for missing data. Sensitivity for recording of SMI as any mental health diagnosis was 76.7% (95% CI 76.0-77.4). Category-level sensitivity (e.g., proportion of individuals with schizophrenia spectrum disorders (F20-29) who received any F20-29 diagnosis in hospital records) was 56.4% (95% CI 55.4-57.4) for schizophrenia spectrum disorder and 49.7% (95% CI 48.1-51.3) for bipolar affective disorder. Sensitivity for SMI recording in emergency admissions increased from 47.8% (95% CI 43.1-52.5) in 2006 to 75.4% (95% CI 68.3-81.4) in 2017 (ptrend < 0.001). Minority ethnicity, being married, and having better mental and physical health were associated with less accurate diagnostic recording. The main limitation of our study is the potential for misclassification of diagnosis in the reference-standard mental healthcare data. Our findings suggest that there have been improvements in recording of SMI diagnoses, but concerning under-recording, especially in minority ethnic groups, persists. Training in culturally sensitive diagnosis, expansion of liaison psychiatry input in general hospitals, and improved data sharing between physical and mental health services may be required to reduce inequalities in diagnostic practice.

Clinical impact of 18F-FDG-PET among memory clinic patients with uncertain diagnosis

PurposeTo assess the clinical impact and incremental diagnostic value of 18F-fluorodeoxyglucose (FDG-PET) among memory clinic patients with uncertain diagnosis.MethodsThe study population consisted of 277 patients who, despite extensive baseline cognitive assessment, MRI, and CSF analyses, had an uncertain diagnosis of mild cognitive impairment (MCI) (n = 177) or dementia (n = 100). After baseline diagnosis, each patient underwent an FDG-PET, followed by a post-FDG-PET diagnosis formulation. We evaluated (i) the change in diagnosis (baseline vs. post-FDG-PET), (ii) the change in diagnostic accuracy when comparing each baseline and post-FDG-PET diagnosis to a long-term follow-up (3.6 ± 1.8 years) diagnosis used as reference, and (iii) comparative FDG-PET performance testing in MCI and dementia conditions.ResultsFDG-PET led to a change in diagnosis in 86 of 277 (31%) patients, in particular in 57 of 177 (32%) MCI and in 29 of 100 (29%) dementia patients. Diagnostic change was greater than two-fold in the sub-sample of cases with dementia “of unclear etiology” (change in diagnosis in 20 of 32 (63%) patients). In the dementia group, after results of FDG-PET, diagnostic accuracy improved from 77 to 90% in Alzheimer’s disease (AD) and from 85 to 94% in frontotemporal lobar degeneration (FTLD) patients (p < 0.01). FDG-PET performed better in dementia than in MCI (positive likelihood ratios >5 and < 5, respectively).ConclusionWithin a selected clinical population, FDG-PET has a significant clinical impact, both in early and differential diagnosis of uncertain dementia. FDG-PET provides significant incremental value to detect AD and FTLD over a clinical diagnosis of uncertain dementia.

Evaluating Changes in Diagnostic Accuracy of Ultrasound for Appendicitis: Does Practice Make Perfect?

Ultrasound (US) is the preferred method of initial evaluation for appendicitis in pediatrics. However, limited accuracy of US for appendicitis is an obstacle to implementation of US-first protocols at facilities less experienced with US. The primary objective was to demonstrate changes in diagnostic accuracy of US for appendicitis over time, after implementation of an US-first protocol. Secondary objectives included evaluating trends in utilization and factors associated with accuracy of US. We reviewed 5years of pediatric emergency department encounters that included US evaluations for appendicitis. The primary outcome was conclusive US (fully visualized normal appendix or unequivocal appendicitis) vs. equivocal US (partially visualized or nonvisualized appendix). We also analyzed rates of conclusive US over time; accuracy, sensitivity, and specificity of US for appendicitis; and associations of US accuracy with patient gender, body mass index, and ultrasonographer's experience. A conclusive US report was found in 267 of 1058 encounters (25.2%); overall accuracy rate was 24.5%. Over 5years, the diagnostic accuracy of US for appendicitis improved significantly from 13.9% to 31.5% (p=0.001). Overall sensitivity was 80.7% and specificity was 77.6%. Male gender and dedicated US of the appendix were significantly associated with conclusive US (ps<0.001). Higher body mass index was significantly associated with equivocal US (p<0.001). Ultrasonographer experience was not significantly associated with conclusive US (p=0.22). An US-first imaging protocol for appendicitis in children shows chronologic improvement in diagnostic accuracy. This may provide encouragement to facilities using computed tomography-based diagnostic protocols to implement US-first protocols to reduce childhood radiation exposure.

Analysis of Treatment Outcome Associated with Pre-Operative Diagnostic Accuracy Changes and Dental Treatment Timing in Odontogenic Sinusitis Involving Unilateral Maxillary Sinus

Background and Objectives Unilateral sinusitis is caused by various factors. Odontogenic sinusitis; especially, is different from non-odontogenic sinusitis in clinical features and prognosis. The purpose of this study is to evaluate the prognosis of odontogenic sinusitis in accordance with the changes in diagnostic accuracy over time and the timing of dental treatment. Subjects and Method 195 patients who underwent endoscopic sinus surgery for unilateral sinusitis within the interval from 2006 to 2017 were reviewed to analyze the etiologies and clinical characteristics. Preoperative CT was assessed to identify patients who had not been diagnosed with odontogenic sinusitis in the past. In the unilateral bacterial sinusitis, we identified changes in incidence, diagnostic accuracy, and outcome in the odontogenic sinusitis. We divided odontogenic sinusitis patients into three groups: preoperative and intraoperative dental treatment group, postoperative dental treatment group, and untreated group. Then we analyzed the difference in prognosis of these three groups. Results The total number of patients with odontogenic sinusitis was 86 (44%), which accounted for about 36% until 2011, but increased to about 48% after 2013. From 2006 to 2011, there were 15 cases of missed diagnosis of odontogenic sinusitis, but there was 1 case in 2012 and no cases since 2013. The treatment outcome of unilateral bacterial sinusitis was significantly increased from 84.1% before 2011 to 96% after 2012. The success rate was 97.1% in the case of accurate diagnosis of odontogenic sinusitis, but the success rate was 43.8% in case of missed diagnosis. In odontogenic sinusitis, the success rate was low when dental treatment was not performed. However, there was no difference in success rate among different dental treatment timings. Conclusion The incidence of odontogenic sinusitis has steadily increased over the last decade. The prognosis has been improved by appropriate treatment under accurate diagnosis through preoperative examination and radiological evaluation. There was no difference in the prognosis of odontogenic sinusitis according to the dental treatment time. Therefore, it is a good choice for tooth preservation to have an endoscopic sinus surgery first and then decide the dental treatment timing. Key words: Chronic rhinosinusitis ㆍ Odontogenic sinusitis ㆍ Treatment strategy

Trends of incidence and survival of patients with chronic myelomonocytic leukemia between 1999 and 2014: A comparison between Swiss and American population-based cancer registries

BackgroundChronic myelomonocytic leukemia (CMML) is a rare hematopoietic malignancy. Treatment with hypomethylating agents (HMA) was introduced between 2004 and 2006 but its impact on population-based survival remains controversial. The aim of this study was to investigate epidemiological characteristics and survival before and after introduction of HMA treatment. MethodsWe performed a population-based analysis of CMML cases reported to the Cantonal Cancer Registries in Switzerland (SWISS) and the Surveillance, Epidemiology, and End Results (SEER) Program from the United States for 1999–2006 (before HMA) and 2007–2014 (after HMA). Time trends were compared for these two time periods. Results423 and 4144 new CMML cases were reported to the SWISS and SEER registries, respectively. We observed an increasing proportion of older patients ≥75 years in the SWISS (50.3%–62.3%) compared to a decreasing one in the SEER population (59.1%–55.1%). Age standardized incidence-rates were similar and remained stable in both countries (0.32–0.38 per 100’000 py). Relative survival (RS) improved significantly in the SEER (3 years 27%–37%; 5 years 19%–23%; p < 0.001 for both) but remained stable in the SWISS population (3 years 48% to 40%; 5 years 34% to 26%; n.s. for both). ConclusionsWith the exception of opposing age-trends, epidemiologic characteristics are similar in both countries and comparable to other population-based registries. RS remains poor and different time trends of population-based survival cannot be faithfully explained by HMA but most likely by changes in diagnostic accuracy within prognostically distinct age-groups.

Detection and Diagnostic Overall Accuracy Measures of Medical Tests.

BackgroundOverall accuracy measures of medical tests are often used with unclear interpretations.ObjectivesTo develop methods of calculating the overall accuracy of medical tests in the patient population.MethodsAlgebraic equations based on Bayes’ theorem.ResultsA new approach is proposed for calculating overall accuracy in the patient population. Examples and applications using published data are presented.ConclusionsThe overall accuracy is the proportion of the correct test results. We introduce a clear distinction between the overall accuracy measures of medical tests that are aimed at the detection of a disease in a screening of populations for public health purposes in the general population and the overall accuracy measures of tests aimed at determining a diagnosis in individuals in a clinical setting. We show that the overall detection accuracy measure is obtained in a specific study that explores test accuracy among persons with known diagnoses and may be useful for public health screening tests. It is different from the overall diagnostic accuracy that could be calculated in the clinical setting for the evaluation of medical tests aimed at determining the individual patients’ diagnoses. We show that the overall detection accuracy is constant and is not affected by the prevalence of the disease. In contrast, the overall diagnostic accuracy changes and is dependent on the prevalence. Moreover, it ranges according to the ratio between the sensitivity and specificity. Thus, when the sensitivity is greater than the specificity, the overall diagnostic accuracy increases with increasing prevalence, and vice versa, that is, when the sensitivity is lower than the specificity, the overall diagnostic accuracy decreases with increasing prevalence so that another test might be more useful for diagnostic procedures. Our paper suggests a new and more appropriate methodology for estimating the overall diagnostic accuracy of any medical test. This may be important for helping clinicians avoid errors.

The slow dynamics of mycoplasma infections in a tortoise host reveal heterogeneity pertinent to pathogen transmission and monitoring

The epidemiology of infectious diseases depends on many characteristics of disease progression, as well as the consistency of these processes across hosts. Longitudinal studies of infection can thus inform disease monitoring and management, but can be challenging in wildlife, particularly for long-lived hosts and persistent infections. Numerous tortoise species of conservation concern can be infected by pathogenic mycoplasmas that cause a chronic upper respiratory tract disease (URTD). Yet, a lack of detailed data describing tortoise responses to mycoplasma infections obscures our understanding of URTDs role in host ecology. We therefore monitored Mycoplasma agassizii infections in 14 captive desert tortoises and characterised clinical signs of disease, infection intensity, pathogen shedding and antibody production for nearly 4 years after initial exposure to donor hosts. Persistent infections established in all exposed tortoises within 10 weeks, but hosts appeared to vary in resistance, which affected the patterns of pathogen shedding and apparent disease. Delays in host immune response and changes to clinical signs and infection intensity over time resulted in inconsistencies between diagnostic tools and changes in diagnostic accuracy throughout the study. We discuss the implications these results have for URTD epidemiology and past and future research assessing disease prevalence and dynamics in tortoise populations.

Impact of partial-volume correction in oncological PET studies: a systematic review and meta-analysis

PurposePositron-emission tomography can be useful in oncology for diagnosis, (re)staging, determining prognosis, and response assessment. However, partial-volume effects hamper accurate quantification of lesions <2–3× the PET system’s spatial resolution, and the clinical impact of this is not evident. This systematic review provides an up-to-date overview of studies investigating the impact of partial-volume correction (PVC) in oncological PET studies.MethodsWe searched in PubMed and Embase databases according to the PRISMA statement, including studies from inception till May 9, 2016. Two reviewers independently screened all abstracts and eligible full-text articles and performed quality assessment according to QUADAS-2 and QUIPS criteria. For a set of similar diagnostic studies, we statistically pooled the results using bivariate meta-regression.ResultsThirty-one studies were eligible for inclusion. Overall, study quality was good. For diagnosis and nodal staging, PVC yielded a strong trend of increased sensitivity at expense of specificity. Meta-analysis of six studies investigating diagnosis of pulmonary nodules (679 lesions) showed no significant change in diagnostic accuracy after PVC (p = 0.222). Prognostication was not improved for non-small cell lung cancer and esophageal cancer, whereas it did improve for head and neck cancer. Response assessment was not improved by PVC for (locally advanced) breast cancer or rectal cancer, and it worsened in metastatic colorectal cancer.ConclusionsThe accumulated evidence to date does not support routine application of PVC in standard clinical PET practice. Consensus on the preferred PVC methodology in oncological PET should be reached. Partial-volume-corrected data should be used as adjuncts to, but not yet replacement for, uncorrected data.

The Impact of Fatigue on Satisfaction of Search in Chest Radiography

To assess the nature of the satisfaction of search (SOS) effect in chest radiography when observers are fatigued; determine if we could replicate recent findings that have documented the nature of the SOS effect to be due to a threshold shift rather than a change in diagnostic accuracy as in earlier film-based studies. Nearing or at the end of a clinical workday, 20 radiologists read 64 chest images twice, once with and once without the addition of a simulated pulmonary nodule. Half of the images had different types of "test" abnormalities. Decision thresholds were analyzed using the center of the range of false-positive (FP) and true-positive (TP) fractions associated with each receiver operating characteristic (ROC) point for reporting test abnormalities. Detection accuracy was assessed with ROC technique and inspection time was recorded. The SOS effect was confirmed to be a reduction in willingness to respond (threshold shift). The center of the FP range was significantly reduced (FP = 0.10 without added nodules, FP = 0.05 with added nodules, F(1,18) = 19.85, P = 0.0003). The center of the TP range was significantly reduced (TP = 0.39 without added nodules, TP = 0.33 with added nodules, F(1,18) = 10.81, P = 0.004). This study suggests that fatigue does not change the nature of the SOS effect, but rather may be additive with the SOS effect. SOS reduces both TP and FP responses, whereas fatigue reduces TPs more than FPs.

The Role of Laryngoscopy in the Diagnosis of Spasmodic Dysphonia

Spasmodic dysphonia (SD) can be difficult to diagnose, and patients often see multiple physicians for many years before diagnosis. Improving the speed of diagnosis for individuals with SD may decrease the time to treatment and improve patient quality of life more quickly. To assess whether the diagnosis of SD can be accurately predicted through auditory cues alone without the assistance of visual cues offered by laryngoscopic examination. Single-masked, case-control study at a specialized referral center that included patients who underwent laryngoscopic examination as part of a multidisciplinary workup for dysphonia. Twenty-two patients were selected in total: 10 with SD, 5 with vocal tremor, and 7 controls without SD or vocal tremor. The laryngoscopic examination was recorded, deidentified, and edited to make 3 media clips for each patient: video alone, audio alone, and combined video and audio. These clips were randomized and presented to 3 fellowship-trained laryngologist raters (A.D.R., A.T.H., and A.M.K.), who established the most probable diagnosis for each clip. Intrarater and interrater reliability were evaluated using repeat clips incorporated in the presentations. We measured diagnostic accuracy for video-only, audio-only, and combined multimedia clips. These measures were established before data collection. Data analysis was accomplished with analysis of variance and Tukey honestly significant differences. Of patients with SD, diagnostic accuracy was 10%, 73%, and 73% for video-only, audio-only, and combined, respectively (P < .001, df = 2). Of patients with vocal tremor, diagnostic accuracy was 93%, 73%, and 100% for video-only, audio-only, and combined, respectively (P = .05, df = 2). Of the controls, diagnostic accuracy was 81%, 19%, and 62% for video-only, audio-only, and combined, respectively (P < .001, df = 2). The diagnosis of SD during examination is based primarily on auditory cues. Viewing combined audio and video clips afforded no change in diagnostic accuracy compared with audio alone. Laryngoscopy serves an important role in the diagnosis of SD by excluding other pathologic causes and identifying vocal tremor.