Changes In Diagnostic Testing Research Articles

Abstract 14113: Impact of Clinician Telemedicine Use on Diagnostic Testing for Heart Failure Patients

Introduction: Previous studies have reported decreased diagnostic testing with telemedicine visits early in the COVID-19 pandemic. The effect of telemedicine use on diagnostic testing for a panel of heart failure (HF) patients is unknown. We sought to use clinician-level variation in telemedicine use over time to determine the association of telemedicine care delivery with changes in diagnostic testing for HF patients. Methods: Patients with HF diagnostic codes seen at an academic cardiovascular center from May 2019 to Nov 2022 were included. Clinicians performing the majority of cardiology visits for at least 10 HF patients were identified. Early pandemic visits (March 2020-May 2020) were excluded. The remaining time was divided into 4 10-month periods with the first ending before the pandemic. We used a linear regression model with clinician and period fixed effects to estimate the association of the fraction of a clinician’s visits delivered by telemedicine in each period with the number of orders for Holter monitors, EKGs, transthoracic echocardiograms (TTEs), and laboratory tests per visit. Results: There were 6,420 patients seen by 45 clinicians. Clinician telemedicine fraction across periods ranged from 0 to 100 percent. Mean telemedicine fraction decreased from 55.4% to 34.6% from periods 2 to 4. A 25-percentage point increase in telemedicine use was associated with significantly fewer orders for EKGs (-0.078 orders/visit) and TTEs (-0.021 orders/visit), representing decreases of 33% and 13% relative to period 1 respectively. Higher telemedicine use was associated with non-significant decreases in orders for Holter monitors and laboratory tests (Table). Conclusions: Greater clinician telemedicine use was associated with decreased diagnostic testing orders per visit for HF patients. Further research is needed to characterize the value of these potentially avoided tests and understand the impact of telemedicine on the quality of care for HF patients.

Herpes zoster: A primary care approach to diagnosis and treatment.

Herpes zoster, or shingles, caused by a reactivation of the chickenpox virus, can occur in patients of any age, but is more common in older adults. Patient history is critical in reaching a diagnosis, not only to manage the outbreak effectively, but also to prevent severe complications such as dissemination of the virus into the central nervous system. This article describes recent changes in diagnostic testing, treatment, prevention, and practice guidelines as well as the approach clinicians should take when evaluating patients with herpes zoster and assessing risk for complications.

The Impact of Changes in Diagnostic Testing Practices on Estimates of COVID-19 Transmission in the United States.

Estimates of the reproductive number for novel pathogens such as severe acute respiratory syndrome coronavirus 2 are essential for understanding the potential trajectory of the epidemic and the level of intervention that is needed to bring the epidemic under control. However, most methods for estimating the basic reproductive number (R0) and time-varying effective reproductive number (Rt) assume that the fraction of cases detected and reported is constant through time. We explore the impact of secular changes in diagnostic testing and reporting on estimates of R0 and Rt using simulated data. We then compare these patterns to data on reported cases of coronavirus disease and testing practices from different states in the United States from March 4 to August 30, 2020. We find that changes in testing practices and delays in reporting can result in biased estimates of R0 and Rt. Examination of changes in the daily number of tests conducted and the percent of patients testing positive may be helpful for identifying the potential direction of bias. Changes in diagnostic testing and reporting processes should be monitored and taken into consideration when interpreting estimates of the reproductive number of coronavirus disease.

Diagnostic patterns of non-small-cell lung cancer at Princess Margaret Cancer Centre.

Accurate classification of lung cancer subtypes has become critical in tailoring lung cancer treatment. Our study aimed to evaluate changes in diagnostic testing and pathologic subtyping of advanced non-small-cell lung cancer (nsclc) over time at a major cancer centre. In a review of patients diagnosed with advanced nsclc at Princess Margaret Cancer Centre between 2007-2009 and 2013-2015, diagnostic method, sample type and site, pathologic subtype, and use of immunohistochemistry (ihc) staining and molecular testing were abstracted. The review identified 238 patients in 2007-2009 and 283 patients in 2013-2015. Over time, the proportion of patients diagnosed with adenocarcinoma increased to 73.1% from 60.9%, and diagnoses of nsclc not otherwise specified (nos) decreased to 6.4% from 18.9%, p < 0.0001. Use of diagnostic bronchoscopy decreased (26.9% vs. 18.4%), and mediastinal sampling procedures, including endobronchial ultrasonography, increased (9.2% vs. 20.5%, p = 0.0001). Use of ihc increased over time to 76.3% from 41.6% (p < 0.0001). Larger surgical or core biopsy samples and those for which ihc was performed were more likely to undergo biomarker testing (both p < 0.01). Customizing treatment based on pathologic subtype and molecular genotype has become key in treating patients with advanced lung cancer. Greater accuracy of pathology diagnosis is being achieved, including through the routine use of ihc.

Effect of Genetic Diagnosis on Patients with Previously Undiagnosed Disease

BackgroundMany patients remain without a diagnosis despite extensive medical evaluation. The Undiagnosed Diseases Network (UDN) was established to apply a multidisciplinary model in the evaluation of the most challenging cases and to identify the biologic characteristics of newly discovered diseases. The UDN, which is funded by the National Institutes of Health, was formed in 2014 as a network of seven clinical sites, two sequencing cores, and a coordinating center. Later, a central biorepository, a metabolomics core, and a model organisms screening center were added.MethodsWe evaluated patients who were referred to the UDN over a period of 20 months. The patients were required to have an undiagnosed condition despite thorough evaluation by a health care provider. We determined the rate of diagnosis among patients who subsequently had a complete evaluation, and we observed the effect of diagnosis on medical care.ResultsA total of 1519 patients (53% female) were referred to the UDN, of whom 601 (40%) were accepted for evaluation. Of the accepted patients, 192 (32%) had previously undergone exome sequencing. Symptoms were neurologic in 40% of the applicants, musculoskeletal in 10%, immunologic in 7%, gastrointestinal in 7%, and rheumatologic in 6%. Of the 382 patients who had a complete evaluation, 132 received a diagnosis, yielding a rate of diagnosis of 35%. A total of 15 diagnoses (11%) were made by clinical review alone, and 98 (74%) were made by exome or genome sequencing. Of the diagnoses, 21% led to recommendations regarding changes in therapy, 37% led to changes in diagnostic testing, and 36% led to variant-specific genetic counseling. We defined 31 new syndromes.ConclusionsThe UDN established a diagnosis in 132 of the 382 patients who had a complete evaluation, yielding a rate of diagnosis of 35%. (Funded by the National Institutes of Health Common Fund.)

Six years of INSTAND e. V. sIgE proficiency testing: An evaluation of in vitro allergy diagnostics.

BackgroundEven though allergies are an important health issue, wide manufacturer-dependent differences in the detected amounts of allergen-specific IgE (sIgE) have repeatedly been found. These discrepancies hinder diagnostics and research into clinically significant cutoff points for life-threatening symptoms.MethodsTo evaluate whether the reported differences have led to changes in diagnostic testing, we analyzed data from six years of round robin testing (RRT, also known as proficiency testing) at the Gesellschaft zur Förderung der Qualitätssicherung in medizinischen Laboratorien e.V.  (Society for Promoting Quality Assurance in medical Laboratories) for the important allergen sources bee venom, wasp venom, and birch pollen. The results of the four main suppliers of in vitro diagnostic sIgE testing were compared in a pseudo-anonymized form using overlay images of box plot graphs for the semiquantitative data and allergen class results. Coefficients of variation (CV) were obtained to study the development of interlaboratory comparability.ResultsWe found that the large differences between the manufacturer collectives remained constant between January 2010 and April 2015 without any real improvement. The CVs were good for two of the four analyzed suppliers, one was marginal and one above the quality level of 20%.ConclusionThe numerous publications that have found discrepancies in the sIgE results of the different suppliers did not change the status quo within the last six years. Unfortunately, this is unlikely to change until there is a characterized standard material with known values of sIgE.

Aggregate and hospital-level impact of national guidelines on diagnostic resource utilization for children with pneumonia at children's hospitals.

National guidelines for the management of community-acquired pneumonia (CAP) in children were published in 2011. These guidelines discourage most diagnostic testing for outpatients, as well as repeat testing for hospitalized patients who are improving. We sought to evaluate the temporal trends in diagnostic testing associated with guideline implementation among children with CAP. Children 1 to 18 years old who were discharged with pneumonia after emergency department (ED) evaluation or hospitalization from January 1, 2008 to June 30, 2014 at any of 32 children's hospitals participating in the Pediatric Health Information System were included. We excluded children with complex chronic conditions and those requiring intensive care or who underwent early pleural drainage. We compared use of diagnostic testing (blood culture, complete blood count [CBC], C-reactive protein [CRP], and chest radiography [CXR]) before and after release of the guidelines, and assessed for temporal trends using interrupted time series analysis. We also calculated the cost impact of these changes on diagnostic utilization and evaluated the variability of the guideline's impact across hospitals. Overall, 220,539 patients were included; 53% were male and the median age was 4 years (interquartile range, 2-7). For patients discharged from the ED with CAP, diagnostic utilization rates for blood culture, CBC, CRP, and CXR were higher after guideline publication compared with expected utilization rates without guidelines. In contrast, initial testing and repeat testing among patients hospitalized with CAP was lower after guideline publication. There were modest reductions in estimated costs associated with these changes. However, wide variability was observed in the impact of the guidelines across hospitals. Publication of national pneumonia guidelines in 2011 was associated with modest changes in diagnostic testing for children with CAP. However, the changes varied across hospitals, and the financial impact was modest. Local implementation efforts are warranted to ensure widespread guideline adherence. Journal of Hospital Medicine 2016;11:317-323. © 2016 Society of Hospital Medicine.

The Clinical Utility of Gene Expression Testing on the Diagnostic Evaluation of Patients Presenting to the Cardiologist With Symptoms of Suspected Obstructive Coronary Artery Disease

Accurate, noninvasive evaluation for obstructive coronary artery disease (CAD) remains challenging and inefficient. In this study, 171 patients presenting with stable chest pain and related symptoms without a history of CAD were referred to 6 cardiologists for evaluation. In the prospective cohort of 88 patients, the cardiologist's diagnostic strategy was evaluated before and after gene expression score (GES) testing. The GES is a validated, quantitative blood-based diagnostic test measuring peripheral blood cell expression levels of 23 genes to determine the likelihood of obstructive CAD (at least 1 vessel with ≥ 50% angiographic coronary artery stenosis). The objective of the study was to measure the effect of the GES on diagnostic testing using a pre/post study design. There were 83 prospective patients evaluable for study analysis, which included 57 (69%) women, mean age 53 ± 11 years, and mean GES 12.5 ± 9. Presenting symptoms were classified as typical angina, atypical angina, and noncardiac chest pain in 33%, 60%, and 7% of patients (n = 27, 50, and 6), respectively. After GES, changes in diagnostic testing occurred in 58% of patients (n = 48, P < 0.001). Of note, 91% (29/32) of patients with decreased testing had low GES (≤ 15), whereas 100% (16/16) of patients with increased testing had elevated GES (P < 0.001). A historical cohort of 83 patients, matched to the prospective cohort by clinical factors, had higher diagnostic test use compared with the post-GES prospective cohort (P < 0.001). In summary, the GES showed clinical utility in the evaluation of patients with suspected obstructive CAD presenting to the cardiologist's office.

Response to Dosanjh et al.

To the Editor: Dosanjh et al. (1) highlight several points that are important and worthy of further discussion. The first issue with the referenced paper is the potential issue of surveillance bias and the possible increased recognition of celiac disease which may have resulted in increased diagnostic testing in later years, potentially biasing incidence estimates upwards. We agree and, thus, were careful to phrase our findings using terminologies such as “diagnosis rate” in lieu of simply “incidence rate.” However, recent work has documented a true increase in prevalence in the US population quite independent of clinical diagnosis rate (2). Furthermore, as pointed out we also highlighted the possibility for changes in diagnostic testing as an important point in the first paragraph of our discussion where it was stated that temporal trends for serologic celiac disease tests would assist in differentiating surveillance bias with true incidence changes; however, those data were unavailable. Importantly, additional studies could be undertaken using the Department of Defense serum repository to conduct serologic testing on a carefully selected subset of individuals to characterize the changes in celiac-related antibodies over time; though as noted by the authors, histology remains the gold standard for diagnosis and limitations may persist.

CDC Update on Pertussis Surveillance and Tdap Vaccine Recommendations

Pertussis is the most poorly controlled bacterial vaccine-preventable disease. Since the early 1980s there has been an increase in reported cases of pertussis. Multiple factors have likely contributed to the increase, including waning immunity, increased recognition, and changes in diagnostic testing and reporting. Of the four combination vaccines used to prevent diphtheria, tetanus, and pertussis, one dose of Tdap should be used to vaccinate preteens as well as teens and adults who have not yet received this booster dose. It is the position of NASN that immunizations, including the Tdap vaccine, are key to primary prevention of diseasefrom infancy through adulthood. The school nurse is in a critical position to create awareness and influence action-related national and state recommendations for the Tdap vaccine.

A Population-Based Study of Dystrophin Mutations in Canada

We carried out a population-based study of dystrophin mutations in patients followed by members of the Canadian Paediatric Neuromuscular Group (CPNG) over a ten-year period. We aimed to describe the changes in diagnostic testing for dystrophinopathy and to determine the frequency of dystrophin mutations from 2000 to 2009. De-identified data containing the clinical phenotypes, diagnostic methods, and mutational reports from dystrophinopathy patients followed by CPNG centres from January 2000 to December 2009 were analyzed using descriptive statistics. 773 patients had a confirmed diagnosis of dystrophinopathy based on genetic testing (97%), muscle biopsy (2%), or family history (1%). 573 (74%) had complete deletion/duplication analysis of all 79 exons or whole gene sequencing, resulting in 366 (64%) deletions, 64 (11%) duplications, and 143 (25%) point mutations. The percentage of patients who were diagnosed using currently accepted genetic testing methods varied across Canada, with a mean of 63% (SD 23). 246 (43%) mutations involved exons 45 to 53. The top ten deletions (n=147, 26%) were exons 45-47, 45-48, 45, 45-50, 45-55, 51, 45-49, 45-52, 49-50, and 46-47. 169 (29%) mutations involved exons 2 to 20. The most common duplications (n=29, 5.1%) were exons 2, 2-7, 2-17, 3-7, 8-11, 10, 10-11, and 12. This is the most comprehensive report of dystrophin mutations in Canada. Consensus guidelines regarding the diagnostic approach to dystrophinopathy will hopefully reduce the geographical variation in mutation detection rates in the coming decade.