The accuracy vs. coverage trade-off in patient-facing diagnosis models.

A third of adults in America use the Internet to diagnose medical concerns, and online symptom checkers are increasingly part of this process. These tools are powered by diagnosis models similar to clinical decision support systems, with the primary difference being the coverage of symptoms and diagnoses. To be useful to patients and physicians, these models must have high accuracy while covering a meaningful space of symptoms and diagnoses. To the best of our knowledge, this paper is the first in studying the trade-off between the coverage of the model and its performance for diagnosis. To this end, we learn diagnosis models with different coverage from EHR data. We find a 1% drop in top-3 accuracy for every 10 diseases added to the coverage. We also observe that complexity for these models does not affect performance, with linear models performing as well as neural networks.

Age, Sex and Weight Effects on Lactate and Leukocyte Response to Exercise in Children and Adolescents.

Post-exercise leucocytosis has been found in children and adults in response to exercise. When normalized to the work performed, children demonstrate a lower lactate response to exercise than in adults. This study examines the association between leukocyte and lactate response in children following exercise. 148 healthy children participated in this study. Each subject performed a ramp exercise on a cycle ergometer followed by ten 2-minute bouts of constant work rate separated by 1-minute rest intervals. Lactate, leukocyte and leukocyte subtype levels were taken pre- and post-exercise. Older children showed a significantly higher pre-to post-exercise leukocyte compared to younger children (3599 ± 165 cells/mL, 2544 ± 163, p<0.0001). Compared to older children, younger children demonstrated a smaller median fold change in lactate (2.7 (1.4-8.1), 4.1 (1.7-29.6)) and leukocyte levels (1.4 (1.0-2.1), 1.6 (1.2-2.8)) after exercise, with a larger leukocyte to lactate fold change ratio. CONCLUSION: Younger children have a greater leukocyte to lactate fold change ratio compared to older children. This finding may be due to the lower anaerobic dependence that is found in younger children.

Tele-Exercise as a Promising Tool to Promote Exercise in Children With Cystic Fibrosis.

Introduction: Cross-infection risk from contact exposure limits exercise opportunities in children with cystic fibrosis (CF). The purpose of this study is to evaluate the feasibility of a new live-streamed platform which delivered supervised and interactive group exercise sessions to CF children via digital devices while avoiding contact exposure. Methods: Ten CF children participated in a 6-week tele-exercise program. The program consisted of three 30-min sessions per week for a total of 18 sessions and included aerobic, resistance, and flexibility exercises. Sessions were streamed via a HIPAA compliant VSee telemedicine platform. Instructors and participants were able to interact in real-time online. Heart rate (HR) monitors were used to evaluate exercise intensity with a goal of moderate-vigorous physical activity ≥10 min, 70% of the sessions. System usability scale (SUS) and qualitative questionnaires were used to gauge participants' satisfaction and feedback. Results: On average participants attended 85% of the sessions. For the overall sessions participants exercise 21.1 ± 6.9 min at moderate-vigorous physical activity. Nine out of 10 participants used the exercise platform without parental guidance. Qualitative questionnaire and System Usability Scale (SUS) indicated that all participants enjoyed the tele-exercise program and highly rated the exercise platform 90.8 out of 100 (passing > 68). Conclusions: Tele-exercise platform is a promising new approach to promote exercise in children with CF. The online platform allows supervised virtual group exercise experience with optimal participation and no risk for cross-infection. This approach might prove to be useful in enhancing the use of exercise as therapy in children with CF.

Vigorous Exercise Can Cause Abnormal Pulmonary Function in Healthy Adolescents.

RATIONALE: Although exercise-induced bronchoconstriction is more common in adolescents with asthma, it also manifests in healthy individuals without asthma. The steady-state exercise protocol is widely used and recommended by the American Thoracic Society (ATS) as a method to diagnose exercise-induced bronchoconstriction. Airway narrowing in response to exercise is thought to be related to airway wall dehydration secondary to hyperventilation. More rigorous exercise protocols may have a role in detecting exercise-induced bronchoconstriction in those who otherwise have a normal response to steady-state exercise challenge. OBJECTIVES: The objective of this study was to determine the effect of two different exercise protocols--a constant work rate protocol and a progressive ramp protocol--on pulmonary function testing in healthy adolescents. We hypothesized that vigorous exercise protocols would lead to reductions in lung function in healthy adolescents. METHODS: A total of 56 healthy adolescents (mean age, 15.2 ± 3.3 [SD] years) were recruited to perform two exercise protocols: constant work rate exercise test to evaluate for exercise-induced bronchoconstriction (as defined by ATS) and standardized progressive ramp protocol. Pulmonary function abnormalities were defined as a decline from baseline in FEV1 of greater than 10%. MEASUREMENTS AND MAIN RESULTS: Ten participants (17.8%) had a significant drop in FEV1. Among those with abnormal lung function after exercise, three (30%) were after the ATS test only, five (50%) were after the ramp test only, and two (20%) were after both ATS and ramp tests. CONCLUSION: Healthy adolescents demonstrate subtle bronchoconstriction after exercise. This exercise-induced bronchoconstriction may be detected in healthy adolescents via constant work rate or the progressive ramp protocol. In a clinical setting, ramp testing warrants consideration in adolescents suspected of having exercise-induced bronchoconstriction and who have normal responses to steady-state exercise testing.