Data Collection during the COVID-19 Pandemic: Learning from Experience, Resulting in a Bayesian Repertory.

BACKGROUND: A novel pandemic disease offered the opportunity to create new, disease-specific, symptom rubrics for the homeopathic repertory. OBJECTIVE: The aim of this study was to discover the relationship between specific symptoms and specific medicines, especially of symptoms occurring frequently in this disease. MATERIALS AND METHODS: Worldwide collection of data in all possible formats by various parties was coordinated by the Liga Medicorum Homeopathica Internationalis. As the data came in, more symptoms were assessed prospectively. Frequent analysis and feedback by electronic newsletters were used to improve the quality of the data. Likelihood ratios (LRs) of symptoms were calculated. An algorithm for combining symptom LRs was programmed and published in the form of an app. The app was tested against 18 well-described successful cases from Hong Kong. RESULTS: LRs of common symptoms such as 'Fatigue' and 'Headache' provided better differentiation between medicines than did existing repertory entries, which are based only on the narrow presence or absence of symptoms. A mini-repertory for COVID-19 symptoms was published and supported by a web-based algorithm. With a choice of 20 common symptoms, this algorithm produced the same outcome as a full homeopathic analysis based upon a larger number of symptoms, including some that are traditionally considered more specific to particular medicines. CONCLUSION: A repertory based on clinical data and LRs can differentiate between homeopathic medicines using a limited number of frequently occurring epidemic symptoms. A Bayesian computer algorithm to combine symptoms can complement a full homeopathic analysis of cases.

Predictors of recurrence following radiofrequency ablation for persistent atrial fibrillation.

AIMS: To establish clinical factors affecting success in persistent atrial fibrillation (AF) ablation. METHODS AND RESULTS: Wide area circumferential ablation with linear and electrogram-based left atrial (LA) ablation was performed in 191 consecutive patients for persistent AF. After mean follow-up of 13.0 ± 8.9 months, overall success was 64% requiring a mean of 1.5 procedures. Single procedure success rate was 32%. Left atrial size was a univariate predictor of recurrence after a single procedure (P =0.04). Only LA size [hazard ratio (HR) 1.05/mm with 95% confidential interval (CI) 1.02-1.08] was an independent predictor of recurrence after a single procedure. Only LA size was a univariate predictor of recurrence after multiple procedures (P < 0.01). Left atrial size (HR 1.07/mm with 95% CI 1.02-1.11) and hypertrophic cardiomyopathy (HCM; HR 2.42 with 95% CI 1.06-5.55) were independent predictors of recurrence after multiple procedures. Ablation strategy did not affect success after a single procedure. Left atrial size of <43 mm predicted long-term success with a sensitivity of 92%, specificity 52%, positive predictive value 49%, and negative predictive value 93%. With LA size >43 mm, HCM (HR 3.09 with 95% CI 1.70-7.5) and AF duration (HR 1.07/year with 95% CI 1.00-1.13) were independent predictors of recurrence. CONCLUSION: Left atrial size is the major independent determinant of AF recurrence after ablation for persistent AF. This has important implications for patient selection for persistent AF ablation and the evaluation of AF ablation clinical trial results.

Acute high-altitude illness: a clinically orientated review.

Acute high-altitude illness is an encompassing term for the range of pathology that the unacclimatised individual can develop at increased altitude. This includes acute mountain sickness, high-altitude cerebral oedema and high-altitude pulmonary oedema. These conditions represent an increasing clinical problem as more individuals are exposed to the hypobaric hypoxic environment of high altitude for both work and leisure. In this review of acute high-altitude illness, the epidemiology, risk factors and pathophysiology are explored, before their prevention and treatment are discussed. Appropriate ascent rate remains the most effective acute high-altitude illness prevention, with pharmacological prophylaxis indicated in selected individuals. Descent is the definitive treatment for acute high-altitude illness, with the adjuncts of oxygen and specific drug therapies.