You are presented with a paragraph from a COVID-19 literature. Classify the topics of this piece of text by choosing from the following categories:

- Epidemic Forecasting: The content relates to predictions about the spread of COVID-19.
- Treatment: The paragraph discusses therapeutic methods or medication for COVID-19.
- Prevention: The content covers measures to prevent the spread of COVID-19.
- Mechanism: The paragraph explains the biological mechanisms of the virus.
- Case Report: The content is a report of a COVID-19 case.
- Transmission: The paragraph discusses how COVID-19 is transmitted.
- Diagnosis: The content is about diagnosing COVID-19 in individuals.

Your classification should be provided as an element within a JSON array. The array should be formatted with topics enclosed in double quotes and separated by commas, following the JSON format, for example: ["Topic1", "Topic2", ...]. Include all applicable topics within the array. Your output should be a valid JSON array, and no additional text should be included in your response.

Article:

AIM: The aim of the current study was to evaluate the index of Cardiac Electrophysiological Balance (iCEB) in hospitalized COVID-19 patients receiving Hydroxychloroquine / azithromycin (HCQ / AZ) combination therapy to determine the susceptibility to ventricular arrhythmia among these patients. METHOD: Sixty-seven COVID-19 patients admitted to the ward were included in the study. Electrocardiograms (ECGs) were obtained from all patients before the initiation of treatment and on treatment day 5. QT/QRS (iCEB) and QTc/QRS (iCEBc) ratios were calculated. RESULTS: QRS, QT and QTc intervals were significantly prolonged on day 5 measurements compared to pre-treatment period (p <0.05). Overall, mean iCEB was 3.6+/-0.4 before treatment and 3.8+/-0.4 on day 5 in the study population (p <0.001). Considering the iCEBc values, a significant increase was observed in patients receiving HCQ/AZ treatment compared to pre-treatment period (4.1+/-0.5 vs 4.4+/-0.6; p <0.001). CONCLUSIONS: To the best of our knowledge, this was the first study to investigate iCEB and iCEBc parameters in patients with COVID-19 on HCQ/AZ therapy. In this study, we demonstrated significantly increased iCEB and iCEBc values following HCQ/AZ treatment in COVID-19 patients. iCEB and iCEBc may serve as a noninvasive, simple, and novel biomarker for detecting increased pro-arrhythmia risk in COVID-19 patients (Tab. 3, Fig. 3, Ref. 36).
["Diagnosis", "Treatment"]