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:

Background: The coronavirus disease 2019 pandemic is a major international public health crisis, which has led to over 3 million deaths as of April 2021. Several therapeutics have been tried for this deadly illness including antivirals, immunosuppressive agents and convalescent plasma (CP). In this study, we present our inner-city safety net hospital experience with CP therapy. Methods: This was a retrospective chart review of hospitalized patients with confirmed COVID-19 who were treated with CP. Results: A total of 60 patients received CP during the study period. The mean age for patients in this study was 58.95 years. The most common presenting symptoms were shortness of breath (85%) and cough (73%). Hypertension (65%) and diabetes mellitus (55%) were the most common comorbidities in our patients. In our multivariate regression analysis, male sex, nausea and loss of appetite at presentation were associated with improvement in oxygenation after CP. Total survival time, history of obstructive airway disease, home use of angiotensin-converting enzyme inhibitors and angiotensin-receptor blockers were associated with decreased survival, whereas Hispanic ethnicity showed a trend towards lower survival after CP therapy. Conclusions: Our study highlights several important characteristics of inner-city safety net hospital patient population who might benefit from CP therapy.
["Treatment", "Diagnosis"]