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 Patients with coronavirus disease 2019 (COVID-19) usually have fever and respiratory tract complaints; however, many report gastrointestinal (GI) symptoms. The frequency of GI symptoms ranges from 16% to 61%. Although COVID-19 morbidity and mortality are related to pulmonary disease, poor outcomes have been linked to GI symptoms. Therefore, this study aimed to determine the outcomes of COVID-19 patients who presented with GI symptoms. Methods We conducted a retrospective cohort study at Isra University Hospital in Hyderabad, Pakistan, from April 2020 to October 2020. Results In total, 395 polymerase chain reaction-positive individuals were included. No differences in age or comorbidities were found. Of the 84 patients who needed intensive care unit admission, 17 had GI symptoms (P= 0.357). Moreover, GI symptoms were reported in 9/42 patients who required mechanical ventilation (P = 0.674) and 35/184 patients who required non-invasive ventilation (P = 0.029). GI symptoms were reported in 47/206 patients discharged on room air (without supplemental oxygen) (P= 0.549), 11/77 who died (P = 0.025), 2/11 who were referred elsewhere due to financial issues (P = 0.999), 7/32 who left against medical advice (P = 0.764), and 28/69 who were discharged requiring oxygen at home (P = 0.001). Conclusions Patients with GI symptoms had reduced odds of mortality, and increased odds of discharge requiring supplemental oxygen.
["Diagnosis", "Treatment"]