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 Acute ischemic stroke (AIS) in the context of COVID-19 has received considerable attention for its propensity to affect patients of all ages. We aimed to evaluate the effect of age on functional outcome and mortality following an acute ischemic event. Methods and Results A prospectively maintained database from comprehensive stroke centers in Canada and the United States was analyzed for patients with AIS from March 14 to September 30, 2020 who tested positive for SARS-CoV-2. The primary outcome was Modified Rankin Scale score at discharge, and the secondary outcome was mortality. Baseline characteristics, laboratory values, imaging, and thrombectomy workflow process times were assessed. Among all 126 patients with COVID-19 who were diagnosed with AIS, the median age was 63 years (range, 27-94). There were 35 (27.8%) patients with AIS in the aged </=55 years group, 47 (37.3%) in the aged 56 to 70 group, and 44 (34.9%) in the aged >70 group. Intravenous tissue plasminogen activator and thrombectomy rates were comparable across these groups, (P=0.331 and 0.212, respectively). There was a significantly lower rate of mortality between each group favoring younger age (21.9% versus 45.0% versus 48.8%, P=0.047). After multivariable adjustment for possible confounders, a 1-year increase in age was significantly associated with fewer instances of a favorable outcome of Modified Rankin Scale 0 to 2 (odds ratio [OR], 0.95; 95 CI%, 0.90-0.99; P=0.048) and higher mortality (OR, 1.06; 95 CI%, 1.02-1.10; P=0.007). Conclusions AIS in the context of COVID-19 affects young patients at much greater rates than pre-pandemic controls. Nevertheless, instances of poor functional outcome and mortality are closely tied to increasing age.
["Diagnosis", "Treatment"]