∙ To be enrolled in the study, participants must meet all inclusion criteria:

• Individuals ≥ 60 years old at the time of screening (calculated from the date of birth to the date of screening)

• ARI or exacerbation of cardiopulmonary diseases diagnosed at the time of admission. ARI or ARI-compatible symptoms were defined as either:

‣ New onset or increase from baseline of: nasal congestion, rhinorrhea, sore throat, hoarseness, cough, sputum production, dyspnea, wheezing, hypoxemia, or

⁃ Admitting diagnosis suggestive of ARI (e.g., pneumonia, upper respiratory infection, bronchitis, influenza, cough, viral respiratory illness, respiratory distress, or respiratory failure), or

⁃ Admitting diagnosis was the exacerbation of an underlying cardiac or pulmonary disease involving acute respiratory symptoms within the previous 2 weeks (e.g., congestive heart failure \[CHF\], chronic obstructive pulmonary disease \[COPD\], or asthma exacerbation).

• The participant agrees to voluntarily participate in this study.