The following additional data will be obtained: vital signs (blood pressure, pulse, temperature, respiratory rate, oxygen saturation level); dyspnea assessment (MMRC & University of California San Diego SOBQ); estimate of daily sputum production over last 72 hours; sputum color (using a standardized color "paint-chip" scale); changes in medication usage, with special attention to elicit any history of increased use of potent inhaled steroids, or patient-initiated use of oral steroids or antibiotics. If there is fever or focal findings on chest examination, a chest X-ray will be obtained as part of usual clinical care.