Hospitals are expected to face major cash flow constraints in 2021 due to lower patient volumes, rising expenses and a worsening payer mix, a new analysis from Moody's finds. The analysis, released Friday, predicts a negative outlook for the not-for-profit hospital industry that has been wrecked by the pandemic. "Our outlook assumes it is unlikely that an effective vaccine will be widely available before the middle of 2021," the report said. The report predicts that operating cash flow is going to decline thanks to declines in patient volumes.