FIG: 8: This Figure lists the risk factors for hospital readmission that are specific for patients with COPD, from a recent paper by Shah et al.[7]  Some factors – such as black race, male sex, or enrollment in Medicare or Medicaid – are demographic factors that may influence access to care.  Again, however, it is comorbid conditions that are important in contributing to the need for readmission.  Also patients who were lean (low BMI) and patients who were sicker and had longer hospital stays were at increased risk of early remission.  Finally, it is once again hypercarbia, ie, a raised serum arterial CO2 level, that is an additional objective risk factor for patients to be readmitted after they were admitted initially for COPD exacerbation.