4. Assessment of treatment effect In this pilot proposal, the treatment effect of roflumilast vs. placebo to prolong the time to event of a combined endpoint of death or re-hospitalization will be assessed in an intention to treat manner. In a similar manner, the treatment effect of roflumilast vs. placebo to effect all of the secondary endpoints proposed to be measured in the pivotal phase III trial will also be measured (time to respiratory death or respiratory re-hospitalization during the 180 days post-randomization; rate of death or readmission at 30 days post-discharge; treatment failure [see definition below]; change in health status, change in FEV1, and dyspnea during the 180 days post-randomization; length of hospital stay during the index hospitalization; and the tolerance of roflumilast vs. placebo in hospitalized AECOPD).