i think carol levine will talk more about this. so what factors are driving these trend? non-clinical factors. medicare payment policy changes. increased scrutiny. audits, denials of short inpatient stays. there are efficiency advantages. it is quicker to triage from the emergency room to observation, thus observation can reduce e.r. crowding and allow fewer ambulance diversions. there is increased reporting. since medicare won't pay for extra, won't pay extra for observation visits lasting more than 48 hours, many hospitals used to truncate their reporting time and observation but more recently hospitals modified their billing systems to report the full duration of long observation visits. diagnosis and case mix we looked at but those changes do not appear likely to account for growth in the use of observation. since readmission penalties were started in 2012, observation is not counted as a an admission or readmission. so these penalties may continue to drive up the future growth of observation. over the effect of readmission penalties is not reflected in our data which

carol costello. thanks so much for being with me. we begin with a shocking new report about an american who has been missing in iran for nearly seven years. bob levinment when he disappeared. here is more. >> reporter: i've confirmed with a source that's been deeply involved in this matter that there is proof that he was allegedly working for the cia undercover or under contract for years while at the same time working as a private investigator. obviously, there is a lot of concern about revealing this very sensitive information will mean for his safety. the ap says the reason it moved forward with the story is this. thetds after documenting the information long ago in 2010, they agreed to hold back three times at the government's request because the u.s. government said it had promising leads to bring him home, yet nothing has happened for six and a half years. and it's ex-strikely likely that by now the people know of his ties of the cia. now the source involved in the matter agree that after so long of being in captivitity, that his captures more than likely he no that he was working undercover. in an exclusive interview with cnn's christiane am