from diagnosis of HIV infection and reporting, to follow-up across public health and medical providers for HIV/AIDS, leading to a reduction in patients being out of care. The approach was to develop a secure data exchange that allowed individuals presenting in the IDN’s hospitals and clinics who were not receiving adequate monitoring or treatment for HIV disease to be immediately identiﬁed. For example, when a patient who has been identiﬁed by LaPHIE as out of care for HIV for >12 months presents to the emergency department for an asthma exacerbation, real-time LaPHIE CDS logic triggers an alert within the workﬂow of nurses and physicians accessing the IDN’s in-house developed EMR known as CLIQ (for CLinical InQuiry).17 This point of service LaPHIE alert contains notiﬁ- cation to the provider that the patient is in need of HIV treat- ment, patient-speciﬁc public health advice, and clinical recommendations (eg, assessment of symptoms, conﬁrmatory testing, need for referral into care, tool for discrete documenta- tion of actions, etc) to address the out-of-care patient’s diag- nosis. Recommendations are intentionally designed to support clinicians who may be unfamiliar with the management of HIV. This system adopts a ‘no wrong door ’ approach so that untreated individuals with encounters anywhere in the IDN can be treated and/or referred, irrespective of their initial point of clinical service. Development of the LaPHIE data set Public health legislation in Louisiana mandates the reporting of communicable conditions such as HIV. Names-based reporting of HIV infection has been in place in Louisiana since 1993 and all public and private laboratories and healthcare providers are mandated to report results consistent with reportable commu- nicable diseases. OPH, through laboratory surveillance, receives and conﬁrms reports of new HIV infections, and quantiﬁes a population of persons deemed ‘out of care’dthose who have never entered care or those who have dropped out of care as measured by an absence or interruption of CD4 or viral load testing for >12 months in laboratory surveillance data. Criteria have been developed using ﬁrst order logic to create the LaPHIE out-of-care data set. These criteria are purposefully conservative, erring on the side of avoiding unnecessarily characterizing Figure 1 Message ﬂow. LaPHIE, Louisiana Public Health Information Exchange. Case report a person as out of care. This data set of out-of-care persons populates the OPH database which interfaces via the LaPHIE system with the IDN’s patient registration and EMR systems. LaPHIE message ﬂow LaPHIE functionality is enabled by the integration of the disparate surveillance and clinical information systems of LSU HCSD and OPH which are now connected via a secure point-to- point tunnel over a designated wide area network connection (ﬁgure 1). Demographics collected at registration for a clinical encounter ﬂow in real time from the IDN’s Admit Discharge Transfer system via an HL7 interface and open-source interface engine to a LaPHIE server at OPH where the LaPHIE matching algorithm is applied. The IDN’s patient demographics are tested against the OPH LaPHIE data set to determine in real-time if the registered patient is an individual for whom a LaPHIE alert should be issued. In order to reduce error of issuing an alert on the wrong patient, patient data must match exactly with the last name, ﬁrst name, date of birth, and social security number of a record in the OPH LaPHIE cohort. When records match exactly, a LaPHIE alert message, issued as a standard HL7 Patient Problem (PPR) message, is sent back to CLIQ where the LaPHIE alert is presented to providers on the opening screen of the patient’s recorddThe Patient Summary Screen. Alerts are only visible to nurse and physician security roles to limit visibility to those clinicians with a speciﬁc informational need and who are in a position to take action. When clinicians see the alert, they have an option to Take Action Now or Take Action Later. When they select Take Action Now, they are directed to a screend LaPHIE Intervention Notedthat includes the clinical support recommendations outlined earlier and a structured documenta- tion tool to record the clinical actions taken (ﬁgure 2). Clinician actions taken are committed to the CLIQ repository and upon patient discharge, are sent to OPH via a standard HL7 Patient Problem Response (PRR) message. Logic is applied to the PRR messages to determine if the actions taken are sufﬁcient to remove individuals from the OPH data set of out-of-care persons, or if they should remain as a person still in need of follow-up treatment. When a provider selects to take action J Am Med Inform Assoc 2012;19:448e452. doi:10.1136/amiajnl-2011-000412 449