Outpatient Systems
                              
            (Introduction to Medical Informatics)
         (http://www.cpmc.columbia.edu/edu/textbook)

LAST REVIEWED:  21 October 1996
(see also lecture on Medical Records)

OUTPATIENT SYSTEMS

stats
     340,000 / 450,000 physicians are office-based
     636 million outpatient visits per year
     2.7 per person on average
     25 patients per MD per day

outpatient practice
     
     support staff
          patient calls for appointment
          patient arrives and registers
          chart is retrieved
          patient (and chart) is placed in room
     
     physician
          interviews patient
               includes background if first visit
          physical exam
          assessment
          plan (possibly some tests immediately)
          charges
          documentation
     
     support staff
          patient is charged
          future appointments are scheduled
     
     outside of patient visit
          results of tests are collected
          call to patient with results
          bill is sent
          insurance forms are filed
          payments are collected

information systems offer
     appointment scheduling
     patient surveillance and recall (eg, mammogram)
     history taking
     risk assessment (eg, cardiac)
     decision support (eg, diagnosis)
     medication lists and prescriptions
     patient education
     bibliographic retrieval
     business systems (billing, payroll, management)

comprehensive clinical systems are less common
     expense of system
     data entry
     time to use system

variety of commercial systems available
     ex:  Emtek; PHAMIS; Med-Trak; HP; etc.

key issues in installation (Barnett)
     user training
     tech support
     encounter form/user interface design
     must fit in workflow
     cost justification
          automating conventional tasks costs $0.87/encounter [1982]
          consider additional functions:  automation saves 
               $0.72/encounter [1982]

case example:  COSTAR
     uses preprinted encounter (turnaround) forms
          highlight problem list; meds; health maintenance
          configurable to fit local practice
          provides space for notes
     structured vocabulary
          used for problems, meds, tests
          narrative text linked to vocabulary items
     ability to link instances of concepts over time
          each encounter is a collection of concepts pertaining
               to a particular patient on a particular visit
          concepts can be grouped by encounter or by class
               over time
                  ex:  can group all notes on "hypertension"
          can link problems over time (as diagnosis evolves)
     comprehensive:  financial, records, query, decision support
     configurable to site
     query language (MQL):  users can create their own reports

case example:  CCC system (Safran, 1996)
     similar clinical scope =>  problem lists, meds, tests, 
          health maintenance, decision support (but not financial)
     decision support:
          delivers alerts (more urgent) and reminders (less urgent, 
              typically given at patient visit)
          helps complete recommended task
              e.g., offers alternative doses if an alert describes
                   an inappropriate medication dose
          rules:  If-then statements
          provides access to care manuals
          provides documentation of available research protocols
              (e.g., treatment of patients with HIV = HIV ProtoCall)
     assessment:
          decreased median time to intervention for alerts 52 -> 11 d
                                                    reminders >500 d -> 14 d

related reading:
     Barnett GO. The application of computer-based medical-
     record systems in ambulatory practice. N Engl J Med
     1984:310(25):1643-50.

     Safran C, Rind DM, Sands DZ, Davis RB, Wald J, Slack WV.  
     Development of a knowledge-based electronic patient record.
     M.D. Computing 1996;13(1):46-54,63.