Patient Status

We need the ability to track patients through a workflow or state diagram. This could be used for studies, therapeutic plans, and any other process that needs to track patients through states.

The model and API should support:

• Patient-centric states
• A way to define simple state diagrams (workflows)
  • Name
  • List of valid states
  • For each state, list of valid "next" states (valid transitions)
• Method to get current state for a patient:

 myWorkflow.getPatientStatus(myPatient)

• Method to get all patients within a given state:

 myWorkflow.getAllPatients(status)
 myWorkflow.getAllPatients(status, fromDate, toDate)

Tables (a work in progress):

 create table program (
   program_id int not null,
   name varchar(255),
   description mediumtext,
   creator int not null, /* FK to users */
   date_created datetime not null,
   voided boolean,
   voided_by int, /* FK to users */
   void_reason varchar(255),
   date_voided datetime
 );

 create program_workflow (
   patient_workflow_id int not null primary key,
   program_id not null, /* FK to program */
   name varchar(255),
   description mediumtext,
   creator int not null, /* FK to users */
   date_created datetime not null,
   voided boolean,
   voided_by int, /* FK to users */
   void_reason varchar(255),
   date_voided datetime
 );

 create table program_workflow_state (
   program_workflow_id int not null, /* FK to program_workflow */
   status_id not null, /* FK to concept */
   name varchar(255)
   creator int not null, /* FK to users */
   date_created datetime not null,
   voided boolean,
   voided_by int, /* FK to users */
   void_reason varchar(255),
   date_voided datetime
 );

 create table program_workflow_transition (
   from_state int not null, /* FK to program_workflow_state */
   to_state int not null, /* FK to program_workflow_state */
   creator int not null, /* FK to users */
   date_created datetime not null,
   voided boolean,
   voided_by int, /* FK to users */
   void_reason varchar(255),
   date_voided datetime
 );

 create table patient_program (
   patient_program_id int not null, /* primary key (autonumber) */
   program_id int not null, /* FK to program */
   patient_id int not null /* FK to patient */
   date_started datetime not null,
   date_completed datetime
   creator int not null, /* FK to users */
   date_created datetime not null,
   voided boolean,
   voided_by int, /* FK to users */
   void_reason varchar(255),
   date_voided datetime
 )

 create table patient_status (
   patient_status_id int not null primary key,
   patient_program_id int not null, /* FK to patient_program */
   program_workflow_id int not null, /* FK to program_workflow */
   status_id not null, /* FK to concept */
   creator int not null, /* FK to users */
   date_created datetime not null,
   voided boolean,
   voided_by int, /* FK to users */
   void_reason varchar(255),
   date_voided datetime
 )

We could live without fully described workflows in the model for now (let that knowledge live in the code for the moment), but it would be nice to have a concept or something to define different types of state "groupings" rather than one big glom of states attached to patients. Also, the method calls are critical

See ticket

There's a good article about state machines on Wikipedia

Service

PatientStatusService:

 /* Get patient's state at any given time */
 public ProgramWorkflowStatus getPatientStatus(Patient p, Program program, Date onDate);

 /* Return all patients within a specific state during a date range */
 public Patient[] getPatients(Program program, ProgramWorkflowStatus status, Date fromDate, Date toDate);