The power to command has never meant the power to remain mysterious.
This chapter analyzes workﬂow number 2: Order/Computerized Physician Order
Entry (CPOE) from the same two perspectives as the previous Prescribe/eRx
workﬂow: processes and data elements.
Initially, we isolate the Order workﬂow from the higher-level diagram
(dataﬂow diagram [DFD] 0), and using top-down analysis we decompose it into
lower-level processes: DFD 2.x.
We identify similarities with the Prescribe workﬂow, and this allows us
to reuse, with some changes, most of the Prescribe processes in the Order
workﬂow. Still, there are enough differences between eRx and CPOE to justify a
two-chapter approach. The similarities and differences will help us deﬁne DFD 2
and its lower subprocesses and activities.
Using the dataﬂows from the DFD 2.x, we uncover the discrete data elements
required by the Order workﬂow to perform its functions. Dataﬂows may relate to
external actors or to the Medications database. We identify both the data struc-
tures involved in the interactions with the external actors and the data elements
used by the evolving logical model.
110 ◾ Electronic Health Record: A Systems Analysis of the Medications Domain
DFD 2 Order Workﬂow
First, let us isolate the Order workﬂow from the Medications system:
Healthcare → Medications → Order
From DFD 0: Medications system (Figure2.3), we cut and paste workﬂow number
2 with its external entities, data stores, and other processes attached (Figure4.1).
The Order workﬂow is similar to Prescribe workﬂow in many aspects (1–3). In
terms of processes, an ordering clinician may need to:
◾ Review patient data
◾ Select a new drug
◾ Select an existing drug (and Modify, Stop, Hold, or Renew)
◾ Select a dose
◾ Communicate with other external actors
◾ Consider Formulary information
◾ Consider CDS (clinical decision support) recommendations
◾ Sign and distribute order
The seven processes in the column in Figure4.2 (Communicate, Review
Patient Data, Select Drug, Select Dose, Consider Formulary, CDS, and Sign) with
some minor differences are actually common to all the clinical workﬂows related
to the medications domain—Prescribe, Order, Dispense and Administer—and
we consider reusing processes from the previous chapter as much as possible. In
Patient ID, Order
Patient parameters, CDS, Formulary
Patient ID, Order
Figure 4.1 Order workﬂow: Isolated from DFD 0.
Order/CPOE ◾ 111
addition, the Order workﬂow has two speciﬁc processes to be detailed further in
◾ Use Order Set
◾ Reconcile Meds
Let us examine the differences between the Prescribe and Order workﬂows
There are a couple of preconditions to DFD 2 that must be satisﬁed before the
system may proceed with the Order workﬂow:
1. Clinician is uniquely identiﬁed.
2. Clinician is authorized to use system in lieu of ordering medications.
3. Patient is uniquely identiﬁed.
4. All system’s activities are logged.
Figure 4.2 Common processes: Order, Prescribe, Dispense, and Administer.
112 ◾ Electronic Health Record: A Systems Analysis of the Medications Domain
The Order workﬂow is decomposed into eight main processes (bubbles):
2.1 Communicate Order
2.2 Review Patient Data
2.3 Select Drug
2.4 Select Dose
2.5 Consider Formulary
2.6 Sign Order
2.7 Use Order Set
2.8 Reconcile Meds
If we compare the Order workﬂow (Figure4.3) with the Prescribe workﬂow
from Chapter 3 (Figure3.2), we can see several differences:
Patient and PBM (pharmacy beneﬁt management)—external actors in
Prescribe—are not participating in the Order workﬂow. The Patient is not
planned to interact directly with the Order workﬂow.
The role of PBM in the Prescribe workﬂow is represented by the hospital
PHARMACY in the Order workﬂow.
There are a couple of new actors (ORDER SET REPOSITORY and RULES
REPOSITORY) and two new processes: 2.7 Use Order Set and 2.8 Reconcile
Meds. The other six processes, 2.1–2.6, are reused, with some minor changes
from DFD 1.x Prescribe into DFD 2.x Order.
Even though several processes mentioned use it, CDS does not appear on DFD
2.x. As workﬂow number 5, it should not appear on a lower DFD. Still, we
deﬁne the dataﬂows to and from CDS related to Order workﬂow, as we will
see that several Order processes use CDS on medications. Details about the
CDS can be found in Chapter 8.
Let us proceed with the top-down analysis of the Order workﬂow and decom-
pose DFD 2 into its children processes: the DFD 2.x.
Table4.1 Differences between Prescribe and Order Workﬂows
Setting Private practice, outpatient Inpatient, ambulatory
Pharmacy Community, mail, independent Hospital pharmacy
Formulary PBM Hospital pharmacy
Complexity Simple Complex
Order set Rare Common
Meds reconciliation Rare Common
Need to cosign Rare Common
Order/CPOE ◾ 113
RECOMMENDED DRUG DOSE
Use Order Set
Figure 4.3 DFD 2: Order workﬂow.