<s>
The	O
Composite	B-Application
Health	I-Application
Care	I-Application
System	I-Application
(	O
CHCS	B-Application
)	O
is	O
a	O
medical	O
informatics	O
system	O
designed	O
by	O
Science	O
Applications	O
International	O
Corporation	O
(	O
SAIC	O
)	O
and	O
used	O
by	O
all	O
United	O
States	O
and	O
OCONUS	O
military	O
health	O
care	O
centers	O
.	O
</s>
<s>
In	O
1988	O
,	O
SAIC	O
won	O
a	O
competition	O
for	O
the	O
original	O
$1.02	O
billion	O
contract	O
to	O
design	O
,	O
develop	O
,	O
and	O
implement	O
CHCS	B-Application
.	O
</s>
<s>
CHCS	B-Application
is	O
module	O
based	O
:	O
modules	O
include	O
RAD	O
(	O
radiology	O
)	O
,	O
LAB	O
(	O
Laboratory	O
)	O
,	O
PHR	O
(	O
Pharmacy	O
)	O
,	O
PAS	O
(	O
Patient	O
Appointing	O
&	O
Scheduling	O
)	O
,	O
MCP	O
(	O
Managed	O
Care	O
Program	O
;	O
used	O
to	O
support	O
TRICARE	O
enrollees	O
by	O
enrolling	O
them	O
to	O
Primary	O
Care	O
Managers	O
)	O
,	O
PAD	O
(	O
Patient	O
Administration	O
)	O
:	O
MRT	O
(	O
Medical	O
Records	O
Tracking	O
)	O
,	O
MSA	O
(	O
Medical	O
Service	O
Accounting	O
)	O
medical	O
billing	O
,	O
WAM	O
(	O
Workload	O
Assignment	O
Module	O
)	O
,	O
DTS	O
(	O
Dietetics	O
)	O
,	O
CLN	O
(	O
CLinical	O
:	O
Nursing	O
,	O
Physician	O
,	O
and	O
Allied	O
Health	O
)	O
,	O
DAA	O
(	O
Database	O
Administration	O
)	O
,	O
ADM	O
(	O
Ambulatory	O
Data	O
Module	O
)	O
Medical	O
Coding	O
of	O
outpatient	O
visits	O
,	O
and	O
TOOLS	O
(	O
FileMan	O
)	O
.	O
</s>
<s>
Currently	O
all	O
appointments	O
are	O
booked	O
in	O
CHCS	B-Application
,	O
except	O
for	O
Walk-Ins	O
and	O
Telephone	O
Consults	O
,	O
which	O
can	O
now	O
be	O
booked	O
in	O
AHLTA	O
.	O
</s>
<s>
CHCS	B-Application
is	O
a	O
text	O
based	O
BBS/ANSI	O
like	O
display	O
accessed	O
via	O
DEC	O
VT320	O
terminal	O
emulation	O
.	O
</s>
<s>
CHCS	B-Application
supports	O
outpatient	O
Order	O
Entry	O
(	O
LAB	O
,	O
RAD	O
,	O
PHR	O
,	O
Consults	O
(	O
ancillary	O
procedures	O
)	O
,	O
one-time	O
and	O
scheduled/multiple	O
appointment	O
consults	O
.	O
</s>
<s>
CHCS	B-Application
can	O
also	O
support	O
Inpatient	O
charting	O
and	O
Order	O
Entry	O
with	O
multi-paging	O
with	O
a	O
page	O
for	O
each	O
ward	O
the	O
patient	O
is	O
transferred	O
,	O
but	O
this	O
feature	O
is	O
not	O
fielded/enabled	O
at	O
many	O
medical	O
centers	O
.	O
</s>
<s>
Instead	O
Clinicomp	O
's	O
Essentris	O
product	O
is	O
deployed	O
at	O
all	O
MHS	O
hospitals	O
and	O
has	O
replaced	O
the	O
use	O
of	O
CHCS	B-Application
Inpatient	O
module	O
for	O
nurse	O
charting	O
.	O
</s>
<s>
An	O
interface	O
solution	O
to	O
allow	O
Essentris	O
Orders	O
to	O
be	O
transferred	O
into	O
CHCS	B-Application
order	O
entry	O
is	O
being	O
deployed	O
.	O
</s>
<s>
This	O
information	O
is	O
then	O
sent	O
into	O
CHCS	B-Application
and	O
its	O
subsystems	O
(	O
ADM	O
-	O
ambulatory	O
data	O
module	O
)	O
provide	O
the	O
official	O
repository	O
of	O
the	O
medical	O
coding	O
information	O
and	O
handle	O
the	O
transmission	O
of	O
those	O
encounters	O
via	O
the	O
Comprehensive	O
Ambulatory	O
Patient	O
Encounter	O
Record	O
(	O
CAPER	O
)	O
interface	O
.	O
</s>
<s>
This	O
CDR	O
contains	O
information	O
from	O
AHLTA	O
,	O
CHCS	B-Application
,	O
and	O
AHLTA-Theater	O
.	O
</s>
<s>
CHCS	B-Application
shares	O
its	O
original	O
codebase	O
with	O
the	O
VA	O
's	O
VistA	B-Application
system	O
.	O
</s>
<s>
Security	O
in	O
CHCS	B-Application
works	O
by	O
a	O
number	O
of	O
mechanisms	O
and	O
includes	O
the	O
concept	O
of	O
least	O
privilege	O
.	O
</s>
<s>
Many	O
CHCS	B-Application
files	O
are	O
now	O
more	O
easily	O
accessed	O
with	O
MUMPS	B-Language
routines	O
that	O
can	O
make	O
more	O
efficient	O
use	O
of	O
the	O
internal	O
data	O
structures	O
.	O
</s>
<s>
CHCS	B-Application
,	O
which	O
now	O
runs	O
on	O
InterSystems	B-Language
Caché	I-Language
with	O
the	O
MUMPS	B-Language
globals	O
being	O
converted	O
into	O
Caché	B-Language
objects	O
and	O
the	O
MUMPS	B-Language
routines	O
accessing	O
them	O
,	O
now	O
can	O
be	O
accessed	O
with	O
.NET	O
tools	O
to	O
query	O
the	O
Caché	B-Language
database	O
.	O
</s>
<s>
Many	O
facilities	O
have	O
developed	O
special	O
queries	O
of	O
CHCS	B-Application
or	O
new	O
tools	O
to	O
facilitate	O
workflow	O
and	O
processes	O
.	O
</s>
<s>
One	O
such	O
tool	O
is	O
an	O
intranet	O
web	O
application	O
to	O
facilitate	O
printing	O
of	O
lab	O
specimen	O
labels	O
to	O
special	O
printers	O
with	O
formats	O
not	O
possible	O
with	O
the	O
regular	O
CHCS	B-Application
print	O
devices	O
and	O
label	O
printing	O
methods	O
.	O
</s>
<s>
The	O
introduction	O
of	O
AHLTA	O
,	O
previously	O
known	O
as	O
the	O
Composite	B-Application
Health	I-Application
Care	I-Application
System	I-Application
II	O
,	O
ushered	O
in	O
a	O
significant	O
new	O
era	O
in	O
health	O
care	O
for	O
the	O
MHS	O
and	O
the	O
nation	O
.	O
</s>
<s>
AHLTA	O
and	O
a	O
significant	O
portion	O
of	O
CHCS	B-Application
are	O
slated	O
to	O
be	O
replaced	O
by	O
a	O
VA/DoD	O
interagency	O
iEHR	O
program	O
.	O
</s>
<s>
CHCS	B-Application
has	O
a	O
function	O
to	O
merge	O
patients	O
,	O
but	O
not	O
to	O
unmerge	O
.	O
</s>
<s>
Over	O
100	O
CHCS	B-Application
host	O
systems	O
,	O
DEERS	O
(	O
Defense	O
Enrollment	O
Eligibility	O
Reporting	O
System	O
)	O
,	O
and	O
AHLTA	O
Theater	O
(	O
the	O
version	O
being	O
used	O
in	O
Iraq	O
and	O
other	O
areas	O
)	O
all	O
contributed	O
patients	O
into	O
the	O
CDR	O
when	O
it	O
was	O
created	O
from	O
25	O
month	O
data	O
pulls	O
back	O
in	O
2004	O
.	O
</s>
<s>
Each	O
CHCS	B-Application
patient	O
registration	O
links	O
into	O
AHLTA	O
,	O
some	O
link	O
to	O
existing	O
patients	O
,	O
but	O
others	O
are	O
newly	O
created	O
.	O
</s>
<s>
Complexity	O
with	O
patient	O
names	O
and	O
methods	O
of	O
identifying	O
them	O
with	O
other	O
demographics	O
can	O
lead	O
to	O
duplication	O
,	O
both	O
in	O
a	O
local	O
CHCS	B-Application
system	O
and	O
in	O
the	O
central	O
AHLTA	O
CDR	O
.	O
</s>
