Download Appendix 1: Structured data from VA electronic health records used

Appendix 1: Structured data from VA electronic health records used to create an automated version
of the clinically-guided approach
Below is a brief summary of structured data used to create the automated version of the clinicallyguided approach, followed by a more detailed description.
Brief summary:
Visit types were determined through unique clinic “stop codes” that identify clinic type. The presence of
acute infections or pain during visits was assessed with encounter codes for common acute bacterial or
viral infections and codes indicating injuries including sprains, strains, and fractures. Comorbid
conditions were defined by the presence of 2 or more ICD9 codes for relevant conditions from discharge
diagnoses or outpatient encounters forms over the 2 years prior to February 1, 2009. Adverse effects of
antihypertensive treatment were assessed through the presence of encounter codes for hypotension
(including orthostatic hypotension) on 2 visits separated by at least 7 days over the 2-year study period.
Current antihypertensive medication use was assessed using VA pharmacy data, assessing medications
that were active or recently expired (within 90 days) and whose refill history was consistent with having
received a sufficient quantity of drug to last at least 30 days prior to February 1, 2009. Competing and
clinically dominant comorbidities were assessed using encounter codes and discharge diagnoses, and
encounter codes for hospice or palliative care services. Other patient factors (such as patient
preferences) were not assessed using computerized clinical data given the absence of corresponding
data fields.
Detailed description:
Defining eligible visits for blood pressure measurement:
Blood pressure readings used to evaluate longitudinal blood pressure control were taken only from
eligible visits. Visits meeting the following criteria were considered eligible for blood pressure
assessment.
 NEXUS clinic visit (VA NEXUS clinics include 13 primary care medicine, medicine subspecialty,
and psychiatry clinics)
 Absence of an encounter diagnosis for that visit consistent with acute infection, including the
following conditions as defined by the HCUP Clinical Classification Software (CCS), which maps
clinical diagnoses to ICD9 codes using a hierarchical classification system.
 1.1 bacterial infections
 1.3.3 other viral infections (does not include HIV, hepatitis)
 1.4 other infections including parasitic
 6.8.1 otitis media and related conditions
 8.1 respiratory infections
 9.1 intestinal infections
 10.1.4 urinary tract infections
 12.1 skin and soft tissue infections
 Absence of an encounter diagnosis for that visit consistent with acute pain, including the
following CCS condition codes:
 16 injury or poisoning (includes sprains, strains, and fractures; does not
include chronic arthropathies, i.e. OA, RA).
Appendix Page 1

Absence of hospitalization in a VA facility up to 7 days before or 14 days after the visit.
Comorbid conditions:
Comorbid conditions were assessed using encounter codes from outpatient visits and/or hospital
discharge diagnoses, with specific conditions defined by the CCS. We considered a condition to be
present if it was mentioned 2 or more times over the 2 years prior to February 1, 2009.
o Ischemic heart disease
 7.2.3 acute myocardial infarction
 7.2.4 coronary atherosclerosis and other heart disease
 7.2.5 nonspecific chest pain
o Cerebrovascular accident
 7.3 cerebrovascular disease
o Peripheral vascular disease
 7.4.1 peripheral and visceral atherosclerosis
 7.4.2 Aortic; peripheral; and visceral artery aneurysms
 7.4.3 Aortic and peripheral arterial embolism or thrombosis
 [not 7.4.4 Other circulatory disease (includes hypotension)]
o Congestive heart failure
 7.2.11 Congestive heart failure; nonhypertensive
 ALSO: ICD9s as follows [these are not captured in 7.2.11]
 402.01: hypertensive heart disease, malignant, with heart failure
 402.11: hypertensive heart disease, benign, with heart failure
 402.91: hypertensive heart disease, unspecified, with heart failure
 404.01, 404.03: hypertensive heart and kidney disease, malignant, with
heart failure
 404.11, 404.13: hypertensive heart and kidney disease, benign, with
heart failure
 404.91, 404.93: hypertensive heart and kidney disease, unspecified,
with heart failure
o Chronic renal insufficiency
 10.1.3 Chronic renal failure
 10.1.2.2 Unspecified renal failure
 3.3.2 Diabetes with renal manifestations
 ALSO: ICD9s as follows [not captured elsewhere]
 403 hypertensive kidney disease
 404.02, 404.03 Hypertensive heart and kidney disease, malignant, with
chronic kidney disease
 404.12, 404.13 Hypertensive heart and kidney disease, benign, with
chronic kidney disease
 404.92, 404.93 Hypertensive heart and kidney disease, unspecified, with
chronic kidney disease
o Diabetes Mellitus
 3.2 Diabetes mellitus without complication
 3.3 Diabetes mellitus with complications
Adverse effects of antihypertensive treatment:
Appendix Page 2
Most adverse drug effects from antihypertensive medications are difficult to ascertain using
administrative data. We evaluated evidence of orthostasis using the following criteria:
 Outpatient or inpatient visit with diagnosis of orthostasis in the past two years, where
orthostasis is defined by the following CCS code:
o 7.4.4.1 hypotension
 Includes ICD9 458.0 orthostatic hypotension, 458.1 chronic hypotension, 458.8
other specified hypotension, 458.9 hypotension, unspecified
 Does not include ICD9 458.2 Iatrogenic hypotension (this includes intradialysis hypotension and postoperative hypotension)
 To provide evidence of persistent orthostasis, we required patients with have ≥2 encounters for
orthostasis in the prior 2 years separated by >7 days
Current Medication Use:
Current use of antihypertensive medications was assessed by evaluating VA pharmacy records. To be
considered currently in use, an antihypertensive medication needed to meet both of the following
criteria:
 Prescription status of (a) ACTIVE; or (b) SUSPENDED; or (c) EXPIRED within 90 days before
Feb 1, 2009; and
 The last fill/refill of that drug provided a days supply sufficient to last to any date on or after
Jan 2, 2009 (i.e. days supply expected to last to ≤30 days prior to Feb 1, 2009 ).
To calculate the daily dose of each eligible antihypertensive drug, we multiplied pill strength (in mg) by
the quantity supplied and divided by the days supply of drug. Using a reference text, we created a list of
effective daily doses (minimum and maximum recommended doses), and cross-referenced patient drug
information to assess whether a given drug was prescribed at an effective dose.
Competing or clinically dominant comorbidities
Any of the following:
 Does patient have any cancers that typically have very poor prognosis (yes/no)
o A yes answer requires the presence of 2 or more diagnoses within 2 years prior to the
blood pressure index data for any of the following 3 diseases as defined by the CCS
 2.2.1 - Cancer of esophagus
 2.2.3 - Cancer of liver and intrahepatic bile duct
 2.2.4 - Cancer of pancreas
o Diagnoses can come from outpatient encounters or inpatient stays
 Is patient enrolled in hospice or palliative care (yes/no)
o A yes answer requires the presence of 2 or more encounters in any venue (inpatient or
outpatient) in the past 2 years with a secondary ICD9 code of V66.7
 Does the patient have dementia (yes/no)
o A yes answer requires 2 or more diagnoses with any of the following CCS codes in the 2
years prior to the index visit (can include outpatient encounters or inpatient stays)
o CCS code consistent with dementia
 5.3.1 Senile dementia, uncomplicated
 5.3.2 Arteriosclerotic dementia
 5.3.5 Presenile dementia, uncomplicated
 5.3.6 Senile dementia with delirium
 5.3.7 Other senility and organic mental disorders
Appendix Page 3
Appendix 2: Correspondence of structured data from electronic health records with chart review data
Correspondence between the 2 methods was limited at several points along the algorithm, as follows.
For ease of terminology, herein we will use the term “computerized clinical data” in referring to
structured data from electronic health records.
Step 1: Assessing which patients had sufficient contact with VA clinics to merit inclusion in the
performance measurement system
Defining eligible visits was sensitive to the exact definition of clinic types employed, with minor
discrepancies in definitions leading to substantial disagreement between chart review and computerized
clinical data in defining which patients had sufficient contact with VA to merit further assessment for
blood pressure control.
Table A1: Sufficient prior contact (≥2 eligible visits in past year, 1 eligible “anchoring” visit 1-2 years
prior).
Chart review
No
Yes
Computerized clinical data
No
Yes
19 (9%)
16 (8%)
34 (17%)
132 (66%)
53 (26%)
148 (74%)
35 (17%)
166 (83%)
Sensitivity 46%, specificity 80%
Step 2: Defining which patients had prior cardiovascular disease or risk equivalents.
Agreement between chart review and computerized clinical data varied for each of 6 diagnoses of
coronary heart disease or risk equivalents (ischemic heart disease, cerebrovascular disease, peripheral
vascular disease, congestive heart failure, chronic renal insufficiency, diabetes mellitus), which in
computerized clinical data were assessed by the presence of 2 or more disease-consistent ICD9
diagnoses12 and in chart review by mention of the condition within the electronic problem list or free
text in chart notes.
Table A2: Presence of ischemic heart disease or risk equivalents
Chart review
Not present
Present
Computerized clinical data
Not present
Present
73 (36%)
12 (6%)
21 (10%)
95 (47%)
94 (47%)
107 (53%)
85 (42%)
116 (58%)
Sensitivity 82%, specificity 86%
Appendix Page 4
Step 3: Adverse effects of treatment.
There was perfect agreement between chart review and computerized clinical data for the presence of
adverse effects of treatment, insofar as this variable was dichotomized as sufficient number of adverse
effects to merit non-intensification of treatment, defined as adverse reactions to 3 or more major
antihypertensive drug classes for lower-risk patients and all major antihypertensive drug classes for
higher-risk patients (or orthostatic hypotension to 2 or more drug classes). No patients had a sufficient
number of detectable adverse effects to merit exclusion by this criteria.
Table A3: Presence of sufficient number of adverse drug events to merit non-intensification of
treatment
Chart review
Not present
Present
Computerized clinical data
Not present
Present
201 (100%)
0 (0%)
0 (0%)
0 (0%)
201 (100%)
0 (0%)
0 (0%)
0 (0%)
Sensitivity N/A, specificity 100%
Step 4: Number of antihypertensive medications given at effective doses.
There was 92% agreement between chart review and computerized clinical data for the number of
antihypertensive medications at effective doses that were currently prescribed. For purposes of the
algorithm, we dichotomized this variable as prescription of < 4 vs. ≥4 drugs (from 4 different classes) at
effective doses
Table A4: Presence of sufficient number of adverse drug events to merit non-intensification of
treatment
Chart review –
number of drugs at
effective doses
0
1
2
3
4
5
6+
0
26
12
2
6
0
1
1
48
Computerized clinical data –
Number of drugs at effective doses
1
2
3
4
5
6
1
0
0
0
35
6
0
0
0
11
32
4
1
0
7
11
18
4
0
2
2
4
4
0
0
0
1
1
3
0
0
0
0
0
61
52
27
10
3
6+
0
0
0
0
0
0
0
0
33
53
50
46
12
6
1
Sensitivity 42%, specificity 97% (dichotomized at <4 or ≥4 drugs at effective doses)
Appendix Page 5
Grey shading shows dichotomization at <4 or ≥4 drugs at effective doses. Green shading shows
the areas of perfect concordance.
Step 5: Presence of competing or clinically dominant comorbidities
There was limited agreement between chart review and computerized clinical data for the presence of
competing or clinically dominant comorbidities (in chart review, generally defined as diagnosis of
pancreatic, hepatic, biliary tract, or esophageal cancer, chart diagnosis of limited life expectancy,
enrollment in hospice, dementia, or uncontrolled mental illness; in computerized clinical data, diagnosis
of cancers as above, enrollment in hospice, or diagnosis of dementia).
Table A5: Presence of clinically dominant comorbidities
Chart review
Not present
Present
Computerized clinical data
Not present
Present
195 (97%)
0 (0%)
6 (3%)
0 (0%)
201 (100%)
0 (0%)
195 (97%)
6 (3%)
Sensitivity 0%, specificity 100%
Step 6: Other patient factors
This step evaluated other patient factors including goals of care and refusal to take antihypertensive
medications (with evidence of physician education / intervention to encourage use). As there is no
ready way to encode this using computerized clinical data, we evaluated this criterion only via chart
review.
Table A6: Presence of other patient factors
Chart review
Not Present
Present
192 (96%)
9 (4%)
201 (100%)
Sensitivity n/a, specificity n/a
Combined results
We combined the results of steps 3, 4, 5 and 6. (Step 2 defines risk level but does not directly include or
exempt patients from the algorithm, and although we found substantial disagreement in Step 1 it could
conceivably be performed entirely with administrative data without major sacrifice to construct
validity). In this analysis, after exempting patients excluded in step 1 by clinical chart review, overall
agreement for the remaining 4 steps was 69%.
Appendix Page 6
Table A7: Combined results
Chart review
Ineligible
Eligible
Computerized clinical data
Ineligible
Eligible
4 (2%)
22 (13%)
29 (17%)
111 (67%)
33 (20%)
133 (80%)
26 (16%)
140 (84%)
Sensitivity 15%, specificity 79 %
* Eligible = not exempted by any criterion; ineligible = exempted by one or more criteria.
Appendix Page 7
Appendix 3: Results stratified by site of care and health system
Patient characteristics: stratified by site of care
Characteristic
Patient in
Patients in
P value for
hospital-
community-
difference
based
based clinics
clinics
(n=91)
(n=107)
Mean (SD) age, years
71 +/- 10
69 +/- 12
0.16
Male sex
100 (93)
80 (88)
0.18
57 (53)
37 (41)
0.02
Black
8 (7)
2 (2)
Other
9 (9)
3 (3)
33 (31)
49 (54)
24 (22)
23 (25)
0.64
Cerebrovascular disease
4 (4)
2 (2)
0.53
Heart failure
5 (5)
3 (3)
0.62
42 (39)
37 (41)
0.84
Chronic renal insufficiency
9 (8)
4 (4)
0.26
Peripheral vascular disease
6 (6)
6 (7)
0.77
68 (64)
48 (53)
0.12
Race
White
Declined to answer or unknown
Comorbid conditions
Ischemic heart disease
Diabetes
Any secondary prevention disease *
Appendix Page 8
Number of antihypertensive medications
1.9 + 1.3
1.9 + 1.4
0.46
Systolic blood pressure
138 +/- 18
134 +/- 16
0.09
Diastolic blood pressure
76 +/-10
76 +/-12
0.72
San Francisco region
25 (23)
36 (40)
0.01
Palo Alto region
82 (77)
55 (60)
(mean, SD)
Most recent blood pressure (mean, SD)
(mm Hg)
VA site
* 3 patients were excluded from this analysis due to uncertainty about which type of clinic was responsible for their care.
Appendix Page 9
Frequency of exemptions from performance measure: results stratified by health system and site of care
Reason
Hospitalbased clinics
n=109*
Communitybased clinics
N=91*
P value
San Francisco
system
n=63
Palo Alto
system
n=138
P value
17 (16)
16 (18)
0.75
12 (19)
23 (17)
0.68
9 (8)
10 (11)
0.54
4 (6)
15 (11)
0.31
Competing or clinically dominant comorbidities
2 (2)
3 (3)
0.52
3 (5)
3 (2)
0.32
Adverse effects of treatment
0 (0)
0 (0)
N/A
0 (0)
0 (0)
N/A
Other patient factors
6 (6)
3 (3)
0.44
2 (3)
7 (5)
0.55
32 (30)
27 (30)
0.97
18 (29)
43 (31)
0.71
Insufficient opportunity to manage hypertension
Pre-existing use of ≥4 antihypertensive
medications
Any exclusion
* 3 patients were excluded from this analysis due to uncertainty about which type of clinic was responsible for their care.
Appendix Page 10