Appendices
Appendix Table 1. Diagnostic codes used to define diabetes patients in the diabetes measure
ICD-9-CM code
250.00
250.01
250.02
250.03
250.10
250.11
250.12
250.13
250.20
250.21
250.22
250.23
250.30
250.31
250.32
250.33
250.40
250.41
250.42
250.43
250.50
250.51
250.52
250.53
250.60
250.61
250.62
250.63
250.70
250.71
250.72
250.73
250.80
250.81
Description
Diabetes without mention of complication, controlled
Diabetes without mention of complication, T1, controlled
Diabetes without mention of complication, T2, uncontrolled
Diabetes without mention of complication, T1, uncontrolled
Diabetes with ketoacidosis, T2, diabetes controlled
Diabetes with ketoacidosis, T1, diabetes controlled
Diabetes with ketoacidosis, T2, diabetes uncontrolled
Diabetes with ketoacidosis, T1, diabetes uncontrolled
Diabetes with hyperosmolarity, T2, diabetes controlled
Diabetes with hyperosmolarity, T1, diabetes controlled
Diabetes with hyperosmolarity, T2, diabetes uncontrolled
Diabetes with hyperosmolarity, T1, diabetes uncontrolled
Diabetes with other coma, T2, diabetes controlled
Diabetes with other coma, T1, diabetes controlled
Diabetes with other coma, T2, diabetes uncontrolled
Diabetes with other coma, T1, diabetes uncontrolled
Diabetes with renal manifestations, T2 controlled
Diabetes with renal manifestations, T1 controlled
Diabetes with renal manifestations, T2 uncontrolled
Diabetes with renal manifestations, T1 uncontrolled
Diabetes with ophthalmic manifestations, T2 controlled
Diabetes with ophthalmic manifestations, T1 controlled
Diabetes with ophthalmic manifestations, T2 uncontrolled
Diabetes with ophthalmic manifestations, T1 uncontrolled
Diabetes with neurological manifestations, T2 controlled
Diabetes with neurological manifestations, T1 controlled
Diabetes with neurological manifestations, T2 uncontrolled
Diabetes with neurological manifestations, T1 uncontrolled
Diabetes with peripheral circulatory disorders, T2 controlled
Diabetes with peripheral circulatory disorders, T1 controlled
Diabetes with peripheral circulatory disorders, T2 uncontrolled
Diabetes with peripheral circulatory disorders, T1 uncontrolled
Diabetes with other specified manifestations (Diabetic hypoglycemia
NOS, Hypoglycemic shock NOS), T2 controlled
Diabetes with other specified manifestations (Diabetic hypoglycemia
NOS, Hypoglycemic shock NOS), T1 controlled
1
ICD-9-CM code
250.82
250.83
250.90
250.91
250.92
250.93
357.20
362.01
362.02
362.03
362.04
362.05
362.06
366.41
Description
Diabetes with other specified manifestations (Diabetic hypoglycemia
NOS, Hypoglycemic shock NOS), T2 uncontrolled
Diabetes with other specified manifestations (Diabetic hypoglycemia
NOS, Hypoglycemic shock NOS), T1 uncontrolled
Diabetes with unspecified complication, T2 controlled
Diabetes with unspecified complication, T1 controlled
Diabetes with unspecified complication, T2 uncontrolled
Diabetes with unspecified complication, T1 uncontrolled
Polyneuropathy in diabetes
Background diabetic retinopathy
Proliferative diabetic retinopathy
Nonproliferative diabetic retinopathy NOS
Mild nonproliferative diabetic retinopathy
Moderate nonproliferative diabetic retinopathy
Severe nonproliferative diabetic retinopathy
Diabetic cataract
We required at least one inpatient or two outpatient claims for diabetes (in any position on the
claim) within the two years prior to the measurement period. We used outpatient diagnoses
from at least two distinct encounters because defining the cohort from fewer outpatient
encounters decreases specificity. To define the diabetes cohort we used diagnosis codes in any
position on the claim because studies have validated this approach for identifying patients with
diabetes using claims data.8-10 Diabetes is rarely the principal diagnosis for hospitalization, but
we also include a single inpatient claim in any position in the algorithm consistent with prior
studies.8-10 Patients identified with diabetes based on hospital admission claims alone
comprised a very small proportion of our diabetes cohort (approximately 2%). Our analyses
showed that restricting to a one-year timeframe would miss >10% of patients with diabetes
compared with using two years of claims data.
2
Appendix Table 2. Diagnostic codes used to define heart failure patients in the heart failure
measure
ICD-9-CM code
398.91
402.01
402.11
402.91
404.01
404.03
404.11
404.13
404.91
404.93
428.0
428.1
428.20
428.21
428.22
428.23
428.30
428.31
428.32
428.33
428.4
428.41
428.42
428.43
428.9
Description
Rheumatic heart failure
Malignant hypertensive heart disease with congestive heart failure (CHF)
Benign hypertensive heart disease with CHF
Hypertensive heart disease with CHF
Malignant hypertensive/renal disease with CHF
Malignant hypertensive/renal disease with CHF/Renal Failure
Benign hypertensive/renal disease with CHF
Benign hypertensive/renal disease with CHF/Renal Failure
Hypertensive/renal disease NOS with CHF
Hypertensive/renal disease NOS with CHF/Renal Failure
Congestive heart failure
Left heart failure
Systolic heart failure NOS
Acute systolic heart failure
Chronic systolic heart failure
Acute on chronic systolic heart failure
Diastolic heart failure NOS
Acute diastolic heart failure
Chronic diastolic heart failure
Acute on chronic diastolic heart failure
Systolic/diastolic heart failure NOS
Acute systolic/diastolic heart failure
Chronic systolic/diastolic heart failure
Acute/chronic systolic/diastolic heart failure
Heart failure NOS
We required at least one hospital claim with a principal diagnosis code for heart failure or two
claims (inpatient or outpatient) with codes for heart failure in any position within the two years
prior to the measurement period. Studies have demonstrated good sensitivity and specificity
when a single hospital principal diagnosis for heart failure is used to identify patients with true
heart failure. However, the positive predictive value is significantly diminished when the heart
3
failure codes appear in other positions on the claim; similarly, requiring only one outpatient
heart failure code is associated with a low positive predictive value for true heart failure.
Restricting to a one-year timeframe would miss >10% of patients with heart failure compared
with using two years of data.
4
Selection of Clinical Variables
We considered variables for risk adjustment based on the existing literature, clinical judgment,
and input from our TEP and other experts. We considered factors that may impact the rate of
admission, including patient-level factors (e.g., demographics, SES, or clinical risk factors on
admission); we also considered the impact of other non-clinical factors such as patient and
community resources as well as health behaviors.
To select candidate variables for risk adjustment, we used Medicare Part A and B data from one
year prior to the measurement year for 100% of the Medicare FFS patients included in the
cohort (2012 Medicare Full Sample). We reviewed 189 diagnostic condition groups included in
CMS’s Hierarchical Condition Category (HCC) clinical classification system.28 We defined
comorbidities using condition categories (CCs), which are clinically meaningful groupings of
more than 15,000 ICD-9-CM diagnosis codes. Two clinicians reviewed all 189 CCs and excluded
those that were not relevant to the Medicare FFS population or that were not clinically relevant
to the acute admission outcome (e.g., attention deficit disorder or female infertility). The
remaining 181 clinically relevant CCs were considered as candidate variables. Among the 181
clinically relevant CCs, we calculated the prevalence of the CC in the year preceding the
measurement period (i.e., 2011), the number of hospital admissions per patient-year during the
measurement period (i.e., 2012) among patients with and without the CC, and the rate ratio for
the number of hospital admissions associated with each CC. We independently reviewed these
data for both the diabetes and heart failure cohorts, and reduced the list of CCs to 92 from the
initial list of 181 clinically relevant CCs; in this group of 92 CCs, most were prevalent among >3%
of the cohort and were associated with a rate ratio of >1.3. Among the 92 CCs, we combined
5
conditions that were clinically coherent and carried a similar rate ratio for the number of
hospital admissions, resulting in 22 candidate variables, plus age.
Final Variable Selection
We identified 24 candidate risk-adjustment variables for each measure. For both the diabetes
and heart failure measures, the best combination of variables (i.e., with the lowest AIC value)
resulted in a distinct set of 23 variables, all of which were significantly associated with the
outcome (p<0.05). The Appendix Table 3 and 4 shows the final 23 variables for each measure.
6
Appendix Table 3. Condition categories (CCs) and International Classification of Diseases,
Ninth Revision, Clinical Modification (ICD-9-CM) codes used to define final risk model
variables in diabetes measure
CC or ICD-9-CM code
Description
High risk cardiovascular (CV) factors
CC 81
Acute myocardial infarction
CC 82
Unstable Angina and Other Acute Ischemic Heart Disease
CC 89
Hypertensive Heart and Renal Disease or Encephalopathy
CC 104
Vascular Disease with Complications
Low risk CV factors
Angina Pectoris/Old Myocardial Infarction
CC 83
Coronary Atherosclerosis/Other Chronic Ischemic Heart Disease
CC 84
Other and Unspecified Heart Disease
CC 94
Vascular Disease
CC 105
Other Circulatory Disease
CC 106
Arrhythmia
CC 92
CC 93
Advanced cancer
CC 7
CC 8
CC 9
CC 11
Dementia
CC 49
CC 50
Heart failure
CC 80
Dialysis status
CC 130
Disability/frailty
CC 21
CC 67
CC 68
CC 69
CC 100
Specified Heart Arrhythmias
Other Heart Rhythm and Conduction Disorders
Metastatic Cancer and Acute Leukemia
Lung, Upper Digestive Tract, and Other Severe Cancers
Lymphatic, Head and Neck, Brain, and Other Major Cancers
Other Respiratory and Heart Neoplasms
Dementia/Cerebral Degeneration
Nonpsychotic Organic Brain Syndromes/Conditions
Congestive Heart Failure
Dialysis Status
Protein-Calorie Malnutrition
Quadriplegia, Other Extensive Paralysis
Paraplegia
Spinal Cord Disorders/Injuries
Hemiplegia/Hemiparesis
7
CC or ICD-9-CM code
Description
Legally Blind
CC 116
Decubitus Ulcer of Skin
CC 148
Chronic Ulcer of Skin, Except Decubitus
CC 149
Vertebral Fractures without Spinal Cord Injury
CC 157
Amputation Status, Lower Limb/Amputation Complications
CC 177
Amputation Status, Upper Limb
CC 178
GI/GU Gastrointestinal and Genitourinary disorders
Other Hepatitis and Liver Disease
CC 29
Gallbladder and Biliary Tract Disorders
CC 30
Intestinal Obstruction/Perforation
CC 31
Inflammatory Bowel Disease
CC 33
Peptic Ulcer, Hemorrhage, Other Specified Gastrointestinal Disorders
CC 34
Urinary Obstruction and Retention
CC 133
Artificial Openings for Feeding or Elimination
CC 176
Hematological disorders
Severe Hematological Disorders
CC 44
Coagulation Defects and Other Specified Hematological Disorders
CC 46
Infectious and immune disorders
HIV/AIDS
CC 1
Central Nervous System Infection
CC 3
Tuberculosis
CC 4
Opportunistic Infections
CC 5
Disorders of Immunity
CC 45
Heart Infection/Inflammation, Except Rheumatic
CC 85
Kidney disease
Kidney Transplant Status
CC 128
Renal Failure
CC 131
Nephritis
CC 132
Liver disease
End-Stage Liver Disease
CC 25
Cirrhosis of Liver
CC 26
Chronic Hepatitis
CC 27
Acute Liver Failure/Disease
CC 28
Neurological disease
Delirium and Encephalopathy
CC 48
Profound Mental Retardation/Developmental Disability
CC 61
Other Developmental Disability
CC 65
Muscular Dystrophy
CC 70
Multiple Sclerosis
CC 72
Parkinson's and Huntington's Diseases
CC 73
8
CC or ICD-9-CM code
Description
Seizure Disorders and Convulsions
CC 74
Coma, Brain Compression/Anoxic Damage
CC 75
Cerebral Hemorrhage
CC 95
Ischemic or Unspecified Stroke
CC 96
Precerebral Arterial Occlusion and Transient Cerebral Ischemia
CC 97
Cerebral Atherosclerosis and Aneurysm
CC 98
Cerebrovascular Disease, Unspecified
CC 99
Cerebral Palsy and Other Paralytic Syndromes
CC 101
Speech, Language, Cognitive, Perceptual Deficits
CC 102
Cerebrovascular Disease Late Effects, Unspecified
CC 103
Major Head Injury
CC 155
Psychiatric illness/Substance abuse
Drug/Alcohol Psychosis
CC 51
Drug/Alcohol Dependence
CC 52
Drug/Alcohol Abuse, Without Dependence
CC 53
Schizophrenia
CC 54
Major Depressive, Bipolar, and Paranoid Disorders
CC 55
Reactive and Unspecified Psychosis
CC 56
Personality Disorders
CC 57
Depression
CC 58
Anxiety Disorders
CC 59
Other Psychiatric Disorders
CC 60
Pulmonary disease
Pleural Effusion/Pneumothorax
CC 114
Cystic Fibrosis
CC 107
Chronic Obstructive Pulmonary Disease
CC 108
Fibrosis of Lung and Other Chronic Lung Disorders
CC 109
Asthma
CC 110
Other Lung Disorders
CC 115
Other advanced organ failure
Cardio-Respiratory Failure and Shock
CC 79
Respirator Dependence/Tracheostomy Status
CC 77
Iron deficiency anemia
Iron Deficiency and Other/Unspecified Anemias and Blood Disease
CC 47
Major organ transplant
Major Organ Transplant Status
CC 174
Other organ transplant
Other Organ Transplant/Replacement
CC 175
Hip fracture/major fracture
Hip Fracture/Dislocation
CC 158
9
CC or ICD-9-CM code
Description
Major Fracture, Except of Skull, Vertebrae, or Hip
CC 159
Variable definition: Diabetes severity index
*Diabetes severity index is based on the number of complications associated with diabetes,
ranges from zero to seven, and has been adapted from Young et al.30
10
Appendix Table 4. Condition categories (CCs) and International Classification of Diseases,
Ninth Revision, Clinical Modification (ICD-9-CM) codes used to define final risk model
variables in heart failure measure
CC or ICD-9-CM code
Description
High risk cardiovascular (CV) factors
CC 81
Acute myocardial infarction
CC 82
Unstable Angina and Other Acute Ischemic Heart Disease
CC 89
Hypertensive Heart and Renal Disease or Encephalopathy
CC 104
Vascular Disease with Complications
Low risk CV factors
Angina Pectoris/Old Myocardial Infarction
CC 83
Coronary Atherosclerosis/Other Chronic Ischemic Heart Disease
CC 84
Other and Unspecified Heart Disease
CC 94
Vascular Disease
CC 105
Other Circulatory Disease
CC 106
Arrhythmia
Specified Heart Arrhythmias
CC 92
Other Heart Rhythm and Conduction Disorders
CC 93
Structural heart disease
Valvular and Rheumatic Heart Disease
CC 86
Major Congenital Cardiac/Circulatory Defect
CC 87
Other Congenital Heart/Circulatory Disease
CC 88
Advanced cancer
Metastatic Cancer and Acute Leukemia
CC 7
Lung, Upper Digestive Tract, and Other Severe Cancers
CC 8
Lymphatic, Head and Neck, Brain, and Other Major Cancers
CC 9
Other Respiratory and Heart Neoplasms
CC 11
Dementia
Dementia/Cerebral Degeneration
CC 49
Nonpsychotic Organic Brain Syndromes/Conditions
CC 50
Diabetes w/ complications
Diabetes with Renal or Peripheral Circulatory Manifestation
CC 15
Diabetes with Neurologic or Other Specified Manifestation
CC 16
Diabetes with Acute Complications
CC 17
Diabetes with Ophthalmologic or Unspecified Manifestation
CC 18
11
CC or ICD-9-CM code Description
Diabetes without Complication
CC 19
Proliferative Diabetic Retinopathy and Vitreous Hemorrhage
CC 119
Diabetic and Other Vascular Retinopathies
CC 120
Dialysis status
CC 130
Dialysis Status
Disability/frailty
Protein-Calorie Malnutrition
CC 21
Quadriplegia, Other Extensive Paralysis
CC 67
Paraplegia
CC 68
Spinal Cord Disorders/Injuries
CC 69
Hemiplegia/Hemiparesis
CC 100
Legally Blind
CC 116
Decubitus Ulcer of Skin
CC 148
Chronic Ulcer of Skin, Except Decubitus
CC 149
Vertebral Fractures without Spinal Cord Injury
CC 157
Amputation Status, Lower Limb/Amputation Complications
CC 177
Amputation Status, Upper Limb
CC 178
Gastrointestinal and Genitourinary disorders
Other Hepatitis and Liver Disease
CC 29
Gallbladder and Biliary Tract Disorders
CC 30
Intestinal Obstruction/Perforation
CC 31
Inflammatory Bowel Disease
CC 33
Peptic Ulcer, Hemorrhage, Other Specified Gastrointestinal Disorders
CC 34
Urinary Obstruction and Retention
CC 133
Artificial Openings for Feeding or Elimination
CC 176
Hematological disorders
Severe Hematological Disorders
CC 44
Coagulation Defects and Other Specified Hematological Disorders
CC 46
Infectious and immune disorders
HIV/AIDS
CC 1
Central Nervous System Infection
CC 3
Tuberculosis
CC 4
Opportunistic Infections
CC 5
Disorders of Immunity
CC 45
Heart Infection/Inflammation, Except Rheumatic
CC 85
Kidney disease
Kidney Transplant Status
CC 128
Renal Failure
CC 131
Nephritis
CC 132
Liver disease
12
CC or ICD-9-CM code Description
End-Stage Liver Disease
CC 25
Cirrhosis of Liver
CC 26
Chronic Hepatitis
CC 27
Acute Liver Failure/Disease
CC 28
Neurological disease
Delirium and Encephalopathy
CC 48
Profound Mental Retardation/Developmental Disability
CC 61
Other Developmental Disability
CC 65
Muscular Dystrophy
CC 70
Polyneuropathy
CC 71
Multiple Sclerosis
CC 72
Parkinson's and Huntington's Diseases
CC 73
Seizure Disorders and Convulsions
CC 74
Coma, Brain Compression/Anoxic Damage
CC 75
Cerebral Hemorrhage
CC 95
Ischemic or Unspecified Stroke
CC 96
Precerebral Arterial Occlusion and Transient Cerebral Ischemia
CC 97
Cerebral Atherosclerosis and Aneurysm
CC 98
Cerebrovascular Disease, Unspecified
CC 99
Cerebral Palsy and Other Paralytic Syndromes
CC 101
Speech, Language, Cognitive, Perceptual Deficits
CC 102
Cerebrovascular Disease Late Effects, Unspecified
CC 103
Major Head Injury
CC 155
Psychiatric illness/Substance abuse
Drug/Alcohol Psychosis
CC 51
Drug/Alcohol Dependence
CC 52
Drug/Alcohol Abuse, Without Dependence
CC 53
Schizophrenia
CC 54
Major Depressive, Bipolar, and Paranoid Disorders
CC 55
Reactive and Unspecified Psychosis
CC 56
Personality Disorders
CC 57
Depression
CC 58
Anxiety Disorders
CC 59
Other Psychiatric Disorders
CC 60
Pulmonary disease
Pleural Effusion/Pneumothorax
CC 114
Cystic Fibrosis
CC 107
Chronic Obstructive Pulmonary Disease
CC 108
Fibrosis of Lung and Other Chronic Lung Disorders
CC 109
Asthma
CC 110
13
CC or ICD-9-CM code Description
Other Lung Disorders
CC 115
Other advanced organ failure
Respirator Dependence/Tracheostomy Status
CC 77
Cardio-Respiratory Failure and Shock
CC 79
Iron deficiency anemia
Iron Deficiency and Other/Unspecified Anemias and Blood Disease
CC 47
Major organ transplant
Major Organ Transplant Status
CC 174
Other organ transplant
Other Organ Transplant/Replacement
CC 175
Pacemaker/cardiac resynchronization therapy/implantable cardiac device
Implantation of cardiac resynchronization pacemaker without
ICD-9-CM code 0.50
mention of defibrillation, total system [CRT-P]
Implantation of cardiac resynchronization defibrillator, total system
ICD-9-CM code 0.51
[CRT-D]
Implantation or replacement of transvenous lead [electrode] into left
ICD-9-CM code 0.52
ventricular coronary venous system
Implantation or replacement of cardiac resynchronization pacemaker
ICD-9-CM code 0.53
pulse generator only [CRT-P]
Implantation or replacement of cardiac resynchronization defibrillator,
ICD-9-CM code 0.54
pulse generator only (CRT-D)
ICD-9-CM code V45.01 Cardiac pacemaker in situ
ICD-9-CM code V53.31 Fitting and adjustment of cardiac pacemaker
ICD-9-CM code V53.39 Fitting and adjustment of other cardiac device
Insertion, revision, replacement, and removal of lead(s); insertion of
ICD-9-CM code 37.70
temporary pacemaker system; or revision of cardiac device pocket
ICD-9-CM code 37.71 Initial insertion of transvenous lead [electrode] into ventricle
Initial insertion of transvenous leads [electrodes] into atrium and
ICD-9-CM code 37.72
ventricle
ICD-9-CM code 37.73 Initial insertion of transvenous lead [electrode] into atrium
ICD-9-CM code 37.74 Insertion or replacement of epicardial lead (electrode) into epicardium
ICD-9-CM code 37.75 Revision of lead (electrode)
Replacement of transvenous atrial and/or ventricular lead(s)
ICD-9-CM code 37.76
(electrode[s])
ICD-9-CM code 37.77 Removal of lead(s) (electrodes) without replacement
ICD-9-CM code 37.78 Insertion of temporary transvenous pacemaker system
ICD-9-CM code 37.79 Revision or relocation of pacemaker pocket
Insertion of permanent pacemaker, initial or revision, type of device
ICD-9-CM code 37.80
not specified
Initial insertion of single-chamber pacemaker device, not specified as
ICD-9-CM code 37.81
rate responsive
14
CC or ICD-9-CM code
ICD-9-CM code 37.82
ICD-9-CM code 37.83
Description
Initial insertion of single-chamber pacemaker device, rate responsive
Initial insertion of dual-chamber pacemaker device
Replacement of any type pacemaker device with single chamber
ICD-9-CM code 37.85
device, not specified as rate responsive
Replacement of any type pacemaker device with single chamber
ICD-9-CM code 37.86
device, rate responsive
ICD-9-CM code 37.87 Replacement of any type pacemaker device with dual chamber device
ICD-9-CM code 37.89 Revision or removal of pacemaker device
ICD-9-CM code V45.02 Automatic implantable cardiac defibrillator in situ
ICD-9-CM code V53.32 Fitting and adjustment of automatic implantable cardiac defibrillator
Implantation or replacement of automatic cardioverter-defibrillator
ICD-9-CM code 37.94
(AICD), total system
ICD-9-CM code 37.95 Implantation of automatic cardioverter/defibrillator lead(s) only
Implantation or replacement of automatic cardioverter-defibrillator
ICD-9-CM code 37.96
pulse generator only
ICD-9-CM code 37.97 Replacement of automatic cardioverter/defibrillator lead(s) only
Replacement of automatic cardioverter-defibrillator (AICD), pulse
ICD-9-CM code 37.98
generator only
ICD-9-CM code 37.99 Other operations on heart and pericardium
15
Appendix Figure 1. Comparison of observed versus predicted probability of each number of hospital admissions (0, 1, 2, …, 10)
among diabetes patients in the diabetes measure by risk quartile
16
Appendix Figure 2. Comparison of observed versus predicted probability of each number of hospital admissions (0, 1, 2, …, 10)
among heart failure patients in the heart failure measure by risk quartile
17