Surveys defined chronic conditions in similar ways for the purposes of displaying data on the Health System Measurement Project. The definitions vary slightly due to survey methodology and data constraints. The full description of how chronic conditions were defined by each survey is below.
The Medical Expenditure Panel Survey (MEPS) defined chronic conditions derived from the Clinical Classification Codes (CSS)of MEPS, and included the following codes and conditions:
CCS Code and Name
1-Tuberculosis
5-HIV infection
6-Hepatitis
11-Cancer of head and neck
12-Cancer of esophagus
13-Cancer of stomach
14-Cancer of colon
15-Cancer of rectum and anus
16-Cancer of liver and intrahepatic bile duct
17-Cancer of pancreas
18-Cancer of other GI organs; peritoneum
19-Cancer of bronchus; lung
20-Cancer; other respiratory and intrathoracic
21-Cancer of bone and connective tissue
22-Melanomas of skin
23-Other non-epithelial cancer of skin
24-Cancer of breast
25-Cancer of uterus
26-Cancer of cervix
27-Cancer of ovary
28-Cancer of other female genital organs
29-Cancer of prostate
30-Cancer of testis
31-Cancer of other male genital organs
32-Cancer of bladder
33-Cancer of kidney and renal pelvis
34-Cancer of other urinary organs
35-Cancer of brain and nervous system
36-Cancer of thyroid
37-Hodgkin's disease
38-Non-Hodgkin's lymphoma
39-Leukemias
40-Multiple myeloma
41-Cancer; other and unspecified primary
42-Secondary malignancies
43-Malignant neoplasm without specification of site
44-Neoplasm of unspecified nature or uncertain behavior
45-Maintenance chemotherapy; radiotherapy
48-Thyroid disorders
49-Diabetes mellitus without complication
50- Diabetes mellitus with complications
51-Other endocrine disorders
52-Nutritional deficiencies
53-Disorders of lipid metabolism
54-Gout and other crystal arthropathies
56-Cystic fibrosis
57-Immunity disorders
61-Sickle cell anemia
62-Coagulation and hemorrhagic disorders
79-Parkinson's disease
80-Multiple sclerosis
81-Other hereditary and degenerative nervous conditions
82-Paralysis
83-Epilepsy; convulsions
84-Headache; including migraine
85-Coma; stupor; and brain damage
87-Retinal detachments; defects; vascular occlusion; and retinopathy
88-Glaucoma
89-Blindness and vision defects
96- Heart valve disorders
97-Peri-; endo-; and myocarditis; cardiomyopathy (except that caused by tuberculosis or sexually transmitted disease)
98-Essential hypertension
99-Hypertension with complications and secondary hypertension
101-Coronary atherosclerosis and other heart disease
103-Pulmonary heart disease
104-Other and ill-defined heart disease
105-Conduction disorders
106-Cardiac dysrhythmias
108-Congestive heart failure; nonhypertensive
113-Late effects of cerebrovascular disease
114-Peripheral and visceral atherosclerosis
115-Aortic; peripheral; and visceral artery aneurysms
117-Other circulatory disease
127-Chronic obstructive pulmonary disease and bronchiectasis
128-Asthma
132-Lung disease due to external agents
144-Regional enteritis and ulcerative colitis
146-Diverticulosis and diverticulitis
150-Liver disease; alcohol-related
151-Other liver diseases
156-Nephritis; nephrosis; renal sclerosis
158-Chronic renal failure
164-Hyperplasia of prostate
169-Endometriosis
170-Prolapse of female genital organs
173-Menopausal disorders
199-Chronic ulcer of skin
202-Rheumatoid arthritis and related disease
203-Osteoarthritis
205-Spondylosis; intervertebral disc disorders; other back problems
206-Osteoporosis
210-Systematic lupus erythematosus and connective tissue disorders
211-Other connective tissue disease
213-Cardiac and circulatory congenital anomalies
214-Digestive congenital anomalies
215-Genitourinary congenital anomalies
216-Nervous system congenital anomalies
217-Other congenital anomalies
227-Spinal cord injury
650-Adjustment disorder
651-Anxiety disorder
652-Attention deficit, conduct, and disruptive behavior disorder
653-Delirium, dementia, and amnestic and other cognitive disorders
654-Developmental disorders
655-Disorders usually diagnosed infancy, childhood, and adolescence
656-Impulse control disorders, NEC
657-Mood disorders
658-Personality disorders
659-Schizophrenia and other psychotic disorders
660-Alcohol-related disorders
661-Substance-related disorders
The National Health Interview Survey (NHIS), defined a count of chronic conditions differently for adults and children.
For adults aged 18 years and over, chronic conditions included in the count were as follows:
- Ever being told by a doctor or other health professional that they had cancer,
- Ever being told by a doctor or other health professional that they had hypertension,
- Ever being told by a doctor or other health professional that they had coronary heart disease,
- Ever being told by a doctor or other health professional that they had a myocardial infarction,
- Ever being told by a doctor or other health professional that they had any other heart disease or condition,
- Ever being told by a doctor or other health professional that they had a stroke,
- Ever being told by a doctor or other health professional that they had asthma,
- Ever being told by a doctor or other health professional that they had diabetes (all types with the exception of diabetic conditions related to pregnancy),
- Ever being told by a doctor or other health professional that they had emphysema,
- Ever being told by a doctor or other health professional that they had arthritis,
- Ever having hepatitis,
- Being told by a doctor or other health professional that they had a liver condition during the past 12 months,
- Being told by a doctor or other health professional that they had chronic bronchitis during the past 12 months,
- Having a severe headache or migraine during the past three months,
- Being blind or unable to see at all.
For children aged 17 years and under, chronic conditions included in the count were as follows:
- Ever being told by a doctor or other health professional that they had Down Syndrome,
- Ever being told by a doctor or other health professional that they had mental retardation,
- Ever being told by a doctor or other health professional that they had any other developmental delay,
- Ever being told by a doctor or other health professional that they had cerebral palsy,
- Ever being told by a doctor or other health professional that they had muscular dystrophy,
- Ever being told by a doctor or other health professional that they had Attention Deficit Hyperactivity Disorder (ADHD) or Attention Deficit Disorder (ADD),
- Ever being told by a doctor or other health professional that they had cystic fibrosis,
- Ever being told by a doctor or other health professional that they had sickle cell anemia,
- Ever being told by a doctor or other health professional that they had autism,
- Ever being told by a doctor or other health professional that they had diabetes,
- Ever being told by a doctor or other health professional that they had arthritis,
- Ever being told by a doctor or other health professional that they had congenital heart disease,
- Ever being told by a doctor or other health professional that they had any other heart condition,
- Ever being told by a doctor or other health professional that they had asthma,
- Being told by a doctor or other health professional that they had seizures during the past 12 months,
- Being told by a doctor or other health professional that they had repeated or frequent diarrhea or colitis during the past 12 months,
- Being blind or unable to see at all.
For purposes of the Health System Measurement Project, for adults, multiple types of cancers were only counted once for the count of chronic conditions. Multiple types of heart conditions (for adults: coronary heart disease, myocardial infarction, other heart disease or condition; for children: congenital heart disease, other heart condition) were also only counted once. Adults with emphysema and/or chronic bronchitis were considered to have chronic obstructive pulmonary disease (COPD); therefore prevalence of both conditions was only counted once. For children, multiple types of developmental conditions (Down syndrome, mental retardation, other developmental disorder) were only counted once.
For adults, the following NHIS variables were used in creation of the count of chronic conditions for all years: CANEV; HYPEV; CHDEV; STREV; EPHEV; AASMEV; CBRCHYR; LIVYR; DIBEV; AMIGR; ABLIND; AHEP. For 2000, data on arthritis were unavailable. For 2001-2010, data on arthritis were available but for 2001 the question regarding arthritis differs from the one asked from 2002-2009. The 2001 arthritis question (variable ARTH) only asks about arthritis, and the 2002-2009 arthritis questions (variable ARH1) include rheumatoid arthritis, gout, lupus, and fibromyalgia.
For children, the following NHIS variables were used in creation of the count of chronic conditions for all years: AMR1; AMR2; AODD1; AODD2; ADD2; CASHMEV; SEIZE1; SEIZE2; CBLIND; DIARH1; DIARH2. For 2000-2007, the following variables were used: CONDL1; CONDL2; CONDL3; CONDL4; CONDL5; CONDL6; CONDL7; CONDL8; CONDL9; CONDL10. For 2008-2009, the following variables were used: CCONDL01; CCONDL02; CCONDL03; CCONDL04; CCONDL05; CCONDL06; CCONDL07; CCONDL08; CCONDL09; CCONDL10.
The National Health and Nutrition Examination Survey (NHANES) defined chronic conditions as ever being told by a health professional that an individual had cancer, hypertension, coronary heart disease, myocardial infarction, heart disease, stroke, asthma, diabetes, arthritis, liver condition, chronic bronchitis or if they had measured hepatitis antibodies.
The National Ambulatory Medical Care Survey (NAMCS) defined chronic conditions as if a sampled visit had any of the following conditions on their chart: arthritis, asthma, cancer, cerebrovascular disease , chronic renal failure, congestive heart failure, COPD, depression, diabetes, hyperlipidemia, hypertension, ischemic heart disease, obesity, or osteoporosis.
The confidence interval measures the statistical probability that the range obtained from the sample contains the true population value. For example, a 95% confidence interval is expected to contain the true population value in 95% of samples.
All federal data collections are required to use the Office of Management and Budget (OMB) minimum data standards for race and ethnicity. The OMB’s government-wide standards were originally issued in 1997 after a comprehensive public engagement process and extensive field testing. These standards had to be implemented by 2003. A detailed explanation of these standards is available at: www.whitehouse.gov/omb/fedreg_1997standards/.
Most surveys now include the new classifications though some are still in the process of converting to the new questions. Prior to 2003, racial and ethnic classifications were: American Indian or Alaskan Native; Asian or Pacific Islander; Black; Hispanic; and White. As of 2003, surveyors were encouraged to use a two-question format with ethnicity asked separately and before the question on race, and must provide respondents with the option of identifying with more than one race . The first question asks for self-identified ethnicity, with the classifications: Hispanic or Latino; and Not Hispanic or Latino. The second question asks for self-identified race, with the classifications: American Indian or Alaska Native; Asian; Black or African American; Native Hawaiian or Pacific Islander, or White. In rare instances, surveyors may also use a combined, single-question format, with the classifications: American Indian or Alaska Native; Asian; Black or African American; Native Hawaiian or Pacific Islander; White; and Hispanic or Latino. Please note that samples sizes for some categories, particularly American Indian or Alaskan Natives, may be small and estimates may not be available for all categories for all years in all measures.
Where data are available, the following six categories are used:
All federal data collections are required to use the Office of Management and Budget (OMB) minimum data standards for race and ethnicity. The OMB’s government-wide standards were originally issued in 1997 after a comprehensive public engagement process and extensive field testing. These standards had to be implemented by 2003. A detailed explanation of these standards is available at: www.whitehouse.gov/omb/fedreg_1997standards/.
Most surveys now include the new classifications though some are still in the process of converting to the new questions. Prior to 2003, racial and ethnic classifications were: American Indian or Alaskan Native; Asian or Pacific Islander; Black; Hispanic; and White. As of 2003, surveyors were encouraged to use a two-question format with ethnicity asked separately and before the question on race, and must provide respondents with the option of identifying with more than one race . The first question asks for self-identified ethnicity, with the classifications: Hispanic or Latino; and Not Hispanic or Latino. The second question asks for self-identified race, with the classifications: American Indian or Alaska Native; Asian; Black or African American; Native Hawaiian or Pacific Islander, or White. In rare instances, surveyors may also use a combined, single-question format, with the classifications: American Indian or Alaska Native; Asian; Black or African American; Native Hawaiian or Pacific Islander; White; and Hispanic or Latino. Please note that samples sizes for some categories, particularly American Indian or Alaskan Natives, may be small and estimates may not be available for all categories for all years in all measures.