Definition of Reported Measures
- Hospitalizations due to Chronic Obstructive Pulmonary Disease (COPD) represents the number of hospitalizations due to COPD among California residents 25 years and over; expressed as a rate per 10,000 California residents.
- Emergency department (ED) visits due to Chronic Obstructive Pulmonary Disease (COPD) represents the number of ED visits due to COPD among California residents 25 years and over; expressed as a rate per 10,000 California residents.
How to Read Tables, Charts, and Maps
- The 95% confidence interval (CI) is the range of values that likely contains the true rate in the population.
- Crude rates express the number of outcomes relative to the size of the population. N/A indicates that the data are not available due to the number of events being less than 12.
- Total counts are listed next to rates unless the total number of events is less than 12.
- The map legend displays the data with four class breaks, where the data is divided into four equal bins known as quartiles.
- Some counties have a greater proportion of people who are old or young than other counties, which makes it difficult to compare across counties or over time. Scientists often fix this problem through a technique called age adjustment so comparisons can be made. In addition to crude rates, we also present age-adjusted rates.
- Effective October 1, 2015, hospital record (HCAI) data transitioned from ICD-9 to ICD-10-CM. Differences between counts and rates in years prior to 2015 compared with 2015 and subsequent years could be a result of this coding change and not an actual difference in the number of events.
- Prior to 2019, data for Asians and Pacific Islanders were combined into a single group (Asian/PI). Beginning in 2019, data were reported separately for Asians and Native Hawaiian Pacific Islanders (NHPI). Data were also reported for Multi-race individuals starting in 2019.
Data Sources
- Emergency Department and Patient Discharge Datasets are from the California Department of Health Care Access and Information (HCAI), formerly known as the Office of Statewide Health Planning and Development (OSHPD).
- Denominators for rates are based on estimates from the California Department of Finance.
Methods
Cases of COPD hospitalizations and emergency department visits are identified by using the following ICD-9-CM codes or ICD–10–CM codes as the primary diagnosis.
| ICD-9 Code | Code Description |
| 490 | Bronchitis, not specified as acute or chronic |
| 491 | Chronic bronchitis |
| 492 | Emphysema |
| 496 | Chronic airway obstruction, not elsewhere classified |
| 493.2 (primary) + other diagnoses = 490, 491, 492, 496 | Chronic obstructive asthma |
| ICD-10 Code | Code Description |
| J40 | Bronchitis, not specified as acute or chronic |
| J41 | Simple and mucopurulent chronic bronchitis |
| J42 | Unspecified chronic bronchitis |
| J43 | Emphysema |
| J44 | Other chronic obstructive pulmonary disease |
Limitations of the data
- Data Collection Purpose- Diagnosis codes are recorded by hospitals for reimbursement purposes and not for public health surveillance.
- The rates provided include ED visits and hospitalizations for California residents. Out-of-state residents and unhoused patients with no recorded address are excluded from the rates.
- Low-level of resolution- Hospitals are not mandated to report patient addresses. The level of geographic resolution of the data is limited to state, county, and zip code.
- Zip code level data- Zip codes are not geographic areas; Zip codes may change from year to year and even within a year; Zip codes can cross city or county boundaries; and Zip code populations are estimates. Only Zip codes with data are displayed.
Suggested Citation
Tracking California, Public Health Institute. Chronic Obstructive Pulmonary Disease Related Emergency Department & Hospitalization data. Accessed [Month/Day/Year] from https://data.trackingcalifornia.org
Notes about the data (PDF)