Background and Significance
Asthma is defined as a chronic disease where the airways extending from the lungs suffer from inflammation 1. Asthma is the most prevalent chronic disease with approximately 5-10% of the world population suffers from asthma 2,3. In 2014, the age-adjusted hospitalization rate for Florida was 13.6 per 10,000 persons 4. In children under the age of 15, asthma is the 3rd leading cause of emergency room visits and hospitalizations 5. To limit the severity of asthma, estimates of high-risk populations are needed.
While the exact cause of asthma is unknown, it is believed that genetics, allergies, respiratory infections, and the environment play a role in the development of asthma 5. When a patient presents with severe asthmatic symptoms they may need to be admitted to the hospital. To assess the need for medical care, a measurement of the airway obstruction through spirometry is taken 6. If asthma is left untreated, the risk for respiratory failure, obesity, and death increases 7. Therefore, to improve outcomes, we need to understand and optimize the management of asthma.
Hospital admissions for asthma can be a great source of information on epidemiological trends of disease 8. Collecting information on the hospitalization for asthma, as well as, patient characteristics, outcomes, use of mechanical ventilation, and length of stay is useful in evaluating the burden of disease.
The objective of this study was to assess trends of asthma-related hospitalizations among Florida residents from 1988-2012. The number of people with asthma in the US continues to grow each year, with an increase from 7% in 2001 to 8% in 2009 of the US population being diagnosed with asthma. Following the rise in asthma diagnoses, we hypothesized that asthma-related hospitalizations would also increase during the time period following previous research.
METHODS
The Office of Data Collection and Quality Assurance (DCQA) within the Agency for Health Care Administration in Florida (AHCAF), collects patient discharge data from licensed hospitals, ambulatory surgical centers, and emergency departments. This data collection started because of Florida statute 408.061, and the agency still collects information in accordance with this statute (Appendix C) 10. The statute states the AHCAF shall require submission of information from all health care facilities, health care providers, and health insurers to collect any data necessary to carry out the agency’s duties 11. The primary responsibility of the AHCAF is to supervise Florida’s estimated $25.2 billion Medicaid program, control licensure of Florida’s health care facilities, and to share health care data through the Florida Center for Health Information and Policy Analysis 12. This database created by the AHCAF and DCQA contains information from Florida’s approximately 48,500 healthcare facilities on hospital characteristics, patient demographics, billing information, and discharge status 9. We analyzed inpatient hospital admissions from 1988 to 2012, collected by the Florida Agency for Healthcare Administration. This dataset contains each hospital admission for the state of Florida, totaling 55,301,794 observations. Each observation comprises quantitative information on hospital characteristics, diagnoses, procedures performed, patient demographics, billing information, and discharge status. We identified hospitalizations for asthma based on the International Classification of Diseases 9th Clinical Modification (ICD-9-CM) codes. For each year between 1988 and 2012, we determined the total number of hospitalizations related to asthma with an ICD-9-CM diagnosis code of 493. We excluded non-residents of Florida to compare to previous published asthma-related hospitalization rates 4. Additional variables that were accessed were sex, age, race, and length of stay.
The AHCAF Florida hospitalization data set lacks a patient identifying number to link patient hospitalizations. The lack of an identifier can be misleading to overestimate the rates and possible misclassification bias. Due to de-identified hospital observations, we cannot directly link observations to each other. A record or ID number cannot be used to detecting patients with repeat hospitalizations in the initial dataset. We were able to remove duplicates by matching all variables in the original dataset (this includes variables not used in this study). If a discharged patient is readmitted within 7 days, it should be considered the same hospitalization.
The primary outcome was the rate of hospitalizations due to asthma. Using trend analysis, age-adjusted hospitalization rats are presented as cases per 10,000 population. The population denominator was among Floridians to match previous publications 4.
RESULTS
Table 1. Asthma Characteristics from the Agency for Health Care Administration Data
| Characteristics | Year | ||
| 1992-2012
n = 529958 |
1992
n = 21895 |
2012
n = 28664 |
|
| Gender, n(%) | |||
| Male | 202861 (38.28) | 9159 (41.83) | 10388 (36.24) |
| Female | 327092 (61.72) | 12736 (58.17) | 18276 (63.76) |
| Age Group, n (%) | |||
| 0-4 Years | 98458 (18.58) | 5578 (25.48) | 3688 (12.87) |
| 5-64 Years | 313064 (59.07) | 11871 (54.22) | 17420 (60.77) |
| 65+ Years | 118436 (22.35) | 4446 (20.31) | 7556 (26.36) |
| Race/Ethnicity | |||
| Non-Hispanic White | 272990 (51.90) | 12810 (58.91) | 13043 (46.15) |
| Non-Hispanic Black | 148530 (28.24) | 6055 (27.84) | 8420 (29.79) |
| Hispanic | 90739 (17.25) | 2352 (10.82) | 6181 (21.87) |
| Other | 13725 (2.61) | 529 (2.43) | 616 (2.18) |
| LOS days, median (IQR) | 3 (3) | 4 (4) | 3 (3) |
| Insurer | |||
| Medicare | 145334 (27.42) | 4898 (22.37) | 10071 (35.13) |
| Medicaid | 153337 (28.93) | 6372 (29.10) | 9433 (32.91) |
| Commercial | 158627 (29.93) | 7616 (34.78) | 4972 (17.35) |
| Self-Pay | 44509 (8.40) | 2117 (9.67) | 2551 (8.90) |
| Other | 28151 (5.31) | 892 (4.07) | |
| LOS: Length of StayIQR: Inter Quartile Range*Variable may not add up to total due to missing | |||
Table 1 shows that the overall number of Asthma-related hospitalizations increase from 1992 to 2012. The length of stay decreased over that time period. The most popular insurer in 1992 for an asthma-related hospitalization was a commercial insurer, while in 2012 it became medicare. The average age of those hospitalized with asthma increased from 1992 to 2012.
Figure 1. Age-Adjusted Asthma Related Hospitalization Rates in Florida from 1990 and 2010 by County
The above figure shows the rates of asthma-related hospitalization per county in 1990 and 2010. It appears to be getting worse in metropolitan areas where there have been considerable population changes during the same time. For example, Orange County (where Orlando is located) has experienced a large increase in population density and tourism in the past 2 decades.
Figure 2. Asthma-Related Hospitalization Rates in Florida from 1988 to 2012
We hypothesized that asthma-related hospitalizations would increase from 2001 to 2009. According to the figure above it does appear to increase strictly from 2001 to 2009. The overall pattern in the figure does not show an increase. There is an increase in the raw number of hospitalizations, but this may be due to the population size increases.
References
- Asthma | AAAAI. The American Academy of Allergy, Asthma & Immunology https://www.aaaai.org/conditions-and-treatments/conditions-dictionary/asthma (2019).
- Bousquet, J., Bousquet, P. J., Godard, P. & Daures, J.-P. The public health implications of asthma. Bull. World Health Organ. 7 (2005).
- Kim, S. Y., Lim, H., Lim, J.-S. & Choi, H. G. Analysis of the Relationship between Adult Asthma and Stroke: A Longitudinal Follow-Up Study Using the Korean National Sample Cohort. BioMed Res. Int. 1–8 (2019) doi:10.1155/2019/8919230.
- Florida Department of Health. Asthma Emergency Department Visits and Hospitalizations in Florida. http://www.floridahealth.gov/diseases-and-conditions/asthma/_documents/ed-hosp-factsheet2017.pdf (2015).
- American Lung Association. What Causes Asthma? https://www.lung.org/lung-health-and-diseases/lung-disease-lookup/asthma/asthma-symptoms-causes-risk-factors/what-causes-asthma.html (2019).
- Corre, K. A. & Rothstein, R. J. Assessing severity of adult asthma and need for hospitalization. Ann. Emerg. Med. 14, 45–51 (1985).
- Cattamanchi, A. Asthma Complications: Long- and Short-Term Effects. https://www.healthline.com/health/asthma-complications (2017).
- Gonzalez-Barcala, F. J. et al. Trends in adult asthma hospitalization: gender-age effect. Multidiscip. Respir. Med. 6, 82–86 (2011).
- Unick, G. J. & Ciccarone, D. US regional and demographic differences in prescription opioid and heroin-related overdose hospitalizations. International Journal of Drug Policy 46, 112–119 (2017).
- Agency for Healthcare Administration. AHCA: FCHIPA Home. https://ahca.myflorida.com/schs/DataCollection/DataCollection.shtml (2020).
- Florida Legislature. Statutes & Constitution :View Statutes : Online Sunshine. The 2019 Florida Statutes http://www.leg.state.fl.us/statutes/index.cfm?App_mode=Display_Statute&Search_String=&URL=0400-0499/0408/Sections/0408.061.html (2019).
- Agency for Healthcare Administration. AHCA: About AHCA. http://ahca.myflorida.com/Inside_AHCA/index.shtml (2020).