In asthma, consistent control of chronic airway inflammation is crucial, and the use of asthma-controller medication has been emphasized. Our purpose in this study is to compare the incidence of acute exacerbation and healthcare costs related to the use of asthma-controller medication.
By using data collected by the National Health Insurance Review and Assessment Service, we compared one-year clinical outcomes and medical costs from July 2014 to June 2015 (follow-up period) between two groups of patients with asthma who received different prescriptions for recommended asthma-controller medication (inhaled corticosteroids or leukotriene receptor antagonists) at least once from July 2013 to June 2014 (assessment period).
There were 51,757 patients who satisfied our inclusion criteria. Among them, 13,702 patients (26.5%) were prescribed a recommended asthma-controller medication during the assessment period. In patients using a recommended asthma-controller medication, the frequency of acute exacerbations decreased in the follow-up period, from 2.7% to 1.1%. The total medical costs of the controller group decreased during the follow-up period compared to the assessment period, from $3,772,692 to $1,985,475. Only 50.9% of patients in the controller group used healthcare services in the follow-up period, and the use of asthma-controller medication decreased in the follow-up period.
Overall, patients using a recommended asthma-controller medication showed decreased acute exacerbation and reduced total healthcare cost by half.
Asthma is a chronic inflammatory disease of airways, and the progression of airway inflammation leads to recurrent episodes of symptoms, such as wheezing, breathlessness, chest tightness, and cough [
Given this background, the Health Insurance Review and Assessment Service (HIRA) since 2013 has annually done qualitative assessments of asthma management provided by all medical institutions that care for asthma in South Korea [
The HIRA is an agency responsible for evaluating all medical claims data in South Korea, which has adopted a single mandatory government-established health-insurance system [
The appropriate management of asthma was assessed qualitatively by means of the following seven items: (1) performance rate of pulmonary function test, (2) percentage of visits to the same medical institution for asthma management, (3) prescription rate of ICS, (4) prescription rate of anti-inflammatory controllers for asthma, such as LTRAs and ICS, (5) prescription rate of LABA without ICS, (6) prescription rate of SABA without ICS, and (7) prescription rate of oral corticosteroids (OCS) without ICS.
Among these seven items, the items numbered 1 to 4 were sub-categorized as mandatory.
We evaluated 831,613 asthma patients from 16,804 institutions in South Korea for the qualitative assessment of asthma management (
We divided the study subjects into two groups; patients who were prescribed recommended asthma-controller medication at least once during the assessment period (controller group), and patients who had not been prescribed such a medication (non-controller group) during the assessment period. By collecting and reviewing healthcare-visit claims data during the study period (1-year assessment period, from July 2013 to June 2014, followed by a one-year follow-up period from July 2014 to June 2015) (
This study was approved by the Institutional Review Board of the Catholic University of Korea, Seoul St. Mary’s Hospital (No. KC16RESI0560). Requirement for informed consent was waived because the study was retrospective.
We used the Student t-test for continuous variables and the chi-square test for categorical variables and did all statistical analyses using SAS version 9.2 (SAS Institute Inc., Cary NC, USA).
We included 51,757 patients who met the criteria in this study. Among them, 13,702 patients (26.5%) were prescribed a recommended asthma-controller medication during the assessment period (controller group). The remaining 38,055 patients were classified into the non-controller group.
The median age of patients in the controller group was lower than that of the non-controller group during the assessment period (61.8±16.5 vs. 64.0±16.2, p=0.001), and the proportion of male patients was lower in the controller group (39.9% vs. 42.1%, p=0.001) (
The frequency of acute exacerbation was higher in the controller group than in the non-controller group in both the assessment and the follow-up periods (2.7% vs. 0.5%, 1.1% vs. 0.5%) (
Only 50.9% (n=6,970) among 13,702 patients in the controller group used healthcare services in the year following the assessment period. As a result, the total medical costs of the controller group decreased in the follow-up period from what they had been during the assessment period (from $3,772,692 to $1,985,475) (
Our purpose in this large retrospective population study was to characterize the features of asthma management in South Korea and to measure the frequency of acute exacerbations during the asthma qualitative assessment period in terms of the use of asthma-controller medication using the South Korean national database from HIRA. Among 51,757 patients included, 26.5% were prescribed a recommended asthma-controller medication during the assessment period. In patients with asthma-controller medication, the frequency of acute exacerbations and total medical costs decreased in the follow-up period from what they had been in the assessment period.
This is the first study to compare medical cost and the frequency of asthma exacerbation using the results of a national qualitative assessment on asthma management. Because asthma-controller medications are effective in preventing acute exacerbations [
However, the following issues should be considered in interpreting our results. First, information on the baseline asthma severity of both groups was not defined in this study, because of the limitations of the data source. This limitation could imply selection bias, in that high-risk patients are more likely to use asthma-controller medication than are low-risk patients. To compensate for this limitation, we excluded patients who had visited tertiary hospitals or were prescribed controller medication before the assessment period. These strategies could indirectly correct the difference in severity between groups by excluding severe patients. Next, a direct comparison of total medical costs between groups was not available, because of loss of patients in the follow-up period. If the former comparison is satisfied, the use of controller medication to reduce medical costs will become a practice that is more evidence-based. Third, we aimed only to describe the trend of outcomes during two periods, and did not do statistical analysis of the repeated outcome measures. Finally, we should consider that the prescribing behavior of individual doctors affects controller use and that individual adherence to prescribed medication differs between patients.
Poor adherence and discontinuation of asthma treatment without visiting doctors have been raised as issues where asthma is not controlled properly by asthma specialists. According to a report from a survey conducted in eight areas in the Asia-Pacific region [
Through this study, we were able to analyze the characteristics of asthma treatment in Korea. Still, many patients were not using the recommended asthma-controller medication. Given the chronic nature of asthma and the need for long-term follow-up and management for a favorable prognosis, nationwide long-term educational strategies for asthma management are warranted.
Conceptualization: Lee SY, Park YB, Yoo KH. Methodology: Lee SY, Kim K, Park YB, Yoo KH. Software: Kim K. Validation: Kim K. Formal analysis: Kim K. Data curation: Lee SY, Kim K. Writing - original draft preparation: Lee SY. Writing - review and editing: Lee SY, Park YB, Yoo KH. Approval of final manuscript: all authors.
No potential conflict of interest relevant to this article was reported.
This study was supported by HIRA (Join Project on Quality Assessment Research).
Flow diagram of study population (A) and study duration (B).
The frequency of acute exacerbation was decreased in the follow-up period from that in the assessment period in the controller group (2.7% to 1.1%), although there was no difference between the assessment period and the follow-up period in the non-controller group (0.5% to 0.5%). ER: emergency room.
The total medical costs of the controller group decreased in the follow-up period from what it was in the assessment period ($3,772,692 to $1,985,475). OPD: outpatient department.
The use of both ICS-containing inhalers and LTRAs decreased in the follow-up period. ICS: inhaled corticosteroid; LABA: long-acting beta2-agonists; LTRA: leukotriene antagonist; SABA: short-acting beta2-agonists; OCS: oral corticosteroid; LAMA: long-acting muscarinic antagonists; PFT: pulmonary function test; PA: posteroanterior.
Demographics of asthma patients with and without recommended asthma-controller medications (2013 Jul–2014 Jun)
Controller group (n=13,702) | Non-controller group (n=38,055) | p-value | |
---|---|---|---|
Age, yr | 61.8±16.5 | 64.0±16.2 | <0.001 |
Male sex | 5,464 (39.9) | 16,028 (42.1) | <0.001 |
Composition of hospital | |||
Secondary hospitals | 1,854 (13.5) | 2,453 (6.4) | <0.001 |
Clinics | 13,050 (95.2) | 36,306 (95.4) | 0.438 |
Physical specialty | |||
Internal Medicine | 12,068 (88.1) | 31,541 (82.9) | <0.001 |
Others | 6,402 (46.7) | 14,547 (38.2) | <0.001 |
Type of insurance coverage | |||
Medical insurance | 12,490 (91.2) | 34,762 (91.3) | 0.494 |
Medical care | 1,212 (8.8) | 3,293 (8.7) | |
OPD visits | 8.1±8.8 | 7.2±8.7 | <0.001 |
Medication use | |||
ICS | 2,683 (19.6) | - | |
ICS/LABA | 3,502 (25.6) | - | |
LTRA | 10,404 (75.9) | - | |
Amount of used medication | |||
ICS (No. of inhalant) | 3.7±4.8 | - | |
ICS/LABA (No. of inhalant) | 1.9±1.6 | - | |
LTRA, day | 35.9±62.7 | - |
Values are presented as mean±SD or number (%).
OPD: outpatient department; ICS: inhaled corticosteroid; LABA: long-acting beta2-agonists; LTRA: leukotriene antagonist.