|Year : 2013 | Volume
| Issue : 2 | Page : 129-133
Risk factors for asthma hospitalization and emergency department visit in Nigeria: The role of symptoms frequency and drug utilization
Olufemi Olumuyiwa Desalu1, Joseph Olusesan Fadare2, Adekunle Olatayo Adeoti3, Adebowale Olayinka Adekoya4
1 Department of Medicine, University of Ilorin Teaching Hospital, Ilorin, Nigeria
2 Department of Pharmacology, Ekiti State University Teaching Hospital, Ado-Ekiti, Nigeria
3 Department of Medicine, Ekiti State University Teaching Hospital, Ado-Ekiti, Nigeria
4 Department of Medicine, Lagos State University Teaching Hospital, Lagos, Nigeria
|Date of Web Publication||4-Jan-2014|
Olufemi Olumuyiwa Desalu
Department of Medicine, University of Ilorin Teaching Hospital, Ilorin
Source of Support: None, Conflict of Interest: None
Background: Substantial proportion of the economic cost of asthma care is due to hospitalization and emergency department (ED) visit. The objective of our study was to identify the role of frequency of asthma symptoms and drug utilization as risk factors for asthma related hospitalization and ED visit among adult patients in selected hospitals in Nigeria. Patients and Methods: We carried out a cross sectional study of a sample of adult patients in selected hospitals in Nigeria. Demographic, clinical information, and use of asthma medications were obtained from the patients that were hospitalized or visited ED and those not hospitalized or visited ED in previous 12 months. Results: A total of 102 patients participated in the study. Fifty (49.0%) of the patients were hospitalized or visited the ED and 52 (51.0%) were neither hospitalized nor visited ED. Asthma patients who experienced frequent nocturnal symptoms (relative risk (RR)-3.50, 95% confidence interval ( C I) 2.05-4.96), frequent use of rescue medication (RR-2.89, 95% CI 1.66-4.12), increased daytime (RR-2.32, 95% CI 1.32-3.32), and nasal symptoms (RR-2.30, 95% CI 1.11-3.48) were more likely to be hospitalized or visited ED. Patients who used oral theophylline (RR-2.19, 95% CI 1.35-2.33) without doctor's prescription were two times more likely to be hospitalized or visited ED. The use of inhaled corticosteroids (ICS, RR-0.69, 95% CI 0.45-0.99) and oral corticosteroids (OCS; RR-0.73, 95% CI 0.00-1.59) were not associated asthma related hospitalization and ED visit. Conclusion: There is a need for pragmatic interventions in patients who reported increased asthma and nasal symptoms, increased use of rescue medication, and nonprescription use of oral theophylline in order to prevent acute asthma hospitalization and emergency visit.
Keywords: Asthma, emergency department visit, hospitalization, ICS, Nigeria, risk factors, symptoms
|How to cite this article:|
Desalu OO, Fadare JO, Adeoti AO, Adekoya AO. Risk factors for asthma hospitalization and emergency department visit in Nigeria: The role of symptoms frequency and drug utilization. Indian J Allergy Asthma Immunol 2013;27:129-33
|How to cite this URL:|
Desalu OO, Fadare JO, Adeoti AO, Adekoya AO. Risk factors for asthma hospitalization and emergency department visit in Nigeria: The role of symptoms frequency and drug utilization. Indian J Allergy Asthma Immunol [serial online] 2013 [cited 2017 Apr 30];27:129-33. Available from: http://www.ijaai.in/text.asp?2013/27/2/129/124395
| Introduction|| |
Asthma is currently one of the world's most common long-term conditions and its prevalence is increasing especially in low and middle income countries with large populations.  Asthma causes significant morbidity, mortality, and socioeconomic consequences to patients, their families, employers, communities, and health systems.  In 1997, Smith et al., reported that a substantial proportion of the direct costs in the USA are due to asthma hospitalization and emergency department (ED) visits.  Acute asthma hospitalization and emergency visits can be reduced by numerous measures among which are: Treatment with controller medicines, such as inhaled corticosteroids (ICS), and other nonpharmaceutical measures like specialty care, personalized asthma education, and self-management plans. , These outlined measures may seem simple and straightforward yet they are said to be currently unachievable for a large proportion of people with asthma in the world.  The most cost effective intervention is targeting and early identification of the subgroup of asthma patients that are at high risk of hospitalization and ED visit and ensuring early intervention and prevention. Assessment of symptoms frequency and medication use in the clinic may help the physician in identifying severity of disease and those at risk of asthma related hospitalization and ED visits. , Quite a number of studies in the developed countries have identified the factors associated with asthma related hospitalization and ED visits. , There is paucity of data on risk factors for asthma hospitalization in the low- and middle income countries of sub-Saharan Africa which are least able to absorb the socioeconomic impact of the disease. The objective of this study was to identify the role of asthma symptoms frequency and drug utilization as risk factors for asthma related hospitalization and ED visit among adult patients in selected hospitals in Nigeria.
| Patients and Methods|| |
This was a cross-sectional study among a sample of adult patients (≥ 18 years) in Nigeria from January 2009 to January 2010. The survey was conducted in two tertiary and one private hospital. These are Federal Medical Centre in Birnin-Kebbi, Northwestern Zone, Federal Medical Centre in Ido-Ekiti and BLW Medical Centre, Ikeja, Southwestern Nigeria.
A convenient sample size of 100 was adopted based on the number adult patients that received treatment in previous year at the participating centers which ranged from 60 to 80. For Federal Medical Centre, Birnin-Kebbi, northwest Nigeria, the rate of admission was 20; Federal Medical Centre, Ido-Ekiti, Southwest Nigeria (30); and BLW Medical Centre, Lagos, southwest Nigeria (10). We anticipated a nonparticipation rate 20% which necessitated increasing the sample size to 93. The asthma patients were subdivided into two groups, Group I had hospitalization and ED visit and Group II had no hospitalization and ED visit in the previous 12 months.
Group I (Hospitalization and emergency department visit)
Group I participants were recruited from inpatients in the medical ward, ED, and the outpatient clinic. The eligible patients were approached by a medical doctor (intern, medical officer, or resident) in the pulmonary division and invited to participate in the study. The inclusion criteria for the recruited cases were: All asthma patients who met Global Initiative on Asthma (GINA) definition of asthma prior to admission (recorded a reversibility of 12% in forced expiratory volume (FEV) 1 or change of 60 L/min in peak expiratory flow rate),  were willing to participate in the study, adult patients (>18 years), patients who have received treatment for acute asthma attack in the past 12 months. Patients were excluded if they were newly diagnosed, refused to participate, and had chronic obstructive pulmonary diseases (COPD) or had never had a lung function test. Patients with severe or life-threatening asthma or who had altered mental state were excluded from the study until their condition was stable.
Group II (No hospitalization and emergency department visit)
The Group II patients were mostly recruited from the hospital patients that have been previously diagnosed by a physician using the GINA criteria. Secondly, they must not have sought and received treatment for acute asthma attack in past 12 months. The hospital patients were recruited when they came for follow-up in the outpatient clinic and while the others were contacted through their mobile phone using telephone contact in their medical folder by one of the investigator. Patients who agreed to participate in the study were then invited to the hospital for data collection.
The survey instrument used was a pretested, structured questionnaire prepared by the investigators. The questionnaire was in English, which is the official language of communication in Nigeria; it was adapted and translated to Yoruba and Hausa languages for those who could not communicate in English. The Yoruba language is the indigenous language of the Yoruba tribe of the southwestern part of Nigeria, while Hausa is the indigenous language of the Hausa-Fulani people of the northwestern region of Nigeria. The survey instrument has not been previously validated or used in any other study. The questionnaire was interviewer administered by the researchers to asthma patients depending on their language of communication. Sociodemographic information, clinical data: Duration of asthma since diagnosis, tobacco smoking, self-reported asthma symptoms, and symptoms of rhinitis were obtained.
In addition, the patients' medications and the doses used 1 month prior to questionnaire administration were also obtained. The administration of questionnaire was followed by anthropometric measurement. The body mass index (kg/m 2 ) was calculated from weight (kg) and height (m) by dividing weight by the square of the height (m 2 ).
Definition of terms
Asthma symptoms frequency
The asthma severity was based on the level of symptoms over a period of four weeks according to the GINA guidelines and these categorizations were used in defining the frequency of symptoms in this study, The symptom frequency was assessed over a period of 4 weeks prior to the survey. Increased daytime symptom was defined as ≥ two daytime asthma symptoms per week over 4 weeks. An increased nocturnal symptom was defined as having night time symptoms more than twice a month. 
Persistent nasal symptoms
Persistent symptoms are present at least 4 days a week and for at least 4 weeks. 
Use of asthma medication
Increased use of rescue medication was defined as the use of inhaled short-acting β2 agonist ≥two times per week. Use of corticosteroids was defined as daily use of inhaled or oral corticosteroids (OCS). The use of theophylline was defined as nonprescription use of oral theophylline in 1 month before the study. 
The recorded information was reviewed manually for missing data and appropriate coding was done before data entry. Data obtained were analyzed using Statistical Package for Social Sciences (SPSS) software version 15 (SPSS Inc., Chicago, IL, USA). The data was also checked for outliers and normality of distribution of the continuous variables. Descriptive statistics was used to examine the general characteristics of the patients. Independent Student's test was used to compare the means of normally distributed continuous variable and Mann-Whitney U test for nonparametric variables. Chi-square and Fisher's exact test were used to determine the association of hospitalization with independent variables. The crude and adjusted relative risk (RR) was obtained. P value less than 0.05 was considered significant.
The study was approved by the ethical committee of participating federal institutions and chief medical officer of the private institution.
| Results|| |
A total of 102 asthma patients were recruited in the study. Fifty patients (49.0%) were in Group I and 52 (51.0%) were in Group II. Thirty-two of the patients (31.4%) were males, while 70 (68.6%) were females giving a male to female ratio of 1:2. There were no significant differences in the mean ages (± standard deviation (SD)) (38.5 ± 13.7 vs 43.0 ± 14.0, P = 0.10); median duration of asthma (25.0 vs 30.0 years, P = 0.59) and mean body mass index (24.6 ± 3.3) vs 23.4 ± 3.7 kg/m 2 P = 0.21) and other sociodemographic characteristic of patients in Group I and II [Table 1]. The patients in Group 1 reported more daytime symptoms (44/50; 88.0% vs 20/52; 38.5%), nocturnal symptoms (44/50; 88.0% vs 18/52; 34.6%), and nasal symptoms (27/50; 54.0% vs 14/52; 26.9%) and used more rescue medication, corticosteroids, and nonprescribed aminophylline than patients in Group 2 [Table 2]. A univariate analysis was performed to determine the relationship between frequency of asthma symptoms and drug use. To determine the effect of confounders we used stratification method and adjustment was made to the RR obtained. The RR showed that patients with frequent nocturnal symptoms (RR-3.50, 95% CI 2.05-4.96) were almost four times more likely to be hospitalized or visit the ED, while those with increased use of rescue medication (RR-2.89, 95% CI 1.66-4.12) were three times more likely be hospitalized in the preceding 12 months. Patients with increased frequency of asthma symptoms (RR-2.32, 95% CI 1.32-3.32), persistent nasal symptoms (RR-2.30, 95% CI 1.11-3.48), and who used of oral theophylline without prescription (RR-2.19, 95% CI 1.35-2.33) were twice more likely to visit ED and hospitalized. In this study, patients on ICS (RR-0.69, 95% CI 0.45-0.99) and OCS (RR-0.73, 95% CI 0.00-1.59) were unlikely to have asthma related hospitalization and ED visit in preceding 12 months [Table 3].
|Table 1: General characteristics according of respondents to hospitalization and ED visit|
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|Table 2: Frequency of symptoms and drug use according to hospitalization and ED visit|
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|Table 3: The association between symptoms frequency, drug use, and hospitalization and ED visit|
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| Discussion|| |
The result of this study showed that increased frequency of daytime and night time symptoms were strongly and independently associated with hospitalization and ED visit, nocturnal asthma symptoms being the strongest factors. A study among 299 people in Alberta, Canada; observed that those that had ED visit for asthma was associated with recent nocturnal symptoms.  Also, Meng et al., in a cross-sectional study of 4,359 adult asthma patients in a California Health Interview Survey found that adults who visited the ED for asthma reported frequent daily or weekly asthma symptoms.  The increase in asthma symptoms often signal the severity of disease, deterioration in the level of control, and is also a final pathway leading to acute exacerbation and warning sign on the need to step up the therapy to achieve optimal control. The presence of nocturnal symptoms is related to the degree of airway hyperresponsiveness. This mechanism may be ascribed to a nocturnal increase in the number of inflammatory cell and daytime increase in cellular activation and mediator of inflammatory reaction in both the bronchioalveolar lavage and peripheral blood of nocturnal symptoms. 
The use of rescue medication via pressurized metered dose inhaler (pMDI) or nebulizer is indicated in the treatment of all level of severity and acute exacerbation of asthma. GINA guideline recommended a review of treatment if rescue medication is used more than twice per week.  In this study, we discovered that patients who frequently used a rescue medication via pMDI over a period of 1 week were three times more likely to have been hospitalized or visited ED compared with those who were not hospitalized or visited ED. This study is in agreement with another study by Silver et al., where it was found that excessive pharmacy dispensation of short-acting beta (2)-adrenergic agonist (SABA) quarterly was associated with asthma exacerbations in the subsequent quarter.  Schatz et al., also reported a similar trend in their study which involved both children and adults. 
The result of this study also revealed that those patients that were hospitalized or visited ED were two and half times more likely to report persistent nasal symptoms when compared with the other group. This result is similar to observation by Bousquet et al.,  in a double blind multicentric clinical trial investigation of montelukast among 1,490 adults with chronic asthma. He found that the presence of concomitant allergic rhinitis (AR) in patients with asthma increases the likelihood of emergency room visit and asthma attack. The association between asthma and rhinitis may be due to similar pathophysiologic findings which support the theory that AR and asthma are linked by a common airway and moreover, the type of inflammation in AR and asthma involving type 2 helper T cells, mast cells, and eosinophils is very similar. , The presence of AR commonly exacerbates asthma, increasing the risk of attacks, emergency visits, and hospitalization. Asthma comorbidity places a significant burden on individuals and the healthcare system and should be considered in the management of asthma.
We also found that patients who used over-the-counter oral theophylline (nonprescription use of oral theophylline) were twice more likely to report asthma related hospitalization or ED visit, an observation made in a previous study.  These patients mostly resorted to the nonprescription use of oral theophylline as reliever because of lack of inadequate knowledge about asthma management, asthma medications, poor inhaler technique, and the high cost of ICS.
The use of ICS and OCS were negatively associated with asthma related hospitalization or ED visit. The negative association can be explained by the anti-inflammatory effect of corticosteroids. The use of ICS has been shown to be cost effective, reduce frequency of health care utilization and overall outcome. 
The limitation of the study was the small sample size and the mode of recruiting of participants which is subjected to selection bias. Despite these limitations, our study has demonstrated the role of increased asthma symptoms and drug use as a risk factor for asthma related hospitalization and ED visit from the perspective of a resource poor setting in sub-Saharan Africa. Our observations may serve as template for future large scale epidemiological and clinicolaboratory studies on asthma.
In conclusion, there is a need for pragmatic interventions in patients who report increased asthma and nasal symptoms, increased use of rescue medication, and nonprescription use of oral theophylline in order to prevent acute asthma hospitalization and emergency visit.
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[Table 1], [Table 2], [Table 3]