|Year : 2018 | Volume
| Issue : 1 | Page : 12-16
A clinical evaluation of asthma control test to assess the control of asthma and its relation to the severity of asthma
Bhagyashri Patil, Ajith Eti, Mitchelle Lolly, Sujeer Khan, Avya Bansal
Department of Pulmonary Medicine, KLE University's, Jawaharlal Nehru Medical College, Belgaum, Karnataka, India
|Date of Web Publication||1-Mar-2018|
Dr. Bhagyashri Patil
JNMC Quarter No. A 1/1, Nehru Nagar, Belgaum - 590 010, Karnataka
Source of Support: None, Conflict of Interest: None
INTRODUCTION: Bronchial asthma is one of the most common chronic diseases in the world affecting around 5% of the world's population. More simple and inexpensive tools are required to assess asthma control, especially in resource-poor countries where pulmonary function tests are not feasible. The effectiveness of asthma control test (ACT) in assessing asthma control and its correlation with asthma severity is unknown.
AIM: The aim of this study is to evaluate the effectiveness of ACT in assessing asthma control and its relation to the severity of asthma by comparing with a global initiative for asthma (GINA) classification.
MATERIALS AND METHODS: In a tertiary care hospital, 106 bronchial asthma patients were enrolled. All patients underwent clinical evaluation, spirometry to assess the severity according to the GINA classification and were given ACT questionnaire to assess asthma control. Patients were further followed by two visits 3 months apart. Correlation between the ACT and GINA classification was assessed at each visit.
RESULTS: ACT was able to give sensitivity of 82.3%, specificity of 69.4%, positive predictive value (PPV) was 56%, and negative predictive value (NPV) was 89.2% at the first visit (P < 0.05). At the second visit, the sensitivity of the ACT increased to 85.71%, and specificity to 96.77%, PPV was 94.73%, and NPV was 90.90% (P < 0.05). At the third visit, the sensitivity of ACT was 92%, specificity of ACT was 85.18%, PPV was 85.71%, and NPV was 92%, (P < 0.05).
CONCLUSIONS: ACT with high sensitivity, specificity, and PPV, could be a potential alternative diagnostic tool in assessing asthma severity even without aid of a spirometer or a peak flow meter.
Keywords: Asthma control test, asthma control, asthma severity, global initiative for asthma
|How to cite this article:|
Patil B, Eti A, Lolly M, Khan S, Bansal A. A clinical evaluation of asthma control test to assess the control of asthma and its relation to the severity of asthma. Int J Health Allied Sci 2018;7:12-6
|How to cite this URL:|
Patil B, Eti A, Lolly M, Khan S, Bansal A. A clinical evaluation of asthma control test to assess the control of asthma and its relation to the severity of asthma. Int J Health Allied Sci [serial online] 2018 [cited 2018 Mar 17];7:12-6. Available from: http://www.ijhas.in/text.asp?2018/7/1/12/226262
| Introduction|| |
Bronchial asthma is characterized by intermittent variable airflow obstruction, airflow inflammation, and bronchial hyperresponsiveness. It is one of the most common chronic diseases in the world. It is estimated that around 300 million people in the world currently have asthma constituting around 5% of the world's population. In spite of advanced methods in the detection and treatment of the condition, it remains the cause of significant morbidity and economic burden.
Pulmonary function tests (PFTs) are crucial to assess not only the control and severity of asthma but also response to treatment. However, in busy clinical practice with limited time and resources where PFT is not feasible, there is a need for a simple method for assessing asthma control with or without PFT.
Many proprietary questionnaire instruments such as the asthma control questionnaire (ACQ), the asthma therapy assessment questionnaire (ATAQ), and the asthma control test (ACT) have been studied, validated, and used worldwide for assessment of the asthma control. Very less research work have been done in terms of literature to evaluate the ACT test for the control of asthma and its comparison with the severity of asthma.
With its high sensitivity, specificity, and positive predictive value (PPV), ACT can serve as an alternative diagnostic tool in assessing asthma severity even without the aid of a spirometer or a peak flow meter on an outpatient basis or as home based. Hence, the present study is being conducted to evaluate the effectiveness of ACT in assessing the control of asthma and its relation to the severity of asthma by comparing with a global initiative for asthma (GINA) classification for the severity of asthma by forced expiratory volume at the end of 1 s (FEV1) and peak expiratory flow rate (PEFR) at an outpatient level.
| Materials and Methods|| |
Source of data
All the diagnosed cases of bronchial asthma who visited outpatient Department of Pulmonary Medicine, KLE'S Dr. Prabhakar Kore Hospital, Belagavi, Karnataka India over a period of 1 year.
The study design was a longitudinal observational study. The study was carried out from January 2013 to December 2014. A total of 106 patients were included in the study.
- Diagnosed patients with bronchial asthma more than 12 years of age
- Bronchial asthma associated with allergic rhinitis, atopy, diabetes, and hypertension was also included.
- Patients with chronic obstructive pulmonary disease
- Hospitalized patients with bronchial asthma
- Children <12 years.
All diagnosed patients with bronchial asthma were included in the study. The patients were subjected to detailed history assessment and clinical examination. As per the GINA guidelines the patients were classified as intermittent and mild persistent asthma if the FEV1 score >80%, moderate persistent asthma if the FEV1 score 60%–80%, severe persistent asthma if FEV1 <60%. Further, asthma control of these subjects was assessed through ACT questionnaire.
The ACT questionnaire includes following five questions:
- In the past 4 weeks, how much of the time did your asthma keep you out from getting routine work done at, school or at home?
- All of the time
- Most of the time
- Some of the time
- A little of the time
- None of the time.
- During the past 4 weeks, how often have you had shortness of breath?
- More than once a day
- Once a day
- 3.3 to 6 times a week
- Once or twice a week
- Not at all.
- During the past 4 weeks, how often did your asthma symptoms (wheezing, coughing, and shortness of breath, chest tightness, or pain) wake you up at night or earlier than usual in the morning?
- 4 or more nights a week
- 2 or 3 nights a week
- Once a week
- Once or twice
- Not at all.
- During the past 4 weeks, how often have you used your rescue inhaler or nebulizer medication?
- 3 or more times per day
- 1 or 2 times per day
- 2 or 3 times per week
- Once a week or less
- Not at all.
- How would you rate your asthma control during the past 4 weeks?
- Not controlled at all
- Poorly controlled
- Somewhat controlled
- Well controlled
- Completely controlled.
According to the obtained ACT score, the patients were classified as uncontrolled asthma (ACT score ≤19) and controlled asthma (ACT score >19). An association between ACT and the GINA classification of asthma symptom severity was assessed. The individuals were followed after an interval of 3 months and 6 months. At each follow-up, ACT score was calculated and severity was assessed as per the GINA guidelines on the basis of spirometry and clinical history. The results were compared at each visit. At each visit, the specificity and sensitivity of ACT was calculated. PPV and negative predictive value (NPV) of ACT was calculated. McNemar's Chi-square test was calculated to evaluate the correlation between the ACT and FEV1 and PEFR.
Before the commencement of the study, the ethical clearance was obtained from the Ethical and Research Committee, Jawaharlal Nehru Medical College, Belgaum. All the patients fulfilling the selection criteria were explained about the nature of the study, and a written informed consent was obtained before enrolment.
| Results|| |
The patients were studied over 1 year. All the patients were confirmed cases of bronchial asthma and on regular treatment [Table 1]. A total of 106 patients were studied. Out of 106 patients, 62 (58.5%) were female patients and 44 (41.50%) were male patients. Most of the patients were in the age group of >40 years, 28 (45.1%). The number of patients in the age group <25 years were 34 (32.07%), between the age group of 25 and 40 years were 28 (26.41%), and in the age group of >40 years were 44 (41.50%). Fifty-four (50.9%) patients had allergic rhinitis and 52 (49.05%) patients were without allergic rhinitis. Only 8 patients (7.54%) were smokers.
|Table 1: Asthma control test scores and forced expiratory volume in 1 s/peak expiratory flow rate percentage at the first visit|
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At the first visit, 12 (11.3%) patients had ACT score between 5 and 14, 38 (35.8%) patients had scores between 15 and 19 and 56 (52.85%) patients had score between 20 and 25. After spirometry, 74 (69.81%) patients were in the mild persistent group, 16 (15.09%) patients each were in moderate and severe persistent group, respectively. Fifty patients were in the uncontrolled group, and 56 patients were in controlled group according to ACT questionnaire. In the uncontrolled group of patients, 20 (40%) patients had mild persistent asthma, 12 (24%) patients had moderate asthma, 18 (36%) patients had severe persistent asthma according to the GINA guidelines based on the spirometry results. In the controlled group, 50 (89.28%) patients were in mild persistent and 6 (10.7%) patients were in moderate persistent asthma group. There were no patients in the severe persistent group. At the first visit, the sensitivity of the ACT was 82.3%, specificity was 69.4%, PPV was 56%, and NPV was 89.2%.
At the second visit, only 8 (7.5%) patients were in the ACT score of 5–14. 42 (39.6%) patients were in the ACT score group of 15–19. Remaining of the 56 (52.83%) patients were in the ACT score group of 20–25. Fifty-eight patients (54.7%) had mild persistent asthma, 38 patients (35.84%) patients had moderate persistent asthma, and only 10 (9.4%) patients were in the severe persistent group. Fifty patients were in uncontrolled category and 56 patients were in the controlled category. However in the uncontrolled group, mild persistent asthma consisted of only 8 (16%) patients. In the moderate persistent asthma group, there were 28 (56%) patients and in severe persistent asthma group, there were 14 (28%) patients. In the controlled group, 50 patients (89.28%) had mild persistent asthma, 4 (7.14%) patients had moderate persistent asthma, whereas only one patient had the severe persistent asthma. The sensitivity of the ACT was 92%, specificity of the test was 85.18%, PPV was 85.71%, and NPV was as 92% [Table 2].
|Table 2: Asthma control test scores and forced expiratory volume in 1 s/peak expiratory flow rate percentage at the second visit|
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At the third visit, 8 (7.54%) patients were in the ACT score group of 5–14, 24 (22.6%) patients were in the ACT score group of 15–19, and 74 (69.81%) patients were in the ACT score group of 20–25. Out of 106 patients, most of the patients, i.e., 68 (64.15%), had mild persistent asthma [Table 3]. In the remaining patients, 18 (16.9%) and 20 (18.8%) patients had moderate and severe persistent asthma, respectively. Thirty-two patients were uncontrolled, 74 patients were controlled according to the ACT score. Out of 32 uncontrolled patients, 16 patients (50%) had severe persistent asthma, 14 patients (43.75%) were in the moderate persistent category, only two patients were in the mild persistent category. Out of 74 controlled patients, 66 patients (89.18%) had mild persistent, 4 patients (5.40%) each was in moderate and severe persistent category, respectively. The sensitivity of the ACT test was 85.71%, specificity was 96.77%, PPV was 94.73%, and NPV was 90.90%.
|Table 3: Asthma control test score and forced expiratory volume in 1 s percentage at the end of the 6 months|
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The value of P was calculated as <0.05 each time. This showed that both the test had agreement between each other. From the study, it was concluded that ACT score more than 19 can classify patient as in mild to intermittent or controlled asthmatics with an of FEV1 and PEFR of >80% predicted while an ACT score of less than 19 can classify the patient as in moderate-to-severe persistent or uncontrolled asthmatics with an FEV1 and PEFR of <80% predicted [Table 4].
| Discussion|| |
In our study, there was an association noted between the ACT and the GINA classification of asthma symptom severity, FEV1 (L and %) as well as PEFR (%predicted). At the first visit, ACT was able to give a sensitivity of 82.3%, specificity of 69.4%. The PPV was 56% and NPV was 89.2%. The value of P < 0.05 showed that there was an agreement between the ACT and GINA classification according to FEV1 and PEFR.
At the second visit, it showed improvement in the readings as the sensitivity of the ACT increased to 85.71%, and specificity to 96.77%. The PPV was 94.73% and NPV was 90.90%. This also showed improvement compared to the first visit. The P < 0.05 showed good agreement between the two comparative parameters.
At the third visit, the sensitivity of ACT was 92%, specificity of ACT was 85.18%. The PPV was 85.71% and NPV was 92%, (P < 0.05).
These values correlated well with the other study by Mendoza et al. the ACT score was able to give a 92.3% sensitivity and 90.5% specificity with the area under the curve of 0.972 (97.2%). Similarly, the PPV was 98% and the NPV was 79%. In another study done by Fanny et al., ACT score of ≤20 best correlated with uncontrolled asthma (area under the curve = 0.76) but with a sensitivity of 70.5%, specificity 76%, PPV 76.2% and NPV 70.2% which were less compared to the present study.
From this study, an ACT score of >19 can classify a patient as intermittent or controlled asthmatics with an of FEV1 and PEFR of >80% predicted, while an ACT score of <19 can classify the patient as in persistent or uncontrolled asthmatics with an FEV1 and PEFR of <80% predicted. The same results were obtained from the study done by Mendoza et al.
In another study done by Thomas et al, the area under the receiver operating characteristics curve for ACT score predicting GINA control was 0.84 (95% confidence interval 0.82–0.85). An ACT score of <19 (not well-controlled asthma) correctly predicted GINA-defined partly controlled/uncontrolled asthma 94% of the time, while an ACT score of >20 predicted GINA-defined controlled asthma 51% of the time, with kappa statistic of 0.42, representing moderate agreement. In another study by Zhou et al., the mean ACT score of the controlled group (22.20 ± 2.29) was significantly higher than those of the partly controlled group (18.70 ± 3.9); P < 0.0001 and the uncontrolled group (13.97 ± 3.94); P < 0.0001.
In the present study, ACT is compared with the asthma severity classification according to the GINA guidelines, but it is not compared with the other control measures such as ACQ, ATAQ, ACSS or the inflammatory markers such as exhaled FeNO. In a study done by Alvarez-Gutiérrez et al, ACT was evaluated with lung function and fractionated exhaled nitric oxide level (FeNO). They found a correlation between baseline FEV1 and ACT (r = 0.19, P < 0.01) and between ACT and FeNO (r = −0.16, P < 0.01).
Despite its limitation, this study has demonstrated that ACT with a high PPV as well as high sensitivity and specificity making it a good screening tool in asthmatics. Between the ACT and GINA classification of the asthma according to symptom severity as well as according to FEV1 (L and %) and PEFR (%) values, ACT can be used as a surrogate test in assessing asthma severity, especially in places where spirometry and peak flow meter are not feasible.
| Conclusion|| |
ACT with its high sensitivity, specificity, and PPV, it can be used as an alternative diagnostic tool in assessing asthma severity even without an aid of a spirometer or a peak flow meter on an outpatient basis or as home based. It can also serve as a guide in the management of bronchial asthma patients. Therefore, ACT is a simple, inexpensive tool that can be useful, especially in resource-poor countries like India.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3], [Table 4]