Bronchial Asthma: The Evidence Behind the Pathway

A 24-year-old software engineer comes to the clinic for “an inhaler refill”. She was told she had asthma at college. She uses a salbutamol inhaler when she is breathless, takes nothing else, and bought five canisters last year. She was admitted once, overnight, during the monsoon. Nobody has ever measured her lung function. This is an illustrative case, not a real patient.

The Bronchial Asthma Pathway tells you what to do for her: how to confirm the diagnosis, which step of treatment she belongs on, which inhaler to use as her reliever, and what to do in an attack. It no longer tells you all of the why. The trials, the history and the Indian figures that used to sit in its Protocols and Evidence tabs have moved here, so that the tool stays quick at the bedside. By the end of this article you will know why her salbutamol inhaler, on its own, is the wrong prescription.

1. Test before you write the word asthma

She carries the label, but was it ever tested? This matters more than it seems. In one adult cohort with a physician diagnosis of asthma within the previous 5 years, one third could not be confirmed as having asthma after 12 months of repeated testing with staged withdrawal of ICS. ICS means inhaled corticosteroid, the preventer. The tool keeps that figure in its Evidence tab and in its result; it names no paper for it, and neither can this article.

“So should I stop her inhaler and test her?” Not like that. The tool asks you to test before treating where you can, and where a patient is already on treatment, to step down slowly and test again. A single normal spirogram in a variable disease excludes nothing. For listening to her chest while you wait for the spirometry, see Respiratory Auscultation: A Bedside Guide to Breath Sounds on this site.

2. Why the blue inhaler alone was retired

Five canisters a year is the number that should worry you. The tool keeps the SABINA figure that explains it: three or more canisters a year raises the risk of an attack, and mortality rises stepwise with use (Nwaru 2020). A SABA, a short-acting beta-2 agonist such as salbutamol, opens the airway. It does nothing for the inflammation underneath.

“But she feels better within minutes. Isn’t that the point?” It is, and that is the problem. She treats the symptom and never the disease. What changed practice was a set of trials of a different reliever.

• The trials behind the anti-inflammatory reliever. The SYGMA trials randomised over 3,800 patients each; as-needed budesonide-formoterol reduced severe exacerbations by nearly two thirds against as-needed terbutaline, at a fraction of the steroid dose of maintenance budesonide (O’Byrne 2018). Novel START and PRACTICAL repeated the result in open-label, real-world designs (Beasley 2019; Hardy 2019).
• The insight is behavioural as much as pharmacological. Patients with mild asthma take relief when they feel symptoms and abandon maintenance inhalers when they feel well, so putting the corticosteroid inside the reliever delivers it exactly when inflammation flares. The patient’s own poor adherence becomes the dosing schedule.

That last sentence is worth reading twice. We usually fight non-adherence. Here the treatment is designed around it. Every time she reaches for her inhaler, she gets a dose of steroid with the bronchodilator.

The same holds for children. In a trial of children and adolescents aged 5 to 15, as-needed budesonide-formoterol roughly halved moderate to severe exacerbations compared with SABA. The tool gives that result without naming the trial.

“Won’t she overuse it, and take too much steroid?” The tool sets a ceiling for the day and asks her to seek help the same day if she needs more. In practice the fear is larger than the habit. In the trials of as-needed budesonide-formoterol, patients averaged only 3 to 4 inhalations a week.

3. Why a LABA never travels alone

Formoterol is a LABA, a long-acting beta-2 agonist. Why does the tool insist that a LABA is only ever given inside a combination inhaler with a steroid? Because of history. Salmeterol monotherapy raised asthma deaths, and the scar shaped a generation of guidance.

The answer to that history came from a very large pooled analysis. The FDA-mandated safety trials, analysed together across 36,010 patients, settled the modern position: combined ICS-LABA showed no significant excess of serious asthma-related events over ICS alone, and fewer exacerbations (Busse 2018). FDA is the Food and Drug Administration of the United States. So the danger was never the LABA with a steroid. It was the LABA without one. That is the whole reason the tool restricts the reliever-and-maintenance regimen to ICS-formoterol: the steroid cannot be left behind.

4. The size of the problem in India

Is she unusual? She is not.

• INSEARCH interviewed about 170,000 adults across 12 districts and put adult asthma prevalence at 2.05 per cent, an estimated 17.2 million adults, on a conservative questionnaire definition (Jindal 2012).
• The Global Burden of Disease analysis counted 37.9 million Indians with asthma in 2016 and found the health loss per case 2.4 times the global average: not because Indian asthma is biologically worse, but because it is under-diagnosed, under-treated and under-supplied with ICS (India State-Level Disease Burden Initiative 2018).

Read the second point slowly. The extra harm in India is not in the lungs. It is in the gap between the patient and the steroid inhaler. That is why the tool ends its India section on an affordable steroid inhaler, used correctly.

Back to the clinic

Our patient is booked for spirometry with a bronchodilator test, so that her diagnosis is confirmed rather than inherited. Her five canisters a year put her at higher risk of an attack, so her salbutamol inhaler alone is replaced by ICS-containing treatment. On the tool’s preferred track her reliever is low-dose budesonide-formoterol, with the daily ceiling written down for her. Her inhaler technique is watched, not asked about. She leaves with a written action plan. Each of those steps is a line in the tool. Now you know what stands behind each line.

Try this

A 40-year-old man with asthma takes a salmeterol inhaler every morning, bought over the counter, and a beclometasone inhaler that he “uses when he remembers”. He feels well. Is there a problem? Illustrative case.

Answer. Yes. On the days he forgets the steroid, he is on a LABA alone, which is exactly what raised asthma deaths. The fix is architectural, not a lecture: one combination ICS-LABA inhaler, so that the steroid cannot be left behind.

Take-home points

• Confirm asthma with lung function before the label sticks: in one cohort a third of the diagnoses could not be confirmed.
• No adult, adolescent or child of 6 or more is treated with a SABA alone. Ask how many canisters a year, not how many puffs.
• An ICS-formoterol reliever puts the steroid in the inhaler she actually uses.
• A LABA is prescribed only inside a combination inhaler with a steroid.
• In India the gap is access to an inhaled steroid, used correctly. Watch the technique at every visit.

Declaration: the author built and maintains the tool. It is free to use. The figures in this article are those the tool carried in its Protocols and Evidence tabs on 4 November 2026, each from the source named beside it; where the tool names no source, the article says so. The Bronchial Asthma Pathway is still in administrator preview, pending clinical review.

References

1. Global Initiative for Asthma. Global Strategy for Asthma Management and Prevention, 2026 update. Available from ginasthma.org. Source of the diagnostic thresholds, the two-track stepwise treatment, the initial-treatment selection, and the 2026 changes applied here: oxygen only below 92 per cent saturation, adrenaline first where anaphylaxis features coexist, ICS-SABA at Track 2 Step 1, and the PRAM recommendation for children.
2. Global Initiative for Asthma. GINA Summary Guide for Asthma Management and Prevention. 2026.
3. Global Initiative for Asthma. Difficult-to-Treat and Severe Asthma in Adolescent and Adult Patients: Diagnosis and Management. 2026.
4. Reddel HK, Bacharier LB, Bateman ED, et al. Global Initiative for Asthma strategy 2021: executive summary and rationale for key changes. Am J Respir Crit Care Med. 2022;205(1):17-35.
5. O’Byrne PM, FitzGerald JM, Bateman ED, et al. Inhaled combined budesonide-formoterol as needed in mild asthma. N Engl J Med. 2018;378(20):1865-1876.
6. Beasley R, Holliday M, Reddel HK, et al. Controlled trial of budesonide-formoterol as needed for mild asthma. N Engl J Med. 2019;380(21):2020-2030.
7. Hardy J, Baggott C, Fingleton J, et al. Budesonide-formoterol reliever therapy versus maintenance budesonide plus terbutaline reliever therapy in adults with mild to moderate asthma (PRACTICAL). Lancet. 2019;394(10202):919-928.
8. Busse WW, Bateman ED, Caplan AL, et al. Combined analysis of asthma safety trials of long-acting beta-2 agonists. N Engl J Med. 2018;378(26):2497-2505.
9. Nwaru BI, Ekström M, Hasvold P, Wiklund F, Telg G, Janson C. Overuse of short-acting beta-2 agonists in asthma is associated with increased risk of exacerbation and mortality: a nationwide cohort study of the global SABINA programme. Eur Respir J. 2020;55(4):1901872.
10. Agarwal R, Dhooria S, Aggarwal AN, et al. Guidelines for diagnosis and management of bronchial asthma: Joint ICS/NCCP (I) recommendations. Lung India. 2015;32(Suppl 1):S3-S42.
11. Jindal SK, Aggarwal AN, Gupta D, et al. Indian study on epidemiology of asthma, respiratory symptoms and chronic bronchitis in adults (INSEARCH). Int J Tuberc Lung Dis. 2012;16(9):1270-1277.
12. India State-Level Disease Burden Initiative CRD Collaborators. The burden of chronic respiratory diseases and their heterogeneity across the states of India: the Global Burden of Disease Study 1990-2016. Lancet Glob Health. 2018;6(12):e1363-e1374.