Evidence

The case for testing lungs,
in plain words.

Why lung function testing matters, what each test adds, and what the published evidence says. Every claim links to its source, with limitations next to findings.

55MIndians with COPD (GBD 2016)
40–50%of COPD diagnoses made without spirometry
1 in 4smokers with normal spirometry show small-airway disease
36%fewer asthma admissions with self-management

01 · The problem

India carries a third of the world's chronic lung disease.

Asthma and COPD are common, under-diagnosed and often mislabelled. Most patients first meet a doctor in primary care, where lung function is rarely tested.

32%of global chronic respiratory disease burden is in India, home to 18% of the world's people

  • 55 million Indians had COPD and 38 million had asthma in 2016. Chronic respiratory disease caused 1 in 10 deaths.

    Source

    India State-Level Disease Burden Initiative CRD Collaborators. The burden of chronic respiratory diseases and their heterogeneity across the states of India: GBD 1990–2016. Lancet Glob Health 2018;6(12):e1363–e1374.

    Open source ↗

  • More than half of 204,912 patients seen in Indian primary care in one day had respiratory symptoms.

    Source

    Salvi S, Apte K, Madas S, et al. Symptoms and medical conditions in 204 912 patients visiting primary health-care practitioners in India (POSEIDON). Lancet Glob Health 2015;3(12):e776–e784.

    Open source ↗

  • In one Indian centre, 29 of 40 patients labelled as COPD were misdiagnosed. The authors call spirometry use dismally low.

    Source

    Barthwal MS, Tyagi R, Shrinath V, et al. Asthma-COPD misdiagnosis: cause for concern or false alarm? Monaldi Arch Chest Dis 2025;96(3).

    Note. Small single-centre study (85 patients).

    Open source ↗

02 · Spirometry

The diagnostic standard, when it can be done well.

Spirometry is required to confirm COPD and is the guideline test for asthma. It depends on a maximal, coached effort, and in routine practice many tests miss quality criteria.

39%of routine general-practice spirometry tests met both quality criteria in a Dutch study

  • The international standard for performing and reporting spirometry.

    Source

    Graham BL, Steenbruggen I, Miller MR, et al. Standardization of Spirometry 2019 Update: an official ATS/ERS technical statement. Am J Respir Crit Care Med 2019;200(8):e70–e88.

    Open source ↗

  • GOLD requires post-bronchodilator spirometry to confirm COPD. Studies cited by GOLD found 40 to 50% of patients diagnosed with COPD never had spirometry.

    Source

    Singh D, Stockley R, Anzueto A, et al. GOLD Science Committee recommendations for the use of pre- and post-bronchodilator spirometry for the diagnosis of COPD. Eur Respir J 2025;65:2401603.

    Open source ↗

  • About 1 in 5 older patients could not perform guideline-quality spirometry, linked to cognitive and functional impairment.

    Source

    Pezzoli L, Giardini G, Consonni S, et al. Quality of spirometric performance in older people. Age Ageing 2003;32(1):43–46.

    Note. The authors note most older people can perform spirometry.

    Open source ↗

  • 38.8% of routine GP spirometry tests met acceptability and reproducibility criteria.

    Source

    Schermer TR, Crockett AJ, Poels PJ, et al. Quality of routine spirometry tests in Dutch general practices. Br J Gen Pract 2009;59(569):e376–e382.

    Note. Dutch practices, older ATS 1994 criteria.

    Open source ↗

03 · Oscillometry

Normal breathing. Earlier signals.

Oscillometry measures airway resistance and reactance while the patient breathes quietly. It has an ERS technical standard and Indian reference values, and it can show small-airway disease while spirometry is still normal.

1 in 4tobacco-exposed adults with normal spirometry had small-airway dysfunction on oscillometry

  • The ERS technical standard for oscillometry: equipment, quality control, bronchodilator response and reference values.

    Source

    King GG, Bates J, Berger KI, et al. Technical standards for respiratory oscillometry. Eur Respir J 2020;55(2):1900753.

    Open source ↗

  • In 1,628 tobacco-exposed adults, 26% of those with normal spirometry had small-airway dysfunction on oscillometry.

    Source

    Abdo M, Watz H, Trinkmann F, et al. Oscillometry-defined small airway dysfunction in tobacco-exposed adults with impaired or preserved airflow. Am J Respir Crit Care Med 2025.

    Note. Lung-cancer screening cohort, Germany.

    Open source ↗

  • Indian reference equations for oscillometry in children aged 5 to 17.

    Source

    De S, Banerjee N, Tiwari RR. Regression equations of respiratory impedance measured by forced oscillation technique for Indian children. Indian J Pediatr 2020;87:192–199.

    Open source ↗

04 · Better together

Two tests. Two different questions.

Expert reviews describe oscillometry as complementary to spirometry. In patients with symptoms but normal spirometry, oscillometry found small-airway problems about three times as often.

3×more small-airway dysfunction detected by oscillometry than spirometry in symptomatic patients with preserved lung function

  • Oscillometry is complementary to spirometry and suits patients who cannot perform a forced manoeuvre.

    Source

    Kaminsky DA, Simpson SJ, Berger KI, et al. Clinical significance and applications of oscillometry. Eur Respir Rev 2022;31:210208.

    Note. Review; the authors call for more evidence before routine diagnostic use.

    Open source ↗

  • In 209 symptomatic patients with preserved lung function, oscillometry flagged 60.8% and spirometry 20.1%.

    Source

    Li LY, Yan TS, Yang J, et al. Impulse oscillometry for detection of small airway dysfunction in subjects with chronic respiratory symptoms and preserved pulmonary function. Respir Res 2021;22:68.

    Note. Single centre; R5 alone is not very specific.

    Open source ↗

05 · Six-minute walk test

How the patient copes, in metres.

The walk test is standardised and repeatable. Shorter walk distance predicts death in COPD, and the BODE index, which includes it, predicts outcomes better than FEV1 alone.

0.74predictive accuracy (C statistic) of BODE for COPD mortality, versus 0.65 for FEV1 alone

  • The ERS/ATS technical standard for field walking tests. A change of 30 m is clinically important.

    Source

    Holland AE, Spruit MA, Troosters T, et al. An official ERS/ATS technical standard: field walking tests in chronic respiratory disease. Eur Respir J 2014;44(6):1428–1446.

    Note. Prognostic link is weaker in interstitial lung disease.

    Open source ↗

  • Each 1-point rise in BODE increased the risk of death by 34%.

    Source

    Celli BR, Cote CG, Marin JM, et al. The body-mass index, airflow obstruction, dyspnea, and exercise capacity index in COPD. N Engl J Med 2004;350(10):1005–1012.

    Open source ↗

06 · Monitoring at home

Self-management keeps people out of hospital.

Asthma self-management with a written action plan, which in adults can be based on peak flow, reduces hospital admissions. For COPD, remote monitoring evidence is mixed, so it works best as part of a care programme.

36%fewer asthma hospitalisations with self-management education and regular review

  • Across 36 trials, self-management education cut hospitalisations (RR 0.64) and emergency visits (RR 0.82). Written action plans appeared more effective.

    Source

    Gibson PG, Powell H, Coughlan J, et al. Self-management education and regular practitioner review for adults with asthma. Cochrane Database Syst Rev 2003;(1):CD001117.

    Note. Benefit is from self-management as a whole, not peak flow alone.

    Open source ↗

  • UK guidance: offer a personalised action plan; in adults it may be based on symptoms, peak flow or both.

    Source

    BTS, NICE, SIGN. Asthma: diagnosis, monitoring and chronic asthma management (NG245). 2024.

    Open source ↗

  • For COPD, remote monitoring alone was no better than usual care overall, though readmissions may fall.

    Source

    Janjua S, Carter D, Threapleton CJD, et al. Telehealth interventions: remote monitoring and consultations for people with COPD. Cochrane Database Syst Rev 2021;(7):CD013196.

    Note. We state this honestly: monitoring needs a care team that acts on it.

    Open source ↗

07 · Our evidence

Studies and clearances for alveofit devices.

Peer-reviewedalveoair · 2021

alveoair agrees closely with an established smart spirometer.

Sixty healthy people did the same breathing test on alveoair and on NuvoAir, a smart spirometer already cleared in the US and Europe. The two gave almost the same results for every main measurement.

Design
Prospective, cross-sectional, tertiary care centre
Participants
60 healthy adults and students, aged 15 to 45
Comparator
NuvoAir smart spirometer
Measures
FEV1, FVC, PEF, FEV1/FVC
  • Pearson r: FEV1 0.988, FVC 0.986, PEF 0.951, FEV1/FVC 0.91 (all p < 0.0001)
  • ICC: FEV1 0.966, FVC 0.952, PEF 0.947, FEV1/FVC 0.91
  • Bland-Altman: 95% to 98% of differences within the limits of agreement
  • No statistically significant difference in means between devices
Pearson rICC
0.850.900.951.00FEV1FVCPEFFEV1/FVCrICC
Agreement with NuvoAir, by measure. 1.00 is perfect agreement.
Citation and limitations

Shinde PS, Kulkarni RR, Kulkarni GV. Validation of portable Bluetooth enabled smart spirometer (Alveoair) for the measurement of various lung functions in healthy subjects. Natl J Physiol Pharm Pharmacol. 2021;11.

Limitations. Healthy participants only, at a single centre. The comparator is a portable device, not a laboratory spirometer. Patients with lung disease need further study.

Read the paper (DOI) ↗
Conference abstract · ATS 2025alveoair · 2025

A handheld test found lung abnormalities in nearly half of walk-in patients.

Doctors from AIIMS New Delhi and TMU Moradabad tested 250 people who walked into a medicine OPD with alveoair. Nearly half had an abnormal result, including many who had no breathing complaints. Each test took about five minutes.

Design
Cross-sectional, medicine OPD
Participants
250 walk-in patients, aged 12 to 90
Institutions
AIIMS New Delhi; TMU Moradabad
Device
alveoair handheld spirometer
  • Abnormal spirometry in 46.4% (95% CI 40.2 to 52.6%)
  • 41.1% of asymptomatic and 69.5% of symptomatic patients
  • Patterns: 53.6% normal, 20.8% obstructive, 16.8% restrictive, 8.8% mixed
  • Pollution exposure associated with disease (p < 0.001); about 5.3 minutes per test
Spirometry patterns in 250 walk-in patients.
Citation and limitations

Sinha A, Titiyal R, Singh VK, Sinha S. To Determine the Prevalence of Respiratory Diseases in Walk-in Patients Using Handheld Spirometer in North India. Am J Respir Crit Care Med. 2025;211(Suppl 1):A2567. ATS 2025 International Conference.

Limitations. Conference abstract, not yet a full peer-reviewed paper. Single-site OPD sample. Industry support from alveofit as stated in the abstract.

Read the abstract (DOI) ↗
US FDA 510(k)alveoair · 2023

alveoair is cleared by the US FDA.

The US Food and Drug Administration cleared alveoair as a diagnostic spirometer for use by healthcare professionals in adults.

Clearance
510(k) K222525, 28 August 2023
Class
II, diagnostic spirometer
Indication
Basic lung function and spirometry, patients aged 22 and over, prescription use
Standards
ISO 26782, ISO 23747, ATS/ERS 2019
  • Predicate: Air Next (K183089); reference device Spirobank G (K072979)
  • Volume accuracy ±2.5% of reading or ±0.050 L; flow 0 to 14 L/s
  • Calculations per ATS/ERS 2019 spirometry standardisation
  • IEC 60601 electrical safety and EMC, IEC 62304 software, ISO 10993 biocompatibility
Citation and limitations

US FDA 510(k) K222525, alveoair Digital Spirometer (Model ALV002), Roundworks Technologies Pvt Ltd. Decision date 28 August 2023. Class II, product code BZG, 21 CFR 868.1840.

Limitations. Clearance is for the alveoair spirometer in the United States, for patients aged 22 and over. It does not extend to other alveofit devices.

Read the FDA summary ↗
In progressalveoflow · 2026

alveoflow compared with a reference oscillometer.

Patients are tested on alveoflow and on a reference oscillometer in the same visit, to show how closely the two agree.

Design
Paired comparison, same session
Device
alveoflow oscillometry
Measures
Resistance and reactance across frequencies
Status
Recruitment and analysis ongoing
  • Agreement analysis for R5, R19 or R20, X5, AX and Fres
  • Results to be published on completion
Citation and limitations

Paired comparison of alveoflow oscillometry against an established reference oscillometer. Study ongoing.

Limitations. No results are reported until the analysis is complete and reviewed.

Evidence map

Where the evidence stands, device by device.

DevicePeer-reviewedConferenceRegulatoryIn progress
alveoairYesYesYesNot yet
alveoflow Pro and NeoNot yetNot yetNot yetYes
alveoAir UltraNot yetNot yetNot yetNot yet
alveoASHANot yetNot yetNot yetNot yet

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08 · Partners and press

What others have said.

“Regular monitoring of lung functions and continuous engagement with care providers improve the overall treatment efficacy.”

Dr Anil Kukreja, VP Medical Affairs and Regulatory, AstraZeneca India, on the alveofit partnership (BioVoice News, 2022)
AstraZeneca India partners alveofit to scale up diagnosis and treatment of lung diseasesBioVoice News · August 2022Pune-based startup alveofit receives US FDA clearance for alveoair spirometerBioSpectrum India · 2023alveofit receives FDA approval for portable digital spirometerMedical Device Network · September 2023FDA clears alveoair digital spirometerRespiratory Therapy · 2023Alveofit's alveoair spirometer receives US FDA clearanceDigital Health News · 2023alveofit technology profile, BIRAC supportedIndia Science & Technology portal

Customer reviews

Read reviews from doctors and buyers where they were posted.

Amazon.in ↗
  1. Acquisition time of 15–30 seconds of tidal breathing per recording, from the alveoflow FOT System specification. Applies to alveoflow Pro and alveoflow Neo.
  2. FHIR R4 and HL7 v2 export from the alveoflow FOT System specification. ABDM integration supported.
  3. CDSCO Class B under MDR 2017. ISO 13485 and MDSAP as stated on alveo.fit. alveoflow: US 510(k) submission pending; not cleared for sale in the United States. alveoair is US FDA 510(k) cleared (K222525, August 2023).
  4. Screens show example data and do not represent a real patient. Interpretation is the responsibility of the treating clinician.