By Ray Wright, Advanced Medical Engineering · 2026-08-17
ATS/ERS 2019 in the South African occupational-health clinic: what your software must actually do
The 2019 ATS/ERS technical statement is now the reference the South African Thoracic Society points to for adult and paediatric spirometry. Most spirometry software in SA clinics still runs the 2005 rules. Here is the difference, as a checklist you can hold any vendor to - including us.
Why this matters more in occupational health than anywhere else
A pulmonologist looks at a single patient's loop and uses judgement. An occupational-health clinic produces hundreds of tests a year that will be compared with the same worker's baseline five, ten and twenty years later, often by a different nurse on a different device at a different site - and the result may end up in a COIDA / RMA claim, a Certificate of Fitness dispute or a Department of Employment and Labour inspection. Repeatability across years is the whole point, and repeatability is exactly what the 2019 update tightened. Software that "supports ATS/ERS" but silently applies 2005 acceptability rules gives you a report that looks compliant and isn't defensible.
The checklist
| # | Requirement (ATS/ERS 2019) | What to look for on the screen and the report |
|---|---|---|
| 1 | Acceptability judged separately for FEV1 and FVC, with a "usable" category | Each effort marked A / U / unacceptable for FEV1 and for FVC - not one tick per blow. |
| 2 | Back-extrapolated volume (BEV) ≤ 5% of FVC or 0.100 L, whichever is greater | BEV in litres and % printed per effort; time-zero from true back-extrapolation, not from a flow threshold. |
| 3 | No cough in the first second, no glottic closure, no leak, no obstructed mouthpiece, no extra breath | Named flags on the effort, with the coaching prompt the technician saw. |
| 4 | End of forced expiration: plateau (≤ 0.025 L in the last 1 s), or FET ≥ 15 s, or patient cannot continue | FET printed per effort; a 6-second blow without plateau is not automatically "acceptable" for FVC. |
| 5 | Repeatability: two largest FVC within 0.150 L and two largest FEV1 within 0.150 L (0.100 L if FVC ≤ 1.0 L) | Repeatability shown as a number, not just a green light. |
| 6 | Session grade A–F (and U) for FEV1 and FVC separately | "Grade A" on the report header. Grade E or F should be obvious to whoever signs it. |
| 7 | Reference values as z-scores and LLN, GLI equations, race-neutral option | z-score bars; LLN on the report; GLI-2012 and GLI Global 2022 selectable; equation source cited on the printout. |
| 8 | Daily calibration verification with a 3-litre syringe, BTPS-corrected | A calibration log with a pass/fail verdict and date, and a printable calibration certificate - an inspector will ask. |
| 9 | Bronchodilator responsiveness reported as change in % of predicted / z-score, not only "≥ 12% and 200 mL" | Pre/post view with the 2021 ERS/ATS interpretation update available. |
| 10 | Live curves: flow-volume and volume-time visible during the manoeuvre | Both curves on screen while the worker blows; the volume-time curve is where the plateau lives. |
What "graded" actually looks like
An A-grade session has at least three acceptable efforts with the top two within 0.150 L; B has two acceptable within 0.150 L; C two within 0.200 L; D two within 0.250 L; E one acceptable effort (or two more than 0.250 L apart); U no acceptable but at least one usable effort; F nothing usable. The grade tells the reader how much to trust the number. A grade-A FEV1 that has fallen 300 mL since baseline is a signal. A grade-E FEV1 that has fallen 300 mL is a request to repeat the test.
The South African layer
- SATS. The South African Thoracic Society's 2022 spirometry position statement aligns local practice with the 2019 ATS/ERS update and GLI reference equations. If your report cannot state which equations were used, it cannot be shown to follow the statement.
- OHSA 85/1993 and MHSA 29/1996. Medical surveillance under the Hazardous Chemical Agents regulations and mine codes of practice is only as good as the record. Keep the raw efforts, not just the best values, and keep them for the life of the worker's file.
- Reference populations. Race-based equations are scientifically and politically untenable. Use race-neutral GLI Global 2022 by default, and know what your software does when ethnicity is not recorded (it should fail closed, not silently pick "Caucasian").
- Load-shedding and connectivity. A test that needs the cloud is a test that fails at 14:00 on stage 4. Offline-first is a compliance feature, not a convenience.
How SpiroWright answers each line
Every item in the table above is on the SpiroWright report by design: per-effort A/U flags for FEV1 and FVC, BEV and FET printed, EOFE by plateau/15 s/cannot-continue, repeatability in litres, A–F session grade, GLI-2012 and race-neutral GLI Global 2022 with the source cited, z-score bars and LLN, a 3-litre syringe and motor calibration log with an ATS/ERS 2019 verdict and a printable certificate, pre/post bronchodilator view, live flow-volume and volume-time at 335 Hz, and offline-first records. Read the detail on our ATS/ERS 2019 page, or download SpiroWright and run it against this checklist yourself - the first 1000 tokens are free.
Reference: Graham BL, Steenbruggen I, Miller MR, et al. Standardization of Spirometry 2019 Update. Am J Respir Crit Care Med 2019;200(8):e70–e88. Stanojevic S, et al. ERS/ATS technical standard on interpretive strategies for routine lung function tests. Eur Respir J 2022;60:2101499.
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