Dear Sirs,

Following the publication in this journal of the Standards document ‘Diagnostic Spirometry in Primary care: Proposed standards for general practice compliant with American Thoracic Society and European Respiratory Society recommendations’ by Levy et al. in September 2009,1 Fletcher & Loveridge2 from Education for Health felt compelled to challenge the ‘soft’ limit of 150ml for within-session repeatability included in the document and stated that this should be reduced to 100ml. There was further discussion3 around this point, and the assumption was made that further research would provide clarification.

Two years on, guidelines and international primary care resources continue to offer conflicting advice as to whether 100ml or 150ml should be the standard for within-session repeatability, and there still appears to be a lack of research in this area.

At the time of Fletcher and Loveridge's original letter,2 Education for Health undertook an audit of the within-test repeatability of spirometries within the portfolios of 10 recently successful students. These all demonstrated within-test repeatability of between 30–70ml in real patients with respiratory disease.

All Education for Heath spirometry students are assessed (and indeed pass or fail) on the Association for Respiratory Technology and Physiology (ARTP) 100ml standard,4 with the majority achieving lower than 100ml within-session repeatability in three to four relaxed and forced blows. Respiratory Education UK and the ARTP also assess their own students to this standard, and — as outlined in Brendan Cooper's later PCRJ response5 — all physiologists are expected to achieve this.

Interestingly, the recently published GOLD guidelines (GOLD 2011)6 have reverted from 150ml to a lower limit of 100ml or 5%, whichever is greater.

In contrast, however, the PCRS-UK has adhered to 150ml as the standard for within-session repeatability in all its materials and advice, including its spirometry audit, in line with the 2009 PCRJ publication.1 As members of the PCRS-UK Education Committee, we are increasingly concerned that conflicting standards are confusing for primary care health professionals. We look forward to further debate on this issue, and also respectfully request the authors of the original paper to provide further clarification on this issue.