Diagnostic Value of Oral Prednisolone Test for Chronic Obstructive Pulmonary Disorders

We agree with van Schayck that the prednisolone test was deleted as diagnostic test in suspected asthma/COPD from the Dutch guidelines for general practitioners [1,2] because of lack of evidence[3]. However current international GINA guidelines for asthma still state that ‘In the elderly, distinguishing asthma from COPD is particularly difficult and may require a trial of treatment with bronchodilators and/or oral/inhaled corticosteroids.’[4]

We chose the definition for ‘responder’ according to the abovementioned current Dutch guidelines which define ‘reversibility’ after bronchodilation as > 12 % of baseline OR more than 200 millilitre [1,2] whereas some guidelines advice differently. We agree that referring also to these guidelines would have been more appropriate. These discrepancies underline the need for international uniformity in diagnostic criteria, to reduce confusion, allow comparison of research findings and improve patient care.

Finally, we did not state that the responders in our study would be responders to long term inhalation steroids, but do agree that our statement may suggest otherwise. Indeed it has been shown that such a response has no prognostic value. We wanted to emphasize that our finding that a response to oral steroids is associated with COPD, which is still counterintuitive for many practitioners, illustrates the heterogeneity of COPD, also with respect to the involvement of inflammation.

(1) Geijer RM, Smeele IJ, Goudswaard AN. [Summary of the practice guideline 'Asthma in adults' (second revision) from the Dutch College of General Practitioners]. Ned Tijdschr Geneeskd 2008; 152(20):1146-1150. (2) Smeele IJ, van WC, Van Schayck CP, Van Der MT, Thoonen B, Schermer TR et al. NHG-standaard COPD. Huisarts en Wetenschap 2007; 50(8):362-379. (3) Borrill Z, Houghton C, Sullivan PJ, Sestini P. Retrospective analysis of evidence base for tests used in diagnosis and monitoring of disease in respiratory medicine. BMJ 2003; 327(7424):1136-1138. (4) From the Global Strategy for Asthma Management and Prevention, Global Initiative for Asthma (GINA). Available from: http://www ginasthma org 2011.

Competing interests:   None declared

Oral steroid reversibility testing in patients with cough should come to an end. That is why in 2007 the Dutch College of General Practitioners issued a revision of their guidelines on asthma and on COPD, in which the usage of this test was abolished. The test was rejected both as a diagnostic test to discriminate asthma from COPD, and as a test for the efficacy of inhaled corticosteroid therapy. The study by Broekhuizen e.a. is the first prospective study in patient coming with protracted cough and no previous diagnosis of COPD. In an earlier study, the so-called COOPT study, we investigated whether oral steroid testing could predict the effectiveness of inhaled steroid treatment in patients with COPD. [1] This study as well as the Isolde study clearly showed that the test did not predict any beneficial effect on long term use of an inhaled corticosteroid. [1,2] We know already a long time that only a very small minority of patients with COPD benefit from inhaled corticosteroids [3-5] and there is no indication from these studies that it is possible to predict on forehand who will and who will not react positively on this medication.

There is one question to the authors: In the publication of Pellegrino (ref 14) with regard to measurement of bronchodilation a significant bronchodilator response is defined as an increase in FEV1 of more than 12%, relative to baseline, AND a volume response of more than 200mL. In table 2 authors define a responder in a different way. Why did they use another criterion? In their discussion authors state that the high proportion of responders in participants with COPD illustrates a subgroup of patients with COPD that respond well to long-term corticosteroids. First, this cannot be concluded from this diagnostic study and is furthermore contrary to our research findings as wel as our clinical impression.

Jean Muris associate professor, dept General Practice, CAPHRI Maastricht University Medical Centre, Niels Chavannes associate professor Public Health and Primary Care LUMC, Onno van Schayck professor, dept General practice, CAPHRI, Maastricht University Medical Centre, the Netherlands.

1. Chavannes NH, Schermer T, Wouters EF, et al. Predictive value and utility of oral steroid testing for treatment of COPD in primary care: the COOPT study. Int J COPD. 2009(4);2009.

2. Burge PS, Calverley PM, Jones PW, Spencer S, Anderson JA. Prednisolone response in patients with chronic obstructive pulmonary disease: results from the ISOLDE study. Thorax. 2003;58(8):654-658.

3. Schayck CP, van Grunsven PM, Dekhuijzen PNR. Do patients with COPD benefit from treatment with inhaled corticosteroids. Eur Respir J. 1996;9:1969–1972.

4. Chanez P, Vignola AM, O’Shaugnessy T, et al. Corticosteroid reversibility in COPD is related to features of asthma. Am J Resp Crit Care Med. 1997;155:1529–1534.

5. Calverley PMA. Inhaled corticosteroids are beneficial in chronic obstructive pulmonary disease. Am J Resp Crit Care Med. 2000;161:341–342.

Competing interests:   None declared

A diagnosis of COPD or asthma is based on a combination of signs, symptoms and (repeated) spirometry results.This leaves room for interpretation, and therefore for our study an expert panel diagnosis seemed most appropriate. We deliberately chose a panel including a general practitioner with expertise in lung function measurements and a pulmonologist (hence not only referral specialists) to increase the generalisability of the diagnostic findings to primary care.

As David Hahn mentions, the overlap between asthma and COPD has been extensively discussed in the past, and especially in elderly this can complicate a straightforward diagnosis. Indeed, objective and rigorous measures to define presence or absence of asthma or COPD would be most welcome.

Yet, we feel that efforts to distinct asthma from COPD are worthwhile, because treatment differs. Nonetheless, evidence for treatment effect for asthma and COPD was almost solely derived from secondary care patients with more severe disease than seen in primary care. Input from primary care is certainly warranted, to enhance adequate diagnosis, but more importantly to measure which patients benefit from which treatment. We agree with Dr Hahn that more studies in primary care are needed to improve care in asthma/COPD patients at large.

Competing interests:   None declared

In medicine, we do many tests because guidelines suggest them. There is too little research verifying which tests actually change diagnoses much less patient outcomes or cost. It is therefore beneficial to see a paper determining whether something is truly useful. Differentiating COPD and asthma challenges physicians. And, getting the the diagnosis right improves patient outcomes. Guidelines suggest using reversibility (improved spirometry) after a trial of bronchodilators, inhaled glucocorticoids, or oral glucocorticoids to differentiate asthma from COPD. [Cite references 1 and 2 in the original article, Rabe KF and www.ginasthma.org] Asthma is reversible (FEV1/FVC improves); COPD is not. This paper demonstrates that a 2 week trial of oral glucocorticoids followed by repeat spirometry does not differentiate COPD from asthma. It is important to verify diagnostic workup recommendations within well reasoned COPD and asthma guidelines. This paper does just that. The authors have saved us the need to put patients through a test that is not useful; and future guidelines can benefit from the additional research.

Competing interests:   None declared