+1 Recommend
1 collections
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Sputum microbiology predicts health status in COPD

      Read this article at

          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.



          Spontaneous sputum production occurs in a subset of COPD patients; however, its clinical relevance has not been established. Differences in health status and clinical outcomes between patients with and without positive sputum cultures are unknown.


          To compare clinical characteristics and health status of spontaneous sputum producers with a positive culture (SC+) and negative culture (SC−) with nonsputum producers (NP) in a cohort of COPD patients referred for pulmonary rehabilitation.


          In total, 518 clinically stable patients with mild-to-very severe COPD were recruited (mean age: 64.1±9.1 years, 55.6% males, forced expiratory volume in 1 second 48.6%±20.0% predicted). Health status was measured using COPD Assessment Test, St George’s Respiratory Questionnaire, and the Clinical COPD Questionnaire. Symptoms of anxiety and depression were assessed using the Hospital Anxiety and Depression Scale. Exercise capacity was measured using the 6-minute walking distance. Spontaneously expectorated sputum was cultured for microbiology.


          Almost one-third of patients spontaneously produced sputum (n=164, 31.7%). Despite comparable lung function, SC+ reported more frequent exacerbations than NP (≥2 exacerbations <1 year: 43 [81.1%] vs 179 [50.6%], P<0.001). COPD Assessment Test total score and the Clinical COPD Questionnaire total score were significantly worse in SC+ than NP (23.9±6.1 vs 21.1±6.7, P=0.012; 3.1±1.0 vs 2.5±1.0, P=0.002; respectively). Hospital Anxiety and Depression Scale-D score was significantly higher in SC+ than NP (8.7±4.1 vs 7.2±4.3, P=0.046).


          Spontaneous sputum production is common in COPD. Particularly, patients with positive cultures have worse health status and more symptoms of depression. Impact on disease progression and long-term outcomes remain to be established.

          Clinical trial registration

          NTR3416, registered at

          Related collections

          Most cited references 17

          • Record: found
          • Abstract: found
          • Article: not found

          St. George's Respiratory Questionnaire: MCID.

          The SGRQ is a disease-specific measure of health status for use in COPD. A number of methods have been used for estimating its minimum clinically important difference (MCID). These include both expert and patient preference-based estimates. Anchor-based methods have also been used. The calculated MCID from those studies was consistently around 4 units, regardless of assessment method. By contrast, the MCID calculated using distribution-based methods varied across studies and permitted no consistent estimate. All measurements of clinical significance contain sample and measurement error. They also require value judgements, if not about the calculation of the MCID itself then about the anchors used to estimate it. Under these circumstances, greater weight should be placed upon the overall body of evidence for an MCID, rather than one single method. For that reason, estimates of MCID should be used as indicative values. Methods of analysing clinical trial results should reflect this, and use appropriate statistical tests for comparison with the MCID. Treatments for COPD that produced an improvement in SGRQ of the order of 4 units in clinical trials have subsequently found wide acceptance once in clinical practice, so it seems reasonable to expect any new treatment proposed for COPD to produce an advantage over placebo that is not significantly inferior to a 4-unit difference.
            • Record: found
            • Abstract: not found
            • Article: not found

            Global strategy for the diagnosis, management, and prevention of chronic obstructive pulmonary disease

              • Record: found
              • Abstract: found
              • Article: not found

              The chronic bronchitic phenotype of COPD: an analysis of the COPDGene Study.

              Chronic bronchitis (CB) in patients with COPD is associated with an accelerated lung function decline and an increased risk of respiratory infections. Despite its clinical significance, the chronic bronchitic phenotype in COPD remains poorly defined. We analyzed data from subjects enrolled in the Genetic Epidemiology of COPD (COPDGene) Study. A total of 1,061 subjects with GOLD (Global Initiative for Chronic Obstructive Lung Disease) stage II to IV were divided into two groups: CB (CB+) if subjects noted chronic cough and phlegm production for ≥ 3 mo/y for 2 consecutive years, and no CB (CB-) if they did not. There were 290 and 771 subjects in the CB+ and CB- groups, respectively. Despite similar lung function, the CB+ group was younger (62.8 ± 8.4 vs 64.6 ± 8.4 years, P = .002), smoked more (57 ± 30 vs 52 ± 25 pack-years, P = .006), and had more current smokers (48% vs 27%, P < .0001). A greater percentage of the CB+ group reported nasal and ocular symptoms, wheezing, and nocturnal awakenings secondary to cough and dyspnea. History of exacerbations was higher in the CB+ group (1.21 ± 1.62 vs 0.63 ± 1.12 per patient, P < .027), and more patients in the CB+ group reported a history of severe exacerbations (26.6% vs 20.0%, P = .024). There was no difference in percent emphysema or percent gas trapping, but the CB+ group had a higher mean percent segmental airway wall area (63.2% ± 2.9% vs 62.6% ± 3.1%, P = .013). CB in patients with COPD is associated with worse respiratory symptoms and higher risk of exacerbations. This group may need more directed therapy targeting chronic mucus production and smoking cessation not only to improve symptoms but also to reduce risk, improve quality of life, and improve outcomes.; No.: NCT00608764; URL:

                Author and article information

                Int J Chron Obstruct Pulmon Dis
                Int J Chron Obstruct Pulmon Dis
                International Journal of COPD
                International Journal of Chronic Obstructive Pulmonary Disease
                Dove Medical Press
                07 November 2016
                : 11
                : 2741-2748
                [1 ]Department of Research and Education, CIRO, Horn, the Netherlands
                [2 ]Department of Respiratory Medicine, Maastricht University Medical Centre (MUMC+), Maastricht, the Netherlands
                Author notes
                Correspondence: Dionne CW Braeken, Department of Research and Education, CIRO, PO Box 4009, 6080 AB Haelen, the Netherlands, Tel +31 475 587 602, Email dionnebraeken@
                © 2016 Braeken et al. This work is published and licensed by Dove Medical Press Limited

                The full terms of this license are available at and incorporate the Creative Commons Attribution – Non Commercial (unported, v3.0) License ( By accessing the work you hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed.

                Original Research

                Respiratory medicine

                copd, health status, sputum, microbiology, pulmonary rehabilitation


                Comment on this article