1. “Screening: a wasteful use of resources?”
Onno van Schayck, Maastricht University The Netherlands
IPCRG, May 26, Amsterdam, The Netherlands

2. Why should we find patients with COPD?
Is it useful or wasteful?
If useful, what is the most efficient and effective way in finding COPD cases?

3. Underdiagnosis of COPD
How big is the problem of underdiagnosis of COPD?
Several studies in the world indicate that the problem of underdiagnosis is still big

4. What could be the possible reasons for the underdiagnosis of COPD?
Underdiagnosis by GPs or other physicians
Underpresentation of symptoms by patients
Underperception of symptoms by patients

5. General population (n=1150)
Obstruction + symptoms
(n=86)
Schayck CP van et al. Thorax 2000;55:562-5

6. Subjects with obstruction and symptoms (n=86)7%
Schayck CP van, et al. Thorax 2000;55:

7. Subjects who presented symptoms (n=29)
34%
Schayck CP van, et al. Thorax 2000;55:

8. So, who is to blame?
The GP or the patient?

9. Probably both.
But the main reason for underdiagnosis is underpresentation of symptoms by the patient.

10. Perception of dyspnoea?
What could be the reason?
Perception of dyspnoea?

11. PERCEPTION OF DYSPNOEA
Method described by Brand et al.
(Am Rev Respir Dis 1992;146P: )
Degree of dyspnoea scored on Borg scale
during Histamine provocation test
Good perceivers: Decrease in FEV1 is
accompanied by increase in Borg scale

13. Are there other characteristics that can
explain presenting symptoms to the GP
or not?

14. 1 Clinically relevant difference
Mean
Difference
Did
consult GP
(n=99)
Did not
consult GP (n=267) F
Sign.
CRQ: Dyspnoea
.651
5.89
6.54
20.78
p<.001
CRQ: Emotions
.31
5.25
5.56
6.56
.011
CRQ: Fatigue
.561
4.97
5.53
14.49
CRQ: Mastery
.25
6.48
6.73
9.67
.002
1 Clinically relevant difference
Boom G van den, et al. Eur Respir J 1998;11:67-72

15. 1 Clinically relevant difference
Mean
Difference
Did
consult GP
(n=99)
Did not
consult GP (n=267) F
Sign.
CRQ: Dyspnoea
.651
5.89
6.54
20.78
p<.001
CRQ: Emotions
.31
5.25
5.56
6.56
.011
CRQ: Fatigue
.561
4.97
5.53
14.49
CRQ: Mastery
.25
6.48
6.73
9.67
.002
1 Clinically relevant difference
Boom G van den, et al. Eur Respir J 1998;11:67-72

16. 1 Clinically relevant difference
Mean
Difference
Did
consult GP
(n=99)
Did not
consult GP (n=267) F
Sign.
CRQ: Dyspnoea
.651
5.89
6.54
20.78
p<.001
CRQ: Emotions
.31
5.25
5.56
6.56
.011
CRQ: Fatigue
.561
4.97
5.53
14.49
CRQ: Mastery
.25
6.48
6.73
9.67
.002
1 Clinically relevant difference
Boom G van den, et al. Eur Respir J 1998;11:67-72

17. But probably many patients do not want to know that they have symptoms.
They simply deny symptoms as they do not want to stop smoking.
⇒ Cognitive dissonance

18. Also the physician is convinced that the
disease is self-inflicted due to smoking
which closes the vicious circle

19. Is such an identification really efficient?
A question which is often asked is:
Can you identify COPD in smokers?
Is such an identification really efficient?

20. How many smokers have COPD?
Lung Health Study
7300 smokers years
30% had obstruction
Connett et al. Contr Clin Trial 1993

21. How many smokers have COPD?
Polish Study
smokers > 40 years
25% had obstruction
Zielinski, Chest 2001

22. Didasco study (screening of smokers and non-smokers) in Belgium
Early detection of COPD in general
practice. All patients year were screened and 925 subjects performed spirometry
Totally 7.4% had an obstruction
Buffels et al, Chest 2004

23. In the Didasco study, no preselection on the basis of smokers was made.
This method is rather time-consuming for general practice.

24. The implementation of screening in primary care is difficult and case-finding on the basis of smoking is likely to be a more suitable approach in this setting.

25. Case finding of COPD in general practice
The aim of the study was to investigate
how effective case finding of subjects
with a high risk for COPD (i.e. smokers) is as a method.
van Schayck et al. BMJ 2002;324:1370-3

26. Method Two semi-rural general practices, 651 randomly
selected persons aged 35 to 70 years were studied.
Current smokers among these subjects who were
not yet on pulmonary medication were asked to
complete a short standardised questionnaire on
bronchial symptoms.

27. Schayck CP van, et al. BMJ 2002;324:1370-3
Chance of having obstruction (FEV1<80%) in smokers with or without cough with increasing age
Schayck CP van, et al. BMJ 2002;324:1370-3

28. < 16.5 low risk 16.5 – 19.5 increased risk > 19.5 high risk
Symptom-Based Questionnaire for Identifying COPD in Smokers
David B. Price, David G. Tinkelman, R.J. Halbert, Robert J. Nordyke, Sharon Isonaka, Dmitry Nonikov, Elizabeth F. Juniper, Daryl Freeman, Thomas Hausen, Mark L. Levy, Anders Østrem, Thys van der Molen, Constant P. van Schayck
Respiration 2006;73:285–295 DOI: /
< 16.5 low risk
16.5 – 19.5 increased risk
> 19.5 high risk

29. CDQ validation studies compared with original study
Number recruited
for study
Number analysed
Price et al., 2006
898
818
Kotz et al., 2008
826
676
Kawayama et al., 2008
169
Sichletidis et al., 2011
1250
1078
Frith et al., 2011
233
201
Stanley et al., 2014
1631
1054

30. Performance of COPD Diagnostic Questionnaire across comparison studies
Study
Cut-off point (16.5)
Sensitivity (%)
Specificity (%)
Price et al., 2006
80.4
57.5
Kotz et al., 2008
89.2
24.4
Kawayama et al., 2008
93.9
40.4
Sichletidis et al., 2011 91 49
Frith et al., 2011 37
Stanley et al., 2014
79.7
46.8

31. COPD Diagnostic Questionnaire (CDQ) for selecting at-risk patients for spirometry: a cross-sectional study in Australian general practice
Anthony J Stanley, Iqbal Hasan, Alan J Crockett, Onno C P van Schayck & Nicholas A Zwar
Npj Primary Care Respiratory Medicine (2014) 24, 14024; doi: /npjpcrm ; published online 10 July 2014

32. Receiver operating characteristic (ROC) curve comparing the COPD Diagnostic Questionnaire score to chronic obstructive pulmonary disease diagnosis. Cut point 16.5—grey star; 19.5—black star. A ROCauc of 0.5 is indicated by the solid diagonal line.

33. The literature suggests that a cut point with the best balance between sensitivity and specificity based on the ROC curve is considered best at discriminating between diseased and non-diseased cases.
In this study, using these methods would result in 19.5 being the optimal cut point. However, this has a sensitivity of only 63% and 37% of COPD diagnoses would be missed. To some clinicians, this would be considered an unacceptably high rate of missed COPD diagnoses.

34. Performance of CDQ at different cut points Abbreviation: CDQ, COPD Diagnostic Questionnaire.
Sensitivity
Specificity
Positive predictive value (%)
Negative predictive value (%)
Patients below the cut point (%)
9.5
0.978
0.099
14.1
96.8
8.9
10.5
0.964
0.126
14.3
95.9
11.4
11.5
0.190
15.2
97.2
17.0
12.5
0.935
0.228
15.4
20.7
13.5
0.928
0.278
16.2
96.2
25.1
14.5
0.906
0.346
17.3
96.1
31.3
15.5
0.833
0.412
17.6
94.2
38.0
16.5
0.797
0.468
18.4
93.9
43.4
17.5
0.768
0.552
20.5
94.0
51.0
18.5
0.674
0.644
22.2
92.9
60.2
19.5
0.630
0.701
24.1
92.6
65.7
0.572
0.743
92.0
70.2
21.5
0.471
0.823
28.6
91.2
78.5
22.5
0.355
0.864
28.2
89.9
83.5
23.5
0.297
0.893
29.4
89.4
86.8
24.5
0.196
0.927
28.8
88.4
91.1

35. A cut point of 14. 5 is proposed, because of its high sensitivity (90
A cut point of 14.5 is proposed, because of its high sensitivity (90.6%) and high negative predictive value (96%). At the same time, 31% of patients in the low likelihood group do not need to undergo spirometry. For example, choosing a 12.5 cut point would lead to a ~3% increase in sensitivity but would require 10% more spirometries than a 14.5 cut point (21 vs 31% patients below cut point).

37. Early detection of COPD in general practice: patient or practice managed? A randomised controlled trial of two strategies in different socioeconomic environments
Joseph AM Dirven, Huibert J Tange, Jean WM Muris, Karin MA van Haaren, Gerrit Vink, Onno CP van Schayck
Primary Care Respiratory Journal 2013; 22(3):

38. Aims: To compare the effectiveness of two strategies for population-based early detection of COPD, taking into account different socioeconomic status (SES) settings. Methods: In the practice-managed condition, the practice was responsible for the whole procedure, while in the patient-managed condition, patients were responsible for calculating their CDQ risk score and applying for a spirometry test. The main outcome measure was the rate of COPD diagnoses after screening.

39. Results of the CDQ and spirometry test by strategy and socioeconomic status (SES)
Results (by SES setting)
Patient-managed strategy
Practice-managed strategy
All practices
CDQ distributed
6,393
3,715
Responders (% of distributed)
1,715 (27%)
1,855 (50%)
High risk on CDQ (% of responders)
186 (11%)
251 (14%)
Show up for spirometry (% of high riks)
140 (75%)
135 (54%)
COPD diagnosis (% of show up)
25 (18%)
48 (36%)
COPD diagnoses in a standard practice
3.0
8.9

40. Costs to detect one COPD diagnosis in a standard Dutch practice (2350 patients) in low SES vs moderate to high SES practices
Start condition
(by SES setting)
Patient-managed
Practice-managed
All practices
Cost per detected case
€ 698
€ 256
Low SES practices
€ 512
€ 224
Moderate to high SES practices
€ 926
€ 324
Cost per unit: €2 for a CDQ, €28 for a spirometry test (in case of high risk) and €18 for a COPD consultation (in case of positive diagnosis) SES = socioeconomic status

41. Perceived barriers and facilitators and health provider satisfaction
The barriers for successful implementation:
ethnicity
absence of financial compensation
limited supporting staff.
No barriers were perceived in the nature of the programme itself or in the qualifications of the care providers.

42. Conclusions
An important reason for underdiagnosis is the underpresentation of symptoms by the patient.
Case finding of COPD in primary care on the basis of presented symptoms in smokers is effective and efficient.
CDQ has shown to have a relatively high sensitivity in several validation studies in different parts of the world.
CDQ is not appropriate to discriminate between diseased and non-diseased cases, but is highly effective and efficient to select smokers for spirometry in order to diagnose COPD.
A practice managed strategy in which the GP takes the initiative to invite patients leads to three times more detection of COPD cases costing less than half the money compared to patients taking the initiative.