Belgian Pulmonary Function Study (BPFS)

• % correct preferential diagnoses [ Time Frame: end of study ] [ Designated as safety issue: No ]
  To determine the effect of stepwise addition of various pulmonary function tests (spirometry, volumes, resistance and diffusing capacity in that order) on preferential diagnoses and their reflection of the gold standard (final diagnosis), the number and percentage of correct preferential diagnoses will be analysed after every pulmonary function test and compared by a generalized estimating equation model (GEE)
• N differential diagnoses in the subgroup with correct preferential diagnosis [ Time Frame: end of study ] [ Designated as safety issue: No ]
  To determine the effect of stepwise addition of various pulmonary function tests (spirometry, volumes, resistance and diffusing capacity in that order) on the number of differential diagnoses and their reflection of the gold standard (final diagnosis), the number of differential diagnoses in patients with correct preferential diagnosis will be analysed after each pulmonary function test and compared with Poisson GEE
• subgroup analyses [ Time Frame: end of study ] [ Designated as safety issue: No ]
  The primary endpoint (1/n differntial diagnoses) and 2 secondary endpoints (% correct preferential diagnoses, n differential diagnoses within correct preferential diagnosis) will be analysed in subgroups with final gold standard diagnosis of COPD, asthma, interstitial lung disease and " no pulmonary abnormality"
• Sensitivity analysis [ Time Frame: end of study ] [ Designated as safety issue: No ]
  Primary endpoint (1/n differntial diagnoses) and 2 secondary endpoints (% correct preferential diagnoses, n differential diagnoses within correct preferential diagnosis) and subgroup analyses (asthma, COPD, interstitial lung disease and no primary pulmonary abnormality) will be evaluated not only considering final diagnosis as standard but als correct side diagnosis

Pulmonary function tests including spirometry, lung volumes, measurements of resistance and diffusing capacity are essential in the diagnosis of several pulmonary diseases. These tests are an integral part of the diagnosis and treatment of lung diseases, but until now there is no clear evidence for the use of many of the pulmonary function tests because of a lack of adequate studies. The obscurity largely pertains to the conditions under which combinations of the various tests are indicated. Therefore the Belgian Thoracic Society, assembling all pulmonologists and the pneumology LOK/GLEM‟s, will investigate this matter.

Caucasian outpatients with respiratory symptoms but without diagnosis

Inclusion Criteria:

• Males and females
• Age between 18 and 75 years old
• New outpatients with respiratory symptoms as dyspnoea, cough, sputum, but without firm diagnosis
• Results of the tests are available and acceptable
• Standardized list of complaints
• Capability of patient for doing pulmonary function tests
• Seen by a Pneumologist
• Written informed consent

Exclusion Criteria:

• Patients with diagnosed respiratory disease
• Younger than 18 and older than 75 years old
• Recent heart attack
• Pneumothorax
• hemoptoic
• Suspicion of Tuberculosis
• Not capable to do pulmonary function tests