الفهرس 
Historical remarks
Subjects and MethodsOnly 14 pages are availabe for public view
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Abstract
The present study was conducted in The National Center of Chest Diseases of Imbaba. Two groups were
chosen: the first group included fifty known COPD patients, diagnosed according to GOLD
2014, on their medications and the second group was fifty apparently healthy smokers.
Subjects were all males from EL-Giza governorate in the period between January 2014 and July 2014.
The aim of this study was to validate the use of the five items of modified Lung Function
Questionnaire to detect those appropriate for spirometry testing for airflow obstruction.
Exclusion criteria: history of atopy, younger than forty, patients with acute respiratory illness,
patients with known (non-respiratory) disease causing dyspnea and history of concomitant lung
diseases like sarcoidosis.
All subjects were submitted to:
Full medical history taking. Thorough clinical examination.
The weight in Kg, the height in Cm and BMI.
Radiological examinations: Plain postero-anterior chest X-ray was done to exclude any chest
lesion if present.
Participants answered the questions covering demographics and symptoms by Arabic
translation of modified Lung Function Questionnaire which is five questions with scoring system
from five to twenty five according to research developed by Yawn and colleagues in 2010.
Simple spirometry, prebronchodilator and postbronchodilator, according to GOLD
guidelines
2014. Pulmonary function tests were performed using smart pft USB, medical equipment
Europe Dr.-Georg- Schaefer-Str. 1497762 Hammelburg, Germany.
Results were tabulated and statistically analyzed:
The prevalence of COPD in the studied sample (50 smokers) was 30% slightly higher
than known numbers and it cannot be generalized because the sample was small and may be biased by
convenient sampling.
There was significant difference between the fifteen
newly diagnosed COPD cases and the thirty five healthy smokers as regard: weight, BMI,
prebronchodilator FEV1/FVC, MEF25-75 and MMRC dyspnea scale. Also comparison between them
considering how they answered the modified LFQ, there was statistically significant difference as
regard the first, second and third questions.
Logistic regression of the five items of the modified LFQ found that the third question
(shortness of breath) was the only item which significantly predict airway obstruction (p-value =
0.04). Also the total score significantly predicted airway obstruction (p-value =
0.01).
The ROC curve for the modified LFQ found that at cut point 13 (LFQ score = 13) the sample had
sensitivity
73.5%, specificity 73.3%, positive predictive value
86.2% and negative predictive value 55% with fairly high area under the ROC curve 0.79%.
The ROC curve for every question of the modified LFQ alone showed that the first and third
questions (cough and dyspnea respectively) alone already related significantly with the diagnoses
of COPD with AUC of 0.77% and 0.75% respectively.
Lower cut-point levels were associated with greater detection of patients with airflow
obstruction (higher sensitivity) but also included some subjects not having airflow obstruction
(low specificity). The opposite was true at higher scores. Thus, selection of a particular
cut-point value can be adapted for a particular application.
Conclusion:
Using modified Lung Function Questionnaire can aid as a first-line screening tool to identify
patients with airflow obstruction for further investigations using spirometry to identify
patients with COPD.