Cigarette and Waterpipe Smoking Decrease Respiratory Quality of Life in Adults: Results from a National Cross-Sectional Study

Table 3

Respiratory-related quality of life (CCQ¹) scores.

Categories	Number	Score mean	Score standard deviation
Respiratory diseases
Healthy	978	0.31	0.60
COPD^2	233	2.45	1.50
Chronic bronchitis	326	2.12	1.61
Reversible COPD^2	51	2.06	1.76
Total	1588	1.05	1.44
P value for ANOVA^3	<0.001
COPD grades^4
Grade 1 (FEV1 ≥ 0.8)	37	2.48	1.39
Grade 2 (0.5 ≤ FEV1 < 0.8)	124	2.44	1.49
Grade 3 (0.3 ≤ FEV1 < 0.5)	43	3.03	1.55
Grade 4 (FEV1 < 0.3)	8	3.63	1.68
P value for ANOVA	<0.001
Individuals with all COPD^5
Taking inhalation therapy	63	3.00	1.48
Not taking inhalation therapy	221	2.21	1.53
P value for ANOVA	<0.001
Individuals with chronic bronchitis
Taking inhalation therapy	56	3.42	1.60
Not taking inhalation therapy	270	1.85	1.48
P value for ANOVA	<0.001
MRC dyspnea scale^6
MRC = 0	999	0.33	0.67
MRC > 0	589	2.27	1.57
P value for ANOVA	<0.001

¹CCQ: Clinical COPD Questionnaire; ² COPD: Chronic Obstructive Pulmonary Disease according to GOLD and LLN5% definitions; ³For CCQ, healthy individuals significantly differed from all disease categories (P < 0.001); COPD, chronic bronchitis and reversible COPD disorders did not differ significantly (P > 0.05); ⁴COPD classification according to GOLD guidelines; ⁵Patients with reversible and irreversible COPD; ⁶ MRC: Medical Research Council scale for dyspnea.