Prevalence of smoking in a psychiatric hospital and its relationship with respiratory symptoms and the prevalence of COPD

Figures & data

Table 1 Characteristics of psychiatric patients studied overall, and according to smoking status

	Total (n=276)	Smokers and ex-smokers (n=197)	Non-smokers (n=79)	P-value
Age (years)	56.9 (16.2)	55.1 (14.4)	60.9 (19.4)	0.009
Men, %	73.5	79.2	59.4	0.01
Body mass index (kg/m^2)	25.5 (4.4)	25.2 (4.2)	26.2 (4.7)	0.08
Charlson Index	1.37 (1.6)	1.44 (1.7)	1.19 (1.2)	0.23
Consumption of toxic substances (alcohol and drugs), %	9	15	1.5	0.21
Schizophrenia, n (%)	156 (56.5)	140 (71)	16 (20.2)	<0.001
Depressive or anxiety disorders, n (%)	46 (16.7)	25 (12.7)	21 (26.6)	0.005
ID-dementia, n (%)	74 (26.8)	32 (16.2)	42 (53.2)	<0.001

Note: Data are expressed as mean (SD) except when indicated otherwise.

Abbreviation: ID, intellectual disability.

Figure 1 Distribution of the psychiatric diagnoses based on smoking.

Table 2 Respiratory symptoms, previous respiratory diagnoses, hospital admission, and previous medical visits for respiratory disease

	Total (n=276)	Smokers and ex-smokers (n=196)	Non-smokers (n=79)	P-value
Previous diagnosis of COPD, %	19.5	23.3	10.1	0.012
Previous diagnosis of asthma, %	3.9	5	1.3	0.33
Previous hospitalization for respiratory disease, %	5.6	7	3	0.31
Dyspnea (MRC score ≥2), %	8.4	9.1	7.1	0.54
Dyspnea on climbing one flight of stairs, %	13.8	15.2	10.6	0.56
Cough, %	33.7	47.6	2.4	0.03
Expectoration, %	29.3	41.4	2.4	0.01
Wheezing, %	17.4	23	4.7	0.04
Chronic bronchitis, %	26.1	36.6	2.4	0.001

Abbreviation: MRC, Medical Research Council.

Table 3 Comparison of the results of the spirometry, prevalence of COPD, and distance walked by smokers and non-smokers

	Total (n=173)	Smokers and ex-smokers (n=139)	Non-smokers (n=34)	P-value
Respiratory medication, %	11.2	14.7	3.5	0.03
Pre-bronchodilator spirometry
FVC, mL	2,800 (1,100)	2,910 (1,160)	2,390 (930)	0.32
FVC, %	63 (19.1)	64.8 (20.2)	58.7 (16.7)	0.41
FEV1, mL	2,270 (894)	2,343 (901)	1,990 (751)	0.07
FEV1, %	67.6 (22.2)	68.5 (23.1)	63.9 (20.3)	0.42
FEV1/FVC	81.8 (14.9)	81.6 (14.5)	82.8 (15.1)	0.78
Post-bronchodilator spirometry
FVC, mL	2,930 (1,174)	3,010 (1,110)	2,620 (1,020)	0.27
FVC, %	66.7 (21.2)	66.7 (22)	66.4 (21.1)	0.81
FEV1, mL	2,270 (890)	2,367 (906)	2,020 (743)	0.45
FEV1, %	67.7 (21.9)	68.9 (22.1)	64.0 (21)	0.76
FEV1/FVC	78.9 (13.9)	79.7 (13.8)	76.1 (12.6)	0.71
Prevalence of COPD (%)	50/173 (28.9)	46/139 (26.3)	4/34 (11.7)	0.021
Distance walked in 6MWT (meters)	289 (56)	301 (60)	252 (29)	0.07

Note: All the values are expressed as mean (SD), except when indicated otherwise.

Abbreviations: FEV₁, forced expiratory volume in 1 second; FVC, forced vital capacity; 6MWT, 6-minute walk test.

Table 4 Results of the quality of life EuroQoL-5 dimensions (EQ-5D) and physical activity (London Chest Activity on Daily Living scale [LCADL]) questionnaires in the study groups

	Total (n=276)	Smokers and ex-smokers (n=197)	Non-smokers (n=79)	P-value
EQ-5D	0.69 (0.16)	0.74 (0.21)	0.57 (0.16)	0.001
Impact on respiration*
Great (%)	3	3	0
A little (%)	9.9	6.9	3	0.217
None (%)	87.1	60.3	29.7
Total LCADL score	10.6 (1.81)	11.7 (2.23)	8.79 (1.66)	0.001
LCADL self-care	3.69 (0.89)	3.92 (1.01)	3.17 (0.98)	0.002
LCADL household activity	1.93 (0.33)	2.31 (0.98)	1.01 (0.22)	0.001
LCADL physical activity	2.11 (0.15)	2.21 (0.16)	1.87 (0.11)	0.001
LCADL leisure activity	2.87 (0.77)	3.16 (0.89)	2.74 (0.74)	0.007

Notes: All the values are expressed as mean (SD), except when indicated otherwise.

* Corresponds to the question in the LCADL scale, “How do your usual activities affect your breathing?”.