Hypercapnic COPD patients and NIV at home: is there any benefit? Using the CAT and BODE index in an effort to prove benefits of NIV in these patients

Figures & data

Table 1 Sample characteristics at baseline

	n (%)
Sex
Men	52 (91.2)
Women	5 (8.8)
Age, years, mean (SD)	68.8 (8.0)
BMI, kg/m^2, mean (SD)	28.5 (5.4)
BMI
Normal	14 (25.0)
Overweight	18 (31.6)
Obese	25 (43.9)
AHI, number of apnea-hypopnea/hour, mean (SD)	8.5 (4.6)
S1, minutes, mean (SD)	6.7 (4.3)
S2, minutes, mean (SD)	62.2 (17.1)
S3+S4, minutes, mean (SD)	14.4 (13.6)
REM, minutes, mean (SD)	12.3 (7.6)
SAT <90%, mean (SD)	71.7 (24)
SAT <80%, median (IQR)	4.1 (1.3–8.9)
Mean saturation, mean (SD)	86.2 (2.7)
Min saturation, mean (SD)	74.7 (6.1)
OD, number of oxygen desaturation/hour, median (IQR)	10 (4.8–17)

Abbreviations: AHI, Apnea-Hypopnea Index; BMI, body mass index; IQR, interquartile range; OD, oxygen desaturation; REM, rapid eye movement; SAT, saturation.

Table 2 Changes in study parameters through the follow-up period

	Baseline	6 months	12 months	Effect size	p-value** baseline vs 6 months	p-value** 6 vs 12 months	p-value** baseline vs 12 months
PO2, median (IQR)	58.0 (54.0–59.0)	62 (58–68)	63 (58–67)	0.39	<0.001	0.919	<0.001
PCO2, median (IQR)	52.9 (50.0–55.0)	46 (43–50)	45 (43–48)	0.67	<0.001	0.663	<0.001
pH, median (IQR)	7.41 (7.39–7.41)	7.42 (7.40–7.43)	7.41 (7.40–7.42)	0.25	<0.001	0.266	0.021
FEV1, median (IQR)	30.0 (27.0–46.0)	38 (25–52)	33 (26–50)	0.15	0.013	0.439	0.652
FVC, mean (SD)	49.6 (15.1)	53.5 (17.7)	54.6 (16.5)	0.14	0.071	1.000	0.028
FEV1/FVC, mean (SD)	56.0 (9.9)	55.1 (11.5)	53.6 (11.5)	0.15	1.000	0.180	0.115
MRC, mean (SD)	2.79 (0.92)	2.51 (0.98)	2.50 (1.07)	0.11	0.009	0.672	<0.001
BMI, mean (SD)	28.5 (5.4)	29.3 (5.6)	28.9 (5.6)	0.07	0.062	0.760	1.000
6MWT, mean (SD)	247.5 (106.8)	268.9 (114.6)	254.2 (134.9)	0.11	0.049	0.420	1.000
BODE, mean (SD)	5.8 (2.2)	4.8 (2.4)	5.2 (2.7)	0.32	<0.001	0.143	0.113
EXACERB, median (IQR)	1 (1–2)	0 (0–1)	0 (0–1)	0.39	<0.001	0.196	<0.001
CAT, mean (SD)	18.7 (6.9)	16.2 (6.8)	15.5 (8.4)	0.22	<0.001	0.499	0.001

Notes: Repeated measurements ANOVA. Effects reported include differences between the groups in the degree of change over the follow-up period.

** Pairwise comparisons after Bonferroni correction. Log transformations were used in analysis. Bold values are statistically significant.

Abbreviations: 6MWT, 6 minute walk test; ANOVA, analysis of variance; CAT, COPD Assessment Test; EXACERB, exacerbations; FEV₁, forced expiratory volume in 1 second; FVC, forced vital capacity; IQR, interquartile range; MRC, Medical Research Council.

Figure 1 Mean BODE and CAT levels during follow-up.

Abbreviation: CAT, COPD Assessment Test.

Figure 2 BODE Index changes during follow-up, according to age groups.

Figure 3 PO₂ changes during the follow-up, according to BMI status.

Abbreviation: BMI, body mass index.