Palliative care and prognosis in COPD: a systematic review with a validation cohort

Figures & data

Figure 1 Flowchart diagram of systematic review.

Abbreviation: PC, palliative care.

Table 1 Variables related with 1-year mortality in the systematic review

Variables	N	H.M. (%)	L.M. (%)	Mean (SD)
Epidemiological
Age ≥70 years	3	51	10	27 (21.4)
Unmarried	1	5	5
Physical dependence	1	60	60
Poor quality of life	6	27	5	16.7 (7.1)
Systemic variables
BMI ≤21 kg/m^2	4	56	15	32.3 (19.4)
Serum albumin <25 mg/dL	0
Comorbidities	2	40	8	24 (22.6)
Depression	4	25	10	19.8 (6.7)
Anemia	1	40	40
Cor pulmonale/PH	3	30	8	15.7 (12.4)
Respiratory variables
Previous hospitalization	9	42	5	23.4 (12)
FEV1 ≤30%	9	24	4	12.6 (5.9)
Dyspnea (mMRC scale)	2	15	14	14.5 (0.7)
Hypoxemia	4	35	20	25.3 (6.7)
Hypercapnia	3	30	12	20.6 (7.4)
Invasive ventilation	4	54	43	47.5 (4.7)
NIV	4	48	22	35.8 (11)
Multicomponent index
BODE	5	20	10	13.8 (4.8)

Notes: N, number of studies retrieved; H.M., higher percentage of 1-year mortality in retrieved articles; L.M., lower percentage of 1-year mortality in retrieved articles; Mean (SD), mean and standard deviation of 1-year mortality in retrieved articles.

Abbreviations: PH, pulmonary hypertension; BMI, body mass index; mMRC, modified dyspnea Medical Research Council; NIV, noninvasive ventilation; BODE, Body mass index, Obstruction, Dyspnea and 6 minutes walking test.

Figure 2 Systematic review, number of studies and 1-year mortality.

Notes: The number of circles in each variable represents the number of articles retrieved and their position with respect to Y axis, the mean average mortality.
Abbreviations: Exacer, severe exacerbations of COPD in the previous year; Comor, comorbidity; Depres, depression; QoL, quality of life; BMI, body mass index; CP, cor pulmonale; IV, invasive ventilation; NIV, noninvasive ventilation; BODE, Body mass index, Obstruction, Dyspnea and 6 minutes walking test.

Table 2 Characteristics of the cohort study population and 1-year mortality

Variables	Alive (575)	Dead (122)	Total (697)	P-value
Age, years (SD)	71.8 (9.4)	75.8 (9.3)	72.5 (9.5)	0.001
Male (%)	539 (94%)	111 (91%)	650 (93%)	0.32
Smoking (pack-years) (SD)	57.2 (28.5)	61.7 (34.4)	57.9 (29.5)	0.23
Physical dependence (Katz) (SD)	5.4 (1.1)	5.1 (1.2)	5.4 (1.2)	0.008
Quality of life (SGRQ) (SD)	50.5 (16)	56.9 (19.4)	51.5 (16.8)	0.02
Body mass index (SD)	27.3 (4.9)	25.9 (4.9)	27 (4.9)	0.006
Albumin, mg/dL (SD)	40.6 (4.9)	39.9 (4.6)	40.5 (4.9)	0.33
Comorbidities (Charlson) (SD)	2.5 (1.6)	3 (2)	2.6 (1.7)	0.004
Depression (Yesavage) (SD)	4.5 (3.4)	6.2 (3.8)	4.8 (3.5)	0.001
Cor pulmonale (%)	170 (30%)	43 (35%)	213 (31%)	0.23
Hospital admissions in the previous year (SD)	1.4 (1.7)	1.7 (2)	1.4 (1.7)	0.047
FEV1 % post-PBD (SD)	43.1 (15.2)	42 (14.9)	42.9 (15.2)	0.49
FVC % post-PBD (SD)	67 (18.6)	64.2 (18.1)	66.5 (18.5)	0.14
FEV1/FVC (SD)	49.4 (11.2)	49 (12.3)	49.4 (11.4)	0.67
Dyspnea (mMRC scale) (SD)	2.3 (1.2)	2.7 (1.5)	2.4 (1.2)	0.001
pO2 (SD)	61.7 (17.3)	60.9 (18.5)	61.6 (17.5)	0.65
pCO2 (SD)	45 (13)	45.5 (15.4)	45 (13.4)	0.7
Chronic oxygen therapy (%)	159 (27.7%)	47 (38.5%)	206 (29.6%)	0.02
BODE (SD)	4.6 (2)	5.8 (2.6)	4.7 (2.1)	0.02
BODEX (SD)	4.4 (2.3)	5.2 (2.6)	4.5 (2.3)	0.001
CODEX (SD)	5 (2.2)	6.3 (2)	5.2 (2.2)	0.001

Note: Analysis was performed with ANOVA, Mann–Whitney U test or chi-square test according to the properties of the variables.

Abbreviations: SD, standard deviation; SGRQ, Saint George’s Respiratory Questionnaire; mMRC, modified dyspnea Medical Research Council; ANOVA, analysis of variance; BODE, Body mass index, Obstruction, Dyspnea and 6 minutes walking test; BODEX, Body mass index, Obstruction, Dyspnea and severe exacerbations; CODEX, Comorbidity, Obstruction, Dyspnea and severe exacerbations; FVC, forced vital capacity; PBD, postbronchodilatation.

Table 3 Predictive mortality variables in the cohort study

Variables	%	1-year mortality (%)	Sen	Spe	Y	P-value	HR	95% CI
Age ≥70 years	64	20	0.74	41.6	0.16	0.001	2	1.3–3
Unmarried	23	25	0.42	0.60	0.02	0.29	n.c.	0.5–1.5
Physical dependence (loss ≥3 activities of daily living)	8	22	0.11	0.92	0.02	0.31	1.36	0.75–2.48
Poor quality of life (SGRQ ≥61)	33	28	0.53	0.71	0.24	0.001	2.6	1.44–4.66
BMI ≤21 kg/m^2	10	27	0.17	0.91	0.07	0.02	1.81	1.1–3
Albumin ≤35 mg/dL	10	33	0.19	0.92	0.11	0.03	2.2	1.6–4.5
Comorbidities (Charlson ≥3)	23	22	0.28	0.78	0.07	0.07	1.4	0.97–2.14
Depression (Yesavage ≥5 points)	57	27	0.61	0.61	0.21	0.003	2.24	1.32–3.8
Cor pulmonale	31	21	0.35	0.7	0.05	0.28	1.2	0.85–1.8
≥1 hospitalization in the previous year	63	18	0.68	0.47	0.15	0.24	1.27	0.87–1.84
Chronic oxygen therapy	30	22	0.39	0.72	0.11	0.01	1.6	1.1–2.3
FEV1 ≤30%	22	19	0.25	0.78	0.3	0.5	1.12	0.74–1.69
Dyspnea (mMRC scale ≥3)	55	24	0.59	0.57	0.16	0.002	1.8	1.25–2.61
pO2 ≤50 mmHg	21	21	0.28	0.77	0.06	0.1	1.33	0.88–2.1
pCO2 ≥50 mmHg	26	21	0.31	0.75	0.06	0.2	1.3	0.87–1.94
BODE ≥7	21	24	0.47	0.82	0.29	0.007	3.74	1.4–9.7
BODEX ≥7	18	24	0.21	0.84	0.05	0.07	1.49	0.97–2.3
CODEX ≥7	21	29	0.49	0.73	0.22	0.001	2.42	1.7–3.5

Notes: %, percentage of the population with the variable criteria. Statistical significance, HRs, and 95% CIs were calculated with Cox logistic regression analysis.

Abbreviations: HR, hazard ratio; CI, confidence interval; SGRQ, Saint George’s Respiratory Questionnaire; BMI, body mass index; mMRC, modified dyspnea Medical Research Council; Sen, sensitivity; Spe, specificity; Y, Youden’s index; n.c., non calculated; BODE, Body mass index, Obstruction, Dyspnea and 6 minutes walking test; BODEX, Body mass index, Obstruction, Dyspnea and severe exacerbations; CODEX, Comorbidity, Obstruction, Dyspnea and severe exacerbations.

Figure 3 Kaplan–Meier curves for (A) age, (B) depression, (C) dyspnea, and (D) CODEX index.

Abbreviations: mMRC, modified dyspnea Medical Research Council; CODEX, Comorbidity, Obstruction, Dyspnea and severe exacerbations.

Table 4 AUC for selected variables in the cohort study

Variables	AUC	P-value	95% CI
Age, years	0.62	0.0001	0.58–0.65
Physical dependence (Katz index)	0.59	0.0005	0.55–0.62
Quality of life (SGRQ)	0.52	0.01	0.48–0.55
BMI	0.59	0.001	0.55–0.63
Albumin	0.5	0.9	0.46–0.54
Comorbidities (Charlson index)	0.56	0.02	0.52–0.6
Depression (Yesavage scale)	0.63	0.001	0.57–0.68
FEV1	0.52	0.5	0.48–0.55
Dyspnea	0.58	0.002	0.55–0.62
pO2, mmHg	0.52	0.52	0.48–0.57
pCO2, mmHg	0.52	0.58	0.48–0.55
BODE	0.54	0.05	0.49–0.57
BODEX	0.59	0.001	0.55–0.63
CODEX	0.68	0.0001	0.62–0.72
Curtis criteria	0.64	0.0001	0.6–0.68

Abbreviations: AUC, area under the curve; CI, confidence interval; SGRQ, Saint George’s Respiratory Questionnaire; BMI, body mass index; BODE, Body mass index, Obstruction, Dyspnea and 6 minutes walking test; BODEX, Body mass index, Obstruction, Dyspnea and severe exacerbations; CODEX, Comorbidity, Obstruction, Dyspnea and severe exacerbations.

Figure 4 ROC curves.

Notes: Black line, CODEX + Yesavage; blue line, CODEX; orange line, Yesavage; red line, Curtis criteria; violet line, dyspnea.
Abbreviations: ROC, receiver operating characteristic; CODEX, Comorbidity, Obstruction, Dyspnea and severe exacerbations.