Patients’ characteristics
USPB vs. CPB before PSM
The demographic characteristics of the patients who received USPB or CPB before PSM are shown in Table 1(Patients’ characteristics between USPB and CPB before and after PSM). Before PSM, the percentage of patients with hydrothorax ADA ≥ 40 was higher in the USPB group compared with the CPB group (P = 0.002), and the percentage of patients in the USPB group with wrap-separated pleural fluid was higher than that of the CPB group (P = 0.041). The maximum anteroposterior diameter of the pleural fluid in the USPB group was less than that of the CPB group (P = 0.047). The remaining variables were not significantly different between the USPB and CPB groups.
Table 1 Patients’ characteristics between USPB and CPB before and after PSM
Variables
|
Before PSM
|
|
|
After PSM
|
|
USPB (n=69)
|
CPB (n=69)
|
P-value
|
USPB (n=40)
|
CPB (n=40)
|
P-value
|
Gender (male%)
|
45 (65.2)
|
45 (65.2)
|
1.000
|
28 (70.0)
|
27(67.5)
|
1.000
|
Age (y, Mean ± SD)
|
44.86±1 9.34
|
44.28±1 9.80
|
0.862
|
42.40±1 8.67
|
42.20±19.26
|
0.962
|
BMI (kg/m2)
|
22.05±3. 19
|
21.82±3. 66
|
0.693
|
22.01±2.89
|
21.42±3.94
|
0.472
|
History of tuberculosis (%)
|
2(2.9)
|
3(4.3)
|
1.000
|
2(5.0)
|
2(5.0)
|
1.000
|
Course of disease (days, n,%)
|
|
|
|
|
|
|
≥21
|
18(26.1)
|
21(30.4)
|
0.706
|
10(25.0)
|
10(25.0)
|
1.000
|
<21
|
51(73.9)
|
48(69.6)
|
|
30(75.0)
|
30(75.0)
|
|
Hydrothorax ADA (U/L)
|
|
|
|
|
|
|
≥40
|
51(73.9)
|
32(46.4)
|
0.002
|
26(65.0)
|
28(70.0)
|
0.500
|
<40
|
18(26.1)
|
37(53.6)
|
|
14(35.0)
|
12(30.0)
|
|
Pleural/serum protein ratio(%)
|
76.01±7.49
|
76.92±7.06
|
0.464
|
76.73±7.53
|
74.87±7.77
|
0.246
|
Wrap-separated pleural fluid (%)
|
40(58.0)
|
27(39.1)
|
0.041
|
23(57.5)
|
19(47.5)
|
0.424
|
Maximum anteroposterior
Diameter of pleural fluid(cm)
|
5.35±2.23
|
6.13±2.33
|
0.047
|
5.62±2.17
|
5.63±2.33
|
0.980
|
Comorbidities (%)
|
|
|
|
|
|
|
Pneumoconiosis
|
3(4.3)
|
3(4.3)
|
1.000
|
2(5.0)
|
2(5.0)
|
1.000
|
Diabetes mellitus
|
6 (8.7)
|
3 (4.3)
|
0.493
|
1(2.5)
|
2(5.0)
|
1.000
|
Hypertension
|
7(10.1)
|
2 (2.9)
|
0.165
|
1(2.5)
|
1(2.5)
|
1.000
|
Coronary heart disease
|
3(4.3)
|
3(4.3)
|
1.000
|
1(2.5)
|
2(5.0)
|
1.000
|
HBV
|
22(31.9)
|
16(23.2)
|
0.341
|
11(27.5)
|
10(25.0)
|
1.000
|
Tumor
|
1(1.4)
|
0(0)
|
1.000
|
0(0)
|
0(0)
|
|
AIDS
|
0(0)
|
1(1.4)
|
1.000
|
0(0)
|
0(0)
|
|
CTD
|
0(0)
|
1(0.9)
|
1
|
0(0)
|
0(0)
|
|
Alcoholism
|
0(0)
|
2(2.9)
|
0.496
|
0(0)
|
0(0)
|
|
MTPB :Medicine thoracoscopic pleural biopsy
USPB :Ultrasound-guided pleural biopsy
CPB :Closed pleural biopsy
PSM: Propensity score matching
ADA:Aadenosine Deaminase
HBV:hepatitis B virus
AIDS:Acquired immunodeficiency syndrome
CTD:Connective tissue disorder
BMI: Body Mass Index
SD: standard deviation
USPB vs. MTPB before PSM
Table 2 (Patients’ characteristics between USPB and MTPB before and after PSM) displays the demographic characteristics of the USPB and MTPB groups before PSM. Before PSM, compared with the MTPB group, patients in the USPB group were older (0.406); the maximum anteroposterior diameter of pleural fluid was less (P = 0.000); and both the percentages with hydrothorax ADA ≥40 or HBV were less (P = 0.026, 0.043, respectively).
The percentage of those with wrap-separated pleural fluid was higher (P = 0.002). The remaining variables under study were not significantly different between these two groups.
Table 2 Patients’ characteristics between USPB and MTPB before and after PSM
Variables
|
Before PSM
|
|
|
After PSM
|
|
|
USPB
(n=69)
|
MTPB
(n=110)
|
P-value
|
USPB
(n=47)
|
MTPB
(n=47)
|
P-value
|
Gender (male%)
|
45 (65.2)
|
79(71.8)
|
0.406
|
30 (63.8)
|
31(66.0)
|
1.000
|
Age (y, Mean ± SD)
|
44.86±1 9.34
|
55.14±1 5.34
|
0.000
|
49.94±1 9.07
|
49.53±14.79
|
0.903
|
BMI (kg/m2)
|
22.05±3. 19
|
21.91±3.0 5
|
0.764
|
22.20±3. 44
|
22.14±2.92
|
0.934
|
History of tuberculosis (%)
|
2(2.9)
|
10(9.1)
|
0.133
|
2(4.3)
|
1(2.1)
|
1.000
|
Course of disease (days, n,%)
|
|
|
|
|
|
|
≥21
|
18(26.1)
|
42(38.2)
|
0.106
|
13(27.7)
|
13(27.7)
|
1.000
|
<21
|
51(73.9)
|
68(61.8)
|
|
34(72.3)
|
34(72.3)
|
|
Hydrothorax ADA (U/L)
|
|
|
|
|
|
|
≥40
|
51(73.9)
|
63(57.3)
|
0.026
|
32(68.1)
|
25(53.2)
|
0.167
|
<40
|
18(26.1)
|
47(42.7)
|
|
15(31.9)
|
22(46.8)
|
|
Pleural/serum protein ratio(%)
|
76.01±7.49
|
76.60±8.13
|
0.621
|
77.93±7.08
|
76.79±6.36
|
0.426
|
Wrap-separated pleural fluid (%)
|
40(58.0)
|
37(33.6)
|
0.002
|
23(48.9)
|
21(44.7)
|
0.824
|
Maximum anteroposterior
Diameter of pleural fluid(cm)
|
5.35±2.23
|
6.92±2.41
|
0.000
|
6.04±2.11
|
5.55±1.97
|
0.201
|
Comorbidities (%)
|
|
|
|
|
|
|
Pneumoconiosis
|
3(4.3)
|
9(8.2)
|
0.375
|
3(6.4)
|
2(4.3)
|
1.000
|
Diabetes mellitus
|
6 (8.7)
|
8 (7.3)
|
0.779
|
5(10.6)
|
5(10.6)
|
1.000
|
Hypertension
|
7(10.1)
|
12 (10.9)
|
1.000
|
7(14.9)
|
3(6.4)
|
0.344
|
Coronary heart disease
|
3(4.3)
|
10(9.1)
|
0.375
|
3(6.4)
|
2(4.3)
|
1.000
|
HBV
|
22(31.9)
|
53(48.2)
|
0.043
|
22(46.8)
|
21(44.7)
|
1.000
|
Tumor
|
1(1.4)
|
0(0)
|
0.385
|
0(0)
|
0(0)
|
|
AIDS
|
0(0)
|
0(0)
|
|
0(0)
|
0(0)
|
|
CTD
|
0(0)
|
1(0.9)
|
1
|
0(0)
|
0(0)
|
|
Alcoholism
|
0(0)
|
0(0)
|
|
0(0)
|
0(0)
|
|
MTPB:Medicine thoracoscopic pleural biopsy
USPB:Ultrasound-guided pleural biopsy
CPB:Closed pleural biopsy
AIDS:Acquired immunodeficiency syndrome
CTD:Connective tissue disorder
BMI: Body Mass Index
ADA:Aadenosine Deaminase
HBV:hepatitis B virus
PSM: Propensity score matching
SD: standard deviation
CPB vs. MTPB before PSM
Table 3 (Patients’ characteristics between CPB and MTPB before and after PSM) shows the demographic characteristics of the CPB and MTPB groups before PSM. Compared with the MTPB group, patients in the CPB group were significantly younger (P = 0.000), the maximum anteroposterior diameter of the pleural fluid was less (P = 0.031), and the percentage with HBV was lower (P = 0.001). However, the ADA and wrap-separated pleural fluid of the two groups were comparable.
After PSM, there were 40, 47, and 52 matched pairs from, respectively, the USPB and CPB, USPB and MTPB, and CPB and MTPB groups. The baseline characteristics were balanced well among the three groups.
Table 3 Patients’ characteristics between CPB and MTPB before and after PSM
Variables
|
Before PSM
|
|
|
After PSM
|
|
|
CPB
(n=69)
|
MTPB
(n=110)
|
P-value
|
CPB
(n=52)
|
MTPB
group (n=52)
|
P-value
|
Gender (male%)
|
45 (65.2)
|
79(71.8)
|
0.406
|
36 (69.2)
|
34(65.4)
|
0.845
|
Age (y, Mean ± SD)
|
44.28±1 9.80
|
55.14±1 5.34
|
0.000
|
48.88±1 9.80
|
51.77±15.89
|
0.341
|
BMI (kg/m2)
|
21.82±3. 66
|
21.91±3.0 5
|
0.871
|
21.93±3. 77
|
22.05±3.41
|
0.860
|
History of tuberculosis (%)
|
3(4.3)
|
10(9.1)
|
0.375
|
2(3.8)
|
1(1.9)
|
1.000
|
Course of disease (days, n,%)
|
|
|
|
|
|
|
≥21
|
21(30.4)
|
42(38.2)
|
0.336
|
15(28.8)
|
23(44.2)
|
0.115
|
<21
|
48(69.6)
|
68(61.8)
|
|
37(71.2)
|
29(55.8)
|
|
Hydrothorax ADA (U/L)
|
|
|
|
|
|
|
≥40
|
32(46.4)
|
63(57.3)
|
0.169
|
26(50.0)
|
20(38.5)
|
0.327
|
<40
|
37(53.6)
|
47(42.7)
|
|
26(50.0)
|
32(61.5)
|
|
Pleural/serum protein ratio(%)
|
76.92±7.06
|
76.60±8.13
|
0.781
|
76.08±7.61
|
76.33±7.12
|
0.874
|
Wrap-separated pleural fluid (%)
|
27(39.1)
|
37(33.6)
|
0.522
|
23(44.2)
|
17(32.7)
|
0.362
|
Maximum anteroposterior
Diameter of pleural fluid(cm)
|
6.13±2.33
|
6.92±2.41
|
0.031
|
6.04±2.38
|
6.25±2.38
|
0.603
|
Comorbidities (%)
|
|
|
|
|
|
|
Pneumoconiosis
|
3(4.3)
|
9(8.2)
|
0.375
|
3(5.8)
|
1(1.9)
|
0.625
|
Diabetes mellitus
|
3 (4.3)
|
8 (7.3)
|
0.534
|
3(5.8)
|
7(13.5)
|
0.344
|
Hypertension
|
2 (2.9)
|
12 (10.9)
|
0.083
|
2(3.8)
|
1(1.9)
|
1.000
|
Coronary heart disease
|
3(4.3)
|
10(9.1)
|
0.375
|
3(5.8)
|
5(9.6)
|
0.687
|
HBV
|
16(23.2)
|
53(48.2)
|
0.001
|
13(25.0)
|
19(36.5)
|
0.286
|
Tumor
|
0(0)
|
0(0)
|
|
0(0)
|
0(0)
|
|
AIDS
|
1(1.4)
|
0(0)
|
0.385
|
0(0)
|
0(0)
|
|
CTD
|
1(0.9)
|
1(0.9)
|
1
|
0(0)
|
0(0)
|
|
Alcoholism
|
2(2.9)
|
0(0)
|
0.147
|
0(0)
|
0(0)
|
|
MTPB :Medicine thoracoscopic pleural biopsy
CPB :Closed pleural biopsy
AIDS:Acquired immunodeficiency syndrome
CTD:Connective tissue disorder
BMI: Body Mass Index
ADA:Aadenosine Deaminase
HBV:hepatitis B virus
PSM: Propensity score matching
SD: standard deviation
Diagnostic sensitivities
Diagnostic sensitivity is measured according to the percentage of patients within a particular population given a definitively positive diagnosis [22]. The pathological diagnoses of the three groups are displayed in Table 4(The analysis of diagnostic sensitivity, complications and hospital stay for the three pairs after PSM). After PSM, no significant differences in diagnostic sensitivities were found between the USPB and CPB (72.5 vs. 55.0%; P = 0.162), USPB and MTPB (70.2 vs. 80.9%; P = 0.337), or CPB and MTPB (61.5 vs. 76.9%; P = 0.152) groups.
Safety findings
The post-procedural complications were inspected, including pleural response, pain, subcutaneous emphysema, subcutaneous hematoma, hemothorax, and iatrogenic pneumothorax (Table 4). The rates for pain and subcutaneous emphysema were higher in the MTPB group than in the USPB or CPB groups (all, P = 0.000). There were nine (19.1%) and two (4.3%) cases of iatrogenic pneumothorax in the MTPB and USPB groups, which was statistically similar. These complications either resolved on their own or treated symptomatically. All these patients underwent closed thoracic drainage and recovered within 3 to 5 days.
Hospitalization
Hospitalization was longer in the MTPB group compared with the other two groups (Table 4). Specifically, the hospitalization of patients given MTPB was significantly longer than that of the USPB group (P = 0.029). While the hospitalization of the MTPB group was longer than that of the CPB group, the difference was not significant (P = 0.313). The hospitalizations of the USPB and CPB groups were similar (P = 0.543).
Table 4 The analysis of diagnostic sensitivity, complications and hospital stay for the three pairs after PSM
USPB vs. CPB after PSM
|
|
USPB vs. MTPB after PSM
|
|
CPB vs. MTPB after PSM
|
|
Variables
|
USPB(n=40)
|
CPB(n=40)
|
P value
|
|
USPB(n=47)
|
MTPB(n=47)
|
P value
|
|
CPB(n=52)
|
MTPB(n=52)
|
P value
|
Serum albumin (g/L)
|
33.88±4.49
|
34.85±4. 75
|
0.202
|
|
33.88±4.49
|
34.85±4. 75
|
0.349
|
|
33.85±3.69
|
35.44±4. 35
|
0.062
|
ESR(mm/h)
|
47.94±21.02
|
47.72±22.08
|
0.839
|
|
47.94±21.02
|
47.72±22.08
|
0.964
|
|
41.23±20.92
|
48.46±23.30
|
0.101
|
TB-Ab(+)
|
1(2.1)
|
3(6.4)
|
0.103
|
|
1(2.1)
|
3(6.4)
|
0.625
|
|
6 (11.5)
|
3 (5.8)
|
0.508
|
Hydrothorax/Serum
CEA(%)
|
75.47±26.16
|
74.30±30.03
|
0.185
|
|
78.01±24.85
|
77.61±22.98
|
0.934
|
|
76.01±27.48
|
80.40±33.18
|
0.463
|
Hydrothorax WBC
(×10 6/L)
|
2397±2214
|
2669±1936
|
0.820
|
|
2397±2214
|
2669±1936
|
0.514
|
|
2206±1590
|
2370±1882
|
0.598
|
Hydrothorax L% (%)
|
84.22±9.71
|
83.87±9.34
|
0.549
|
|
84.22±9.71
|
83.87±9.34
|
0.860
|
|
84.98±10.95
|
82.15±12.82
|
0.252
|
Hydrothorax albumin (g/L)
|
29.82±4. 48
|
29.39±4.16
|
0.005
|
|
29.82±4. 48
|
29.39±4.16
|
0.651
|
|
27.80±4. 15
|
29.22±4.05
|
0.079
|
Hydrothorax ADA (U/L)
|
50.03±20.02
|
44.20±16.00
|
0.311
|
|
50.03±20.02
|
44.20±16.00
|
0.136
|
|
40.55±13.97
|
40.35±16.46
|
0.949
|
Hydrothorax LDH (U/L)
|
552.85±533.56
|
490.95±227.51
|
0.468
|
|
593.89±535.82
|
482.57±268.29
|
0.234
|
|
443.69±214.62
|
407.08±201.68
|
0.371
|
Parietal pleura thickness
(mm)
|
3.46±1.72
|
4.33±1.90
|
0.057
|
|
3.26±1.76
|
3.64±2.27
|
0.315
|
|
4.00±1.78
|
3.52±2.15
|
0.220
|
Pathological results
|
|
|
0.264
|
|
|
|
0.169
|
|
|
|
0.065
|
Tuberculosis
|
29(72.5)
|
22(55.0)
|
|
|
33(70.2)
|
38(80.9)
|
|
|
32(61.5)
|
40(76.9)
|
|
Chronic inflammation
|
9 (22.5)
|
15 (37.5)
|
|
|
11 (23.4)
|
9(19.1)
|
|
|
16(30.8)
|
12(23.1)
|
|
Skeletal muscle
|
2 (5.0)
|
3 (7.5)
|
|
|
3 (6.4)
|
0(0)
|
|
|
4(7.7)
|
0(0)
|
|
Diagnostic sensitivity
(n%)
|
29(72.5)
|
22(55.0)
|
0.162
|
|
33(70.2)
|
38(80.9)
|
0.337
|
|
32(61.5)
|
40(76.9)
|
0.152
|
Complication
|
|
|
|
|
|
|
|
|
|
|
|
Pleural response
|
2(5.0)
|
2(5.0)
|
0.494
|
|
0 (0)
|
1(2.1)
|
1.000
|
|
2(3.8)
|
0(0)
|
0.495
|
Pain
|
2(5.0)
|
7(17.5)
|
0.154
|
|
3 (6.4)
|
27(57.4)
|
0.000
|
|
7(13.5)
|
26(50.0)
|
0.000
|
Subcutaneous
emphysema
|
1(2.5)
|
1(2.5)
|
1
|
|
2 (4.3)
|
18(38.3)
|
0.000
|
|
1(1.9)
|
16(30.8)
|
0.000
|
Subcutaneous hematoma
|
1(2.5)
|
1(2.5)
|
1
|
|
3 (6.4)
|
1(2.1)
|
0.617
|
|
1(1.9)
|
0(0)
|
1
|
Hemothorax
|
0(0)
|
0(0)
|
|
|
0 (0)
|
0(0)
|
|
|
2(3.8)
|
0(0)
|
0.495
|
Air embolism
|
0(0)
|
0(0)
|
|
|
0 (0)
|
0(0)
|
|
|
0(0)
|
0(0)
|
|
Iatrogenic pneumothorax
|
1(2.5)
|
2(5.0)
|
1
|
|
2 (4.3)
|
9(19.1)
|
0.050
|
|
2(3.8)
|
6 (11.5)
|
0.269
|
Hospital stay(d)
|
9.03±3.64
|
9.60±4. 71
|
0.543
|
|
8.74±3.19
|
10.30±3. 59
|
0.029
|
|
9.60±4.46
|
10.46±3. 56
|
0.313
|
USPB :Ultrasound-guided pleural biopsy
CPB :Closed pleural biopsy
MTPB :Medicine thoracoscopic pleural biopsy
PSM: Propensity score matching
WBC: white blood cell
ADA: Aadenosine Deaminase
LDH: lactate dehydrogenase
ESR: erythrocyte sedimentation rate
TB-Ab: tuberculosis antibodies
CEA: carcinoembryonic antigen