Background
Materials and methods
Search strategy
Selection criteria
Outcome and exposure definitions
Data extraction and quality assessment
Statistical analysis
Results
Study selection and characteristics
Number | Author(survey time), province | Study design | Hospital level | Number of PI/ total | JBI score for incidence | JBI score for risk factors |
---|---|---|---|---|---|---|
1 | Yuan Q (201311–201610), Jiangsu | RC | tertiary | 298/37267 | 8 | - |
2 | Zhang DH (201105–201306), Guangdong | PC | secondary | 10/310 | 5 | - |
3 | Zeng WQ (201701–201812), Jiangxi | RC | secondary | 44/1972 | 6 | - |
4 | Wu J (201102–201503), Jiangsu | RC | tertiary | 86/1927 | 8 | - |
5 | Liu YR (201504–201703), Sichuan | PC | secondary | 12/51 | 4 | - |
6 | Xie QB (2018), Hunan | RC | tertiary | 200/20000 | 6 | - |
7 | Zeng XM (200901–201003), Jiangxi | RC | secondary | 6/2008 | 5 | - |
8 | Chang R (201501–201612), Shaanxi | RC | tertiary | 37/2846 | 9 | - |
9 | Zhang QL (201407–201412), Shandong | PC | tertiary | 32/369 | 6 | - |
10 | Xun SL (201501–201503), Jiangsu | RC | tertiary | 195/1030 | 6 | - |
11 | Liu JF (201501–201601), Neimenggu | RC | secondary | 9/1000 | 3 | - |
12 | Wu XM (201701–201901), Guangdong | RC | secondary | 22/1000 | 4 | - |
13 | Huang ZH (201604–201609), Guangdong | RC | tertiary | 44/580 | 7 | - |
14 | Zhang LJ (2013–2017), Neimenggu | RC | tertiary | 39/240 | 3 | - |
15 | Wu P (201401–201410), Shandong | RC | tertiary | 12/320 | 5 | - |
16 | Weng KN (2014–2016), Zhejiang | RC | secondary | 42/899 | 8 | - |
17 | Zhang ZT (201509–201609), Guizhou | RC | tertiary | 32/120 | 3 | - |
18 | Luo YJ (201703–201705), Guangdong | RC | secondary | 52/1641 | 5 | - |
19 | Qiu H (2008–2011), Shandong | RC | secondary | 56/568 | 4 | - |
20 | Yi WN (201701–201901), Shandong | PC | secondary | 9/100 | 4 | - |
21 | Wen Z (201802–202008), Guangxi | PC | tertiary | 3/100 | 3 | - |
22 | Luo QZ (201301–201604), Zhejiang | RC | secondary | 24/280 | 4 | - |
23 | Yue LY (200601–201111), Shanxi | RC | tertiary | 34/1496 | 6 | 8 |
24 | Wang CY (2017–2019), Shaanxi | RC | tertiary | 31/190 | 8 | 9 |
25 | He LP (201601–201701), Shanxi | RC | tertiary | 64/800 | 5 | 9 |
26 | Huang XA (201402–201603), Zhejiang | RC | tertiary | 80/3000 | 7 | 10 |
27 | Huang SJ (201506–201610), Hainan | RC | tertiary | 17/483 | 7 | 9 |
28 | Ai D (2015–2019), Sichuan | RC | tertiary | 89/1957 | 8 | 9 |
29 | Shi SY (201612–201807), Liaoning | RC | secondary | 82/1000 | 8 | 7 |
30 | Xiong F (2012–2015), Sichuan | RC | tertiary | 78/1263 | 7 | 9 |
31 | Zhang R (2017), Zhejiang | RC | tertiary | 187/24195 | 8 | 10 |
32 | Fan LY (201001–201410), Zhejiang | RC | secondary | 85/1828 | 6 | 8 |
33 | Fang J (201702–202001), Zhejiang | RC | tertiary | 92/2138 | 9 | 11 |
34 | Zhang LY (200501–201101), Guangxi | RC | tertiary | 120/5000 | 5 | 7 |
35 | Li X (201710–201909), Henan | RC | tertiary | 219/1560 | 9 | 11 |
36 | Zhao SQ (201402–201512), Ningxia | CC | secondary | 98/300 | 6 | 7 |
37 | Zhang J (201601–201810), Henan | RC | tertiary | 122/2800 | 7 | 10 |
38 | Lin L (201807–201912), Liaoning | RC | tertiary | 34/500 | 8 | 10 |
39 | Liu WL (2013–2015), Henan | RC | tertiary | 64/1026 | 9 | 11 |
40 | Wang M (201008–201208), Shandong | RC | secondary | 27/400 | 5 | 7 |
41 | Huang SL (201403–201602), Guangdong | RC | tertiary | 20/403 | 8 | 9 |
42 | Qu ZY (201607–201912), Liaoning | RC | tertiary | 47/1123 | 9 | 11 |
43 | Shen YL (2014–2015), Zhejiang | CC | secondary | 80/4653 | 8 | 8 |
44 | He LJ (201001–201308), Zhejiang | RC | tertiary | 53/826 | 7 | 7 |
45 | Chen YY (201408–201810), Henan | RC | tertiary | 91/1521 | 8 | 10 |
46 | Liao D (201701–201910), Hainan | RC | tertiary | 20/400 | 9 | 11 |
47 | Li QX (2014), Tianjin | CC | secondary | 40/80 | - | 7 |
48 | Lan FP (201601–201710), Guangxi | CC | secondary | 68/136 | - | 3 |
49 | Cai LF (201101–201501) Zhejiang | CC | secondary | 72/232 | - | 3 |
Incidence of PI
Study characteristics | Incidence (95% CIs) | Meta-regression | |
---|---|---|---|
b coefficient | P value | ||
Sample size | |||
≤ 1000 | 5.38% (4.29%, 6.47%) | -0.013 | 0.176 |
> 1000 | 4.51% (4.14%, 4.88%) | ||
Hospital levels | |||
Secondary hospital | 4.68% (3.37%, 5.96%) | -0.006 | 0.783 |
Tertiary hospital | 4.97% (3.09%, 7.35%) | ||
Median year of data collection | |||
2010–2014 | 4.71% (3.59%, 5.83%) | 0.009 | 0.545 |
2015–2017 | 5.33% (4.59%, 6.06%) | ||
2018–2020 | 5.59% (3.76%, 7.42%) | ||
JBI scores | |||
1–4 | 8.94% (4.29%, 15.24%) | -0.021 | 0.009 |
5–6 | 5.33% (3.17%, 8.00%) | ||
≥ 7 | 4.58% (3.45%, 5.86%) |
Risk factors of PI
The overall OR values
Risk factors | Heterogeneity test | OR (95% CI) | Number of included studies | Fail-safe numberc | Harbord’s modified test | |
---|---|---|---|---|---|---|
Intercept | P value | |||||
Before childbirth | ||||||
Elder | P = 0.79, I2 = 0%a | 1.20 (0.99, 1.45)b | 7 | - | - | - |
Gestational hypertension | P < 0.01, I2 = 90% | 2.14 (1.77, 2.58) | 8 | 399 | 6.67 | < 0.01 |
GDM | P < 0.01, I2 = 84% | 1.82 (1.52, 2.17) | 8 | 253 | 4.96 | < 0.01 |
Primipara | P = 0.62, I2 = 0%a | 0.81 (0.67, 0.97) | 6 | 4 | 2.26 | 0.07 |
Multiple pregnancy | P = 0.12, I2 = 48%a | 1.44 (0.91, 2.25)b | 4 | - | - | - |
Genital tract inflammation | P = 0.15, I2 = 43%a | 2.51 (2.09, 3.02) | 9 | 275 | -2.68 | 0.14 |
AP | P = 0.14, I2 = 43%a | 2.28 (2.01, 2.59) | 15 | 808 | 0.49 | 0.63 |
During childbirth | ||||||
Premature delivery | P = 0.20, I2 = 32%a | 1.21 (0.93, 1.57)b | 6 | - | - | - |
Caesarean section | P < 0.01, I2 = 77% | 2.03 (1.80, 2.29) | 19 | 580 | 0.79 | 0.61 |
Operative vaginal delivery | P = 0.15, I2 = 44%a | 1.23 (0.94, 1.62)b | 4 | - | - | - |
Episiotomy | P = 0.41, I2 = 0%a | 2.64 (1.76, 3.94) | 4 | 35 | 2.19 | 0.09 |
PROM | P < 0.01, I2 = 86% | 2.54 (2.23, 2.89) | 19 | 1165 | 5.31 | 0.01 |
Prolonged labor | P = 0.12, I2 = 48%a | 1.32 (1.10, 1.57) | 8 | 41 | -2.00 | 0.44 |
After childbirth | ||||||
Placenta remnant | P = 0.25, I2 = 23%a | 2.59 (1.94, 3.48) | 7 | 118 | 2.05 | 0.23 |
Postpartum hemorrhage | P = 0.65, I2 = 0%a | 2.43 (2.13, 2.77) | 18 | 1151 | 1.30 | 0.05 |
Subgroup analysis
Study characteristicsa | Gestational hypertension | GDM | Caesarean section | PROM | ||||
---|---|---|---|---|---|---|---|---|
b coefficient | P value | b coefficient | P value | b coefficient | P value | b coefficient | P value | |
Sample size | -0.91 | 0.07b | -0.88 | 0.08b | -0.36 | 0.22 | -0.44 | 0.26 |
Hospital levels | -0.81 | 0.15 | -0.60 | 0.31 | -0.76 | 0.01b | -1.17 | < 0.01b |
Median year of data collection | -0.73 | 0.28 | 0.26 | 0.67 | 0.10 | 0.69 | 0.01 | 0.97 |
Study design | -0.48 | 0.46 | -0.53 | 0.42 | 0.71 | 0.03b | -1.13 | 0.01b |
JBI scores | -0.32 | 0.37 | -0.29 | 0.42 | -0.21 | 0.34 | -0.52 | 0.06b |
Risk factors | Study characteristics | Heterogeneity test | OR (95% CI) | Number of included studies | |||
---|---|---|---|---|---|---|---|
Sample size | Hospital levels | Study design | JBI scores | ||||
Gestational hypertension | ≤ 1000 | - | - | - | P = 0.25, I2 = 27%a | 5.57 (3.90, 7.94) | 4 |
> 1000 | - | - | - | P = 0.63, I2 = 0%a | 1.53 (1.22, 1.91) | 4 | |
GDM | ≤ 1000 | - | - | - | P = 0.14, I2 = 45%a | 4.17 (2.87, 6.08) | 4 |
> 1000 | - | - | - | P = 0.01, I2 = 62% | 1.43 (1.16, 1.77) | 4 | |
Caesarean section | - | Secondary | - | - | P = 0.03, I2 = 58% | 3.63 (2.85, 4.64) | 6 |
- | Tertiary | - | - | P = 0.71, I2 = 0%a | 1.69 (1.47, 1.94) | 13 | |
- | - | CC | - | P = 0.02, I2 = 66% | 3.72 (1.16, 4.96) | 5 | |
- | - | RC | - | P = 0.20, I2 = 31%a | 1.78 (1.56, 2.03) | 14 | |
PROM | - | Secondary | - | - | P = 0.18, I2 = 35%a | 8.48 (6.21, 11.56) | 6 |
- | Tertiary | - | - | P < 0.01, I2 = 61% | 1.82 (1.57, 2.12) | 13 | |
- | - | CC | - | P = 0.13, I2 = 46%a | 8.99 (6.27, 12.90) | 5 | |
- | - | RC | - | P = 0.03, I2 = 57% | 1.94 (1.68, 2.24) | 14 | |
- | - | - | 1–4 | P = 0.75, I2 = 0%a | 5.02 (2.79, 9.03) | 2 | |
- | - | - | 5–7 | P < 0.01, I2 = 83% | 6.19 (4.77, 8.04) | 5 | |
- | - | - | ≥ 8 | P = 0.15, I2 = 45%a | 1.78 (1.52, 2.09) | 12 |
Sensitivity analysis
Study removed | OR (95% CI) | ||||
---|---|---|---|---|---|
Primipara | Multiple pregnancy | Premature delivery | Operative vaginal delivery | Episiotomy | |
54 | - | - | - | - | 2.65 (1.71, 4.10) |
55 | - | - | - | - | 3.88 (2.09, 7.22) |
56 | 0.81 (0.67, 0.97) | - | - | 1.43 (0.94, 1.94) | 2.55 (1.64, 3.96) |
62 | - | 2.02 (1.14, 3.59)a | 1.23 (0.92, 1.64) | - | - |
64 | 0.78 (0.67, 0.96) | 1.13 (0.63, 2.03) | - | 1.24 (0.89, 1.73) | - |
66 | 0.87 (0.69, 0.98) | - | 1.34 (0.94, 1.91) | - | - |
68 | 0.80 (0.65, 0.98) | - | 1.08 (0.81, 1.43) | - | - |
69 | 0.79 (0.65, 0.96) | 1.27 (0.77, 2.09) | 1.22 (0.93, 1.59) | - | - |
70 | 0.77 (0.63, 0.95) | 1.55 (0.97, 2.47) | 1.21 (0.92, 1.59) | - | - |
74 | - | - | - | 1.24 (0.94, 1.65) | 2.28 (1.65, 3.50) |
76 | - | - | - | 1.02 (0.73, 1.43) | - |
77 | - | - | 1.24 (0.95, 1.62) | - | - |