Table 4 Subgroup analyses of observational studies

Total[22–35, 37–47]

26

336,245

0.65 (0.57 to 0.75)

74.3%

Type of effect size

OR[22–26, 29, 31, 33, 34, 37–47]

20

253,013

0.67 (0.57 to 0.78)

74.0%

HR[27, 28, 30, 32, 35, 40]

6

83,232

0.59 (0.38 to 0.91)

78.6%

Type of mortality

In-hospital mortality[22, 26, 29, 37, 40, 41, 44, 45]

9

259,052

0.72 (0.54 to 0.96)

70.1%

90-day mortality[23, 28, 35]

3

4,548

0.93 (0.73 to 1.19)

29.2%

30-day mortality[24, 25, 27, 30–34, 39, 42, 43, 47]

12

71,973

0.57 (0.48 to 0.69)

69.6%

28-day mortality[46]

1

361

0.07 (0.01 to 0.51)

-

15-day mortality[38]

1

311

0.18 (0.04 to 0.78)

-

Statin exposure

Current statin user[22, 24, 26–29, 32, 35, 38, 40, 41],[45]

12

186,004

0.64 (0.48 to 0.85)

75.7%

Former statin user[23, 25, 30, 31, 33, 34, 37, 39],[40, 42–44, 46, 47]

14

150,241

0.65 (0.55 to 0.77)

67.5%

Sample size

<1,000[24, 27–30, 37, 38, 41, 42, 45, 46]

11

4,266

0.49 (0.29 to 0.83)

69.5%

≥1,000[22, 23, 25, 26, 31–35, 39, 40, 43],[44, 47]

15

331,979

0.70 (0.61 to 0.80)

75.1%

Financial support

YES[22, 23, 25, 28, 29, 31, 32, 34],[35, 38, 39, 44, 47]

13

194,211

0.75 (0.64 to 0.87)

78.1%

NO[24, 27, 30, 37, 42, 43]

6

7,289

0.43 (0.26 to 0.73)

67.6%

NA[26, 33, 40, 41, 45, 46]

7

134,745

0.51 (0.33 to 0.76)

57.9%

Data sources

Database[22, 25, 32, 34, 39, 40, 43, 47]

9

318,845

0.66 (0.56 to 0.77)

81.3%

Registry[23, 24, 26–31, 33, 35, 37, 38, 41],[42, 44–46]

17

17,400

0.61 (0.45 to 0.81)

70.6%

Adjusted by propensity score

YES[22, 23, 25, 28, 31, 34, 35, 39],[42, 44]

10

187,420

0.80 (0.70 to 0.91)

71.1%

NO[24, 26, 27, 29, 30, 32, 33, 36–38],[40, 41, 43, 45–47]

16

148,825

0.49 (0.38 to 0.64)

62.5%