Table 2.
List of ICD codes used in included studies
| Study | ICD codes | Primary/secondary/tertiary |
| Scudeller 200918 | No ICD code data available in study | – |
| Fedeli 201126 | ICD 9: 421, 98.84 or 112.81 | P+S |
| Thornhill 201114 | ICD 10: I33 | P+S |
| Ternhag 201316 | ICD 10: I33, I38 or I39 | Unspecified |
| Dayer 20152 | ICD 10: I33 | P+S |
| Cresti 20161 | ICD 9: 421 .x | P+S |
| Erichsen 201624 | ICD 10: I33 or I38.9 | Unspecified (first-time code of incident IE recorded) |
| Keller 20163 | ICD 10: I33 | Unspecified |
| van den Brink 201631 | Insurance-based codes used for case extraction | – |
| Olmos 201717 | ICD 9: 421.0, 421.1, 421.9 or 424.99 | P+S |
| Ahtela 201811 | ICD 10: I33, I38 or I39 (specificity 96.8%) | P (66.3%)+S (24.1%)+T (9.6%) |
| Jordal 201812 | ICD 10: I33.0, I38, or I39.0 (after year 1999) | Unspecified |
| Ortega 201928 | ICD 9: 421.0, 421.1, 421.9, 112.81, 115.04, 115.14, or 115.94 | P+S |
| Jensen 20204 | ICD 10: I33.x, I38.x or I39.8 ICD 8: 421 |
P+S |
| Quan 202025 | ICD 10: I33.0, I33.9, I39.0, I39.8, I01.1, B37.6, or T82.6 | P+S |
| Shah 202013 | ICD 10: I33, I38 or I39 ICD 9: 421.1, 424.91, 424.90 or 424.99 |
Unspecified |
| Thornhill 202015 | ICD 10: I33 | P+S |
| Vähäsarja 202010 | No ICD code data available in study | – |
ICD, International Classification of Diseases.