Table 4.
Association of reporting quality with journal impact factor and citation count
| Reporting item | Reporting adequate | Impact factor 2012 | P-value | Citations per article | P-value | Studies (n) |
|---|---|---|---|---|---|---|
| STROBE related | ||||||
| [S1] Study design in title or abstract | Yes | 3.4 (1.9; 4.5) | 0.87 | 5 (2; 11) | 0.427 | 39 |
| No | 3 (2.3; 3.9) | 4 (2; 9) | 78 | |||
| [S2] Selection criteria of participants | Yes | 3.1 (2.1; 4.5) | 0.737 | 5 (2; 9.5) | 0.973 | 92 |
| No | 3.2 (2.8; 3.9) | 7 (4; 15) | 14 | |||
| [S3] Details on interventions/exposures | Yes | 3.3 (2.2; 4.3) | 0.733 | 5 (2; 11) | 0.268 | 86 |
| No | 3.1 (2.5; 3.2) | 3 (1; 9.5) | 12 | |||
| [S4] Details on outcomes | Yes | 3.4 (2.2; 4.5) | 0.047 | 5 (2; 11) | 0.057 | 87 |
| No | 2.6 (1.9; 3.4) | 4 (1; 10) | 9 | |||
| [S5a] Variables used for analyses listeda | Yes | 3.5 (2.2; 4.9) | 0.027 | 5 (2; 12) | 0.223 | 54 |
| No | 3.2 (2.6; 4.2) | 4.5 (2; 13) | 12 | |||
| [S5b] … described in sufficient detail | Yes | 3.7 (2.4; 5.1) | 0.013 | 6 (3; 11) | 0.277 | 34 |
| No | 3.2 (2.2; 4.2) | 6 (2; 13) | 37 | |||
| RCD related | ||||||
| [R1] Use of RCD/registry data in title/abstract | Yes | 3.3 (2.1; 4.4) | 0.554 | 5 (2; 10) | 0.876 | 89 |
| No | 2.9 (2.3; 3.4) | 3.5 (2; 9) | 34 | |||
| [R2] Coding of participants | Yes | 3.6 (2.8; 5.6) | 0.006 | 5.5 (3; 11) | 0.427 | 26 |
| No | 2.5 (1.9; 3.7) | 2 (1; 7) | 33 | |||
| [R3] Coding of interventions/exposures | Yes | 3.5 (2.3; 4.7) | 0.081 | 5.5 (2.5; 15) | 0.259 | 20 |
| No | 2.3 (1.9; 3.7) | 3 (1; 7) | 32 | |||
| [R4] Coding of outcomes | Yes | 3.6 (2.2; 5.2) | 0.11 | 5 (3; 7) | 0.882 | 29 |
| No | 2.6 (2.2; 3.3) | 3 (1; 11) | 23 | |||
| [R5] Characteristics of data source | Yes | 3.1 (2.2; 4.3) | 0.538 | 4 (2; 11) | 0.471 | 75 |
| No | 2.8 (2.2; 3.7) | 6 (1; 11) | 17 | |||
| [R6] Methods of data linkage | Yes | 2.8 (2.1; 4.8) | 0.963 | 4.5 (3; 10) | 12 | |
| No | 3.3 (2.1; 4.5) | 5 (2; 10) | 0.932 | 28 | ||
| [R7] Data availability/sharing | Yes | 17.2 (2.4; 18) | 0.108 | 14 (4; 19) | 0.135 | 3 |
| No | 3.1 (2.2; 4.1) | 4 (2; 10) | 119 | |||
| [R8] Validation of classification algorithms | Yes | 3.5 (2.5; 5.4) | 0.206 | 6 (4; 8) | 0.466 | 13 |
| No | 2.7 (2.2; 4.2) | 3.5 (1; 8) | 50 | |||
Abbreviations: STROBE, STrengthening the Reporting of OBservational studies in Epidemiology; RCD, routinely collected data.
Impact factors for 2012 were not available for publishing journals of six studies; citations up to February 2015 as of ISI Web of Knowledge (all databases); impact factors and citation counts are medians with interquartile ranges.
a
Or the strategies used to create models reported.