Advertisement
Table 1 Assessment of study quality, risk of bias, and confounding
| Methodological assessment summary (N=59 studies) | %* |
|---|---|
| 1. Exposure definition (sepsis) | |
| i) Consensus [7, 8, 28–32, 35, 37, 39, 40, 44, 45, 47–50, 63–74] | 49 % |
| ii) Claims/ICD codes [11, 24–26, 38, 41, 58, 75–77] | 14 % |
| iii) Pathogen-plus (either positive blood culture or pathogen specified) [27, 34, 36, 46, 53, 78–81] | 20 % |
| iv) Pneumonia [33, 40, 42, 43, 52, 82–85] | 15 % |
| v) Peritonitis [21, 51, 86] | 5 % |
| 2. Ascertainment of exposure | |
| i) Claims/ICD codes data | 13 % |
| ii) Randomized controlled trial cohorts [44, 45, 63, 66, 69, 70] | 10 % |
| iii) Non-interventional study cohorts | 75 % |
| 3. Selection of the control cohort | |
| i) Drawn from ICU patients without sepsis | |
| a. Matched [35] | 2 % |
| b. Not matched [7, 25, 30–32, 37, 41] | 12 % |
| ii) Drawn from hospitalized infected patients (not ICU) | |
| a. Matched | |
| b. Not matched [30, 41] | 3 % |
| iii) Drawn from hospitalized non-infected patients (not ICU) | |
| a. Matched [36] | 2 % |
| b. Not matched [30, 34, 38–41] | 10 % |
| iv) Population controls | |
| a. Matched [30, 33, 37, 41–43] | 10 % |
| b. Not matched [40, 41] | 3 % |
| v) No control cohorts/no controls for mortality comparison | 73 % |
| 4. Comparability of cohorts on the basis of design or analysis | |
| i) Regression models to adjust for confounders | |
| a. Regression models in studies reporting control population | |
| - Post-acute mortality [7, 25, 30, 33–37, 39, 42] | 16 % |
| - Cumulative mortality | |
| - Stratified analysis for post-acute mortality [32, 40, 42, 43] | 5 % |
| - Non-mortality outcome models [31, 38, 41] | 5 % |
| b. Regression models using in studies with no controls | |
| - Post-acute mortality | 22 % |
| - Cumulative mortality | 20 % |
| - No mortality model | 31 % |
| ii) Studies reporting sepsis dose-response [39, 46, 49, 52, 53] | 9 % |
| 5. Assessment of post-acute mortality | |
| i) Record linkage with national or regional databases or outcome assessed by contact with patient or relatives | 90 % |
| ii) No description | 10 % |
| 6. Adequacy of follow up | |
| i) Complete follow up, all participants accounted for | 22 % |
| ii) Loss to follow up unlikely to introduce bias (<20 % loss, or >20 % but those lost described and unlikely to be different from those followed) | 61 % |
| iii) Follow up <80 % and no description of those lost | 3 % |
| iv) No statement | 14 % |
| 7. Report both acute and post-acute mortality (or that information can be determined from the reported data) | |
| i) At one year | 72.9 % |
| ii) Between 2 and 10 years [11, 29–32] | 8.5 % |
| iii) No mortality data/post-acute mortality not estimable/follow-up time unclear [21, 24–28] | 10.2 % |
