Table 5.
Quality assessment of quantitative studies using STROBE criteria [20].
| STROBE criteria | Birkenhead [36]a | Tesema et al. [27] | Pelly et al. [25] | Thurecht et al. [30] | Pelly et al. [29] | Blennerr-hassett et al. [28] | Thurecht et al. [32] | Stickler et al. [31] | |
|---|---|---|---|---|---|---|---|---|---|
| Title and abstract | |||||||||
| 1 | Design in title | * | * | * | * | * | * | ||
| 2 | Informative abstract | * | * | * | * | * | * | * | * |
| Introduction | |||||||||
| 3 | Rationale | * | * | * | * | * | * | * | |
| 4 | Specific objectives | * | * | * | * | * | * | * | * |
| Methods | |||||||||
| 5 | Study design | * | * | * | * | * | * | * | |
| 6 | Setting | * | * | * | * | * | * | * | * |
| 7 | Participants | * | * | * | * | * | * | * | |
| 8 | Variables | * | * | * | * | * | * | * | |
| 9 | Data source | * | * | * | * | * | * | * | |
| 10 | Bias | ||||||||
| 11 | Study size | * | * | * | * | ||||
| 12 | Quantitative variables | * | * | * | * | * | * | * | |
| 13 | Statistical methods | * | * | * | * | * | * | * | * |
| 14 | Subgroups & interactions | * | * | * | * | * | * | * | |
| 15 | Missing data | ||||||||
| 16 | Sampling strategy | NA | N/A | NA | N/A | N/A | N/A | NA | N/A |
| 17 | Sensitivity analysis | ||||||||
| Results | |||||||||
| 18 | Participants | * | * | * | * | * | * | * | |
| 19 | Non-participation | ||||||||
| 20 | Flow diagram | ||||||||
| 21 | Descriptive data | * | * | * | * | * | * | * | |
| 22 | Missing data | * | N/A | N/A | * | * | |||
| 23 | Outcome events | * | * | * | * | * | * | * | |
| 24 | Confounders | ||||||||
| 25 | Category boundaries | N/A | N/A | NA | N/A | N/A | N/A | NA | * |
| 26 | Risk | N/A | N/A | NA | N/A | N/A | N/A | NA | N/A |
| 27 | Other analyses | * | * | * | * | * | * | * | N/A |
| Discussion | |||||||||
| 28 | Key results | * | * | * | * | * | * | * | * |
| 29 | Limitations | * | * | * | * | * | * | * | |
| 30 | Interpretation | * | * | * | * | * | * | * | * |
| 31 | Generalisability | * | * | * | * | * | * | ||
| Other information | |||||||||
| 32 | Funding | * | * | * | * | * | * | ||
| Total score | 20 | 8 | 20 | 22 | 21 | 22 | 22 | 22 | |
Bold values indicate total score of quality based on the sum of the number of items that meet the reporting criteria for each study
* = addressed by authors; P = partially addressed by authors; N/A = not applicable
aMasters thesis
1. Indicate the study’s design with a commonly used term in the title or the abstract
2. Provide in the abstract an informative and balanced summary of what was done and what was found
3. Explain the scientific background and rationale for the investigation being reported
4. State specific objectives, including any prespecified hypotheses
5. Present key elements of study design early in the paper
6. Describe the setting, locations, and relevant dates, including periods of recruitment, exposure, follow-up, and data collection
7. Give the eligibility criteria, and the sources and methods of selection of participants
8. Clearly define all outcomes, exposures, predictors, potential confounders, and effect modifiers. Give diagnostic criteria, if applicable
9. For each variable of interest, give sources of data and details of methods of assessment (measurement). Describe comparability of assessment methods if there is more than one group
10. Describe any efforts to address potential sources of bias
11. Explain how the study size was arrived at
12. Explain how quantitative variables were handled in the analyses. If applicable, describe which groupings were chosen and why
13. Describe all statistical methods, including those used to control for confounding
14. Describe any methods used to examine subgroups and interactions
15. Explain how missing data were addressed
16. Describe analytical methods taking account of sampling strategy
17. Describe any sensitivity analyses
18. Report numbers of individuals at each stage of study, e.g., numbers potentially eligible, examined for eligibility, confirmed eligible, included, completing follow-up, and analysed
19. Give reasons for non-participation at each stage
20. Consider use of a flow diagram
21. Give characteristics of study participants (e.g., demographic, clinical, social) and information on exposures and potential confounders
22. Indicate number of participants with missing data for each variable of interest
23. Report numbers of outcome events or summary measures
24. Give unadjusted estimates and, if applicable, confounder-adjusted estimates and their precision (eg, 95% confidence interval). Make clear which confounders were adjusted for and why they were included
25. Report category boundaries when continuous variables were categorized
26. Consider translating estimates of relative risk into absolute risk for a meaningful time period
27. Report other analyses done, e.g., analyses of subgroups and interactions, and sensitivity analyses
28. Summarise key results with reference to study objectives
29. Discuss limitations of the study, taking into account sources of potential bias or imprecision. Discuss both direction and magnitude of any potential bias
30. Give a cautious overall interpretation of results considering objectives, limitations, multiplicity of analyses, results from similar studies, and other relevant evidence
31. Discuss the generalisability (external validity) of the study results
32. Give the source of funding and the role of the funders for the present study and, if applicable, for the original study on which the present article is based