Data extraction framework
| Bibliometrics | Original trial characteristics | Follow-up trial characteristics |
|---|---|---|
| Authors | Trial name | Time since trial closure |
| Title | Country of origin | |
| Year of publication | Original authors (differ from follow-up study's authors?) | Data sources for follow-up outcomes (eg, health administrative, population registry, EMRs). Linkages fields and type linkage (probabilistic/deterministic); where was linkage conducted (eg, academic, government body, etc)? |
| Publication source | Outcomes (primary and secondary) | Outcomes (primary and secondary); identification of extended trial outcomes: structured data (eg, claims data); unstructured data—information contained in text (eg, EMR) or other documents; technique used for extracting information: manual, text mining |
| Journal impact (low/high) | Timeframe | |
| Intervention applied | ||
| Potential/realised clinical or policy implications | Were the conclusions of the original trial altered? | |
| Funders | Potential/realised clinical or policy implications; for example, evidence supporting or against current guidelines | |
| Comments regarding ethics approval | ||
| Funders | ||
| Challenges, time requirements and costs associated with extension | ||
| Methodological issues (eg, unadjusted time-varying confounding) | ||
| Stated reasons for trial extension (eg, long-term treatment effects, potential ‘legacy’ effects) |
EMR, electronic medical record.