ORBIT classifications
| Primary outcome classifications | Secondary outcome classifications | ||||
|---|---|---|---|---|---|
| Classifications | Description | Level of reporting | Level of suspicion of ORB | Number of trials (percentage overall)† | Number of trials (percentage overall)* |
| Clear that the outcome was measured and analysed | |||||
| A | States outcome analysed but only reported that result not significant (typically stating p>0.05). | Partial | High risk | 75 (6.6%) | 12 (1.8%) |
| B | States outcome analysed but only reported that result significant (typically stating p<0.05). | Partial | Low risk | 13 (1.1%) | 2 (0.3%) |
| C | States outcome analysed but insufficient data presented to be included in meta-analysis or to be considered to be fully tabulated | Partial | Low risk | 53 (4.7%) | 15 (2.2%) |
| D | States outcome analysed but no results reported | None | High risk | 0 (0) | 0 (0) |
| Clear that the outcome was measured | |||||
| E | Clear that outcome was measured but not necessarily analysed | None | High risk | 59 (5.2%) | 26 (3.9%) |
| F | Clear that outcome was measured but not necessarily analysed | None | Low risk | 110 (9.7%) | 15 (2.2%) |
| Unclear that the outcome was measured | |||||
| G | Not mentioned but clinical judgement says likely to have been measured and analysed | None | High risk | 195 (17.1%) | 197 (29.4%) |
| H | Not mentioned but clinical judgement says unlikely to have been measured | None | Low risk | 141 (12.4%) | 256 (38.2%) |
| Clear that the outcome was NOT measured | |||||
| I | Clear that outcome was not measured | N/A | No risk | 0 (0) | 0 (0) |
The ORBIT classifications for review primary outcomes for the 280 RCTs. For the 12 reviews where reviewer input was obtained, classifications for 64 included trials for review secondary outcomes are also shown.
*The denominator used is the total number of data points expected if all 280 eligible trials reported on all review primary outcomes in the 37 reviews (ie, the number of review primary outcomes multiplied by the number of trials within the review for all reviews. This does not include the 102 trials where we were unable to assess primary outcomes).
†The denominator used is the total number of data points expected if all 64 trials reported on all review secondary outcomes in the 12 reviews (ie, the number of review secondary outcomes multiplied by the number of trials within the review for all reviews. This does not include the 59 trials where we were unable to assess secondary outcomes).
ORB, Outcome reporting bias; ORBIT, Outcome Reporting Bias In Trials; RCT, randomised controlled trial.