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Outcome Reporting Bias in Trials


ORBIT classifications (harm outcomes)

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The ORBIT II classification system for missing or complete outcome reporting in harm outcomes

Classification

Description

Level of reporting

Risk of bias*

Explicit specific harm outcome: measured and compared across treatment groups

P1

States outcome analysed but reported only that p-value>0.05.

Partial

High Risk

P2

States outcome analysed but reported only that p-value<0.05.

Partial

High Risk

P3

Insufficient reporting for meta-analysis or full tabulation.

Partial

Low Risk

Explicit specific harm outcome: measured but not compared across treatment groups

Q

Clear that outcome was measured and clear outcome was not compared.

NA

No risk

Explicit specific harm outcome: measured, not clear whether compared or not across treatment groups

R1

Clear that outcome was measured but no results reported.

None

High Risk

R2

Result reported globally across all groups.

None

High Risk

R3

Result reported from some groups only.

None

High Risk

Specific harm outcome not explicitly mentioned: clinical judgment says likely measured and likely compared across treatment groups

S1

Only pooled adverse events reported (could include specific harm outcome).

None

High Risk

S2

No harms mentioned or reported.

None

High Risk

Specific harm outcome not explicitly mentioned: clinical judgment says likely measured but no events

T1

Specific harm not mentioned but all other specific harms fully reported.

None

Low Risk

T2

No description of specific harms.

None

Low Risk

Specific harm outcome not explicitly mentioned, clinical judgment says unlikely measured

U

No harms mentioned or reported.

None

Low Risk

Explicit the specific harm outcome was not measured

V

Report clearly specifies that data on the specific harm of interest was not measured.

NA

No Risk

 

*Bias would occur if specific harm had been measured, but data were presented or suppressed in a way that would mask the harm profile of particular interventions.