Table. Condensed summary of findings and certainty of evidence (as per GRADE).
| Number of participants (number of studies) | Effect estimate (95% CI) | Certainty of evidence | |
|---|---|---|---|
| Income changes and grouped mental health outcomes | |||
| Any income change (effect direction) | 922 428 (54) | 88·9% (77·4 to 95·8) of studies report beneficial effect of income on mental health | Low* |
| 10% income increase | 1510 666 (9) | Standardised β 0·003 (0·0003 to 0·005) | Low* |
| Crossing poverty or subsistence threshold | 42 128 (18) | SMD 0·13 (0·07 to 0·20) | Low† |
| Income decrease (mixed amounts) | 227 804 (11) | SMD –0·21 (–0·30 to – 0·13) | Very low‡ |
| Income changes and grouped wellbeing outcomes | |||
| Any income change (effect direction) | 311 219 (40) | 95·0% (83·1 to 99·4) of studies report beneficial effect of income on wellbeing | Low* |
| 10% income increase | 105 326 (9) | Standardised β 0·003 (0·002 to 0·005) | Very low‡ |
| Crossing poverty or subsistence threshold | 101 350 (8) | SMD 0·38 (0·09 to 0·66) | Low* |
| Income decrease (mixed amounts) | Insufficient evidence§ |
GRADE=Grading of Recommendations Assessment, Development and Evaluation. SMD=standardised mean difference. For full GRADE results, see the appendix (p 93).
*
Downgraded by 2 levels for inconsistency and risk of bias of included studies.
†
Downgraded by 2 levels for inconsistency and indirectness of evidence.
‡
Downgraded by 3 levels for inconsistency, risk of bias of included studies, and publication bias.
§
Insufficient numbers of studies identified to investigate this planned GRADE outcome.