Does persistent precarious employment affect health outcomes among working age adults? A systematic review and meta-analysis.

To evaluate the impact of persistent precarious employment (lasting 12+ months) on the health of working age adults, compared with more stable employment. Persistent precarity reflects a shift towards less secure forms of employment and may be particularly important for health.Nine databases were systematically searched to identify quantitative studies that assessed the relationship between persistent precarious employment and health outcomes. Risk of bias (RoB) was assessed using an adaptation of the Effective Public Health Practice Project tool. Narrative synthesis and random effects meta-analysis were conducted. Certainty of evidence was assessed using the Grades of Recommendations, Assessment, Development and Evaluation (GRADE) approach.Of 12 940 records screened, 50 studies met the inclusion criteria and 29 were included in meta-analyses. RoB was generally high (n=18). The most reported outcome domain was mental health; with evidence also reported relating to general health, physical health,and health behaviours. Of GRADE assessed outcomes, persistent precarious employment was associated with increased risk of poor self-rated health (OR 1.53, 95% CI 1.09 to 2.14, I²=80%) and mental health symptoms (OR 1.44, 95% CI 1.23 to 1.70, I²=65%). The association with all-cause mortality was imprecisely estimated (OR 1.10, 5% CI 0.91 to 1.33, I²=73%). There was very low GRADE certainty across all outcomes.Persistent precarious employment is associated with poorer health, particularly for outcomes with short time lags, though associations are small and causality is highly uncertain. Further research using more robust methods is needed but given potential health harms of persistent precarious employment, exploration of precautionary labour regulations and employment policies is warranted.