Implications for practice and research

• ▪ Even in a highly regarded health sciences centre, increased risk of death was observed for patients exposed to nurse staffing below targeted levels and to unit conditions with high patient turnover, particularly within the first 5 days of admission and for non-intensive care unit patients.

• ▪ Similar studies with variation in hospital sites, staffing, mortality and quality are needed to corroborate these findings.

• ▪ In future studies, deeper probing for a dose-response gradient will strengthen inferences about harmful effects.

• ▪ Observational designs are needed that temporally link shift-level administrative data to clinical outcomes for specific patient populations.

• ▪ Under increasingly constrained financial and human resources, research that accounts for staffing patterns experienced by patients and other modifiable factors influencing outcomes …