Nurse and doctor turnover and patient outcomes in NHS acute trusts in England: retrospective longitudinal study.

Objective: To investigate the association between monthly turnover rates of hospital nurses and senior doctors and patient health outcomes (mortality and unplanned hospital readmissions).

Design: Retrospective longitudinal study.

Setting: All 148 NHS acute trusts in England (1 April 2010 to 30 March 2019), excluding specialist and community NHS hospital trusts.

Participants: Yearly records on 236 000 nurses, 41 800 senior doctors (specialist, associate specialist and specialty doctors, and consultants), and 8.1 million patients admitted to hospital.

Main Outcome Measures: The panel data regression analysis used nine years of monthly observations from administrative datasets at healthcare worker and patient levels. Associations using linear and unconditional quantile regressions were estimated, including controls for seasonality and NHS hospital trust. Four hospital quality indicators (risk adjusted by patient age, sex, and Charlson index comorbidities) were used and measured at a monthly frequency on a percentage scale: mortality risk within 30 days from all cause, emergency, or elective admission to hospital, and risk of unplanned emergency readmission within 30 days from discharge after elective hospital treatment.

Results: A 1 standard deviation (SD) increase in turnover rate for nurses was associated with 0.035 (95% confidence interval 0.024 to 0.045) and 0.052 (0.037 to 0.067) percentage point increases in risks of all cause and emergency admission mortality, respectively, at 30 days. The corresponding values for senior doctors were 0.014 (0.005 to 0.024) and 0.019 (0.006 to 0.033) percentage point increases. Higher nurse turnover rate was associated with higher mortality risk at 30 days in surgical (P<0.01) and general medicine (P<0.01) specialties, as well as mortality for patients admitted to hospital with infectious and parasitic diseases (international classification of diseases, 10th revision; P<0.05) and injury, poisoning, and consequences of external causes (P<0.01). Higher turnover rates for senior doctors were associated with higher mortality risk at 30 days for patients admitted to hospital with infectious and parasitic diseases (P<0.05), mental and behavioural disorders (P<0.05), and diseases of the respiratory system (P<0.05). Turnover rates for hospital nurses and senior doctors were not statistically significantly associated with risk adjusted hospital mortality and unplanned emergency readmissions for elective patients.

Conclusions: Lower turnover rates for nurses and senior doctors at hospital level were associated with better health outcomes for patients with emergency hospital admissions.

Study Registration: Integrated Research Application System project ID 271302.