Hazard of death associated with cumulative hours above or below the mean during the first 5 days (linear and non-linear models)
| Staffing exposure (cumulative sum over the first 5 days) | Adjusted HR | P values | 95% CI |
| Linear model | |||
| RN hours | 0.97 | 0.023 | 0.94 to 1.00 |
| NA hours | 1.01 | 0.394 | 0.98 to 1.04 |
| Df 41; AIC 61 919.4; BIC 42 405.66 | |||
| Non-linear model | |||
| RN hours | 0.98 | 0.200 | 0.95 to 1.01 |
| RN hours2 | 1.00 | 0.621 | 0.99 to 1.01 |
| RN hours3 | 1.00 | 0.930 | 1.00 to 1.00 |
| NA hours | 1.00 | 0.835 | 0.97 to 1.04 |
| NA hours2 | 1.01 | 0.014 | 1.00 to 1.02 |
| NA hours3 | 1.00 | 0.061 | 1.00 to 1.00 |
Df 45; AIC 61 920.19; BIC 62 453.88.
All models include control for turnover (admissions per nurse), patient risk (SHMI), first NEWS, emergency admission and ward (for full model see online supplementary tables g,h).
AIC, Akaike information criterion; BIC, Bayesian information criterion; NA, nursing assistant; NEWS, National Early Warning Score; RN, registered nurse; SHMI, Summary Hospital Mortality Indicator.