RESUMEN
Background: falls by inpatients often result in serious injuries and deterioration in a patient's physical abilities and quality of life, especially among older individuals. Although various factors have been found to be associated with falls, the combined effects of behavioural and ambient factors are not fully evaluated. Objective: we investigated the influence of both behavioural and ambient factors on inpatient falls, focusing on seasonal and diurnal variations. Design: retrospective study. Methods: we surveyed the incident reports related to falls from April 2010 to March 2014 and examined the relationship between the incidents and seasonal and diurnal variations in behavioural and ambient factors, including the sunrise time, the night-time length and temperature. Results: we identified 464 fallers from 3,037 incident reports. The average fall-rate of the study population was 1.4 ± 0.5/1,000 occupied bed-days. The seasonal and diurnal variations in falls were compared. The number of falls around dawn in October-February was higher than that in April-September. Toileting was the behaviour most frequently related to the falls (56.9%, n = 264), and 57.1% of the falls occurred at night. A multivariate analysis showed that the night-time length was significantly related to an increase in night-time falls (P = 0.047). Conclusion: these results suggested that the inpatient falls increased in the early morning from November to March and tended to be related to toileting activities. Considering these results, additional attention and support during the higher risk hours and seasons, especially in relation to toileting activities, might help to reduce the incidence of falls. Clinical trial name, URL and registration number: N/A (Because of retrospective nature).