Fig. 2From: Nurse staffing and patient outcomes: a longitudinal study on trend and seasonalityTrend and seasonal variation in fall rates. Trend is represented by the trajectory of annual mean rate and seasonal variation is represented by the trajectory of (quarterly rate – annual mean rate); rates were aggregated over units within 42 groups. The thick line in each plot is for the group of 1240 units with all 36 quarters of data in 2004–2012. Each vertical dash line denotes the fourth quarter of a yearBack to article page