Figure 5:

Process-control charts for care practices for infants born at gestational age 23 through 32 weeks. Means (solid lines) and upper (UL) and lower (LL) control limits (dotted and dashed lines) calculated using 2004–2017 data. Margins of the limits were recalculated for each period based on the number of infants per 6-month period, and the reported UL and LL correspond to the first 6 months of 2004. Large dots show the percentage of infants admitted each 6-month period who received each care practice among all eligible infants. Denominators used to calculate percentages were all infants (n = 50 831). The median number of infants for each 6-month period was 1937 (range 1182–2152). Note: NICU = neonatal intensive care unit.