FIG 2.

(A) Average number of days from referral to LDAP assessment. (B) Average number of days from referral to diagnosis. Red diamonds and lines represent special-cause variation, that is, it indicate instability in data and represent statistically significant differences; dark blue squares and lines represent in-control points and trends (common-cause variation). The baseline mean is represented by a light blue line, which was fixed and used to identify special-cause variation in the process moving forward. Process change with recalculation of CL occurred with (1) implementation of the outreach clinic and (2) transition to weekly clinics. CL, control limit; LCL, lower control limit; LDAP, Lung Diagnostic Assessment Program; SPC, statistical process control; UCL, upper control limit.