Problem #1

Reducing Delays from Abnormal Mammogram to Biopsy

The medical director of the Worldbest Health Plan was concerned with what he felt were inordinate days in the time between reading an abnormal mammogram and obtaining a definitive biopsy. He collected the average delay time per week for a period of 20 weeks, presented them to a continuous quality improvement (CQI) team, and instructed them to remedy the problem. He felt an average waiting time of 31 days was unacceptable. He also felt that the process was continuing to deteriorate. He pointed to the fact that the delay time reached 40 days during week 14, In addition, during the last six weeks he felt there was a "negative trend" from 26 days to 35 days of wait time.

Using Excel, calculate the median delay time per week and construct a run chart using the data below.Compare the delay times per week to the median. Display your chart.

Question: Does this process show common or special cause variation? Is this something that the medical director should be concerned with? Would it be productive to investigate and eliminate the cause (whether it is common or special)? Why or why not?

Week	Average Delay Time (in days)
1	34
2	30
3	35
4	32
5	28
6	26
7	29
8	28
9	35
10	26
11	34
12	31
13	28
14	40
15	26
16	32
17	31
18	30
19	33
20	35