Table 2

Comparison of detection times betweenprogressor and statpac 2 (Wilcoxon signed rank Z test)

CasesMean rank
Negative ranks13.00
Positive ranks1810.39
Ties0
Total19
• Z = −5.1816, p = 0.0002.

• Negative ranks occur when statpac 2 detects progression in a given field series earlier thanprogressor.

• Positive ranks occur when progressor detects progression in a given field series earlier than statpac 2.

• Ties occur when both algorithms detect progression in a given field series at the same time.