Table:
screening strategy
total cost
total quality-adjusted life-years (qalys) per 1,000 women
incremental cost per qaly
average cost per qaly relative to no screening

$
$

no screening
1,387,948
14,059
..
base case

annual ages 40 to 69
6,668,051
14,094
216,828
150,938

annual ages 40 to 74
6,943,065
14,095
262,828
154,187

annual ages 50 to 69
3,970,099
14,082
159,858
114,778

annual ages 50 to 74
3,970,099
14,083
226,278
120,521

biennial ages 50 to 69
2,885,565
14,075
97,006
95,313

biennial ages 50 to 74
3,083,486
14,076
dominated
100,912

triennial ages 50 to 69
2,511,486
14,071
94,762
94,762

triennial ages 50 to 74
2,652,005
14,072
dominated
99,670

annual ages 40 to 49/ biennial ages 50 to 69
5,572,348
14,088
dominated
146,333

annual ages 40 to 49/ biennial ages 50 to 74
5,767,102
14,089
dominated
146,951

annual ages 40 to 49
4,156,667
14,073
dominated
higher cost/worse outcome

Statement: the lowest incremental ratio was for the trienial screening aged 50 to 69, which was $94,762/qaly.
Question: which screening strategy has the lowest incremental ratio?
Answer: triennial ages 50 to 69