25. 母集団は何か?
• The
STARD
Statement
– ITEM
3
Describe
the
study
populaSon:
the
inclusion
and
exclusion
criteria,
seWng
and
locaSons
where
data
were
collected.
– ITEM
4
Describe
parScipant
recruitment:
was
recruitment
based
on
presenSng
symptoms,
results
from
previous
tests,
or
the
fact
that
the
parScipants
had
received
the
index
tests
or
the
reference
standard?
26. 有病率を考慮した診断法
ベイズの定理 (検査陽性の時)
a+c
pretest odds =
b+d
a a + c a(b + d)
posttest odds = = ×
b b + d b(a + c)
sensitivity
= pretest odds ×
1− specificity
= pretest odds × positive likelihood ratio(LR+)
27. 有病率を考慮した診断法
ベイズの定理 (検査陰性の時)
a+c
pretest odds =
b+d
c a + c c(b + d)
posttest odds = = ×
d b + d d(a + c)
1− sensitivity
= pretest odds ×
specificity
= pretest odds × negative likelihood ratio(LR−)
38. FIGURE. Serum troponin I for detection of myocardial infarction
in subjects with chest pain within 3hours from onset
1.0
0.8
Troponin I
AUC = 0.75
0.6
Sensitivity
0.4
0.2
0.0
0.0 0.2 0.4 0.6 0.8 1.0
1 - specificity
39. FIGURE. Serum troponin I for detection of myocardial infarction
in subjects with chest pain within 3hours from onset
1.0
理想的な検査
AUC
=
1.00
0.8
Troponin I
AUC = 0.75
0.6
Sensitivity
0.4
0.2
0.0
0.0 0.2 0.4 0.6 0.8 1.0
1 - specificity
40. FIGURE. Serum troponin I for detection of myocardial infarction
in subjects with chest pain within 3hours from onset
1.0
0.8
Troponin I
AUC = 0.75
0.6
Sensitivity
サイコロを振るのと同等
0.4
AUC
=0.50
0.2
0.0
0.0 0.2 0.4 0.6 0.8 1.0
1 - specificity
41. FIGURE. Serum troponin I for detection of myocardial infarction
in subjects with chest pain within 3hours from onset
1.0
0.8
Troponin I
AUC = 0.75
0.6
Sensitivity
サイコロを振るのと同等
0.4
AUC
=0.50
LR+ = 1
LR- = 1
0.2
0.0
0.0 0.2 0.4 0.6 0.8 1.0
1 - specificity
42. FIGURE. Serum troponin I for detection of myocardial infarction
in subjects with chest pain within 3hours from onset
1.0
LR+ = +∞
LR- = 0
0.8
Troponin I
AUC = 0.75
0.6
Sensitivity
サイコロを振るのと同等
0.4
AUC
=0.50
LR+ = 1
LR- = 1
0.2
0.0
0.0 0.2 0.4 0.6 0.8 1.0
1 - specificity
43. FIGURE. Serum troponin I for detection of myocardial infarction
in subjects with chest pain within 3hours from onset
1.0
0.8
Troponin I
AUC = 0.75
0.6
Sensitivity
0.4
0.2
0.0
0.0 0.2 0.4 0.6 0.8 1.0
1 - specificity
44. Net
ReclassificaSon
Improvement
• 2つの予測モデルを比較して、
NRI
=
疾患陽性群でのΔ偽陰性率
+ 疾患陰性群でのΔ偽陽性率
Cook,
CirculaSon
2007
Pencina
et
al.,
StaSstMed
2008