Table 1 Parameters used to calculate cost impact and cost-effectiveness

Cost _t

Full cost per PCR test

€

300

Additional file 1

1, 4, 5,

DG

Days gainable on adequate treatment when utilizing PCR+ information

day

2.78 = 80.5/29

[17]^a

2,3,4

$D{u}_{PCR+}^{IA}$

Mean total duration of inadequate treatment (as observed in PCR+ episodes with 0.5 ≤Du _IA ≤ 7.5)

day

3.28 = 0.5 + DG

[17]^a

2, 5,

$F_{LOS}^{IA}$

Factor which translates days on earlier adequate treatment into outcome in terms of mean days reduced length of stay (deltaLOS = LOS _Inad - LOS _Ad )

-

1.15 = 3.763 day/3.276 day

$=\frac{deltaLOS}{D{u}_{PCR+}^{IA}}$ calculated from [3, 4, 17]

3, 4

$I{n}_{PCR+}^{IA}$

Incidence of inadequate treatment in the PCR+ group

-

0.397 = 29/73

Figure 1

4, 5

LY _gained

Mean # years survival of survivors of ICU sepsis, age cohort >60 ^c

yr

5.43 ^b = 12.3 * 488/1105

[26]

6

$M_{PCR+}^{IA}$

Mortality rate of inadequately treated PCR+ patients

-

0.414 = 12/29

Figure 1

5

RR †

Relative risk of non-survival (@ inadequate/adequate treatment)

-

2.315

[3, 4, 17] pooled

5

Sh _PCR+

Share of episodes with at least 1 PCR+ microorganism

-

0.330 = 73/221

Table 2

4, 5

TAT _PCR

Time between PCR sampling and result reported (hours)

hr

12

[17]

2

Utility _health.state

Health state utility after ICU sepsis

QALY/yr

0.68

[26]

6