Table 2 Role of biomarkers in the initiation of antibiotic therapy for lower respiratory tract infection

PCT

Stolz D, [20]

Single-centre, randomised, controlled open study

208

High

Antibiotic exposure and rate of initiation of antibiotic therapy, based on PCT level > 0.25 μg/L

ARR = 32% (40% vs. 72%) of antibiotic prescriptions in the PCT-guided group.

(AECB)

Ab exposure OR = 0.56 [0.43-0.73]

PCT

Schuetz P, [25]

Multicentre, open RCT

1359

High

Antibiotic exposure

ARR = 12% (75.4% vs. 87.7%) in PCT group, Overall antibiotic exposure = - 35% (5.7 vs. 8.7 days).

Noninferiority study

(ED)

Based on a PCT level > 0.25 μg/L for initiating prescription.

PCT

Christ-Crain M, [18]

Single-centre open RCT

302

High

Antibiotic initiation rate

ARR = 14% (85% vs. 99%) in initial antibiotic prescription in PCT group

(ED, ward)

Antibiotic exposure

Based on a PCT level > 0.25 μg/L to initiate therapy

Overall ab exposure: OR = 0.52 [0.48–0.55]

PCT

Kristoffersen KB, [19]

Single-centre, open, RCT

210

High

Antibiotic prescription rate, based on a PCT level > 0.25 μg/L to initiate therapy in PCT group

3% increase in antibiotic prescription (88% vs. 85%) in the PCT group

(ED, ward)

PCT

Long W, [23]

Single-centre, open RCT

127

High

Antibiotic prescription rate, based on a PCT level > 0.25 μg/L in the PCT group

ARR = 11% of antibiotic prescriptions in the PCT group

(ED)

PCT

Long W, [22]

Single-centre, open RCT

156

High

Antibiotic prescription rate, based on a PCT level > 0.25 μg/L in the PCT group

ARR = 13% of antibiotic prescriptions in the PCT group

(ED)

PCT

Burkhardt O, [16]

Single-centre, open RCT, noninferiority

550

High

Antibiotic prescription rate, based on a PCT level > 0.25 μg/L in the PCT group

ARR = 15% (21.5% vs. 36.7%) for antibiotic prescription rate in the PCT group

(PC)

PCT

Briel M, [15]

Multicentre, open RCT, noninferiority

458

High

Antibiotic prescription rate, based on a PCT level > 0.25 μg/L in the PCT group

ARR = 72% [95% CI 66-78] for antibiotic prescription rate in the PCT group

(PC)

PCT

Schuetz P, [30]

Meta-analysis of 14 RCTs

3 119

High

Risk reduction of initial antibiotic therapy: OR = 0.24 (95% CI, 0.2-0.29)

Overall antibiotic exposure:

OR = 0.1 (95% CI = 0.07-0.14), without difference in mortality rates

PCT

Van der Meer V, [28]

Literature review on the use of CRP (13 studies)

13

High

Prediction of LRTI

Bacterial LRTI predicted with a sensitivity varying from 8% to 99% and a specificity varying from 27% to 95%

PCT

Schuetz P, [29]

Review of 8 RCTs using an PCT-based algorithm for the initiation of antibiotic therapy

3 457

High

Antibiotic prescription rate

ARR varying from 6% to 72%

CRP

Cals JW, [24]

Multicentre, open cluster-RCT, testing a CRP-based algorithm

431

High

Antibiotic prescription rate and antibiotic exposure, based on a CRP value < 20 : no antibiotic; CRP >100 : atb recommended, and 20<CRP<99 : reassess for possible therapy

ARR = 22% (31% vs. 53%) of initial antibiotic prescriptions in the CRP group

Overall antibiotic exposure: - 13% (45% vs. 58%)

PCT

Christ-Crain M, [17]

Multicentre, open, cluster-RCT

243

High

Antibiotic prescription rate, based on a PCT level > 0.25 μg/L in the PCT group

ARR = 39% for antibiotic prescription rate in the PCT group

(ED)

Summary of evidence table: Lower respiratory tract infection

Number of studies, n

Total number of patients, n

Highest level of evidence

Directness*

Consistency**

Overall strength of evidence

12

4 412

High

Yes

Yes

Strong