Effect of Automated Telephone Infectious Disease Consultations to Nonacademic Hospitals on 30-Day Mortality Among Patients With Staphylococcus aureus Bacteremia: The SUPPORT Cluster Randomized Clinical Trial

Abstract

Importance: Staphylococcus aureus bacteremia (SAB) is a common and potentially severe infectious disease (ID). Retrospective studies and derived meta-analyses suggest that bedside infectious disease consultation (IDC) for SAB is associated with improved survival; however, such IDCs might not always be possible because of the lack of ID specialists, particularly at nonacademic hospitals.

Objectives: To investigate whether unsolicited telephone IDCs (triggered by an automated blood stream infection reporting system) to nonacademic hospitals improved 30-day all-cause mortality in patients with SAB.

Design, setting, and participants: This patient-blinded, multicenter, interventional, cluster randomized, controlled, crossover clinical trial was conducted in 21 rural, nonacademic hospitals in Thuringia, Germany. From July 1, 2016, to December 31, 2018, 1029 blood culture reports were assessed for eligibility. A total of 386 patients were enrolled, whereas 643 patients were not enrolled for the following reasons: death before enrollment (n = 59); palliative care (n = 41); recurrence of SAB (n = 9); discharge from the hospital before enrollment (n = 77); age younger than 18 years (n = 5); duplicate report from a single patient (n = 26); late report (n = 17); blood culture reported during the washout phase (n = 48); and no signed informed consent for other or unknown reasons (n = 361).

Interventions: During the ID intervention phase, ID specialists from Jena University Hospital provided unsolicited telephone IDCs to physicians treating patients with SAB. During the control phase, patients were treated according to local standards. Crossover was performed after including 15 patients or, at the latest, 1 year after the first patient was included.

Main outcomes and measures: Thirty-day all-cause mortality.

Results: A total of 386 patients (median [IQR] age, 75 [63-82] years; 261 [67.6%] male) were included, with 177 randomized to the IDC group and 209 to the control group. The 30-day all-cause mortality rate did not differ between the IDC and control groups (relative risk reduction [RRR], 0.12; 95% CI, -2.17 to 0.76; P = .81). No evidence was found of a difference in secondary outcomes, including 90-day mortality (RRR, 0.17; 95% CI, -0.59 to 0.57; P = .62), 90-day recurrence (RRR, 0.10; 95% CI, -2.51 to 0.89; P = .89), and hospital readmission (RRR, 0.04; 95% CI, -0.63 to 0.48; P = .90). Exploratory evidence suggested that indicators of quality of care were potentially realized more often in the IDC group than in the control group (relative quality improvement, 0.16; 95% CI, 0.08-0.26; P = .01).

Conclusions and relevance: In this cluster randomized clinical trial, unsolicited telephone IDC, although potentially enhancing quality of care, did not improve 30-day all-cause mortality in patients with SAB.

Trial registration: drks.de Identifier: DRKS00010135.

Figure 1.. Flow Diagram of the SUPPORT Trial

IDC indicates infectious disease consultation. ^aTwenty centers underwent crossover and completed both the IDC and control phases; however, because of very low recruitment rates, 4 centers were combined to form a reasonable cluster size, resulting in 17 clusters for analysis.

Figure 2.. Study Outcomes by Treatment Group

A, Primary and secondary outcomes. B, Kaplan-Meier plot of the composite end point (EP) of recurrence-free survival (exploratory evidence because the CIs may be biased because of the clustering of the data). C, Quality-of-care indicators (QIs). BC indicates blood culture; IDC, infectious disease consultation; RQI, relative QI improvement; RRR, relative risk reduction; TEE, transesophageal echocardiography; and TTE, transthoracic echocardiography.

Figure 3.. Study Outcomes by Treatment Group According to the Sensitivity Analysis Excluding the 2 Centers That Initiated Infectious Disease Consultation (IDC) Services

A, Primary and secondary outcomes. B, Kaplan-Meier plot of the composite end point (EP) of recurrence-free survival (exploratory evidence because the CIs may be biased because of the clustering of the data). C, Quality-of-care indicators (QIs). BC indicates blood culture; RQI, relative QI improvement; RRR, relative risk reduction; TEE, transesophageal echocardiography; and TTE, transthoracic echocardiography.