Table 1.
Summary of the 18 Studies Included in the Systematic Review
| First Author/Publication Year/Location | Setting | Study Design | Adjustment for Confounders | Study Period | Characteristic of Included Patients | Source of Bacteremia | Enterococcus Species | Antimicrobials Studied | Outcome | D&B Score |
|---|---|---|---|---|---|---|---|---|---|---|
| Bartoletti/2019/Bologna, Italy [27] | Single academic center | Quasi-experimental study | Cox proportional hazard regression (result of multivariate analysis not available) | 4 y | Adult, mean age 70 y 20.9% community-acquired 10.3% ICU admission 20.1% DM 24.7% CKD 12.8% cirrhosis 23.1% immunocompromised 23.6% malignancy 7.3% solid organ transplant Excluded polymicrobial bacteremia | UTI 17.7% IAI 36.4% Line-associated 14.4% Endocarditis 9.8% | E. faecalis 56% E. faecium 35.1% Others 8.7% VRE 1.4% | Evaluated appropriateness of therapy and use of combination therapy, with suggested dosages included | Pre–post study of alert system and structured IDC for enterococcal bacteremia; 30-d mortality was the primary outcome. Bivariate analysis showed IDC was protective (HR, 0.42; 95% CI, 0.28–0.62). During the postimplementation period, more patients got appropriate therapy, follow-up blood cultures, echocardiography, and source control. | 20 |
| Britt/2017/USA [28] | 99 Veterans Affairs hospitals | Retrospective cohort study | None | 11 y | Adult patients who had VRE bacteremia treated with either linezolid or daptomycin 32% ICU admission 51.8% CKD 9.5% cirrhosis 3.2% HIV 37.3% malignancy 3.2% transplant Enterococcus with resistance to both linezolid and daptomycin was excluded | UTI 11.6% IAI 4.4% Line-associated 10.8% SSTI 3.3% Endocarditis 8% Unknown 47% Multiple sites 14.9% | E. faecium 100% VRE 100% | Linezolid and daptomycin | IDC was associated with decreased 30-d mortality (370/1335, 27.7%, for IDC vs 549/1444, 38.0%, for NIDC: RR, 0.86; 95% CI, 0.82–0.90; P ≤ .001). The trend is the same among the linezolid therapy group and daptomycin therapy group, but not in the linezolid-to-daptomycin group. | 21 |
| Cattaneo/2021/Freiburg, Germany [23] | Single academic center | Prospective cohort study | Cox regression analysis | 3 y 1 mo | Adult, median age 68 y 26% DM 30% CKD 10% chronic liver disease 3% IVDU 43% malignancy 13% severe immunosuppression 40% polymicrobial bacteremia 42% ICU admission | UTI 14% IAI 33% Line-associated 13% Endocarditis 20% Osteomyelitis 2% Unknown 15% | E. faecalis 100% VRE 0% | Ampicillin as definitive therapy | In multivariate Cox regression analysis, ID was not significantly protective for mortality or recurrence within 90 d (HR, 0.87; 95% CI, 0.45–1.66). IDC was significantly associated with follow-up blood culture (91% vs 56%; P < .001), early source control (89% vs 65%; P = .001), echocardiography (84% vs 25%; P < .001), use of ampicillin as definitive therapy (78% vs 30%; P < .001), and adequate treatment duration (76% vs 43%; P = .001). | 21 |
| Erlandson/2008/Nebraska, USA [29] | 2 academic centers | Retrospective cohort study | None | 12 y 2 mo | 32.7% CKD 61.9% liver dysfunction 40.7% malignancy 55.8% transplant | Not reported | E. faecalis 0.9% E. faecium 99.1% VRE 100% | Linezolid and quinupristin-dalfopristin | Outcome was in-hospital mortality. IDC was associated with higher in-hospital mortality (OR, 2.96; 95% CI, 1.02–8.61; P < .05) but not selected in the multivariate model. | 15 |
| Furuichi/2018/Tokyo, Japan [30] | Single academic center | Retrospective cohort study | Multiple logistic regression | 14 y 9 mo | Pediatric, median age 9.3 mo 31% polymicrobial bacteremia 15% transplant | UTI 9% IAI 19% Line-associated 59% Endocarditis 2% SSI 1% Unknown 10% | E. faecalis 62% E. faecium 30% E. casseliflavus or E. gallinarum 5% Others 3% VRE 2.7% | Penicillins, glycopeptides (ie, vancomycin), and aminoglycosides | 30-d mortality was 8% (8/100) among those who got IDC vs 17% (9/52) among those who did not (OR, 0.42; 95% CI, 0.15–1.15; P = .11). Multivariate analysis showed an OR of 0.55 (95% CI, 0.16–1.71; P = .28). IDC was associated with appropriate empiric therapy and definitive therapy. Source of bacteremia was less likely unknown with IDC (5% IDC vs 19% NIDC). | 20 |
| Gray/2018/Virginia, USA [31] | Single academic center | Quasi-experimental study | None | 3 y 11 mo | Adult, mean age 60 y 73.6% central venous catheter 38.2% community-acquired 38.2% renal failure 15.5% cirrhosis 33.6% immunocompromised 28.2% malignancy 20% transplant Excluded polymicrobial bacteremia | UTI 5.5% IAI 26.4% Line-associated 30.9% SSTI 3.6% Endocarditis 11.8% SSI 5.5% Unknown 16.4% | E. faecalis 30.9% E. faecium 69.1% VRE 59.1% | Penicillins, vancomycin, daptomycin, and linezolid | Relationship between IDC and mortality was not available. | 21 |
| Jindai/2014/Wisconsin, USA [32] | Single academic center | Retrospective cohort study | None | 2 y 10 mo | Adult, mean age 57.1 y 57.1% central venous catheter 13.2% community-acquired 24.3% polymicrobial bacteremia 31.6% DM 12.8% cirrhosis 42.9% malignancy 31.8% transplant | UTI 9.5% IAI 27.5% Line-associated 18.5% | E. faecalis 39.7% E. faecium 56.6% Others 3.7% VRE 39.7% | Not reported | Outcome was in-hospital mortality. IDC was similarly made among those who survived (86/153, 56.2%) vs those who died (20/35, 57.1%; P = .92). As a secondary outcome, IDC was significantly associated with elimination of bacteremia in multivariate analysis (OR, 2.50; 95% CI, 1.32–4.72; P = .005). | 19 |
| Jumah/2018/Singapore [33] | Single academic center | Retrospective cohort study | Multiple logistic regression (result of multivariate analysis not available) | 6 y 5 mo | Adult, median age 75 y 14% ICU admission 36.8% DM 10.5% cirrhosis 7% immunocompromised 31.6% malignancy Excluded polymicrobial bacteremia | UTI 22.8% IAI 31.6% Line-associated 3.5% SSTI 5.3% Endocarditis 5.3% Unknown 24.6% | E. faecalis 36.8% E. faecium 56.1% Others 7% VRE 0% | Vancomycin with and without aminoglycosides | IDC was similarly done for patients who survived after 30 d (28/47, 59.6%) vs those who died within 30 d (5/10, 50%; P = .72). | 22 |
| Lee/2020/Alabama, USA [24] | Single academic center | Retrospective cohort study | Multiple logistic regression | 1 y 6 mo | Adult, median age 59 y 16% community-acquired 53% ICU admission 36% DM 28% CKD 9% cirrhosis 5% IVDU 25% immunocompromised 4% connective tissue disease 2% HIV 8% hematological malignancy 12% transplant | UTI 10% IAI 14% Line-associated 21% SSTI 3% Endocarditis 8% Bone & joint 8% Others 7% Unknown 32% | E. faecalis 65% E. faecium 33% Others 2% VRE 33% | Evaluated appropriateness of therapy; regimen not discussed | 30-d mortality was 12% (16/131) among those who got IDC vs 27% (20/74) among NIDC (P = .007). IDC was a significant protective factor for 30-d mortality (aOR, 0.35; 95% CI, 0.16–0.76; P = .07). IDC was associated with increased likelihood of repeat blood cultures (aOR, 12.83), echocardiography (aOR, 2.45), appropriate antibiotic duration (aOR, 6.65), and decreased likelihood of unknown source of bacteremia (aOR, 0.31). | 21 |
| MacVane/2016/South Carolina, USA [34] | Single academic center | Quasi-experimental study | None | 5 y | Adult, 33.8% community-acquired 20.6% polymicrobial bacteremia 38.2% ICU admission 35.3% DM 19.1% renal replacement therapy 5.9% liver disease 4.4% HIV 47.1% hematological malignancy | UTI 10.3% IAI 26.5% Line-associated 19.1% SSTI 1.5% Unknown 42% | E. faecalis 7% E. faecium 93% VRE 100% | Vancomycin, daptomycin, and linezolid | Outcome was in-hospital mortality; 36.2% (17/47) of patients who got IDC died, and 23.8% (5/21) of patients who did not died (OR, 1.81; 95% CI, 0.31–6.47). | 20 |
| Malone/1986/Ohio, USA [35] | 2 community hospitals | Retrospective cohort study | None | 4 y | Adult, 36.4% community-acquired 38.2% polymicrobial bacteremia | UTI 23.6% IAI 10.9% Line-associated 5.5% SSTI 10.9% | Not reported | Evaluated appropriateness of therapy and use of combination therapy, with regimens included | Unclear what time frame was used for mortality; 54.5% (12/22) of patients who got IDC died, and 36.4% (12/33) of patients who did not died (OR, 2.1; 95% CI, 0.32–5.94). | 15 |
| McKinnell/2011/Alabama, USA [36] | Single academic center | Retrospective cohort study | Multiple logistic regression | 3 y 7 mo | Adult patients with nosocomial VRE bacteremia Mean age 53.7 y 51% polymicrobial bacteremia 39% ICU admission 36% DM 49% CKD 23% liver disease 22% immunocompromised 3% HIV 30% hematological malignancy 16% transplant | Not reported | E. faecalis 3% E. faecium 97% VRE 100% | Linezolid and daptomycin | IDC was done for patients who survived after 30 d (27/153, 18%) vs who died within 30 d (7/82, 9%; P = .06). Multivariate analysis showed that IDC had a nonsignificant trend toward being protective (OR, 0.4; 95% CI, 0.2–1.2; P = .06). | 21 |
| Mercuro/2020/Michigan, USA [37] | Single academic center | Retrospective cohort study | None | 6 y 2 mo | Adult patients with history of solid organ transplant Median age 61 y 75% central venous catheter 36.5% community-acquired 50% polymicrobial bacteremia | UTI 8% IAI 83% Unknown 8% | E. faecium 100% VRE 79% | Daptomycin with or without a beta-lactam, and linezolid | 30-d mortality was 23% (11/48) among those who got transplant IDC. No information about N IDC. Transplant IDC was not associated with mortality in bivariate analysis (OR, 0.3; 95% CI, 0.2–5.2). | 18 |
| Nakagawa/2018/Washington, USA [38] | Single academic center | Retrospective cohort study | None | 3 y 11 mo | Adult, 17.2% DM 10.9% CKD 21.9% cirrhosis 81.3% immunocompromised 1.6% HIV 71.9% malignancy 10.9% solid organ transplant | Not reported | VRE 100% | Daptomycin and linezolid | Relationship between IDC and mortality was not available. | 19 |
| Nakakura/2019/Osaka, Japan [25] | Single academic center | Retrospective cohort study | None | 5 y 11 mo | Adult with Enterococcus faecium bacteremia treated with vancomycin Median age 73 y 26.7% central venous catheter Excluded if received dialysis | UTI 11.1% IAI 11.1% Line-associated 8.9% Biliary tract 48.9% Unknown 20% | E. faecium 100% VRE 0% | Vancomycin | IDC was done for 63.6% of patients who survived after 30 d (21/33) vs 50% of those who died within 30 d (6/12; P = .50). | 20 |
| Narayanan/2019/New Jersey, USA [39] | Single academic center | Retrospective cohort study | None | 4 y 8 mo | Patients with VRE bacteremia treated with either linezolid or daptomycin 59.1% central venous catheter 16.1% community-acquired 28% ICU admission | IAI 17.2% Line-associated 26.9% Endocarditis 5.4% Unknown 45.2% | E. faecium 100% VRE 100% | Linezolid and daptomycin | Outcome was 14-d in-hospital mortality. Mortality was 22.1% (19/86) among those who got IDC vs 14.3% (1/7) among those who did not (P = .629). | 20 |
| Valentin/2021/Graz, Austria [40] | Single academic center | Prospective cohort study | None | 1 y | Not well described Patients after RAST followed by ID consultation were compared with a historical cohort | Not reported | E. faecalis or E. faecium 100% VRE 0% | Evaluated changes in therapy after IDC; specific regimens not discussed | 30-d mortality was 50% (5/10) among those who got RAST and IDC vs 27.7% (13/47) among those who did not. | 14 |
| Zasowski/2016/Michigan, USA [41] | Single academic center | Retrospective cohort study | Multiple logistic regression (result of multivariate analysis for mortality was not available) | 5 y | Adult with hospital-onset enterococcal bacteremia Mean age 63.4 y 32.1% polymicrobial bacteremia 36.3% ICU admission 45.3% DM 53.2% CKD 17.4% cirrhosis 6.8% IVDU 11.6% immunocompromised 4.7% HIV 16.8% malignancy 1.1% transplant | UTI 10.5% IAI 15.8% Line-associated 49.4% SSTI 9.5% Endocarditis 3.7% Unknown 10.5% | E. faecalis 53.2% E. faecium 46.8% VRE 62.6% | Evaluated appropriateness of empiric and definitive therapies, including vancomycin, ampicillin, piperacillin-tazobactam, linezolid, and daptomycin | IDC within 24 h after blood culture was done for 50% of patients who survived after 30 d (22/44) vs 52.1% of those who died within 30 d (76/146; P = .81). IDC was an independent factor for less delayed therapy (adjusted risk ratio, 0.41; 95% CI, 0.26–0.64; P < .001). IDC was also associated with shorter time to appropriate therapy (HR, 0.593; 95% CI, 0.436–0.805; P = .001). | 21 |
Abbreviations: aOR, adjusted odds ratio; CKD, chronic kidney disease; DM, diabetes mellitus; HR, hazard ratio; IAI, intra-abdominal infection; ICU, intensive care unit; ID, infectious diseases; IDC, infectious disease consultation; IVDU, intravenous drug use; NIDC, no infectious disease consultation; OR, odds ratio; RAST, rapid antimicrobial susceptibility testing; RR, relative risk; UTI, urinary tract infection; SSTI, skin and soft tissue infection; VRE, vancomycin-resistant Enterococci.