Impact of the inpatient infectious disease consultations at a tertiary care university hospital

The role of the infectious disease specialist continues to evolve. The purpose of this study is to demonstrate the value of infectious disease consultation in the inpatient setting.METHODS This is a prospective cohort study that took place in a tertiary care university hospital. During the period from April to June 2016, 224 cases of patients receiving antibiotics in the hospital with the request of an infectious diseases’ consultation, were evaluated. The following variables were assessed: the referring department, purpose of the consultation, the antibiotic used before requesting the infectious diseases consultation, the antibiotic modifications after the infectious disease’s visit (changing the type, dose or range of the antibiotic when applicable, modifying the duration of antibiotic use), whenever the antibiotic usage was switched to a mono or bi-therapy.RESULTS The most frequent requesting departments were Oncology (23.2%) and Urology (21.4%). The purpose of the consultations was diagnosis (29%), therapy (41%), both diagnosis and therapy (21%), and prophylaxis (9%). An infectious diseases consultation was given at a rate of 4.9 consultations per 100 hospitalized patients. Antibiotic was discontinued in 14.7% of cases. There was no indication for the antibiotic treatment in 11.6% of cases. Modifying the antibiotic therapy was done in 25.4% of cases. Adjusting the antibiotic dosage was done in only one case. Carbapenem antibiotics were discontinued in 31.6% of cases and Quinolones discontinuation accounted for 22.7% of cases.CONCLUSION Infectious disease consults contributed to the optimization of the diagnostic and therapeutic approaches for suspected or confirmed infections in hospitalized patients.

Antibiotic stewardship programs (ASPs) are programs that optimize antibiotic usage. They are defined 3 by the Infectious Diseases Society of America as "coordinated interventions designed to improve and measure the appropriate use of antimicrobials by promoting the selection of the optimal antimicrobial drug regimen, dose, duration of therapy and route of administration". (5) Several studies reported the importance of such programs to decrease the economic cost and improve effectiveness of the antibiotic usage. (6,7) The role of the infectious disease (ID) specialist has been constantly evolving during the past decade. (8) The ID consultant is not only required to assist in the diagnosis, management and treatment of patients, but also to manage the hospital's infection control. (9,10) The aim of this study is to emphasize the role of infectious disease specialists in providing consultations to patients admitted to a tertiary care hospital.

Methods
This is a prospective cohort study that took place in a tertiary care university hospital located in Beirut, Lebanon. This hospital accounts for a total of 430 care beds. The analysis was conducted on a period of 3 months from April to June 2016. During the study period, the ID department consisted of 3 full-time ID consultants and two fellow residents. The ID consultations are typically initiated by a primary ("attending") physician. The antibiotic control policy of the hospital is that broad-spectrum antimicrobials are restricted, and their use requires approval by an infectious disease physician.
The population studied was all adult patients (18 years and older) that were admitted during that period (April to June 2016) with an infection (primary or secondary) for whom an initial formal ID consultation request was made. All stays transferred to the ID department were excluded from this study. Only adult patients receiving antibiotics were selected. There was no direct patient approach and cases were followed through an electronic medical record. Each unique admission was considered as the unit of analysis. There were 224 cases during that period. The medical committee of the hospital (Hotel Dieu de France, Beirut, Lebanon) approved this study.
The electronic and paper medical records (DX care version 7.7.2) were assessed between April to June 2016 searching for an infectious disease consultation. The following variables were collected using a standardized data collection form: the referring department, purpose of the consultation, the antibiotic used before the infectious diseases consultation was requested, the antibiotic modifications after the infectious disease's visit (changing the type, dose or range of the antibiotic when applicable, modifying the duration of antibiotic use), whenever the antibiotic usage was switched to a mono or bitherapy. All analyses were performed using Excel version 16.0 (Microsoft Corporation).

Results
During the study period, 224 cases of patients receiving antibiotics for an infection in the hospital with the request of an ID consultation, were evaluated. The mean age of the population was 63 years with a standard deviation of 17.9 and a median of 67. The characteristics of the population can be found in table 1. The most frequent requesting from medical departments was Oncology (52 patients) and the most frequent requesting from surgical departments was Urology (48 patients).
The following results were obtained: The purpose of the consultations was diagnosis (29%), therapy (41%), both diagnosis and therapy (21%), and prophylaxis (9%). An ID consultation was given at a rate of 4.9 consultations per 100 hospitalized patients.
Antibiotic was discontinued in 14.7% (33 patients) of cases. There was no indication for the antibiotic treatment in 11.6% (26 patients) of cases. Modifying the antibiotic therapy was done in 25.4% (57 patients) of cases (whenever empirically, after the results of a culture, or based on guidelines).
Changing to a broader spectrum antibiotic was carried in 23 patients whereas changing to an antibiotic with a narrower spectrum of action was conducted in 29 cases. Adjusting the antibiotic dosage was done in only one case. Carbapenem antibiotics were discontinued in 31.6% of cases (31 out of 98 patients) and Quinolones discontinuation accounted for 22.7% of cases (5 out of 22 patients). Prolonging or shortening the duration of the antibiotic therapy was carried in 7 and 13 cases respectively. A dual antibiotic therapy was indicated in 3.57% of patients (8 cases). Changing the treatment to a monotherapy was performed in 54.1% (13 out of 24 cases). Antibiotic was already This study performed over a short period of time shows the impact of the antibiotic stewardship programs and ID consultations on the reduction of the inpatient antibiotic consumption. The percentage of antibiotic discontinuation obtained (14.7%) was slightly lower than the one seen in other studies. (11,12) The most frequent requests for ID consultations came from the Oncology department, probably reflecting the complexity and disease severity of these patients.
The population in this study shows that the most common sites of infection were urinary (32%) followed by pulmonary/ENT infections (18%) and skin and soft tissue infections (17%) respectively.
The rate of ID consults per admission (4.9/100 admissions) is comparable to the one in other studies. There are some limitations to this study: One limitation is that it was conducted at a single center, and the results may not apply to other settings with different consultation styles. It did not evaluate the cost effectiveness nor the outcome of patients. This study lacks to determine the effect of the ID consultations' intervention on patients' bacterial colonization. The medical committee of the hospital (Hotel Dieu de France, Beirut, Lebanon) approved this study.

Consent for publication:
Not applicable.
Availability of data and materials: The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.

Competing interests:
The authors declare that they have no competing interests Funding source: This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors 7 Authors' contributions: DJ collected the data. RW carried the sequence alignment and drafted the manuscript. DJ and EH helped to draft the manuscript. MC participated in the design of the study. JC and GS conceived the study and participated in its design and coordination. All authors read and approved the final manuscript.