The use of antimicrobial agent does not only diverse between countries, but also diverse between the hospitals of a same country. These differencies can be correlated with hospital and patient features, antibiotic policies of the hospitals, physicians preferences and with the differencies in the educational and health systems .
Antimicrobial agents are the most frequently used drugs in Turkey and they constitue 22% of all drugs used .
In our study, the rate of antibiotics used was found to be 47.7%. In similar studies performed in our country the in-hospital rate of antibiotic use ranges between 45.6% and 61%, coinciding with the rates we detected [8, 23, 24]. In the Northern European countries the in-hospital rates of antibiotic use are lower than in our country, ranging between 16.6% and 25% [25, 26].
In this study the proper antibiotic rate of use was found to be 61.9%. While in the departments for internal diseases this rate was 76.6%, in the surgical departments and in the intensive care units the rates were 38.9% and 81.8% respectively. While 32% of the patients received antibiotics for surgical prophylaxis, the use of antibiotics for acute exacerbation of COPD (29.9%) and penumonia (14.3%) draws our attention. High rate of antibiotic use is acceptable because one of the major pharmacologic treatment used in acute exacerbation of chronic obstructive pulmonary disease(COPD) are antibiotics .
When we evaluated the duration of surgical prophylaxis as a whole, the proper antibiotic choice, administration time and way were found to be only 27.7% appropriate. The major reason of the low proper antibiotic use rate in the surgical departments compared to other departments were the errors in the use of surgical prophylaxis. While the antibiotic for surgical prophylaxis was largely properly chosen, what was improper was the duration of prophylaxis. The mean duration of surgical prophylaxis was found to be 4.74 days. In surgical units, where surgical prostheses are implanted, surgical prophylaxis has been observed to be more inappropriate. Surgical prophylaxis was most frequently used in the orthopedics service. Average duration of surgical prophylaxis was 9.5 days and all of the patients were using more than one drug combination containing antibiotics. Urology and ENT were services that implement the most appropriate surgical prophylaxis. In similar studies, no errors were seen in the agent used in the prophylaxis, while the unnecessary extension of therapy was the main problem [28, 29]. The proper antibiotic use in the intensive care units compared to the internal diseases and surgical departments was the use of antibiotic according to ‘evidence based’ (45.5%), and more regularly obtained consultations from the department for infectious diseases. The antibiotic use according to ‘evidence based’ in our hospital consist only 5.4% of the total antibiotic use and it is similar to other studies performed in our country [30, 31]. In order to improve the improper use of antibiotics, eductional activities should be performed periodically, policies of current antibiotic use should be formed by the infection committees of the hospitals and the clinical practices should be controlled.
According to our study cephalosporins constitute 57% of the antimicrobials used in our hospital. Cephalosporins are followed by fluoroquinolones with 14.7% and penicillins with 10% of use. Of the cephalosporins used, 21% were 3rd generation, 20.8% 1st generation and 15.2% 2nd generation, which ranks on the first 3 places of the total drugs used. According to the ARPAC (Antibiotic Resistance, Prevention and Control) project, all hospitals most frequently used penicillins, followed by non-penicillin beta lactams and fluoroquinolones . Antibiotic utilization rate in Turkey was found to be higher compared to the European countries. Especially the use of cephalosporins, penicillins and fluoroquinolones is much higher than in the European countries [33, 34]. The frequent use of cephalosporins and fluoroquinolones lead to the emergence of resistant microorganisms, thus problems such as the emergence of resistant pathogenes in our area would be an inevitable consequence .
The ACI in our hospital was found to be 55.1 DDD/100 bed-days. In the intensive care units the ACI was 87.8 DDD/100 bed-days, in the departments for internal diseases 56.4 and in the surgical departments 49.1 DDD/100 bed-days. Eventhough the proper antibiotic use in the surgical departments was found to be lower than the department for internal diseases and intensive care units, the ACI value was lower. According to Akalın et al.’s study  in a university hospital, the ACI in 2009 was found to be 64.5 DDD/100 bed-days while in 2010 70.5 DDD/100 bed-days. These values are higher than the values in our study. This fact can be linked to the fact that in tertiary hospitals clinically more complicated and seriously ill patients are being treated compared to secondary hospitals. In a study by Vaccheri et al.  conducted in an university hospital in Italy it was shown that, the amount of antibiotics used, rised from 64.9 DDD/100 bed-day in 2002 to 76.7 DDD/100 bed-days in 2004. In the ARPAC Project conducted in 130 European hospitals, the antibiotic use was found to be 792 + 147 DDD/1000 bed-days. According to this large scale study, the antibiotic use in our country is parallel with southern and western Europe but higher than northern, middle and eastern European countries .
If we keep in mind that antibiotics are the most frequently used drugs in the hospitals, than we would know that they constitute an important part of the total drug expenditure. In our hospital the defined cost per infected patient per day was 16.85 USD. As expected, the antibiotic use in the intensive care units for infected patients was higher than in other clinics. Antibiotic use in the surgical departments was found to be 7.86 USD per infected patient per day, which is lower than other departments. Despite of the unnecessary extension of surgical prophylaxis, the reason of this is the choice of less expensive 1st generation cephalosporins. However, as the improper use of antibiotics is still high, the in-hospital antibiotic expenditure can be reduced even more. Reducing improper use of antibiotics would prevent the incidence of life-threatening serious infections, also preventing long hospital stays and higher health expenditures. The department for pulmonary diseases draws attention with the highest number of patients and also with the highest number of patients using antibiotics. The department for pulmonary diseases uses 27.5% of the daily antibiotic costs. Vast majority of the patients are hospitalized in this department due to diseases caused by smoking. Smoking can be considered as one of the factors that increases the use of antibiotics in hospitals.
Our study, carried out with point-prevalence method has certain limitations such as being single-centered, not having resistance ratios calculated and involving only one day of the year. The study was carried out in the summer period. Especially pneumonia and acute exacerbation of COPD are diseases seen more oftenly in the winter, and clinically more complicated diseases are less encountered in the summer period. However, by applying a method inexpensive and easy to implement as the point-prevalence, we can say that we gained detailed knowledge of the antimicrobial use in our hospital.
As a result, the use of ATC/DDD system in hospitals would provide internationally valid data in the evaluation of antimicrobial use. We believe that, more efficient utilization of infectious diseases experts in the use of antibiotics in hospitals, creating of guides for antibiotic use specific to every hospital and more efficient use of the microbiological laboratories may be of benefit in the resolving of existing problems.