Impact of Culture Sensitivity Reports on the Pattern of Antibiotics use and Cost of Therapy: A Prospective Observational study

Abstract Background: There are concerns with inappropriate prescribing of antibiotics in hospitals especially broad spectrum in Pakistan and the subsequent impact on antimicrobial resistance rates. One recognized way to reduce inappropriate prescribing is for empirical therapy to be adjusted according to the result of culture sensitivity reports.Objective: To find the impact of culture sensitivity reports on the use of antibiotics and cost in a leading tertiary care hospital in Lahore.Methods: This prospective observational study was carried out in Ghurki trust teaching hospital. A total of 465 positive culture patients were taken over an 8 month study period using convenient sampling techniques and immediately sent to the microbiology laboratory for pathogen identification and susceptibility testing using the Kirby-Bauer disc diffusion method. Additional data was collected from the patient medical file which included demographic data, sample type, causative microbe, anti-microbial treatment given in empirical and definitive treatment as well as medicine costs. Results: Total of 497 isolates were detected from the 465 patient samples, which included 309 gram-negative rods and 188 gram-positive cocci. Out of 497 isolates, the most common Gram-positive pathogen isolated was MSSA (28.4%) and Gram-negative was E. coli (23.8%). Most of the gram-negative isolates were found to be resistant to ampicillin and co-amoxiclav. Most of the A. baumannii isolates were resistant to carbapenems. Gram-positive microorganism showed the maximum sensitivity to linezolid and vancomycin. The most widely used antibiotics in empirical therapy were cefoperazone+sulbactam, ceftriaxone, amikacin, vancomycin and metronidazole whereas high use of linezolid, clindamycin, meropenem and piperacillin + tazobactam was evidenced in definitive treatment. Empiric therapy was adjusted in 222 (71.8%) cases of Gram-negative infections and 131 (69.6%) cases of gram-positive infections (p-value <0.0001). Compared with empirical therapy, there was a 13.8% reduction in the number of antibiotics in definitive treatment. The average costs of antibiotics in definitive treatment was less than the empirical treatment (8.2%) and the length of hospitalization also decreased.Conclusion: Culture sensitivity reports helped reduce antibiotic utilization, hospital stay and costs as well as helping select the most appropriate treatment. We also found an urgent need for implementing antimicrobial stewardship programs and the development of hospital antibiotic guidelines within the hospital to reduce future unnecessary prescribing of broad-spectrum antibiotics.