Antibiotics play a critical role in orthopaedic inpatient care, particularly for surgical prophylaxis and prevention of implant-associated infections. Surgical site infections are associated with increased postoperative morbidity, prolonged hospital stay, and higher healthcare costs [1,2]. Assessment of prescribing practices using standardised drug utilisation indicators is essential for identifying irrational antibiotic use in hospital settings [3]. Common problems include inappropriate drug selection, unnecessary use of injectable formulations, prolonged duration of therapy, and excessive use of multiple antibiotics. Inappropriate and excessive antibiotic consumption has emerged as a major global public health concern, accelerating the development of antimicrobial resistance [4]. India is among the highest consumers of antibiotics worldwide, and several hospital-based studies have documented irrational prescribing practices [5]. In orthopaedic practice, empirical use of broad-spectrum antibiotics, extended postoperative prophylaxis, and combination therapy are frequently employed, often in the absence of microbiological confirmation [6]. To promote rational antibiotic use, the World Health Organization introduced the Access, Watch and Reserve (AWaRe) classification system to guide antibiotic selection and monitor consumption patterns [7]. However, institution-specific data evaluating antibiotic use among orthopaedic inpatients using the AWaRe framework remain limited. The present study was undertaken to address this gap. Objectives Primary Objective To evaluate antibiotic prescribing patterns among orthopaedic inpatients. Secondary Objectives To assess injectable and combination antibiotic use and to classify prescribed antibiotics according to the WHO AWaRe framework.

Study Design and Setting A record-based cross-sectional observational study was conducted in the Orthopaedic Inpatient Department of Calcutta National Medical College & Hospital, Kolkata, India. Study Period January 2023 to June 2023. Study Population and Sample Size Adult orthopaedic inpatients receiving systemic antibiotics during hospitalisation were included. A total of 60 prescriptions were analysed. As an exploratory drug utilisation study, a convenient sample size was considered appropriate in accordance with WHO recommendations for prescription audit studies [3]. Data Collection Data were collected from Bed Head Tickets using a structured proforma capturing diagnosis, antibiotics prescribed, route of administration, duration of therapy, and use of combination therapy. Statistical Analysis Data were analysed using IBM SPSS Statistics for Windows, Version 25.0. Results were expressed as mean ± standard deviation and percentages [8]. Ethical Considerations The study was approved by the Institutional Ethics Committee (EC-CNMC/175). As this was a record-based study, informed consent was waived.

Antibiotic utilization indicators are summarised in Table 1. The mean number of antibiotics prescribed per patient was 3.18 ± 0.59, indicating a high level of antimicrobial exposure. Injectable antibiotics constituted 98.95% of all prescriptions, and 95% of patients received combination antibiotic therapy. According to the WHO AWaRe classification, 63.87% of the prescribed antibiotics belonged to the Watch group. The pattern of antibiotic therapy is depicted in Table 2. Combination therapy predominated (95%), while monotherapy was used in 5% of cases. Watch group antibiotics (63.87%) were prescribed more frequently than Access group antibiotics (36.13%). Pre-operative surgical prophylaxis practices are shown in Table 3. Injection cefuroxime was prescribed in 85% of patients, followed by injection ceftriaxone in 15%. Post-operative surgical prophylactic antibiotic use is detailed in Table 4. Among 131 post-operative antibiotic prescriptions, injection amikacin (41.98%) and injection cefuroxime (35.11%) were the most frequently used agents. Use of higher-end antibiotics such as meropenem was minimal. Table 1. Antibiotic Utilisation Indicators among Orthopaedic Inpatients (n = 60) Parameter Value Total prescriptions analysed 60 Mean number of antibiotics per prescription (Mean ± SD) 3.18 ± 0.59 Injectable antibiotics used 98.95% Combination therapy 95% Monotherapy 5% Access group antibiotics (AWaRe) 36.13% Watch group antibiotics (AWaRe) 63.87% Reserve group antibiotics 0 The mean number of antibiotics prescribed per patient was 3.18 ± 0.59. Injectable antibiotics were used in nearly all prescriptions (98.95%). Combination therapy predominated (95%). According to WHO AWaRe classification, Watch group antibiotics constituted the majority (63.87%), while Access group antibiotics accounted for 36.13%. No Reserve group antibiotics were prescribed. Table 2. Pattern of Antibiotic Therapy and WHO AWaRe Classification Parameter Number (%) Monotherapy 3 (5%) Combination therapy 57 (95%) Access group antibiotics 36.13% Watch group antibiotics 63.87% Reserve group antibiotics 0 The prescribing pattern showed an overwhelming preference for combination antibiotic therapy (95%). AWaRe analysis demonstrated predominant use of Watch group antibiotics. Table 3. Pre-operative Surgical Prophylactic Antibiotics (n = 60) Antibiotic Number of patients Percentage (%) Injection Cefuroxime 51 85 Injection Ceftriaxone 9 15 For pre-operative prophylaxis, injection cefuroxime was most frequently prescribed (85%), followed by injection ceftriaxone (15%). Table 4. Post-operative Antibiotic Utilisation Pattern (n = 131 prescriptions) Antibiotic Number Percentage (%) Injection Amikacin 55 41.98 Injection Cefuroxime 46 35.11 Injection Metronidazole 13 9.99 Injection Ceftriaxone 9 7.00 Injection Piperacillin 5 3.82 Injection Meropenem 3 2.29 Among post-operative antibiotics, injection amikacin was most commonly prescribed (41.98%), followed by injection cefuroxime (35.11%). Broad-spectrum agents such as piperacillin and meropenem were used sparingly.

The present study demonstrates extensive use of injectable antibiotics and combination therapy among orthopaedic inpatients, with an average of more than three antibiotics prescribed per patient. Similar patterns have been reported in other Indian studies conducted in surgical and orthopaedic settings [9,10]. The high proportion of injectable antibiotic use exceeds WHO prescribing indicator recommendations and raises concerns regarding rational drug use, increased healthcare costs, and injection-related complications [3]. Evidence supports early intravenous-to-oral switch strategies once clinical stability is achieved [11]. Combination therapy was prescribed in the majority of patients. Although appropriate in selected high-risk cases, indiscriminate use without microbiological guidance may accelerate antimicrobial resistance without proportional clinical benefit [12]. From an antimicrobial stewardship perspective, the predominance of Watch-group antibiotics is concerning. WHO recommends prioritising Access-group antibiotics and restricting Watch-group agents to clearly justified indications [7,13]. The preference for cefuroxime in pre-operative prophylaxis aligns with established guidelines for clean orthopaedic surgeries [6]. However, post-operative escalation highlights the need for culture-guided therapy and strict adherence to institutional antibiotic policies [14,15]. Recommendations Regular prescription audits, implementation of institutional antibiotic guidelines, culture-guided therapy, and early intravenous-to-oral switch strategies are recommended to promote rational antibiotic use.

Antibiotic prescribing among orthopaedic inpatients was characterised by predominant use of injectable formulations, frequent combination therapy, and extensive reliance on Watch-group antibiotics. Strengthening antimicrobial stewardship initiatives is essential to optimise antibiotic use and combat antimicrobial resistance.

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