Jackob Aron Ndayomwami

We assessed inpatient antibiotic use over six fiscal years at Tanzania’s national cardiac referral hospital. Overall use was 29.9 defined daily doses per 100 bed-days. Carbapenems were dominant. Reserve agents comprised 47.0%, and watch agents comprised 31.7%. Patterns indicate missed access targets and a need to strengthen stewardship in cardiac care.

Background: Outpatient encounters are significant contributors to avoidable antibiotic exposure. However, the dispensing-based outpatient consumption data for Tanzania are limited. Most national estimates rely on import or sales data that do not reflect patient-level use. Cardiovascular clinics are particularly relevant because cardiopulmonary symptom overlap can lead to precautionary prescribing. Methods: We conducted a retrospective dispensing-based utilization analysis of cardiovascular outpatients at the Jakaya Kikwete Cardiac Institute (JKCI) in Dar es Salaam, Tanzania, from July 2017 to June 2022. Systemic antibacterial agents were mapped to the World Health Organization anatomical therapeutic chemical/defined daily dose (WHO ATC/DDD) and expressed as defined daily doses per 100 outpatients per day. Consumption patterns were summarized by fiscal year, molecule, ATC level 3, and WHO Access/Watch/Reserve (AWaRe) category. Monthly consumption was decomposed to evaluate trends and seasonality. Results: A total of 11,586 outpatients received at least one systemic antibiotic during the study period. Annual outpatient antibiotic utilization remained low and stable, ranging from approximately 0.27 to 0.38 DDD per 100 outpatients per day across fiscal years, with a cumulative total of 1.68 DDD per 100 outpatients per day across the five years. Consumption was dominated by beta-lactam/penicillin antibiotics, with Access antibiotics accounting for 48.5% of cumulative exposure, followed by Watch antibiotics (45.5%) and minimal Reserve use (5.9%). However, the Access proportion was below the WHO Access-60 benchmark for optimal outpatient use. Time-series decomposition revealed a modest upward trend, peaking in early 2021, accompanied by a recurring seasonal pattern of monthly use. Conclusion: Outpatient antibiotic utilization at JKCI was quantitatively low, yet showed persistent exposure dominated by Access antibiotics. Dispensing-based outpatient surveillance is feasible and should be integrated into routine stewardship dashboards to target avoidable outpatient antibiotic use.

Objective: To analyse trends in antibiotic use among cardiovascular inpatients at the Jakaya Kikwete Cardiac Institute (JKCI), Tanzania, from 2016 to 2022, using the World Health Organisation (WHO) Anatomical Therapeutic Chemical/Defined Daily Dose (ATC/DDD) methodology. Design: Retrospective longitudinal study. Setting: Jakaya Kikwete Cardiac Institute, a 150-bed national referral and teaching hospital in Dar es Salaam, Tanzania. Patients: 11,656 cardiovascular inpatients; 6,612 (56.7%) received at least one systemic antibiotic. Methods: Prescription data (250,591 total; 30,885 antibiotic-related) were extracted from the JKCI MedPro dispensing system. Antibiotic use was expressed in Defined Daily Doses per 100 bed-days (DDD/100). Analyses were conducted using Microsoft Excel, SPSS version 26, and time-series forecasting with AutoRegressive Integrated Moving Average (ARIMA) modelling in R. Results: Overall, antibiotic use was 29.88 DDD/100 bed-days. Injections accounted for more than 55% of use. At the ATC Class 4 level, carbapenems (J01DH) dominated (45.6%), followed by third-generation cephalosporins (17.0%) and extended-spectrum penicillins (14.6%). At the molecular level, meropenem contributed 45.6%, with amoxicillin and ceftriaxone also being prominent; the top 11 antibiotics comprised more than 90% of total use (Drug Utilisation 90% [DU90%]). By WHO Access, Watch, Reserve (AWaRe) classification, Reserve agents contributed 46.4% of use, followed by Watch (31.3%) and Access (21.1%). ARIMA (1,1,0) modelling forecasts a continued upward trend through 2026. Conclusions: Antibiotic use among cardiovascular inpatients at JKCI is high, with heavy reliance on broad-spectrum and Reserve agents. Strengthened antimicrobial stewardship measures, such as intravenous-to-oral switch protocols, DU90 audits, and stricter control of Reserve antibiotic prescribing, are urgently needed to mitigate antimicrobial resistance risks.