Point-prevalence survey of outpatient antibiotic prescription at a tertiary medical center in Sri Lanka: opportunities to improve prescribing practices for respiratory illnesses

The emergence and spread of antimicrobial resistance (AMR) poses a serious global public health threat. Annually, antimicrobial-resistant infections contribute to an estimated 23,000 deaths in the United States and 25,000 deaths in Europe [1, 2]. While reliable estimates are lacking in low- and middle- income countries (LMICs), morbidity and mortality attributable to AMR are expected to be even greater in these settings due to a higher prevalence of infectious diseases and lesser access to newer-generation antibiotics [3].

Although epidemiologic surveillance of AMR in Sri Lanka has only recently been implemented, available data reveal a high prevalence of infections caused by drug-resistant organisms. In a multi-center study of gram-negative bacterial bloodstream infections, organisms producing extended-spectrum beta-lactamases (ESBLs) accounted for nearly one-quarter of isolated pathogens [4]. Additionally, national surveillance data of urine culture isolates demonstrated resistance to ciprofloxacin and third-generation cephalosporins at proportions exceeding 50% among enteric gram-negative bacteria [5].

Decades of widespread antibiotic use have created selective pressure for the development of AMR, with increasing antibiotic consumption especially pronounced in LMICs [6]. A recent point-prevalence survey of antimicrobial use in Sri Lankan public hospitals revealed that more than one-half of all inpatients and nearly all patients in intensive care wards were receiving antimicrobials at the time of survey; approximately one-third of antimicrobials were deemed to be potentially inappropriate [7]. Systematic data on outpatient antimicrobial prescribing practices in Sri Lanka, however, remain limited. A 2015 multi-center prescription audit performed in Sri Lanka by the World Health Organization South-East Asia Regional Office reported that 45–67% of patients receiving medications from public pharmacies and 21–27% of private pharmacy clients were prescribed an antibiotic [8]. There are no studies that systematically examine outpatient antibiotic prescription in the context of patient-level data in Sri Lanka.

In this study, we determined the point prevalence of antibiotic prescription and assessed demographic and clinical patterns associated with antibiotic prescription among outpatients at a public tertiary healthcare facility in Southern Province, Sri Lanka.

This single-center point-prevalence survey demonstrates a high prevalence of outpatient antibiotic prescription at a public tertiary medical center in southern Sri Lanka. Antibiotics were prescribed to approximately one-third of patients in this study, similar to the proportions of 33–54% reported in a 2015 World Health Organization audit of Sri Lankan OPDs as well as antibiotic prescribing figures reported in other South East Asian countries [8, 9]. These findings suggest that the prevalence of antibiotic prescription among outpatient care encounters in Sri Lanka may exceed that observed in some high-income settings; in comparison, an overall antibiotic prescription rate of 12% was previously reported in a nationally representative sample of ambulatory care visits in the United States [10]. However, prescription of broad-spectrum antibiotics was relatively infrequent in our study sample. Narrow-spectrum beta-lactam antibiotics represented the predominant choices for therapy while fluoroquinolone use was less frequent, which was consistent with Sri Lankan national clinical practice guidelines for common syndromes including lower respiratory tract infection and skin and soft tissue infection [11].

Our survey revealed limited knowledge and awareness of antibiotics and resultant low prevalence of expectations for antibiotic prescription among patients, suggesting that antibiotic prescribing behavior may have been driven by healthcare providers rather than by patient demand. These data support previous qualitative data from this outpatient setting showing that patient expectations for antibiotic prescription were uncommon [12]. In contrast, physicians’ perceptions that patients desire antibiotics have been identified as a major driver of antibiotic over-prescribing behavior in multiple studies [12‐14]. As such, clinical guidelines and clinician training to improve rational antibiotic prescribing should include strategies to address both actual and perceived patient demand for antibiotics.

Of note, a high proportion of antibiotic prescriptions was given for treatment of respiratory syndromes. Patients with respiratory symptoms comprised nearly one-half of all antibiotic recipients. Conversely, a majority of patients with respiratory illnesses received an antibiotic prescription. These findings parallel previous observations in the inpatient setting in Sri Lanka, where lower respiratory tract infections were the most common indication for antibiotic therapy among hospitalized patients, as well as data from high-income countries showing high rates of outpatient antibiotic prescription for acute respiratory conditions [7, 10, 15]. Interventions targeting prescribing practices for acute respiratory tract infections thus represent a high-yield opportunity for antimicrobial stewardship. It was noteworthy that laboratory or radiographic evaluations to differentiate between upper and lower respiratory tract infections, or between viral and bacterial etiologies, were rarely performed in our study sample. Since the low utilization of diagnostic testing prior to antibiotic prescription may have been influenced by high patient volume and the desire to reduce costs in this public healthcare setting, cost-effectiveness and throughput of testing are important factors to consider when implementing interventions to potentially expand the use of diagnostics. Previous studies in Sri Lanka and other settings have shown that patients with a positive rapid influenza test had lower odds of receiving antibiotics, highlighting a potential role for rapid low-cost diagnostics in reducing antibiotic over-prescription [16, 17].

This study has several limitations. As a point prevalence survey, our data do not capture potential temporal variation in antibiotic prescribing practices in relation to seasonal illnesses such as influenza and dengue. The single center nature of this study precludes the generalization of findings to Sri Lanka due to potential differences between the public and private healthcare sector, primary and secondary/tertiary facilities, and different regions of the country in terms of physician prescribing behavior and patient population. Additionally, all clinical information except for antibiotics prescribed was based on patient self-report and thus may have been subject to reporting bias.

Antimicrobial stewardship represents a growing priority in Sri Lankan public health as well as the global health arena. Our study highlights a particular need for antimicrobial stewardship in ambulatory settings, for which there is limited experience in LMICs and a dearth of best practice guidelines. The development and scale-up of strategies to provide ongoing surveillance of antibiotic use, increase access to and utilization of diagnostic testing, and reinforce rational antibiotic prescribing practices will be important components in global efforts to control the spread of antimicrobial resistance.