To investigate effects on surveillance results of hospital antibiotic use when WHO defined daily doses (WHO DDDs) are adjusted to doses recommended for hospitalized patients [hospital-adjusted defined daily doses (haDDDs)]. Data for antibiotic use in 2006–11 for all 22 Norwegian Health Enterprises were analysed with both WHO DDDs and haDDDs as numerators. The haDDDs were determined from recommendations given in regional and national guidelines on antibiotic use in hospitals. The two ways of calculating the amount of antibiotic use were compared, with either the number of bed days (BDs) or the number of discharges as the denominator. The drug utilization 90% methodology was applied for ranking the use of the various antibiotics. DDD adjustments altered the figures for total antibiotic use from 67.1 WHO DDDs/100 BDs to 49.3 haDDDs/100 BDs (−26.4%). The most marked difference was found for penicillins: 31.1 WHO DDDs/100 BDs versus 13.4 haDDDs/100 BDs (−56.8%). The corresponding figures for broad-spectrum antibiotics were 17.3 and 15.5 (−10.4%), respectively; for these antibiotics, the conversion changes varied significantly between institutions, from −16.7% to −3.3%. Ranking antibiotic use based on haDDDs resulted in higher positions for metronidazole, cefuroxime, cefotaxime and cefalotin/cefalexin compared with the WHO DDD-based ranking, where the penicillins dominated. The low-set WHO DDDs for penicillins caused skewed surveillance results that concealed the real magnitude of broad-spectrum antibiotic use and distorted interhospital comparisons. For surveillance of antibiotic use in hospitals, WHO DDDs should be supplemented with haDDDs.

Antimicrobial resistance (AMR) is a threat to hospital patients. Antimicrobial stewardship programs (ASPs) can counteract AMR. To optimize ASPs, we need to understand what affects physicians’ antibiotic prescription from several contexts. In this study, we aimed to explore the factors affecting hospital physicians’ antibiotic choices in a low-resistance country to identify potential targets for future ASPs. We interviewed 14 physicians involved in antibiotic prescription in a Norwegian hospital. The interviews were audiotaped, transcribed verbatim, and analyzed using thematic analysis. The main factors affecting antibiotic prescription were a high work pressure, insufficient staff resources, and uncertainties regarding clinical decisions. Treatment expectations from patients and next of kin, benevolence towards the patients, suboptimal microbiological testing, and limited time for infectious disease specialists to offer advisory services also affected the antibiotic choices. Future ASP efforts should evaluate the system organization and prioritizations to address and manage potential time-pressure issues. To limit the use of broad-spectrum antibiotics, improving microbiology testing and the routines for consultations with infectious disease specialists seems beneficial. We also identified a need among the prescribing physicians for a debate on ethical antibiotic questions.

Although antibiotic use and resistance are low in Norway, the situation risks changing for the worse. We investigated trends in antibiotic use and assessed them in relation to antibiotic resistance in Norway. We drew on hospital pharmacy sales data to record antibiotic use from 2002 to 2007 in eight hospitals serving 36% of the nation's population. Antibiotic use was measured using different indices with defined daily doses (DDDs) as the numerator (WHO ATC/DDD classification). Total antibiotic use increased from 1.02 to 1.30 DDDs/1000 inhabitants/day (DIDs) and from 61.7 to 72.4 DDDs/100 bed-days (BDs) (17.4%); related to the number of discharges, no significant DDD change was shown. Their use in core units (adult intensive care units, recovery/post-operative wards and departments of internal medicine and surgery with all subspecialties) increased from 64.1 to 80.8 DDDs/100 BDs (26.1%) and by 3.1% related to the number of discharges. The total use of broad-spectrum antibiotics increased by 47.9% when measured as DDDs/100 BDs, and by 19.1% based on the number of discharges; the corresponding figures for core units were 60.5% and 31.2%, respectively. There was a substantial increase in total antibiotic use, and an even more pronounced increase in the use of broad-spectrum antibiotics, which seems unjustified considering the current low antibiotic resistance in Norway.

Surveillance data of antibiotic use are increasingly being used for benchmarking purposes, but there is a lack of studies dealing with how hospital- and patient-related factors affect antibiotic utilization in hospitals. Our objective was to identify factors that may contribute to differences in antibiotic use. Based on pharmacy sales data (2006–2011), use of all antibiotics, all penicillins, and broad-spectrum antibiotics was analysed in 22 Health Enterprises (HEs). Antibiotic utilization was measured in World Health Organisation defined daily doses (DDDs) and hospital-adjusted (ha)DDDs, each related to the number of bed days (BDs) and the number of discharges. For each HE, all clinical specialties were included and the aggregated data at the HE level constituted the basis for the analyses. Fourteen variables potentially associated with the observed antibiotic use – extracted from validated national databases – were examined in 12 multiple linear regression models, with four different measurement units: DDD/100 BDs, DDD/100 discharges, haDDD/100 BDs and haDDD/100 discharges. Six variables were independently associated with antibiotic use, but with a variable pattern depending on the regression model. High levels of nurse staffing, high proportions of short (10 days) hospital stays, infectious diseases being the main ICD-10 diagnostic codes, and surgical diagnosis-related groups were correlated with a high use of all antibiotics. University affiliated HEs had a lower level of antibiotic utilization than other institutions in eight of the 12 models, and carried a high explanatory strength. The use of broad-spectrum antibiotics correlated strongly with short and long hospital stays. There was a residual variance (30%–50% for all antibiotics; 60%–70% for broad-spectrum antibiotics) that our analysis did not explain. The factors associated with hospital antibiotic use were mostly non-modifiable. By adjusting for these factors, it will be easier to evaluate and understand observed differences in antibiotic use between hospitals. Consequently, the inter-hospital differences can be more confidently acted upon. The residual variation is presumed to largely reflect prescriber-related factors.

Development of antibiotic resistance, a threat to global health, is driven by inappropriate antibiotic usage. Respiratory tract infections (RTIs) are frequently treated empirically with antibiotics, despite the fact that a majority of the infections are caused by viruses. The purpose of this study was to determine the prevalence of antibiotic treatment in hospitalized adults with viral RTIs, and to investigate factors influencing the antibiotic decision-making. We conducted a retrospective observational study of patients ≥ 18 years, hospitalized in 2015–2018 with viral RTIs. Microbiological data were taken from the laboratory information system and information on antibiotic treatment drawn from the hospital records. To investigate decisions for prescribing antibiotic treatment, we evaluated relevant factors such as laboratory and radiological results, in addition to clinical signs. In 951 cases without secondary bacterial RTIs (median age 73 years, 53% female), 720 (76%) were prescribed antibiotic treatment, most frequently beta-lactamase-sensitive penicillins, but cephalosporins were prescribed as first-line in 16% of the cases. The median length of treatment (LOT) in the patients treated with antibiotics was seven days. Patients treated with antibiotics had an average of two days longer hospital stay compared to patients with no such treatment, but no difference in mortality was found. Our study revealed that there is still a role for antimicrobial stewardship to further improve antibiotic use in patients admitted for viral RTIs in a country with relatively low antibiotic consumption.

Background: The clinical features and outcomes of viral respiratory tract infections (RTIs) in adults have not been thoroughly studied, especially the respiratory syncytial virus (RSV) disease burden. It has become apparent that outbreaks of RSV in the elderly are associated with increased hospitalization rates. However, little data exists on the severity of such viral RTIs in adults, particularly the need for hospitalization, respiratory support and intensive care.Methods: We conducted a retrospective observational single-center study at Østfold Hospital Trust, Norway, during three winter seasons 2015–2018. Patients ≥18 years with either influenza A, influenza B, RSV A/B, human metapneumovirus, parainfluenza virus 1–4 or adenovirus detected in respiratory specimens were included, if they were hospitalized 14 days prior or following the detection date, with signs of RTI. Hospital records on treatment and outcome were investigated, as well as mortality of all causes up to 30 days from discharge.Results: Of the 1222 infection events that were included, influenza A was the most frequent virus detected (39%), while 179 infection events (14.6%) were due to RSV. Influenza B counted for 24% of the infection events, human metapneumovirus 13%, parainfluenza virus 9% and adenovirus 1%. Patients admitted with RSV more often suffered from COPD and congestive heart failure than patients with influenza A. In addition, RSV patients were overrepresented in the urgent response NEWS score (National Early Warning Score) category ≥5. RSV patients also showed signs of more severe inflammation, with WBC ≥11.1 × 10⁹/L and CRP >100 mg/L, and they were more often treated with antibiotic agents during their hospital stay. However, we found no differences in the need for ICU admission or mortality.Conclusion: Patients with RSV had more often high values for markers of inflammation and elevated NEWS score when compared to patients hospitalized with other common respiratory viruses. Taken into account that they suffered more frequently from comorbidities like COPD, these patients needed hospitalization more urgently. These findings highlight the need for further investigations on RSV disease in adults and the elderly.