Factors associated with the change of antimicrobial prescription before and after the national action plan on antimicrobial resistance: Additional analysis of a nationwide survey conducted by the Japanese Society of Chemotherapy and the Japanese Association for Infectious Diseases.

BACKGROUND: A nationwide survey conducted by the Japanese Society of Chemotherapy and the Japanese Association for Infectious Diseases in 2020 provided insights into antimicrobial prescription practices among clinic doctors. This study aimed to investigate factors influencing changes in antimicrobial prescriptions post-implementation of the National Action Plan on Antimicrobial Resistance (NAPAR) and doctors' inclination to prescribe antimicrobials for common cold cases. METHODS: In September 2020, randomly selected questionnaires were distributed to 3000 community-based medical clinics in Japan. The primary objective was to assess the reduction in antimicrobial prescriptions post-NAPAR implementation. Multivariate linear regression analysis was employed to identify associated factors. RESULTS: Analysis of 632 responses (response rate: 21.1 %) revealed determinants of decreased antimicrobial prescriptions, including familiarity with the Guide to Antimicrobial Stewardship (ß = .482, t = 3.177, p = 0.002) and awareness of NAPAR (ß = .270, t = 2.301, p = 0.022). CONCLUSION: Interventions such as the Guide to Antimicrobial Stewardship may have contributed to the reduction in antimicrobial prescriptions among Japanese physicians. However, targeted strategies are needed to address high-prescription groups. Enhancing awareness and education on appropriate antimicrobial use should be integral components of future initiatives to combat antimicrobial resistance effectively.

Nosocomial Outbreak of SARS-CoV-2 in a Hospital Ward during the Omicron Variant-Dominant Wave with a Review of the Relevant Literature.

Clusters of nosocomial coronavirus disease 2019 (COVID-19) have been reported globally during the recent pandemic. Unfortunately, these clusters negatively affect inpatient morbidity, mortality, and hospital functioning. Using epidemiological data and whole-genome sequencing (WGS) of SARS-CoV-2, this study investigated the outbreak of COVID-19 at a university hospital. Eight inpatients and 13 healthcare workers tested positive for SARS-CoV-2 during a 1-month period. WGS of the virus in 11 patients revealed that the two variants of concern belonging to the Omicron sublineages, BA.2.3 and BA1.1.2, caused an outbreak when the proportion of the Omicron lineage in the community changed. When variants of concern undergo mutation, a response to the outbreak should be made with multiple variants in mind, even in the absence of epidemiological data showing close contact or other potential vectors of infection. Awareness of infection prevention and control should be raised to safeguard patient safety.

Contact tracing in the hospital setting during the omicron wave of the coronavirus disease 2019 pandemic: persons and periods of concern for nosocomial infection prevention and control.

This study evaluating the efficacy of coronavirus disease 2019 contact tracing in the hospital setting during the omicron variant era found a high incidence of nosocomial severe acute respiratory coronavirus virus 2 (SARS-CoV-2) transmission in outbreaks, especially among individuals having close contact with infected persons. Identifying close contacts and outbreaks is essential to prevent nosocomial SARS-CoV-2 transmission.

Comparative evaluation of analytical pipelines for illumina short- and nanopore long-read 16S rRNA gene amplicon sequencing with mock microbial communities.

Utility of a recently developed long-read pipeline, Emu, was assessed using an expectation-maximization algorithm for accurate read classification. We compared it to conventional short- and long-read pipelines, using well-characterized mock bacterial samples. Our findings highlight the necessity of appropriate data-processing for taxonomic descriptions, expanding our understanding of the precise microbiome.

Impact of Invasive Escherichia Coli Disease on Clinical Outcomes and Medical Resource Utilization Among Asian Patients in the United States.

INTRODUCTION: Invasive Escherichia coli disease (IED) can lead to sepsis and death and is associated with a substantial burden. Yet, there is scarce information on the burden of IED in Asian patients. METHODS: This retrospective study used US hospital data from the PINC AI™ Healthcare database (October 2015-March 2020) to identify IED cases among patients aged ≥ 60 years. IED was defined as a positive E. coli culture in blood or other normally sterile body site (group 1 IED) or positive culture of E. coli in urine with signs of sepsis (group 2 IED). Eligible patients with IED were classified into Asian and non-Asian cohorts based on their reported race. Entropy balancing was used to create cohorts with similar characteristics. Outcomes following IED were descriptively reported in the balanced cohorts. RESULTS: A total of 646 Asian and 19,127 non-Asian patients with IED were included (median age 79 years; 68% female after balancing). For both cohorts, most IED encounters had community-onset (> 95%) and required hospitalization (Asian 96%, mean duration 6.9 days; non-Asian 95%, mean duration 6.8 days), with frequent admission to intensive care (Asian 35%, mean duration 3.3 days; non-Asian 34%, mean duration 3.5 days), all standardized differences [SD] < 0.20. Compared to non-Asian patients, Asian patients were more likely to be discharged home (54% vs. 43%; SD = 0.22), and less likely to be discharged to a skilled nursing facility (24% vs. 31%; SD = 0.16). In-hospital fatality rates during the IED encounter were similar across cohorts (Asian 9%, non-Asian 10%; SD = 0.01). Most E. coli isolates showed resistance to ≥ 1 antibiotic (Asian 61%; non-Asian 64%) and 36% to ≥ 3 antibiotic classes (all SD < 0.20). CONCLUSION: IED is associated with a substantial burden, including need for intensive care and considerable mortality, in Asian patients in the USA that is consistent with that observed for non-Asian patients.

Prescription of anti-influenza drugs in Japan, 2014-2020: A retrospective study using open data from the national claims database.

BACKGROUND: Both physicians and patients are proactive towards managing seasonal influenza in Japan and six drugs are approved. Although many countries have national influenza surveillance systems, data on nationwide prescription practices of anti-influenza drugs are lacking. Therefore, we aimed to clarify the status of anti-influenza drug use in Japan by analyzing real-world data. METHODS: This retrospective study analyzed open data from the National Database of Health Insurance Claims and Specific Health Checkups, which covers most claims data from national health insurance. We estimated the annual number of patients prescribed anti-influenza drugs, which drugs they were prescribed, the patients' age and sex distribution, drug costs, and regional disparities for the period 2014-2020. RESULTS: For 2014-2019, an estimated 6.7-13.4 million patients per year were prescribed anti-influenza drugs, with an annual cost of 22.3-48.0 billion JPY (Japanese Yen). In addition, 21.1-32.0 million rapid antigen tests were performed at a cost of 30.1-47.1 billion JPY. In 2017, laninamivir was the most frequently prescribed anti-influenza drug (48%), followed by oseltamivir (36%), while in 2018, the newly introduced baloxavir accounted for 40.8% of prescriptions. After the emergence of COVID-19, the estimated number of patients prescribed anti-influenza drugs in 2020 dropped to just 14,000. In 2018, 37.6% of prescriptions were for patients aged < 20 years compared with 12.2% for those aged ≥ 65 years. Prescriptions for inpatients accounted for 1.1%, and the proportion of prescriptions for inpatients increased with age, with men were more likely than women to be prescribed anti-influenza drugs while hospitalized. CONCLUSIONS: Based on our clarification of how influenza is clinically managed in Japan, future work should evaluate the clinical and economic aspects of proactively prescribing anti-influenza drugs.

Novel insights into genetic characteristics of blaGES-encoding plasmids from hospital sewage.

Introduction: The prevalence of Guiana extended-spectrum (GES)-type carbapenemase producers is increasing worldwide, and hospital water environments are considered as potential reservoirs. However, the genetic features underlying this resistance are not yet fully understood. This study aimed to characterize blaGES-encoding plasmids from a single-hospital sewage sample in Japan. Methods: Carbapenemase producers were screened using carbapenemase-selective agar and polymerase chain reaction. Whole-genome sequencing analyzes were performed on the carbapenemase-producing isolates. Results: Eleven gram-negative bacteria (four Enterobacter spp., three Klebsiella spp., three Aeromonas spp., and one Serratia spp.) with blaGES-24 (n = 6), blaGES-6 (n = 4), and blaGES-5 (n = 1) were isolated from the sewage sample. Five blaGES-24 and a blaGES-5 were localized in IncP-6 plasmids, whereas three blaGES-6 plasmids were localized in IncC plasmids with IncF-like regions. The remaining blaGES-6 and blaGES-24 were, respectively, localized on IncFIB-containing plasmids with IncF-like regions and a plasmid with an IncW-like replication protein. The IncP-6 and IncW-like plasmids had a close genetic relationship with plasmids from Japan, whereas the IncC/IncF-like and IncFIB/IncF-like plasmids were closely related to those from the United States and Europe. All blaGES genes were located on the class 1 integron cassette of the Tn3 transposon-related region, and the IncC/IncF-like plasmid carried two copies of the integron cassette. Eight of the eleven blaGES-encoding plasmids contained toxin-antitoxin system genes. Discussion: The findings on the plasmids and the novel genetic content from a single wastewater sample extend our understanding regarding the diversity of resistance and the associated spread of blaGES, suggesting their high adaptability to hospital effluents. These findings highlight the need for the continuous monitoring of environmental GES-type carbapenemase producers to control their dissemination.

Investigation of oral macrolide prescriptions in Japan using a retrospective claims database, 2013-2018.

Macrolide usage in Japan exceeds that in Europe and the United States. Investigating the actual conditions in which macrolides are used is important for identifying further interventions for appropriate antimicrobial use; however, this situation has not been evaluated in Japan. Therefore, we aimed to clarify the number of macrolide prescriptions and their changes before and after implementation of the Antimicrobial Resistance (AMR) Action Plan. In addition, we also investigated the names of diseases for which macrolides have been prescribed and the number of days of prescription. A retrospective observational study was conducted using JMDC claims data from January 2013 to December 2018. The proportion of all oral antimicrobials and macrolides used during this period and the diseases for which macrolides were used in the 3 years before and after the AMR Action Plan were determined separately for acute (< 14 prescription days) and chronic (> 14 prescription days) diseases. The number of prescriptions for macrolides constituted approximately 30% of those for all oral antimicrobials; of these, clarithromycin accounted for approximately 60%. Most prescriptions for acute diseases were for common cold, whereas allergic and dermatological diseases were included among chronic diseases. The names of these illnesses did not change before and after the AMR Action Plan. Overall, these results indicate that appropriate macrolide use involves a review of their use for common cold along with appropriate evaluation of their long-term use for skin and allergic diseases. They also indicate the need for further fact-finding studies and ongoing AMR measures.

Nationwide Descriptive Epidemiological Study of Patients with COVID-19 Evacuated from Wuhan, China to Japan from January to February, 2020.

We investigated the epidemiological findings regarding the route of coronavirus disease 2019 (COVID-19) and infection prevention and control (IPC) measures among returnees in the emergency evacuation from Wuhan, China to Japan during the COVID-19 outbreak in 2020. A total of 12 of the 14 returnees (median age [range]: 49.5 years [29-65 years]; 9 men [75%]) had confirmed COVID-19. The proportion of returnees with COVID-19 was 12/566 (2.1%) in Flights 1-3 and 2/263 (0.8%) in Flights 4 and 5. Six patients were asymptomatic on admission, while 3 patients developed symptoms thereafter. None of the participants reported a specific history of contact with animals, going to seafood markets, or visiting medical facilities. Two patients were in contact with an individual who was confirmed or suspected of having COVID-19. Most patients resided in hotels in the center of Wuhan City, taking taxis and trains for commute. Patients relatively adhered to IPC measures such as wearing a mask and hand hygiene. However, emphasis on IPC measures such as universal masking and more rigorous avoidance of exposure risk might have been necessary to prevent infection. In addition, forced social distancing due to lockdown might have contributed to the lower infection rates in Flights 4 and 5, compared to Flights 1-3.

Physician practices in the diagnosis and treatment of infectious diseases in home care settings: A questionnaire study.

To elucidate the current practices of infectious disease management in home care settings in Japan, we sent a questionnaire to 36 physicians working at 13 clinics that specialize in providing care to patients in their homes or residential care facilities. The questionnaire described three hypothetical scenarios (aspiration pneumonia, pyelonephritis, and neoplastic fever) in older patients with terminal cancer, and 25 respondents answered questions on testing and treatment strategies. Most respondents chose to obtain cultures for aspiration pneumonia (sputum) and for pyelonephritis (urine), although fewer respondents chose to obtain blood cultures. For neoplastic fever, most of respondents elected to continue observation without antibiotic treatment. The most frequently selected antibiotics were cephalosporins and quinolones. The results indicated that most respondents would perform bacterial culture tests before prescribing antibiotics and observe patients when bacterial infections are not suspected. Standardized guidelines are needed to optimize infectious disease management in home care.

First nationwide survey of infection prevention and control among healthcare facilities in Japan: impact of the national regulatory system.

BACKGROUND: Infection prevention and control (IPC) measures in Japan are facilitated by a financial incentive process at the national level, where facilities are categorized into three groups (Tier 1, Tier 2, or no financial incentive). However, its impact on IPC at the facility level using a validated tool has not been measured. METHODS: A nationwide cross-sectional study was conducted from August 2019 to January 2020 to evaluate the situation of IPC programs in Japan, using the global IPC Assessment Framework (IPCAF) developed by the World Health Organization. Combined with the information on the national financial incentive system, the demographics of facilities and each IPCAF item were descriptively analyzed. IPCAF scores were analyzed according to the facility level of care and the national financial incentive system for IPC facility status, using Dunn-Bonferroni and Mann-Whitney U tests. RESULTS: Fifty-nine facilities in Japan responded to the IPCAF survey: 34 private facilities (57.6%) and 25 public facilities (42.4%). Of these, 11 (18.6%), 29 (49.2%), and 19 (32.3%) were primary, secondary, and tertiary care facilities, respectively. According to the national financial incentive system for IPC, 45 (76.3%), 11 (18.6%), and three (5.1%) facilities were categorized as Tier 1, Tier 2, and no financial incentive system, respectively. Based on the IPCAF total score, more than half of the facilities were categorized as "Advanced" (n = 31, 55.3%), followed by "Intermediate" (n = 21, 37.5%). The IPCAF total score increased as the facility level of care increased, while no statistically significant difference was identified between the secondary and tertiary care facilities (p = 0.79). There was a significant difference between Tier 1 and Tier 2 for all core components and total scores. Core components 5 (multimodal strategies for implementation of IPC interventions) and 6 (monitoring/audit of IPC and feedback) were characteristically low in Japan with a median score of 65.0 (interquartile range 40.0-85.0) and 67.5 (interquartile range 52.5-87.5), respectively. CONCLUSIONS: The national financial incentive system was associated with IPC programs at facility level in Japan. The current financial incentive system does not emphasize the multimodal strategy or cover monitoring/audit, and an additional systematic approach may be required to further promote IPC for more practical healthcare-associated infection prevention.

Interhospital transmission of vancomycin-resistant Enterococcus faecium in Aomori, Japan.

BACKGROUND: Spread of vancomycin-resistant Enterococcus (VRE) is a global concern as a significant cause of healthcare-associated infections. A series of VRE faecium (VREf) outbreaks caused by clonal propagation due to interhospital transmission occurred in six general hospitals in Aomori prefecture, Japan. METHODS: The number of patients with VREf was obtained from thirty seven hospitals participating in the local network of Aomori prefecture. Thirteen hospitals performed active screening tests for VRE. Whole genome sequencing analysis was performed. RESULTS: The total number of cases with VREf amounted to 500 in fourteen hospitals in Aomori from Jan 2018 to April 2021. It took more than three years for the frequency of detection of VRE to return to pre-outbreak levels. The duration and size of outbreaks differed between hospitals according to the countermeasures available at each hospital. Whole genome sequencing analysis indicated vanA-type VREf ST1421 for most samples from six hospitals. CONCLUSIONS: This was the first multi-jurisdictional outbreak of VREf sequence type 1421 in Japan. In addition to strict infection control measures, continuous monitoring of VRE detection in local medical regions and smooth and immediate communication among hospitals are required to prevent VREf outbreaks.

Point Prevalence Surveys of Antimicrobial Prescribing in a Non-Acute Care Hospital in Saitama Prefecture, Japan.

Background: The global point prevalence survey (Global-PPS) is the standard for the surveillance of prescribed antimicrobials among inpatients and provides data for the development of hospital antimicrobial stewardship programs. Aim: To evaluate the prevalence and quality of antimicrobial prescriptions using the universally standardized Global-PPS protocol in a non-acute care hospital in Saitama Prefecture, Japan. Methods: Antimicrobial prescriptions for inpatients, staying at the hospital overnight, were surveyed on three separate week days in November 2018, January 2019, and May 2019. Information on the prescribed antimicrobials on the survey target day was obtained from the in-hospital pharmacy. Survey data were collected by physicians, based on the extracted information. Patient information was anonymized and entered in the Global-PPS Web application by physicians. We report the antimicrobial use prevalence, the indication for prescription, diagnosis, the most prescribed antimicrobials, and a set of quality indicators related to antimicrobial prescribing. Results: In total, 6.7% of the surveyed inpatients (120/1796) were prescribed antimicrobials on the survey day. Sulfamethoxazole/trimethoprim was the most commonly prescribed, with 20.0% of systemic antibiotic prescriptions (ATC J01). Of all antibiotics for systemic use, up to 58.4% were Watch antibiotics, as defined by the World Health Organization AWaRe classification. The most prescribed group of systemic antibiotics was non-penicillin beta-lactam antibiotics (34.4%), followed by penicillin antibiotics in combination with beta-lactamase inhibitors (25.6%), and sulfonamides with trimethoprim (20.8%). Healthcare-associated infections and medical prophylaxis were the most common indications reported in 69.3% and 26.3% of prescriptions, respectively. The most common diagnosis for systemic antibiotic prescriptions was pneumonia (49.6%). Reasons for antimicrobial prescriptions were indicated in the medical records for 67.1% of prescriptions, and the stop/review date was documented to be 50.3%. Compliance with local guidelines reached 66.7%. Conclusions: This study highlights important challenges related to antimicrobial prescription in a highly specific, non-acute care patient population.

Tracheobronchial aspergillosis presenting with black mucus plugs and tracheal ulcers.

Tracheobronchial aspergillosis is a rare but lethal disease with characteristic findings of tracheal plaques and ulcers. It requires appropriate airway management for possible tracheal obstruction with the black mucus plug.

Regional Antimicrobial Stewardship Program in a Provincial Medical Zone in Japan: a Multifaceted Approach.

Antimicrobial resistance (AMR) is a threat to patient health. However, data to optimize antimicrobial use are limited. Furthermore, reducing antibiotic use raises concerns regarding patient safety. The effectiveness of antibiotics in reducing the prevalence of AMR is controversial. Researchers at the Japanese Red Cross Ishinomaki Hospital (JRCIH), the only tertiary care hospital in the medical zone, along with local medical and pharmacy associations and public health centers have been leading the AMR control program since 2018. The program involves lectures aimed at optimizing antimicrobial use, regular publication of surveillance data of drug-resistant strains at the JRCIH, and presentation of first-line treatments for community-acquired infections. The delivery of oral antimicrobial agents across the region in 2020 was 28.7% lower than that in 2013, with delivery of cephalosporins, quinolones, and macrolides decreasing by 34.8%, 46.8%, and 56.0%, respectively. Despite these reductions, there has been no associated increase in the number of patients with severe infectious diseases admitted to the JRCIH. The rates of representative drug-resistant bacterial strains, such as extended-spectrum beta-lactamase-producing Escherichia coli and methicillin-resistant Staphylococcus aureus, decreased by half. Herein, we demonstrated the potential of collaborative efforts to optimize antimicrobial agent use and reduce the AMR prevalence without compromising patient safety.

Outcomes and Future Prospect of Japan's National Action Plan on Antimicrobial Resistance (2016-2020).

The threat from antimicrobial resistance (AMR) continues to grow. Japan's National Action Plan on Antimicrobial Resistance, which was formulated in 2016 and targets six areas, has already had a major impact on the countermeasures implemented against AMR. Particular advances have been made in AMR-related surveillance, and we now know the situation regarding antimicrobial use and antimicrobial-resistant bacteria in the country. Educational and awareness-raising activities for medical professionals and the general public have been actively implemented and seem to have contributed to a gradual move toward an appropriate use of antimicrobials. However, there is still insufficient understanding of the issue among the general public. Determining how to use surveillance results and implementing further awareness-raising activities are crucial to address this. Tasks for the future include both raising awareness and the promotion of AMR research and development and international cooperation. The government's next Action Plan, which will detail future countermeasures against AMR based on the outcomes of and tasks identified in the current Action Plan, has been delayed due to the COVID-19 pandemic and is urgently awaited.

Hospitalization for urinary tract infections in Japan, 2010-2015: a retrospective study using a national inpatient database.

BACKGROUND: Urinary tract infections (UTI) are common and can have severe consequences. However, there are few recent large-scale studies about them. We aimed to determine the incidence of hospitalization for UTI and to elucidate patient characteristics, clinical practice, and clinical outcomes by drawing on a Japanese nationwide database. METHODS: This was a retrospective observational study using a national database that covers half the acute care inpatients in Japan. Patients aged ≥ 15 years who were hospitalized for UTI were eligible. We did not include patients with lower UTI such as cystitis. We investigated the annual number of patients hospitalized in Japan, those patients' characteristics, and risk factors for in-hospital mortality. RESULTS: We identified 232,396 eligible patients from 31 million records of discharge between April 2010 and March 2015. The average age was 73.5 years and 64.9% of patients were female. The estimated annual number of hospitalizations because of UTI was 106,508. The incidence was 6.8 per 10,000 for men and 12.4 for women. The median medical care cost was 4250 USD. In-hospital mortality was 4.5%. Risk factors of poor survival included male sex, older age, lower bed capacity, non-academic hospital, admission in winter, higher Charlson Comorbidity Index score, low body mass index, coma on admission, ambulance use, disseminated intravascular coagulation, sepsis, renal failure, heart failure, cerebrovascular diseases, pneumonia, malignancies, use of anti-diabetic drugs, and use of corticosteroid or immunosuppressive drugs. CONCLUSIONS: We found that older patients of both sexes accounted for a significant proportion of those hospitalized for UTI. The clinical and economic burden of UTI is considerable.

Nationwide multicenter questionnaire surveys on countermeasures against antimicrobial resistance and infections in hospitals.

BACKGROUND: The goals of the National Action Plan on Antimicrobial Resistance (AMR) of Japan include "implementing appropriate infection prevention and control" and "appropriate use of antimicrobials," which are relevant to healthcare facilities. Specifically, linking efforts between existing infection control teams and antimicrobial stewardship programs was suggested to be important. Previous studies reported that human resources, such as full-time equivalents of infection control practitioners, were related to improvements in antimicrobial stewardship. METHODS: We posted questionnaires to all teaching hospitals (n = 1017) regarding hospital countermeasures against AMR and infections. To evaluate changes over time, surveys were conducted twice (1st survey: Nov 2016, 2nd survey: Feb 2018). A latent transition analysis (LTA) was performed to identify latent statuses, which refer to underlying subgroups of hospitals, and effects of the number of members in infection control teams per bed on being in the better statuses. RESULTS: The number of valid responses was 678 (response rate, 66.7%) for the 1st survey and 559 (55.0%) for the 2nd survey. More than 99% of participating hospitals had infection control teams, with differences in activity among hospitals. Roughly 70% had their own intervention criteria for antibiotics therapies, whereas only about 60 and 50% had criteria established for the use of anti-methicillin-resistant Staphylococcus aureus antibiotics and broad-spectrum antibiotics, respectively. Only 50 and 40% of hospitals conducted surveillance of catheter-associated urinary tract infections and ventilator-associated pneumonia, respectively. Less than 50% of hospitals used maximal barrier precautions for central line catheter insertion. The LTA identified five latent statuses. The membership probability of the most favorable status in the 2nd study period was slightly increased from the 1st study period (23.6 to 25.3%). However, the increase in the least favorable status was higher (26.3 to 31.8%). Results of the LTA did not support a relationship between increasing the number of infection control practitioners per bed, which is reportedly related to improvements in antimicrobial stewardship, and being in more favorable latent statuses. CONCLUSIONS: Our results suggest the need for more comprehensive antimicrobial stewardship programs and increased surveillance activities for healthcare-associated infections to improve antimicrobial stewardship and infection control in hospitals.

Determinants of clinic doctors' attitudes concerning antimicrobial prescription for patients with common colds or bronchitis: Additional analysis of a nationwide survey conducted by the Japanese Society of Chemotherapy and the Japanese Association for Infectious Diseases.

BACKGROUND: In 2019, the Japanese Society of Chemotherapy and the Japanese Association for Infectious Diseases reported nationwide, cross-sectional questionnaire survey data investigating the clinical status of clinic doctors' attitudes to antimicrobial stewardship. This study aimed to identify factors determining clinic doctors' attitudes concerning antimicrobial prescription for patients with a common cold or bronchitis. METHODS: In February 2018, 1500 randomly selected community-based medical clinics in Japan were sent a questionnaire. Primary and secondary endpoints were clinic doctors' attitudes concerning antimicrobial prescription, and antimicrobial medication types prescribed for patients with a common cold or bronchitis, respectively. We used multivariable linear regression analysis to identify factors associated with primary and secondary outcomes. RESULTS: We analyzed 269 of 274 responses (response rate, 18.3%). Linear regression analysis was used to identify determinants of proactive attitudes to antimicrobial prescription, including whether clinic doctors encountering patients with upper respiratory symptoms and no underlying illnesses, and diagnosed with a common cold would prescribe antimicrobial medication (ß = 0.283, t = 4.279, p = 0.000); whether clinic doctors frequently experienced requests from patients (or their families) with a common cold to prescribe antimicrobial medication (ß = 0.389, t = 6.133, p = 0.000), and; clinic doctors' awareness of antimicrobial stewardship in the past year (ß = -0.157, t = -2.456, p = 0.015). Determinants of proactive attitudes to prescribing broader-spectrum antimicrobials for patients with a common cold included clinic doctors' attitudes concerning antimicrobial prescription (ß = 0.165, t = 2.622, p = 0.009), whether the respondent was a pediatrician (ß = -0.288, t = -4.583, p = 0.000), and clinic doctors' attitudes to antimicrobial prescription (ß = 0.262, t = 4.075, p = 0.000) for patients with bronchitis. CONCLUSION: This study identified factors among clinic doctors that determined their attitudes to antimicrobial prescription concerning patients with a common cold or bronchitis. Identification and targeting of clinic doctors who unnecessarily prescribe antimicrobial medication is urgently required to promote antimicrobial stewardship in an outpatient setting.