1. Suttajit S a, Tantipidoke R a, Sitthi-amorn C a, Wagner A b, Ross-Degnan D b. a Chulalongkorn University, Bangkok; b Harvard Medical School, USA Problem Statement: Unnecessary use of antibiotics leads to drug resistance and increased health expenditures, which are important problems for low-income and high-risk communities. Objectives: To measure patterns of and to find predictors contributing to antibiotic prescribing for adults with URIs. Study Population: From 2 Bangkok Metropolitan Administration health centers, all prescriptions from 2001 written by physicians for patients over 18 years old diagnosed with URI/cold, pharyngitis, tonsillitis, sinusitis, or otitis media were selected and reviewed. Outcome Measures: % antibiotics prescribed, patterns of treatment for different diagnoses, % compliance with national treatment guidelines, and factors contributing to antibiotic use. Results: Although 91% of the cases were likely to be viral URIs, 63% of all patients were prescribed antibiotics: 60% for viral and 89% for bacterial cases. Amoxicillin was the most frequently prescribed antibiotic regardless of diagnosis. Predictors of antibiotic prescribing differed for viral and bacterial URIs. Those viral URIs cases who were young, male, and self- paying patients were more likely to receive antibiotics; part-time physicians were more likely to prescribe antibiotics for these patients. Among patients with, bacterial URIs, self-paying patients were more likely to receive antibiotics. Compliance with the national treatment guidelines was 36.4% for treatment of viral URIs and 2% for bacterial URIs. Conclusions: There is overprescribing of antibiotics for viral URI patients. In bacterial cases, drugs of choice were not prescribed for adequate treatment duration. Appropriate interventions should be designed and implemented at health centers in Bangkok. Antibiotic Prescribing in Upper Respiratory Tract Infections (URIs): Patterns and Predictors of Physician Prescribing in Health Centers in Bangkok

2. Introduction Most upper respiratory tract infections (URIs) are caused by viruses, and antibiotics are not recommended in their treatment. Unnecessary antibiotic use leads to drug resistance and increased health expenditures. These are important problems for developing countries, including Thailand. Problems even become more significant in congested households of low-income and high-risk communities with high incidence of HIV/AIDS, multi-drug resistant TB, and drug addiction as in our study area. However, recent review highlights the lack of study on factors contribute to inappropriate antibiotic use in developing countries.

3. Objectives 1.To measure patterns of antibiotic prescribing for adults with URIs, and 2.To find predictors contributing to the prescription of antibiotics for URIs. In order to understand the problem and be able to designing effective interventions to improve antibiotic prescribing, the aims of this study are:

4. Methods Design Cross-sectional study. Setting and Study Population Two health centers in Bangkok, Thailand that served poor and congested communities. All prescriptions from 2001 written by 19 physicians for patients over 18 years old diagnosed with URI/cold, rhinitis, pharyngitis, tonsillitis, sinusitis, or otitis media were reviewed.

5. Methods Definition of Appropriate Treatment We classified treatments according to the National Standard Treatment Guideline for Respiratory Tract Infections (MoPH, 1996). Analysis Data were managed and analyzed using SPSS for Windows 12.0 and SAS 8.02. Chi-square and Student’s t-test were applied where appropriate. A P-value <0.05 was considered statistically significant. We developed multilevel models 1 to adjust for clustering by provider while examining predictors of antibiotic prescribing in viral and bacterial URIs. 1 Guo G & Zhao H. (2001). Multilevel modeling for binary data. Annual Review of Sociology, 26, 441-62.

6. Results 1 In 2001, 4,608 adult URIs patients visited the health centers. There was no seasonal pattern of URIs. Almost all (97.9%) patients received a prescription, resulting in 4,512 prescriptions for analysis. Female 70.3 % Age 18-40 45.7 % 41-60 29.9 % > 60 24.4 % Self-payment 57.6 % Characteristics of Patients (n=4,512) Bacterial URIs 9.0 % Pharyngotonsillitis6.8 % Otitis Media (OM) 2.0 % Sinusitis 0.2 % Viral URIs91.0 % Characteristics of Physicians (n=19) Half of the physicians were women and in middle age. Most of them had practiced >10 years and were GPs. Only 4 physicians worked full-time.

7. Results 2 Pattern of Drug Prescribing Nearly all patients received drug, except only 13 patients with viral URIs. Physicians treated viral and bacterial URIs differently. Drug prescribed Viral URIs (n=4107) Bact.URIs (n=405) Antibiotics 60.3 % 89.4 % * Analgesics/ Antipyretics 72.6 %81.0 % * Antihistamines 68.3 %33.3 % * Mucolytics 44.9 %48.9 % * Cough suppressants 32.9 %43.2 % * Vitamins 20.4 %11.4 % * Mean no. of drugs/Rx 3.20+1.07 3.67+1.26* Median Rx cost (baht) 44 76* with antibiotics 5978* with no antibiotics16 *p<0.05 Table 1. Drug prescribed for URIs patients

8. Results 3 Appropriateness of Antibiotics Prescribing Compliance with the national treatment guideline was 36.4% for viral URIs treatment and 2.0% for bacterial URIs. Antibiotics prescribedURIs 2 (n=2247) Pharyngotonsillitis (n=275) OM 2 (n=70) Penicillin V 2.4 %2.9 %4.3 % Erythromycin 3.0 %1.1 %2.9 % Amoxycillin, Ampicillin, Amoxycillin+Clavulanate K 70.6 %71.3 %44.3 % Cotrimoxazole 3.1 %3.3 %7.1 % Doxycyclline 0.8 %0.7 %- Roxithromycin 6.3 %13.5 %5.7 % Dicloxacillin/cloxacillin 9.7 %5.1 %32.9 % Tetracycline 3.9 %1.8 %- Chloramphenicol0.4 %0.7 %35.7 % Table2. Antibiotics prescribed among antibiotic recipients 1 1 only patients with no other diagnosis than URI 2 totals may sum to more than 100% because some patients received >1 antibiotic appropriate antibiotic use

9. Results 4 Factors Associated with Antibiotic Prescribing ● For Viral URIs Characteristics of patient Antibiotic prescribed (%) Adjusted OR (95%CI) Gender: Male64.9%1.47 (1.26-1.72) Female 58.4% Referent Age: 18-40 yr. 68.9%3.62 (2.92-4.50) 41-60 yr. 59.4%2.17 (1.74-2.68) >60 yr. 46.5% Referent Type of payment National health plan 65.5%1.19 (1.00-1.40) Self-payment 53.5% Referent Physician working time Part-time 62.8%2.58 (0.85-7.85) Full-time51.0%Referent ● For bacterial URIs Only payment status was a significant predictor (OR, 2.17, 95% CI, 1.15-4.09)

10. Discussions What’s New? This study adds to the research society about study in developing country and in adults, and determinants of antibiotic prescribing in viral and bacterial URIs. Limitations Potential misclassification of diagnoses, probably of overestimate of inappropriate use of antibiotic. However, there still a significant antibiotics overuse. Application of the results Results of the study were used in designing of intervention, which is now implementing at the health center. For examples, treatment guideline, diagnosis rubber stamps, physician order forms, and follow up the outcome of delaying antibiotic prescribing.

11. Conclusions Physicians in the congested study communities treated viral and bacterial URIs cases differently and the predictors of antibiotic prescribing differed for viral and bacterial URI treatment. Patients with viral URIs frequently received antibiotics and patients with bacterial URIs frequently received inappropriate antibiotics, which leads to economic burden on the system and patients as well as increased drug resistance. Interventions to promote rational use of antibiotics in these communities are urgently needed and evaluated their effect.

12. Acknowledgement Funding organizations: Thailand Research Fund Applied Research on Child Health We thank Ms. Ratana Somrongthong for her continuing support coordinating the project. We also thanks Dr. Pricha Jarusunthornsri, Mr. Weerapong Pinweera, physicians and the staff at the study BMA health centers for facilitating access to their data. WHO Essential Drugs and Medicines Policy Department