Use of administrative healthcare claims to examine the effectiveness of trimethoprim-sulfamethoxazole versus fluoroquinolones in the treatment of community-acquired acute pyelonephritis in women.

OBJECTIVE: To evaluate the effectiveness of trimethoprim-sulfamethoxazole and fluoroquinolones in the treatment of community-acquired acute pyelonephritis. PATIENTS AND METHODS: We identified a population-based cohort of non-pregnant women aged 18-65 years, initially treated with trimethoprim-sulfamethoxazole or a fluoroquinolone for community-acquired pyelonephritis in an ambulatory care setting. Subjects were identified from a healthcare claims database in Manitoba, Canada for the period 15 February 1996 to 31 March 1999. Subsequent treatment failure, as evidenced by the provision of additional treatment up to 42 days post-diagnosis, was compared between the two treatments. RESULTS: A total of 1084 women met inclusion criteria: 653 (60.2%) treated with trimethoprim-sulfamethoxazole and 431 (39.8%) treated with a fluoroquinolone. Treatment outcomes were affected by subject age. At age 20, treatment with a fluoroquinolone resulted in a reduced probability of treatment failure compared with trimethoprim-sulfamethoxazole (odds ratio, 0.56; 95% CI, 0.33-0.97). At age 60, there was no difference in the probability of treatment failure (odds ratio, 1.61; 95% CI, 0.82-3.16). No other subject characteristics impacted comparative effectiveness; however, several characteristics increased the odds of treatment failure irrespective of the initial antibiotic. These included: recent urinary tract infection (odds ratio, 2.07; 95% CI, 1.14-3.57), recent antibiotic use (odds ratio, 1.40; 95% CI, 1.00-1.96;), and a treatment duration of less than 10 days (odds ratio, 2.18; 95% CI, 1.59-2.99). CONCLUSION: Younger subjects ( approximately 20 years) treated with fluoroquinolones were less likely to experience treatment failure than those treated with trimethoprim-sulfamethoxazole. Treatment durations of less than 10 days resulted in a higher probability of treatment failure regardless of the initial antibiotic.

Antibiotic use in a Canadian Province, 1995-1998.

OBJECTIVE: Antibiotics are among the most commonly used classes of agents in community practice; yet, studies of antibiotic use in this setting are scarce. Data from developed countries suggest increasing use of newer broad-spectrum agents, which has implications for the development of antibiotic resistance as well as cost of therapy. In this study, we quantified changing patterns of antibiotic use in community practice in Manitoba, Canada, from 1995 to 1998. DESIGN: A descriptive, population-based study of antibiotic use in Manitoba was facilitated by the Drug Programs Information Network (DPIN) of Manitoba Health; a data management system responsible for recording details of prescriptions dispensed for all Manitoba residents. Antibiotic use data, defined as numbers of prescriptions dispensed, were extracted from the DPIN from January 1, 1995, to March 31, 1998. Antibiotic use is reported as prescriptions per 1000 persons per year (Rx/1000/Yr) based on quarterly use. RESULTS: Penicillins (48.3%), macrolides (16.0%), and sulfonamides (12.5%) accounted for 75% of total antibiotic use; total use decreased 19.1% between 1995 and 1998. Use of the four most commonly prescribed agents decreased over the study period (amoxicillin, -17.4%; erythromycin, -29.0%; trimethoprim/sulfamethoxazole, -18.7%; penicillins G and V, -19.2%). In contrast, use of newer and/or broad-spectrum agents increased (ciprofloxacin, 21.9%; cefuroxime, 30.7%; and azithromycin/clarithromycin, 29.5%). Use of second-line agents as a percentage of total antibiotic use increased from 14.4% to 19.3% between January 1995 and March 1998 (p < 0.001). CONCLUSIONS: Penicillins, macrolides, and sulfonamides accounted for 75% of antibiotic use. Total antibiotic use declined over the study period; however, use of newer, broad-spectrum agents increased while use of older, narrow-spectrum agents decreased.

Antibacterial use in community practice: assessing quantity, indications and appropriateness, and relationship to the development of antibacterial resistance.

Most use of antibacterials occurs in community practice; however, despite the widespread belief of inappropriate use and the resultant increase in antibacterial resistance, little data exist describing antibacterial use in this setting. A MEDLINE search of English-language articles was conducted for epidemiological studies assessing quantity, indication and appropriateness of antibacterial use in community practice. A 1983 study of international antibacterial use described considerable disparities in quantity of use between countries. Subsequent longitudinal studies from the US, Canada, Australia and the UK described changing patterns of antibacterial use. No increase in the total rate of antibacterial use was reported by any of the 4 countries; however, all countries reported increased use of newer and/or broad-spectrum agents (e.g. fluoroquinolones, amoxicillin-clavulanic acid, cephalosporins and new macrolides] coupled with decreased use of older and/or narrow-spectrum agents [e.g. phenoxymethylpenicillin (penicillin V), erythromycin, ampicillin and tetracycline). Most (approximately three-quarters) use of antibacterials was in the treatment of respiratory tract infections. Prescribing rates for respiratory tract infections of presumed viral aetiology (e.g. the common cold) ranged from 17 to 60% in the UK and US, respectively. Among indications for which antibacterials were indicated, the appropriateness of antibacterial use received little study. Correspondingly, the rates of antibacterial resistance among common respiratory pathogens (Streptococcus pneumoniae and Haemophilus influenzae) have increased significantly in the past decade, although disparities exist between countries. Antibacterial use is considered a major factor in the development of antibacterial resistance, although the relationship between community antibacterial use and resistance has been poorly described. Further study of antibacterial usage patterns and associated resistance patterns is fundamental to the development of methods to reduce unnecessary and inappropriate use, thereby slowing the development of antibacterial resistance in the community.