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Trimethoprim resistance is increasingly prevalent in community-acquired urinary infections. The objective of this study was to evaluate the association between exposure to community-prescribed trimethoprim and other risk factors in subjects and subsequent trimethoprim-resistant urinary tract infection. The design was a nested case–control study using a record-linkage database. Study subjects submitted a urine sample to the Ninewells Hospital Laboratory between July 1993 and December 1995. Antibiotic exposure in subjects with trimethoprim-resistant isolates (cases) was compared with antibiotic exposure in subjects with trimethoprim-susceptible isolates (controls). Study subjects were drawn from the catchment area of a large teaching hospital in Tayside, Scotland. There were 13765 males and females aged 1–106 years who submitted their first urine sample for culture during the study period. After adjustment for significant risk factors and confounding variables, logistic regression analysis showed exposure to trimethoprim [odds ratio (OR) 4.35] or any antibiotic other than trimethoprim (OR 1.32) to be predictive of resistance. The growth of Proteus spp. (OR 115.14) and bacterial growth other than Escherichia coli and Proteus spp. (OR 2.83) were also predictor variables. Hospitalization in the previous 6 months was not independently associated with trimethoprim resistance. In conclusion, trimethoprim resistance was independently associated with exposure to trimethoprim and to antibiotics other than trimethoprim. Reduction in trimethoprim prescribing alone may not reduce the prevalence of trimethoprim resistance. [ABSTRACT FROM PUBLISHER]

A cohort design was used to evaluate antibiotic prescribing in relation to patient and general practice characteristics. The study included prescribing to all subjects resident in Tayside, from January to December 1994 and found 215217 antibiotic prescriptions dispensed to 118596 people. Training status of general practitioners (GPs) was found to be the characteristic most associated with prescribing. Adjusting for other GP characteristics had little effect on these results. Training practice status was the dominant factor associated with significant differences in rates of antibiotic prescribing, in class of antibiotic prescribed and in performance indicators of antibiotic prescribing. [ABSTRACT FROM AUTHOR]

The study objective was to determine whether recent community antibiotic prescribing and hospitalization are associated with β-lactam resistance in respiratory isolates of Haemophilus influenzae. Data obtained for hospitalization and community prescribing (in the previous 3 months) from 412 adults (>15 years) in whom an episode of respiratory tract infection had been described, during which H. influenzae was isolated, were analysed. Seventy-three (17.7%) isolates of H. influenzae were resistant to amoxycillin. Resistance was associated with recent hospitalization [odds ratio (OR) 3.2, 1.8–5.6] and antibiotic exposure in the community (2.1, 1.2–3.6). These variables were independently associated with amoxycillin resistance [hospitalization (OR 4.5, 1.7–12.5) and community β-lactam antibiotic exposure (3.9, 1.6–9.8)]. Hospitalized patients probably received antibiotics during their admission although aquisition of the organism or the β-lactamase via plasmids from other Gram-negative organisms in the hospital could also be a factor. Control measures to reduce the inappropriate use of antimicrobials in the community and in hospital need to be reinforced. [ABSTRACT FROM PUBLISHER]

Urine samples with trimethoprim-resistant or trimethoprim-sensitive Gram-negative bacteria and samples with no bacterial growth (NG) were identified. Age-sex matched community controls were generated with each trimethoprim-resistant case. These four groups were evaluated for exposure. Prior trimethoprim use was significantly more common in the trimethoprim-resistant group when compared with the trimethoprim-sensitive or the NG group. Prior hospitalization was significantly less common in the trimethoprim-resistant than the trimethoprim-sensitive group, but not with the NG group. Prior oestrogen exposure was associated with trimethoprim resistance. There were no associations found for diabetes or prior corticosteroid exposure. Community controls were found to be inappropriate controls for the study of trimethoprim-resistant bacteria in urine samples. [ABSTRACT FROM AUTHOR]