Prescribing antibiotics: the use of diagnostic tests in general practice. A register-based study.

OBJECTIVE: To assess (i) the pattern of antibiotic prescribing in Danish general practice, (ii) the use of diagnostic tests [point-of-care (POC) and tests analysed at the hospital laboratory (laboratory tests)], and (iii) the frequency of diagnostic testing in relation to antibiotic prescriptions. DESIGN: Retrospective cross-sectional register-based study. SETTING: General practice in a geographical area of Denmark covering 455,956 inhabitants. SUBJECTS: We studied redeemed antibiotic prescriptions and performed diagnostic tests in general practice from 2013 to 2017 among inhabitants in nine selected municipalities. MAIN OUTCOME MEASURES: Frequency of antibiotic courses. Frequency and type of diagnostic testing performed in relation to types of antibiotics. RESULTS: A total of 783,252 antibiotic courses were redeemed from general practice with an overall decrease of 19% during 2013-2017. Diagnostic testing increased by 6% during this period. POC tests comprised the majority of performed diagnostic tests (83%) with C-reactive protein (CRP) as the most frequently used test. A 27% increase in the use of laboratory tests was observed. Tests were performed in relation to 43% of all antibiotic courses; most in relation to prescriptions for sulphonamide and trimethoprim (57%) and rarely when prescribing tetracyclines (10%). Conflicting with national guidelines, Danish GPs prescribed fluoroquinolones without performing any kind of diagnostic testing in 48% of the cases. CONCLUSIONS: This study provides an overview of the use of diagnostic tests in relation to antibiotics and creates basis for further research into the variability between types of antibiotics. The study indicates that there is room for improvement to use diagnostic tests as an aid to promote prudent antibiotic use.KEY POINTSDiagnostic tests (point-of-care or tests analysed at the hospital laboratory), can increase diagnostic certainty and lead to a reduction in antibiotic use in general practice.A decrease in antibiotic courses in general practice in Denmark was observed during 2013-2017, while the use of diagnostic tests increased.A diagnostic test was performed in relation to 43% of antibiotic courses.Only 52% of prescribed fluoroquinolones was related to a diagnostic test, conflicting with national guidelines.

Prescribing antibiotics: Factors driving decision-making in general practice. A discrete choice experiment.

BACKGROUND: Antimicrobial resistance is a threat to human health. We need to strive for a rational use of antibiotics to reduce the selection of resistant bacteria. Most antibiotics are prescribed in general practice, but little is known about factors influencing general practitioners' (GPs) decision-making when prescribing antibiotics. AIM: To 1) assess the importance of factors that influence decisions by GPs to prescribe antibiotics for acute respiratory tract infections (RTIs) and 2) identify segments of GPs influenced differently when deciding to prescribe antibiotics. METHODS: A questionnaire survey including a discrete choice experiment was conducted. Danish GPs were asked to indicate whether they would prescribe antibiotics in six hypothetical choice sets with six variables: whether the GP is behind schedule, patient's temperature, patient's general condition, lung auscultation findings, C-reactive protein (CRP) level, and whether the patient expects antibiotics. Error component and latent class models were estimated and the probabilities of prescribing in different scenarios were calculated. RESULTS: The questionnaire was distributed to every Danish GP (n = 3,336); 1,152 (35%) responded. Results showed that GPs were influenced by (in prioritised order): CRP level (Relative importance (RI) 0.54), patient's general condition (RI 0.20), crackles at auscultation (RI 0.15), and fever (RI 0.10). Being behind schedule and patient expectations had no significant impact on antibiotic prescription at the aggregate level. The latent class analysis identified five classes of GPs: generalists, CRP-guided, general condition-guided, reluctant prescribers, and stethoscopy-guided. For all classes, CRP was the most important driver, while GPs were heterogeneously affected by other drivers. CONCLUSION: The most important factor affecting Danish GPs' decision to prescribe antibiotics at the aggregate level, in subgroups of GPs, and across latent classes was the CRP value. Hence, the use of CRP testing is an important factor to consider in order to promote rational antibiotic use in the battle against antimicrobial resistance.

Factors associated with C-reactive protein testing when prescribing antibiotics in general practice: a register-based study.

BACKGROUND: The use of C-reactive protein (CRP) tests has been shown to safely reduce antibiotic prescribing for acute respiratory tract infections (RTIs). The aim of this study was to explore patient and clinical factors associated with the use of CRP testing when prescribing antibiotics recommended for RTIs. METHODS: A nation-wide retrospective cross-sectional register-based study based on first redeemed antibiotic prescriptions issued to adults in Danish general practice between July 2015 and June 2017. Only antibiotics recommended for treatment of RTIs were included in the analysis (penicillin-V, amoxicillin, co-amoxicillin or roxithromycin/clarithromycin). Logistic regression models were used to estimate odds ratios for patient-related and clinical factors on performing a CRP test in relation to antibiotic prescribing. RESULTS: A total of 984,149 patients redeemed at least one antibiotic prescription during the two-year period. About half of these prescriptions (49.6%) had an RTI stated as the indication, and a CRP test was performed in relation to 45.2% of these scripts. Lower odds of having a CRP test performed in relation to an antibiotic prescription was found for patients aged 75 years and above (OR 0.82, 95CI 0.79-0.86), with a Charlson Comorbidity Index of more than one (OR 0.93, 95CI 0.91-0.95), unemployed or on disability pension (OR 0.84, 95CI 0.83-0.85) and immigrants (OR 0.91, 95CI 0.88-0.95) or descendants of immigrants (OR 0.90, 95CI 0.84-0.96). Living with a partner (OR 1.08, 95CI 1.07-1.10), being followed in practice for a chronic condition (OR 1.22, 95CI 1.18-1.26) and having CRP tests performed in the previous year (OR 1.78, 95CI 1.73-1.84) were associated with higher odds of CRP testing in relation to antibiotic prescribing. CONCLUSIONS: Differences were observed in the use of CRP tests among subgroups of patients indicating that both sociodemographic factors and comorbidity influence the decision to use a CRP test in relation to antibiotic prescriptions in general practice. Potentially, this means that the use of CRP tests could be optimised to increase diagnostic certainty and further promote rational prescribing of antibiotics. The rationale behind the observed differences could be further explored in future qualitative studies.

C-reactive protein cut-offs used for acute respiratory infections in Danish general practice.

BACKGROUND: GPs can use the C-reactive protein (CRP) point-of-care test (POCT) to assist when deciding whether to prescribe antibiotics for patients with acute respiratory tract infections (RTIs). AIM: To estimate the CRP cut-off levels that Danish GPs use to guide antibiotic prescribing for patients presenting with different signs and symptoms of RTIs. DESIGN & SETTING: A cross-sectional study conducted in general practice in Denmark. METHOD: During the winters of 2017 and 2018, 143 GPs and their staff registered consecutive patients with symptoms of an RTI according to the Audit Project Odense (APO) method. CRP cut-offs were estimated as the lowest level at which half of the patients were prescribed an antibiotic. RESULTS: In total, 7813 patients were diagnosed with an RTI, of whom 4617 (59%) had a CRP test performed. At least 25% of the patients were prescribed an antibiotic when the CRP level was >20 mg/L, at least 50% when CRP was >40 mg/L, and at least 75% when CRP was >50 mg/L. Lower thresholds were identified for patients aged ≥65 years and those presenting with a fever, poor general appearance, dyspnoea, abnormal lung auscultation, or ear/facial pain, and if the duration of symptoms was either short (≤1 day) or long (>14 days). CONCLUSION: More than half of patients presenting to Danish general practice with symptoms of an RTI have a CRP test performed. At CRP levels >40 mg/L, the majority of patients have an antibiotic prescribed.