Antibiotics to outpatients in Norway-Assessing effect of latitude and municipality population size using quantile regression in a cross-sectional study

Association of area-level education with the regional growth trajectories of rates of antibacterial dispensing to patients under 3 years in Norway: a longitudinal retrospective study

OBJECTIVE

To examine the association between area-level education and the local growth trajectories in antibacterial dispensing rates in Norwegian municipalities among children under 3 years old.

DESIGN

Retrospective, longitudinal study using individual primary care prescription data from the Norwegian Prescription Database for the period 2006-2016. Data were collected on the date of dispensing, the type and amount of antibiotic, the patient's age, sex and municipality of residence and linked to municipality-level statistics on education available from Statistics Norway. We used multilevel growth curve modelling, with a linear trend variable modelled as a random effect and a cross-level interaction between linear trends and the proportion of the population in the municipality having received a university or college education.

SETTING

The local government level in Norway. The sample includes all municipalities over the study period.

OUTCOME MEASURE

Number of dispensed antibacterial prescriptions per 100 children in individual primary care by municipality and year.

RESULTS

We identified a significant negative linear trend in the square root of the dispensing rate for children under 3 years old during the period. This trend varied between municipalities. A negative cross-level interaction term between population education levels and random trends showed that municipalities with an average level of population education saw a reduction in their square root dispensing rates of -0.053 (95% CI -0.066 to -0.039) prescriptions per 100 children. Each additional percentage point in population education contributed a further -0.0034 (95% CI -0.006 to -0.001) reduction to the square root dispensing rate.

CONCLUSIONS

Municipalities in which a larger proportion of the local population have high educational achievements have been more successful in reducing antibacterial dispensing rates in children under 3 years old. Adopting area-level strategies and addressing local community disadvantages may help to optimise practices and prescribing patterns across local communities.

Antibiotic use and deprivation: an analysis of Welsh primary care antibiotic prescribing data by socioeconomic status

OBJECTIVES

To examine the association between socioeconomic status (SES) and antibiotic prescribing, controlling for the presence of common chronic conditions and other potential confounders and variation amongst GP practices and clusters.

METHODS

This was an electronic cohort study using linked GP and Welsh Index of Multiple Deprivation (WIMD) data. The setting was GP practices contributing to the Secure Anonymised Information Linkage (SAIL) Databank 2013-17. The study involved 2.9 million patients nested within 339 GP practices, nested within 67 GP clusters.

RESULTS

Approximately 9 million oral antibiotics were prescribed between 2013 and 2017. Antibiotic prescribing rates were associated with WIMD quintile, with more deprived populations receiving more antibiotics. This association persisted after controlling for patient demographics, smoking, chronic conditions and clustering by GP practice and cluster, with those in the most deprived quintile receiving 18% more antibiotic prescriptions than those in the least deprived quintile (incidence rate ratio = 1.18; 95% CI = 1.181-1.187). We found substantial unexplained variation in antibiotic prescribing rates between GP practices [intra-cluster correlation (ICC) = 47.31%] and GP clusters (ICC = 12.88%) in the null model, which reduced to ICCs of 3.50% and 0.85% for GP practices and GP clusters, respectively, in the final adjusted model.

CONCLUSIONS

Antibiotic prescribing in primary care is increased in areas of greater SES deprivation and this is not explained by differences in the presence of common chronic conditions or smoking status. Substantial unexplained variation in prescribing supports the need for ongoing antimicrobial stewardship initiatives.

Geographic Variation in Antibiotic Consumption-Is It Due to Doctors' Prescribing or Patients' Consulting?

Antibiotic consumption varies greatly between Norwegian municipalities. We examine whether this variation is associated with inhabitants' consultation rates or general practitioners' (GP) prescription rates. Our study comprises consultations and antibiotic prescriptions for respiratory tract infections (RTIs) in general practice in all Norwegian municipalities with over 5000 inhabitants in 2014. Data was collected from The Norwegian Prescription Database, The Directorate of Health's system for control and payment of health reimbursements registry and Norway Statistics. Consultation rates and prescription rates were categorised in age- and gender specific quintiles and the effect on antibiotic consumption was analysed using a Poisson regression model. We found that inhabitants with RTIs received 42% more prescriptions if they belonged to a municipality with high consultation rates compared to low consultation rates [incidence rate ratio (IRR) 1.42 (95% CI 1.41-1.44)] and 48% more prescriptions if they belonged to a municipality with high prescription rates versus low prescription rates [IRR 1.48 (95% KI 1.47-1.50)]. Our results demonstrate that inhabitants' consultation rates and GPs' prescription rates have about equal impact on the number of RTI antibiotics prescribed at municipality level. These findings highlight the importance of interventions targeting patients as well as doctors in efforts to reduce unnecessary antibiotic consumption.