A regional analysis of outpatient antibiotic prescribing in Germany in 2010 Free

Abstract

Introduction

Since a number of years, international comparisons of outpatient antibiotic use have become available and have demonstrated considerable variation in antibiotic prescribing between countries. ¹ Many of the observed patterns of use appear to have persisted over time, and sociocultural determinants rather than epidemiological differences may account for this variation. Within-country differences in antibiotic use have also been observed. For example, Belgium has reported significant differences between the French-speaking parts of the country and Flanders. ² Switzerland shows a much higher antibiotic use density in the French-speaking part than in other regions, and in Italy antibiotic consumption increases from the south to the north. ^3,4 According to earlier estimates for prescribed defined daily doses (DDD) per population covered by the statutory health insurance (∼90% of the population in Germany) it was suggested that the eastern (new) states of Germany are low antibiotic consumption areas compared with the western part of Germany, in particular regions near Luxembourg and Belgium and the states of North Rhine-Westphalia. ^5,6 We here used a full analysis set of recent outpatient drug prescription data to evaluate whether regional antibiotic use differences in both children and adults have persisted over time and whether earlier data for children and adults can be confirmed using prescription prevalence as metric rather than antibiotic use density values expressed in DDD per population.

Methods

Almost 90% of Germany’s 81.7 million population (2010) are covered by statutory health insurances ( Gesetzliche Krankenkassen , GKV) with little regional variation in coverage rates. GKV prescription data for the year 2010 with all dispensed WHO-ATC classification-code ‘J01’ drugs (antibiotics for systemic use) were analysed. Prescription prevalence was calculated by counting all WHO-ATC-code ‘J01’ drug prescriptions in 2010 per 100 individuals covered by GKV. Overall and adult (≥15 years of age) prescription prevalence data were directly age-standardized by calculating a weighted average of the region’s age-specific population rates where the weights represent the age-specific sizes of the 2010 reference population (KM6 statistics of the Federal Ministry of Health, www.gbe-bund.de ). The regions were defined by 17 GKV physician associations ( kassenärztliche Vereinigungen, KV) which are geographically similar to German federal states [ Länder , one of the largest states (North Rhine-Westphalia) is separated into 2 KV regions], and were based on the location of the prescriber rather than the home address of the patient.

Results and discussion

The overall outpatient antibiotic prescription prevalence in 2010 was 31.5%. Age-standardized prescription prevalence was higher in western states compared with states in the eastern region. The highest overall annual prescription prevalence (36.6%) was in Saarland, a small state bordering France and Luxembourg. The lowest rate was observed in the new state of Brandenburg (25%) located in the eastern part of the country. The regional pattern of overall antibiotic use was similar using prescribed DDD per population. When compared with the estimated values for DDD per 1000 population and day from the year 2003. ^5,6 the data indicate that the relatively low overall antibiotic consumption in eastern and southern German obviously has persisted since that time.

The prescription prevalence was different according to age group. Patients older than 90 years showed the highest (55.7%), and children showed the second highest prescription prevalence (39.1%) while the prevalence was much lower (<30%) for the age groups 40–74 years.

As shown in figure 1 the regional pattern of antibiotic use in 2010 as measured by prescription prevalence differed between the different regions for children and adults. Surprisingly and as suggested before, ^6,7 high rates among children were observed in Thuringia and several other new eastern states that did not show this pattern for adults. In fact, the prescription prevalence in Thuringia among children (46.1%) was high and similar to the level observed in Saarland (46.1 vs. 46.6%) whereas among adults the levels in these two states were 29.0 vs. 35.1%, respectively. On the other hand, the area with the lowest antibiotic consumption in children in 2010 was the (southern) state of Baden-Wuerttemberg, and this low rank in pediatric antibiotic use was already estimated from the antibiotic use density data from the year 2003 published earlier. ⁶

Figure 1

Antibiotic prescription prevalence for children vs. adults in different regions of Germany. Data are for 2010

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Previous reports used national sample data to explore regional differences in antibiotic use. In contrast, this study used a full analysis set of prescription data and therefore provides a more reliable estimate of regional differences. In addition, because of the limitations of the WHO-ATC DDD definitions specifically for childhood consumption evaluation analyses the present analysis used prescription prevalence to reassess regional use patterns in children (vs. adults) in this country. Most previous antibiotic use studies in children have used prescription prevalence as the best available and suitable metric. ^7,8 The current findings reliably demonstrate that the regional patterns of outpatient antibiotic use in Germany including the poor correlation between use levels for adults and children have remained somehow stable since >5 years.

The reason for the discrepant regional antibiotic use patterns between adults and children is unknown. Most likely the observed patterns represent sociocultural developments and particularities in the young generation of parents living in the east. There has been a discrepant evolution in fertility rates between east and west, with rates becoming higher in the east than in the west in the last decades. ⁹ There are higher employment and much lower marriage rates (and many more single mothers) among women in the east compared with those living in the west and south, in particular. Also, the percentage of children in day care centres in the east is much higher than in the west. ¹⁰ We speculate that these conditions could have led to an increased demand for medicines felt to perhaps more rapidly cure infections among children and, thus, allow mothers to more rapidly go back to work and remain incapacitated for fewer days. Across the regions defined here; however, a preliminary exploratory analysis shows that there is no perfect correlation between employment, income, marriage rate or single parenthood on one side and antibiotic use on the other side. Detailed small area analyses considering sociocultural and demographic data are needed to test such and similar hypotheses and possibly better explain the regional and age-specific differences in antibiotic use patterns observed in this country.

In conclusion, the pattern of regional antibiotic prescription rates for children in Germany differs from those seen in adults. Age-specific antibiotic prescription rates need to be considered when comparing antibiotic consumption between regions and possibly countries, and before planning interventions.

Conflict of interest : None declared.

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