gms | German Medical Science

In Germany the prevalence of asthma during the 1990s continued to rise in children [Ref. 1], [Ref. 2]. Based on data of the Bundesgesundheitssurvey, the Robert Koch-Institute found a decrease of asthma prevalence for the time period 1998 to 2002/2003 in the total population [Ref. 3]. Against the background of these diverging trends we assessed temporal changes in prescriptions for atopic and obstructive airway disease in a sample of German health insurance data covering the period from 2000 to 2003.

Health insurance data (insurance period, sex, date of birth, hospitalization) were linked to prescription data of the ‘Norddeutsches Apotheken Rechenzentrum’ (NARZ) by the personal insurance identification number. Contracts on data transfer and data protection, incorporating the regulations of the data protection concept and general data protection regulations of German law, were concluded with the main institutions providing data. Included regions were Bremen (three different health insurance funds: A, B, Ca) and also Berlin, Hamburg, Lower Saxony, Mecklenburg-Western Pomerania, North Rhine-Westphalia, Saxony-Anhalt and Schleswig-Holstein (one health insurance fund: Cb) comprising more than 3.6 million insured persons and covering the years 2000 to 2003. According to the ATC coding system (ATC: Anatomy, Therapeutic properties, Chemical, pharmacological properties) separate analyses were performed for drugs for obstructive airway diseases (R03), antiallergic drugs (R03BC), Tiotropiumbromid (R03BB04, as a typical drug for chronic obstructive pulmonary disease (COPD) therapy), inhalative sympathomimetics (R03AK), and glucocorticoids (R03BA). Proportions of all insured persons who ever had a prescription in a single calendar year were stratified by sex, age (5-year age classes), health insurance, region (Bremen, non-Bremen) and calendar year.

The health insurance fund enrolees outside Bremen (women 1.46 million, men 1.61 million) represent a mix of rural and urban regions. Gender specific time trends of age-related distributions are analysed within this subpopulation. In a second step these trends are compared between insurances (insurance A: 0.15, 0.14; insurance B: 0.15, 0.10 million women and men, respectively).

With regard to age, peak prevalences of drug prescriptions for obstructive airway diseases were seen for young and old persons: women, age groups 0-4 and 65-79 ; men, age groups 0-4 and 75-79. For the younger and older age groups prevalences for men were higher than for women; for the age interval from 20 to 54 prevalences for women were higher. Prevalences were increasing for men and women in all age groups from 2000 to 2002; for age groups over 55 years an increase was also present until 2003. A similar pattern was seen for inhalative sympathomimetics. Here, prevalences for men showed maxima for the age groups 10-14 and 75-79. A similar pattern emerged in women from 2001 onwards, with peaks at ages 15-19 and 70-79, where a strong increase was observed in the latter age group (Fig. 1 [Fig. 1]). In the period from 2000 to 2003 a decrease of 50% in all age groups occurred for anti-allergic drugs which peaked at age 5-9 for both sexes. Prevalences for glucocorticoids showed two peaks: age 5-9 for both sexes, 65-69 for women and 75-79 for men. A continuous increase of the prevalences was seen for men and women from 2000 to 2003, in particular from 2002 to 2003.

The analysed population shows an age distribution comparable to the general population in Northern Germany, but due to selection of specific occupations of the insured persons, the health insurance funds may differ with regard to socioeconomic status.

Although the ATC coding system is an appropriate tool to produce treatment related differentiation of drugs it does not provide an unambiguous relation to distinct diseases. In addition, the analysed data are based on pharmacy claims, which may not reflect the true disease status of an insured person. However, these data give the opportunity to analyse time-dependent prescription patterns. As expected, for glucocorticoids, sympathomimetica, and other drugs to treat COPD, there was a significant rise of prescriptions with age which corresponds to the higher prevalence of COPD among the elderly. In contrast, anti-allergic drugs were mainly prescribed for children and young adults presumably against allergic asthma. Comparing time trends within prescription patterns of each drug class, a significant rising trend was observed for inhalative sympathomimetica and for glucocorticoids which probably reflects a change in prescriptions by physicians. Suprisingly, the prescription of therapeutical drugs for acute and chronic asthma strongly increased for men and women, especially for women in the higher age groups. This trend cannot be explained by a cohort effect alone. Prescription of drugs for chronic asthma at young age increased while prescription of anti-allergic drugs decreased during the same time period. This may reflect a change in the treatment of allergies.

However, the rising prescriptions of asthma-related drugs among children and young adults may also reflect a rise in the prevalence of asthma, which would correspond to recent findings of the ISAAC (International Study of Asthma and Allergies in Childhood) for the study centre Muenster [Ref. 1], [Ref. 2]). The population-based health survey (GSTel03) found a higher prevalence of asthma for women than for men in 2002/2003 (women 6.1%, men 5.3%) [Ref. 3]. Our results for therapeutic drugs for chronic asthma support these findings for the ages 20 to 65. Based In the years 1995/1996 the prevalence of asthma in 5-7 and 9-11 year old children measured by the use of anti-asthmatic drugs was significantly higher for boys (6.1%) than for girls (3.4%) [Ref. 4]. This is corroborated by our data.