BACKGROUND

Multiple medications is a well-known potential risk factor in terms of patient's health. The aim of the present study was to estimate the prevalence of dispensed drugs and multiple medications in an entire national population, by using individual based data on dispensed drugs.

METHODS

Analyses of all dispensed out-patient prescriptions in 2006 from the Swedish prescribed drug register. As a cut-off for multiple medications, we applied five or more different drugs dispensed (DP >or= 5) at Swedish pharmacies for a single individual during a 3-month, a 6-month, and a 12-month study period. For comparison, results were also calculated with certain drug groups excluded.

RESULTS

6.2 million individuals received at least one dispensed drug (DP >or= 1) during 12 months in 2006 corresponding to a prevalence of 67.4%; 75.6% for females and 59.3% for males. Individuals received on average 4.7 dispensed drugs per individual (median 3, Q1-Q3 2-6); females 5.0 (median 3, Q1-Q3 2-7), males 4.3 (median 3, Q1-Q3 1-6).The prevalence of multiple medications (DP >or= 5) was 24.4% for the entire population. The prevalence increased with age. For elderly 70-79, 80-89, and 90-years, the prevalence of DP >or= 5 was 62.4, 75.1, and 77.7% in the respective age groups. 82.8% of all individuals with DP >or= 1 and 64.9% of all individuals with DP >or= 5 were < 70 years. Multiple medications was more frequent for females (29.6%) than for males (19.2%). For individuals 10 to 39 years, DP >or= 5 was twice as common among females compared to males. Sex hormones and modulators of the genital system excluded, reduced the relative risk (RR) for females vs. males for DP >or= 5 from 1.5 to 1.4. The prevalence of DP >or= 1 increased from 45.1 to 56.2 and 67.4%, respectively, when the study period was 3, 6, and 12 respectively months and the corresponding prevalence of DP >or= 5 was 11.3, 17.2, and 24.4% respectively.

CONCLUSION

The prevalence of dispensed drugs and multiple medications were extensive in all age groups and were higher for females than for males. Multiple medications should be regarded as a risk in terms of potential drug-drug interactions and adverse drug reactions in all age groups.

PURPOSE: To assess polypharmacy in a population with emphasis on regions. METHODS: We studied the individual-based data of all dispensed prescription drugs (DP) during a 3-month study period in Sweden 2006. As an indicator of polypharmacy, five or more (DP > or = 5) different drugs (substances) dispensed were applied. For analysis, we used comparisons of prevalence, correlation of prevalence of polypharmacy with different socioeconomic variables, and a novel weighted polypharmacy index. RESULTS: The national prevalence of polypharmacy, DP > or = 5, was 10.5% (inter-regional variation 9.1-12.1%). The regional variation in the prevalence of polypharmacy was largest for the age groups > or =90 (45.6-59.1%), 80-89 (46.1-53.4%) and 70-79 years (33.1-38.0%). The national prevalence of excessive polypharmacy, DP > or = 10, was 2.2% (inter-regional variation 1.9-2.6%). The regional variation in prevalence of excessive polypharmacy was largest for the age groups > or =90 (9.8-22.3%), 80-89 (11.4-17.1%) and 70-79 years (7.0-9.4%). We found a fairly strong positive correlation between polypharmacy and the age group > or =70 years (r = 0.84 for men and 0.71 for women). The novel weighted polypharmacy index indicated regional differences in the internal distribution of the prevalence of dispensed drugs for individuals with polypharmacy. CONCLUSION: Our findings indicate that the observed regional differences in the prevalence of polypharmacy partly can be explained by the regional age distribution in Sweden. The use of the novel weighted polypharmacy index indicated regional differences in drug therapy for individuals with polypharmacy.

Objectives  To assess the prevalence and the therapeutic intensity of dispensed drug groups for individuals receiving multiple medications.

Methods  The individual-based data of all dispensed outpatient prescriptions in Sweden in 2006 were analysed. Five or more dispensed drugs (DP ≥ 5) during a 12-month period were applied as an indicator of multiple medications. The drugs were categorized according to the second level of the World Health Organization's Anatomic, Therapeutic, Chemical classification. The defined daily dosage per individual during 12 months was applied as an indicator of the therapeutic intensity.

Key findings  For the 2.2 million individuals with DP ≥ 5, the drug groups with the highest prevalences were antibacterials (48.2%), analgesics (40.3%), psycholeptics (35.9%), antithrombotic agents (33.4%) and beta-blocking agents (31.7%). As examples, the level of prevalence increased with age for analgesics, psycholeptics, antithrombotic agents and diuretics, and decreased with age for antibacterials, drugs for obstructive airway diseases and antihistamines for systemic use. Substantial differences in the level of prevalence between women and men were observed for several drug groups; for example, thyroid therapy (13.3 vs 3.6%), psychoanaleptics (26.3 vs 18.2%), drugs used in diabetes (9.1 vs 15.7%) and lipid-modifying agents (18.1 vs 30.7%). Generally, the therapeutic intensity increased with the increasing number of dispensed drugs. For a third of the most common drug groups, the therapeutic intensity increased with an increasing age above the 60–69-year age group.

Conclusion  The number of drugs taken not only increases the potential risks associated with multiple drug use, but also increases the potential burden of an increased therapeutic intensity, especially for older people. The reported findings may enlighten physicians and healthcare stakeholders concerning the complex patterns of multiple drug use in the entire population and the associated expenses. The findings may also be used as a base for interventions aiming to bring about the most appropriate and balanced prescription of medicines to individuals with multiple diseases.

Background:

The total drug sales has increased substantially during the last decades. The increase is assumed to be associated with the observed increase in the individual use of several different drugs, the so-called multiple medications.

Objective:

To analyse the acquisition cost of dispensed prescription drugs for individuals with multiple medications in a national population.

Study design, setting and participants:

An individual based register study of all dispensed prescription drugs (DP) in Sweden in 2006, including 6.2 million individuals. As an indicator of multiple medications, five or more dispensed prescription drugs (DP≥5) during a 12-month period was applied. For comparison, ten or more (DP≥10) and fifteen and more (DP≥15) dispensed drugs during a 12-month period were used.

Results:

The total acquisition cost of dispensed drugs in Sweden in 2006 was SEK 23.2 billion, (corresponding to EUR 2.5 billion 2006). Individuals with DP≥5 (24.5% of total population) accounted for 78.8% of the total drug cost, and individuals with DP≥10 (8.6% of population) and DP≥15 (3.0% of population) accounted for 46.3% and 23.2% respectively.

Individuals with DP>5 younger than 70 years of age (corresponding to 64.9% all individuals with DP>5) accounted for 64.7% of the total acquisition cost for all with DP>5.The highest total drug cost for individuals with DP>5 was displayed in the age group 60-69 followed by 70-79 and 50-59 years, 21.5%, 19.8%, and 17.4%, respectively.

The average acquisition cost per daily defined dosage (DDD) generally decreased with increasing age. For individuals with DP≥5, the average cost per DDD decreased from SEK 8.04 to SEK 2.27 (-72%) for the age group 10-19 to 90 years and above. The highest average cost per DDD was observed for individuals with DP≥10.

The drug cost for women with DP≥5 (corresponding to 60.9% all individuals with DP>5) represented 56.0% of the total cost. Men with DP≥5 (corresponding to 39.1% all individuals with DP>5) represented 44.0% of the total cost.

For individuals with DP≥5, the average cost per DDD was SEK 4.31 (corresponding to EUR 0.46 2006), for women 4.08, and for men 4.62.

Conclusion:

Individuals with ten or more drugs accounted for almost half of the acquisition costs of dispensed drugs. In order to reduce the risks for adverse drug reactions, interactions and inappropriate drug us, interventions with focus on reduction of the number of prescription drugs for the small group of patients with many different drugs, may therefore also give a substantial reduction of the total drug costs.

Purpose

To analyse the development of the prevalence of polypharmacy in an entire national population during a 4-year period.

Methods

By using individual based data on dispensed drugs, we studied all dispensed prescription drugs for the entire Swedish population during a 3-month period during 2005-2008. Five or more (DP ≥5) and ten or more (DP ≥10) dispensed drugs during the 3-month period were used as cut-offs indicating polypharmacy and excessive polypharmacy, respectively.

Results

During 2005-2008, the prevalence of polypharmacy (DP≥5) increased by 8.2% (from 0.102 to 0.111), and the prevalence of excessive polypharmacy (DP≥10) increased by 15.7% (from 0.021 to 0.024).

With exception for the age group 0-9 years, the prevalence of polypharmacy and excessive polypharmacy increased in all age groups. The prevalence of excessive polypharmacy displayed a clear age trend, with the largest increase for the age groups 70 years and above. Generally, the increase in the prevalence of polypharmacy was about twice as high for men as for women.

The mean number of dispensed drugs per individual increased by 3.6% (from 3.3 to 3.4) during the study periods.

Conclusions

In spite of reported efforts to reduce polypharmacy, the prevalence of polypharmacy and excessive polypharmacy and the mean number of dispensed drugs per individual continued to increase year-by-year in Sweden during 2005-2008.