Why has the utilization of antiasthmatics increased in Finland?

Why has the utilization of antiasthmatics increased in Finland?

0895-4356/91 $3.00+ 0.00 PergamonPressplc J Clin EpidemiolVol.44,No. 8, PP.859-863,1991 Printedin Great Britain WHY HAS THE UTILIZATION OF ANTIASTHM...

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0895-4356/91 $3.00+ 0.00 PergamonPressplc

J Clin EpidemiolVol.44,No. 8, PP.859-863,1991 Printedin Great Britain

WHY HAS THE UTILIZATION OF ANTIASTHMATICS INCREASED IN FINLAND? TIMO KLAUKKA,* SIRPA PEURA and JAANA MARTIKAINBN The Research Institute for Social Security, The Social Insurance Institution, Helsinki, Finland (Received for publication

16 May 1991)

Abstract-The sales of antiasthmatics have increased rapidly in the Nordic countries during the 1980s. The causes for this growth in Finland were studied. Four nationwide

population surveys show that the prevalence of self-reported asthma has risen, a larger proportion of asthmatic patients are under medication, the number of antiasthmatics per patient has increased, and the dosage recommendations of inhalation glucocorticoids and B-agonistshave grown. The average cost of medical treatment of an asthmatic patient was FIM 1848(approximately U.S. $510.00)in 1990.The highest average expenses in the 21 districts studied were FIM 2171 and the lowest FIM 1535.To identify the consequences of these variations, the frequency of symptomatic periods as well as the quality of life of the asthmatic patients should be studied. Drug utilization

Regional variations

Cost-benefit

Asthma

face-to-face at the respondents’ homes by local public health nurses, who were specially trained for this task. The methodology in these studies makes the results comparable with each other. The samples were representative of the Finnish non-institutionalized population, and the number of the interviewed adults was 16,715 in 1964, 17,910 in 1968, 16,413 in 1976 and 13,138 in 1987. In addition, data on children’s health

INTRODUCTION

The sales of antiasthmatic drugs have been rapidly increasing in all the Nordic countries during the 1980s [l] (Fig. 1). This trend has important economical consequences, because this medication is relatively expensive. The purpose of this study was to search for explanations to the rapid growth in the sales of antiasthmatics in Finland. Special emphasis was laid on possible changes in morbidity and treatment practices.

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MATERIAL AND METHODS

The Social Insurance Institution of Finland conducted nationwide health interview surveys in 1964, 1968, 1976 and 1987. In all these studies, self-reported chronic morbidity was investigated. In 1976 and 1987 the currently used prescription medicines were also recorded by the interviewers. The interviews were conducted

0’

*All correspondence should be addressed to: Timo Klaukka, The Social Insurance Institution, P.O. Box 78, SF-00381 Helsinki, Finland. 859

Sweden Denmark Norway Finland Iceland

’ ’ 1960 1981 I962

---------

’ I963

’ ’ 1994 896

’ ’ 1966 (987

’ I996

’ I969

Year Fig. 1. The sales of antiasthmatic drugs in the Nordic countries during the 1980s.

Two

860

KLAUKKA

status and use of medicines was collected from their parents in the studies of 1976 and 1987. The number of children studied (under 15 years of age) was 4605 in 1976 and 3131 in 1987. The participation rates were more than 90% in all the studies except the latest one, in which it was 85%. The main results and the methodology of these studies have been reported elsewhere [2-41. Chronic morbidity was assessed in all the studies with two questions: “Have you any defect or injury that lowers your general working capacity or activity, or any chronic illness?” (If yes): “Define or describe this injury or illness.” The diseases were categorized according to a classification of 96 diseases or disease groups aggregated from the International Classification of Diseases. One of these categories was asthma, presented separately from other respiratory diseases. Prescription drug utilization was recorded using the following question: “What prescription drugs do you use at the moment?’ In 1976 it was also inquired as to which of the drugs used were entirely paid for under sickness insurance. In 1987, the corresponding information was collected for each interviewed person from sickness insurance registers. The interviewers copied the names of the drugs from prescription forms or containers. The drugs were further categorized according to the Finnish drug compendium Pharmaca Fen&a. In this classification, antiasthmatics include bronchospasmolytic drugs, i.e. systematically used p-agonists, xanthine derivatives, combination preparations as well as inhalation /3-agonists, glucocorticoids and sodium cromoglycate. National sales statistics of antiasthmatic drugs constituted the basis for analyses of drug consumption [l, 5-71. These statistics provide data on the sales of various categories of medicines to pharmacies and hospitals. The units of measurement are the number of defined daily doses (DDD) per 1000 inhabitants per day, and the monetary value of the sales, analysed as the purchase price payable by the pharmacies. The

et al. 2.4 2.0 1.6

0.0 0.4 0.0 Men Womm 1964

Men

Women Men Mmen 1976

1966

Fig. 2. The self-reported prevalence (%) of asthma in the Finnish adult population in 1964, 1968, 1976 and 1987.

drugs are classified according to the Anatomical Therapeutic Chemical (ATC) classification system, in which antiasthmatics belong to group R 03 [5]. Data on the costs of antiasthmatic medication per patient is derived from the sickness insurance register, which contains information on medication costs of those patients who are entitled to preferentially reimbursed drugs (90% refund) after having fulfilled certain diagnostic criteria of asthma. RESULTS

The self-reported prevalence of asthma rose slightly among adults between the years 1964 and 1976 (Fig. 2). In 1976 it was 1.1% of the total population, and in 1987, 1.9% (Table l), representing an increase of 73%. The rate rose more among females than among males, and the relative growth was biggest (83%) among the middle aged. This increase was also reflected in the number of asthmatic patients who were entitled to preferentially reimbursed medication: the total number in the Finnish population was 45,171 in 1980 and 104,550 in 1990. The 1990 number was thus 2.3 times as high as that in 1980. The respective proportions of the total population were 0.9% in 1980 and 2.1% in 1990.

Table 1. The self-reported prevalence of chronic asthma (%) in the Finnish population, by age and sex, in 1976 and 1987 Age olr) o-14 15-44 45-64 65Total 1976 1987 1976 1987 1976 1987 1976 1987 1976 1987 Males Females Total (n)

1.1 0.5

1.3 0.9

0.7 0.6

1.1 1.3

Men Woman 1967

1.8 1.8

2.5 4.0

3.2 2.5

4.8 2.7

1.2 1.1

1.8 2.0

Increased Use of Antiasthmatics in Finland 21

72

19

10

is 1000 pg, with a maximum of 2000 pug [8,9]. There has been a 2- to 3-fold increase in the recommended dosage of inhalation salbutamol, too.

1976 26

26

17 1967 0

I

I

I

I

I

I

10

20

30

40

60

60

111111111 II 70

60

1

I

90

100

% 0

No medication

ml

drug

w2

drugs

m

3 drugs

m

4 or more

861

drugs

Fig. 3. Distribution of asthmatic patients by the number of antiasthmatic drugs used, in 1976 and 1987.

Of the patients who reported chronic asthma in the interview, 68% were using antiasthmatics in 1976. In 1987 the corresponding share was 83%. The number of antiasthmatic drugs per user had also increased: the average number was 1.7 in 1976 and 2.2 in 1987. Also the proportion of multiusers had grown: 14% of the users used at least three different antiasthmatics in 1976, whereas the proportion in 1987 was 35% (Fig. 3). The financial ability of the asthmatic population to acquire antiasthmatic medication was better at the end of the decennium than at the beginning: according to the health survey, in 1987 two-thirds of asthmatic patients were entitled to preferentially reimbursed medication, whereas the respective proportion in 1976 was only one-third. The sales of antiasthmatic drugs (ATCclassification R03) increased in Finland during the 1980s; the consumption was 19.0 DDD/lOOO inhab/day in 1980 and 48.6 DDD/lOOO inhab/ day in 1989. In 1980, systemically acting medicines were the dominating group in the sales of antiasthmatics. Their share of total sales, measured in the number of DDDs/lOOO inhab/ day, was 57%. Of this, various combination preparations accounted for more than half, i.e. 35 percentage-points. The corresponding share of inhalation medicines was thus 43%. In 1989 the pattern was quite different: the share of inhalation medicines was 74%, that of systemic preparations 26%, and combination preparations were hardly represented at all. The recommended dosage of certain important antiasthmatics has increased during the 1980s. For instance, inhalation beclomethasone was in 1980 available solely as the strength of 50 pg, and the daily dosage recommended by the manufacturers was from 300 to 400 pg. One dose of beclomethasone contains now 250 pg of the substance., and the recommended daily dosage

Costs of antiasthmatic

medication

The Finnish sickness insurance register shows that the cost of medical treatment of asthma was in 1990 on average FIM 1848 (approximately U.S. $510.00) per asthmatic patient who had made use of her/his right to preferentially reimbursed drugs during the year. The highest costs per patient rose to over FIM 27,000 in 1990. The medical treatment of asthma is more expensive than the corresponding costs of, for instance, hypertension, rheumatoid arthritis or cardiac insufficiency, but not quite as high as those of diabetes (Fig. 4). The total sales (in wholesale prices) of group R 03 were in 1989 FIM 114 million, which equals approximately U.S. $32 million. The costs of medication per asthmatic patient varied substantially between the 21 regions of the country. The range in 1990 was from FIM 1535 to FIM 2171. Besides costs, the choice of drugs varied between regions. Of various inhalation glucocorticoids, beclomethasone was the most popular in all regions except one, in which budesonide was also used to a relatively large extent. Salbutamol was the best-selling sympathomimetic medicine in all but one region, in which fenoterol was preferred. The sales of cromoglycate were around 2.0 DDD/lOOO inhab/day in 20 regions, whereas one regionthe most expensive one-showed a rate of 7.0 DDD/lOOO inhab/day. 1 2 3 4 5 6 7 6 9 x) 11

2000 1600 1600 1400

Diabetes melitus Chronic asthma Rheumatoid arthritis Chronic coronary disease Psychoses Chronic hypertension Glaucoma Epilepsy Chronic cardiac insufficiency Chronic urinary infection Thyroid insufficiency

inn

1200 z iz

1000 600 600 400 200

Fig. 4. Annual medicine costs/patient of certain common diseases in Finland in 1990.

862

TIMOKLAUKKAet al. DISCUSSION

The reasons for the increase in the consumption of antiasthmatics in Finland can be summarized as follows: 1. The self-reported occurrence of asthma has increased. 2. A growing proportion of asthmatic patients are under medication. 3. The number of drugs per user has increased. 4. The daily dosage of medication has increased. In addition, a growing proportion of the patients get a preferential refund of their medicine costs (900/, since 1986, 100% before that). This makes it easier for them to purchase the medicines. Thus the growing costs of antiasthmatic medication (Fig. 4) have not slowed down the increase in the sales of this group of medicines. The increase in the sales of antiasthmatics, measured as the number of DDDs/lOOO inhabitants/day (Fig. 1) is in part artificial. Throughout the 1980s the defined daily doses for antiasthmatic drugs have remained constant, although the prescribed doses of inhalation glucocorticoids especially have grown substantially. The value of DDD belongs to the denominator when the statistical rate is being calculated. Thus the growth in the consumption would be less if the actual doses prescribed had been used in the calculations. The growing number of asthmatic patients and the change in their medication do not explain all of the increase in the sales of antiasthmatics. A further factor is that these medicines are increasingly being used in other indications besides asthma. For instance in Sweden the share of antiasthmatic medicines of all medicines prescribed against cough was 5% in 1979 and 10% in 1989 [lo]. An increase in the occurrence of asthma has been earlier suggested by other studies in Finland [ 1l] as well as in Sweden [ 121,Great Britain [13-161, New Zealand [17], France [18] and the U.S. [19]. The evidence shown does not directly indicate to what extent the increase in the occurrence of asthma is due to a growth in the biological occurrence of the disease. Other factors which may have had an influence on the rates are better clinical diagnostics and an increased use of health services, which both may have brought more cases to light. A more positive attitude towards asthma could also have had an increasing effect on the prevalence; this

could make it easier for the doctor to diagnose the disease by its right name and for the patient to report the disease in an interview study. The impact of better diagnostics and increasing use of health services on the morbidity rates should concern all major diseases. In the Finnish national health surveys, however, there was not overall increase in the prevalences of all chronic diseases between the years 1976 and 1987. Remarkable increases concerned only musculoskeletal disorders, asthma and other allergic disorders. The occurrence of all major cardiovascular diseases was lower in the later study, which is also revealed by various statistics on morbidity and mortality. Accordingly it can be assumed that the rates on self-reported morbidity indicate trends in the real prevalence rates. Another Finnish study [ 1l] on the prevalence of asthma also came to the conclusion that a major part of the increase was real. The association of the increasing use of health services with the growing prevalence rate of asthma was not investigated in our study. In Finland, the use of physician services did not increase between 1976 and 1987, so the population did not have a more frequent chance to obtain new diagnoses. In fact, the increase in the utilization rates was most rapid between the years 1964 and 1976 [4], in which period the reported occurrence of asthma grew but slowly. In Sweden, the increase in the prevalence of asthma has been greatest in areas with low utilization of health services [ 121.These findings support the idea, that the role of the increasing use of health services in the growth of asthma prevalence is probably not very important. At the end of 198Os, the prevalence of asthma was relatively low in Finland-about 2% of the total population. This share was derived from two sources: from the health interview (selfreported morbidity), and from the nationwide register of patients entitled to preferentially reimbursed drugs. Both of these sources probably underestimate the real prevalence rate, the former because of underreporting, the latter because of a requirement of a certain grade of severity of the disease. This makes it understandable that higher prevalence rates ranging mainly from 5 to 10% have been presented from other countries [20], though the differences between the countries must in -part be due to variations in the definition of asthma and in the methodology of measuring the prevalence. On the other hand, also the mortality from asthma has been constantly low in Finland-only

Increased Use of Antiasthmatics in Finland

2 per 100,000 inhabitants i.e. around loo-120 cases annually, with no systematic changes during the last 20 years [21]. There is thus reason to believe that the occurrence of asthma in Finland is relatively low, though increasing. Changes in the treatment practice of asthma have had a marked effect on the costs of the medical therapy. When patients are treated with more and more expensive medicines, one would also expect better outcomes of the treatment. Our study did not concentrate on investigating the results of the care. In general, mortality from asthma is now rising in several Western countries [13,15,17,22], which may be a consequence of increased morbidity and severity [19, 23,241 of the disease. In Finland, the mortality of asthma has remained constant for decades, which might indicate an improvement in the quality of therapy. A similar conclusion was made by Higgenbottam and Hay [25]. The big regional differences in antiasthmatic therapy in Finland would offer a good basis to investigate the outcome of the treatment in relation to costs. Indicators such as the occurrence of symptoms, ability to work and changes in the quality of life would be relevant, though difficult to measure.

around

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