Article

International variation in prescribing antihypertensive drugs: Its extent and possible explanations

Informed Choice Research Department, Norwegian Health Services Research Centre, P.O. Box 7004, St. Olavs plass, Oslo, Norway.
BMC Health Services Research (Impact Factor: 1.71). 04/2005; 5(1):21. DOI: 10.1186/1472-6963-5-21
Source: PubMed

ABSTRACT

Inexpensive antihypertensive drugs are at least as effective and safe as more expensive drugs. Overuse of newer, more expensive antihypertensive drugs is a poor use of resources. The potential savings are substantial, but vary across countries, in large part due to differences in prescribing patterns. We wanted to describe prescribing patterns of antihypertensive drugs in ten countries and explore possible reasons for inter-country variation.
National prescribing profiles were determined based on information on sales and indications for prescribing. We sent a questionnaire to academics and drug regulatory agencies in Canada, France, Germany, UK, US and the Nordic countries, asking about explanations for differences in prescribing patterns in their country compared with the other countries. We also conducted telephone interviews with medical directors of drug companies in the UK and Norway, the countries with the largest differences in prescribing patterns.
There is considerable variation in prescribing patterns. In the UK thiazides account for 25% of consumption, while the corresponding figure for Norway is 6%. In Norway alpha-blocking agents account for 8% of consumption, which is more than twice the percentage found in any of the other countries. Suggested factors to explain inter-country variation included reimbursement policies, traditions, opinion leaders with conflicts of interests, domestic pharmaceutical production, and clinical practice guidelines. The medical directors also suggested hypotheses that: Norwegian physicians are early adopters of new interventions while the British are more conservative; there are many clinical trials conducted in Norway involving many general practitioners; there is higher cost-awareness among physicians in the UK, in part due to fund holding; and there are publicly funded pharmaceutical advisors in the UK.
Two compelling explanations the variation in prescribing that warrant further investigation are the promotion of less-expensive drugs by pharmaceutical advisors in UK and the promotion of more expensive drugs through "seeding trials" in Norway.

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    • "Elle ne peut donc pas expliquer à elle seule la stagnation des IEC observée dans notre étude et à l'échelon national par la CNAM. La forte promotion des nouvelles classes thérapeutiques, dont les ARA2, par les laboratoires pharmaceutiques contribue probablement à leur succès [18] [21]. Cependant, l'amplitude du phénomène est considérable en France puisque la prescription des ARA2 y dépasse celles des IEC, contrairement à ce qui est observé dans d'autres pays européens comme l'Allemagne, l'Espagne, l'Italie et l'Espagne, ou encore aux Etats-Unis [22]. "
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    ABSTRACT: PurposeTo determine if trends in antihypertensive drug prescriptions by non-specialist physicians reflect evidence from clinical research.
    Full-text · Article · Oct 2008 · La Revue de Médecine Interne
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    • "Elle ne peut donc pas expliquer à elle seule la stagnation des IEC observée dans notre étude et à l'échelon national par la CNAM. La forte promotion des nouvelles classes thérapeutiques, dont les ARA2, par les laboratoires pharmaceutiques contribue probablement à leur succès [18] [21]. Cependant, l'amplitude du phénomène est considérable en France puisque la prescription des ARA2 y dépasse celles des IEC, contrairement à ce qui est observé dans d'autres pays européens comme l'Allemagne, l'Espagne, l'Italie et l'Espagne, ou encore aux Etats-Unis [22]. "
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    ABSTRACT: To determine if trends in antihypertensive drug prescriptions by non-specialist physicians reflect evidence from clinical research. Comparison of antihypertensive drugs prescribed to patients before they attended a hypertension clinic in 2001 and 2006, with a special consideration for thiazide diuretics in drug combinations and angiotensin converting enzyme inhibitors (ACEI) in hypertensive patients at high cardiovascular risk (diabetes or secondary prevention). Overall, 1072 hypertensive patients attended the hypertension clinic in 2001 (mean age 53.9 years) and 1040 in 2006 (mean age 55.6 years); both genders were equally represented. Patients already treated when they came at the consultation received a mean number of 2.24 antihypertensive drug classes in 2001 and 2.44 in 2006 (p = 0.002). The prescription of three antihypertensive drug classes increased between 2001 and 2006: Calcium channel blockers from 49 % of treated patients in 2001 to 56 % in 2006 (p = 0.007), angiotensin receptor antagonists from 28 to 42 % (p <0.001) and thiazide diuretics from 31 to 39 % (p = 0.001). Thiazide diuretics were included in 48 % of the antihypertensive combinations in 2001 and 55 % in 2006 (p = 0.02). The prescription of ACEI in patients at high cardiovascular risk remained stable around 31 %. Antihypertensive treatments were more intensive in 2006 than 2001, but thiazide diuretics remained underused in drug combinations. The prescription of ACEI did not increase in patients at high cardiovascular risk despite convincing evidence of their benefit.
    Full-text · Article · Feb 2008 · La Revue de Médecine Interne
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    • "Elle ne peut donc pas expliquer à elle seule la stagnation des IEC observée dans notre étude et à l'échelon national par la CNAM. La forte promotion des nouvelles classes thérapeutiques, dont les ARA2, par les laboratoires pharmaceutiques contribue probablement à leur succès [18] [21]. Cependant, l'amplitude du phénomène est considérable en France puisque la prescription des ARA2 y dépasse celles des IEC, contrairement à ce qui est observé dans d'autres pays européens comme l'Allemagne, l'Espagne, l'Italie et l'Espagne, ou encore aux Etats-Unis [22]. "

    Full-text · Article · Jun 2007 · La Revue de Médecine Interne
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