Abstract
In drug utilisation studies, the units of defined daily doses (DDD) and DDD/1000 inhabitants per day standardise for differences in dosage and population size, but not for age-related differences in drug utilisation. There is no consensus as to how age standardisation of DDD data should be carried out. Using cardiovascular drug utilisation data from Sweden and Spain, the current study compared the outcome of different methods of age standardisation. Both indirect methods (based on a comparison of observed and expected drug usage) and direct methods (using different weighting for the age categories) were used.
The largest impact of standardisation was seen for diuretics. The crude rate for men and women combined was 26 DDD/1000 inhabitants per day in Costa de Ponent and 98 DDD/1000 inhabitants per day in Värmland. The corresponding figures when standardising the Costa de Ponent population were 26 and 58, respectively. Using the equivalent average rate (EAR) method, the rate for Värmland was 129 DDD/1000 inhabitants per day. Lesser but still important differences were found for β-adrenoceptor and antihypertensives.
Thus, the results of standardisation differ depending on which method is used and which drugs are evaluated. EAR is recommended for direct standardisation because of its ease of use and because it does not require the choice of a standard population.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Wessling A (1990) The national prescription survey. A data base for drug utilisation studies in Sweden — Results and experiences from the 1970s and 1980s. PhD Thesis. The Karolinska Institute, Stockholm
Agenäs I, Andrew M (1990) Use of statistics on medicines 1987–1989 In: Nordic statistics on medicines 1987–1989 (NLN Publication no. 30) NLN, Uppsala, pp10–19
Capellà D (1993) Descriptive tools and analysis. In: Dukes MNG (ed) Drug utilization studies. Methods and uses (WHO Regional Publications, European Series, no. 45) WHO Regional Office for Europe, Copenhagen, pp 55–77
Nordenstam I, Wennberg M, Kristoferson K (1993) Svensk läkemedelsstatistik (Swedish drug statistics). Apoteksbolaget, Stockholm
Font M, Catalán A, Madrilejos R (1989) Estudio cuantitativo del consumo de antihypertensivos (AHT) en el Area de Gestion 5 del ICS (Costa de Ponent). Atencion Primaria 6: 238–244
Capellà D, Porta M, Laporte JR (1983) Utilization of antihypertensive drugs in certain European countries. Eur J Clin Pharmacol 25: 431–435
Yule GD (1934) On some points relating to vital statistics, more especially statistics of occupational mortality. J R Stat Soc 97: 1–84
Day NE (1976) A new measure of age standardized incidence, the cumulative rate. In: Waterhouse J, Muir C, Correa P, Powell J (eds) Cancer incidence in five countries, vol III. (IARC Scientific Publication no. 15) International Agency for Research of Cancer, Lyon pp 433–452
Nerbrand C (1990) Cardiovascular diseases in seven counties of Sweden — regional differences and risk factors. PhD Thesis, Uppsala University
Öreberg M, Jonsson G, West K, Eberhard-Grahn M, R»stam L, Melander A (1992) Large intercommunity differences in cardiovascular drug consumption: relation to mortality, risk factors and socio-economic differences. Eur J Clin Pharmacol 43: 449–454
Ministerio de Sanidad y Consumo (1986) Memoria estadistica. Madrid
Wessling A, Bergman U, Westerholm B (1991) On the differences in psychotropic drug use between the three major urban areas in Sweden. Eur J Clin Pharmacol 40: 495–500
Isacsson D, Smedby B (1988) Patterns of psychotropic drug use in a Swedish community. Scand J Prim Health Care 6: 50–58
WHO Drug Utilisation Research Group (1985) Validation of observed differences in the utilization of antihypertensive and antidiabetic drugs in Northern Ireland, Norway and Sweden. Eur J Clin Pharmacol 29: 1–8
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Merlo, J., Ranstam, J., R»stam, L. et al. Age standardisation of drug utilisation: comparisons of different methods using cardiovascular drug data from Sweden and Spain. Eur J Clin Pharmacol 46, 393–398 (1994). https://doi.org/10.1007/BF00191899
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00191899