[Estimate of the prevalence of hypothyroidism in Spain based on the use of thyroid hormones (1996-1999)].
BACKGROUND
In view of the highly limited amount of data on the prevalence of hypothyroidism in Spain, the decision was made to estimate this prevalence based on the consumption of its specific treatment, that is, thyroid hormones, employing the drug use study methodology.


METHODS
Calculation of the Daily Inhabitants Doses (DID)' of thyroid hormones (ATC treatment group H03) by means of the Defined Daily Doses (DDD's) for 1996-1999 in the different provinces, autonomous communities and on a nationwide basis. The confidence intervals have been calculated at 95% for the estimated prevalence figures in the autonomous communities and nationwide, in addition to the percentage increases for 1999 as compared to 1996. The prescription-related data was furnished by the Spanish Ministry of Health and Consumer Affairs.


RESULTS
Nationwide hypothyroidism prevalence is estimated at 3.19 cases per 1,000 inhabitants for 1996 and at 4.33 cases per 1000 inhabitants for 1999, totaling a percentage increase of 26.38%. The DID results revealed prevalence figures which vary from one province to another: Guadalajara having totaled the highest figures for the two years studied (5.02 and 7.01 cases per 1,000 inhabitants/day respectively in 1996 and 1999), Melilla having recorded the lowest (1.07 and 1.60 cases per 1,000 inhabitants/day). The DID revealed an increase in all of the provinces and autonomous communities in 1999 as compared to 1996. This lowest increase was in Asturias (9.62%), the highest having been in La Rioja (35.26%).


CONCLUSIONS
The 3.19 and 4.33 DDD per 1,000 inhabitants/day respectively in 1996 and 1999 may be interpreted as the prevalence of diagnosed and treated hypothyroidism. These figures fall within the range found in other studies, although one must be highly cautious when drawing comparisons among studies in which different methodologies are employed. The reason for the increased consumption found could best be said to lie in this disease being diagnosed to a better degree more than its being due to any actual increase in prevalence per se.
Morant Ginestar
C
C
Sección de Investigación y Docencia, Centro Regional de Salud Pública Carretera de Extremadura, Km 114, 45600-Talavera de la Reina, Toledo.
Criado-Alvarez
J J
JJ
García-Pina
R
R
Pérez Garrido
B
B
D004358:Drug Therapy / Q000706:statistics & numerical data; D004812:Epidemiologic Methods; D006801:Humans; D007037:Hypothyroidism / Q000188:drug therapy* / Q000453:epidemiology*; D015995:Prevalence; D013030:Spain / Q000453:epidemiology; D013963:Thyroid Hormones / Q000627:therapeutic use*
D013963:Thyroid Hormones