Lenne X, Allenet B, Laurent P, Lebrun T, Wemeau J L
CRESGE-LABORES (CNRS URA n(o) 362), Lille.
Ann Endocrinol (Paris). 1999 Nov;60(5):398-407.
The aim of the study was to assess the economic consequences of the early screening and management for overt hypothyrodism in elderly women suffering from hypercholesterolaemia.
A cost analysis was performed using screening decision tree followed by a Markov model, targeted on an hypothetical cohort of elderly women (i.e. > or = 55 years of age) suffering from hypercholesterolaemia. Two arms were compared, "no diagnosis", patients being treated by lipid lowering drugs in the long run, "diagnosis", patients being screened for thyroid disturbance and proposed adequate correction by hormone treatment. Relevant clinical data introduced into the model were obtained from published data and from experts. At the end of the initial diagnostic, patients could enter three different health states: euthyroidism, subclinical hypothyroidism or overt hypothyroidism. During 30 years, patients were assumed to be seen each year by a general practitioner for clinical examination and cholesterol dosage, plus, according to the health state evolution, TSH and T4 screening. In the baseline analysis, euthyroidian patients who had a inexplicable degradation of hypercholesterolaemia control were tested for TSH and, if abnormal, T4 serum; for subclinical hypothyroidian patients, TSH and T4 were measured every year. The direct costs taken into account were concerning medical supervision, drug treatment and biologic exams. Costs were analysed from the societal perspective and were expressed in 1998 French Francs (FF) with an accounting rate of 5% by year. A sensitivity analysis was also performed.
The total cost at 30-year was equal to 25,006 F for "diagnosis" strategy, to 24,390 F for "no diagnosis" strategy. The incremental cost of the first strategy decreased according to the time horizon. It was 6.8% at 5-year and 2.5% at 30-year. Results were sensitive to variation in response rate of hypercholesterolaemic patients to hormone treatment of hypothyroidism (0.25 in base-case).
The investment cost in screening and treatment of hypercholesterolemic female patient aged 55 and more can be considered offset in the long run (30 years). Considering the other important outcomes in favour of hormonal drug treatment of hypothyroidism, such as enhancement of well-being, functional capacities and quality of life, the "diagnosis" strategy can be recommended in the ambulatory medical practice.
