Abstract
The aim of this study was to determine the effectiveness of annual screening for hypothyroidism requiring thyroxine treatment (HRTT) in a hospitalโbased diabetes clinic.
A retrospective study of case records of patients attending a hospitalโbased diabetes clinic was undertaken. Random samples of 400 patients with type 1 diabetes and 400 patients with type 2 diabetes were included. Patient data including thyroid function tests and thyroxine use were recorded. The outcomes were the prevalence of HRTT, and the costโperโdiagnosis of screening for HRTT in the diabetes clinic.
Type 1 diabetes patients were younger (41 vs 60 years, p<0.001) and their diabetes was of longer duration (median 9.5 vs 5 years, p<0.05) than those with type 2 diabetes. Hypothyroidism was common in patients with type 1 (10.8%) or type 2 diabetes (10.8%). The prevalence of HRTT was 6.8% in type 1 diabetes and 6.0% in type 2 diabetes, with the majority being female (81% and 83%). The prevalence of HRTT increased after 50 years of age in type 1 diabetes, and somewhat later in type 2 diabetes, in the over 60s reaching 18.8% in type 1 diabetes and 8.4% in type 2 diabetes. Annual screening detected one case of HRTT for every 470 blood tests, equating to ยฃ4600 per diagnosis.
In conclusion, hypothyroidism was common in patients with type 1 or type 2 diabetes who attended a hospitalโbased diabetes clinic. However, annual screening at the hospital clinic only rarely found new cases of HRTT, and so is questionable from a cost:benefit viewpoint. Copyright ยฉ 2010 John Wiley & Sons.