Thyroxine replacement monitoring using a computerised register: the North Trent experience
S Lee1, V Stevens2, A Parramore1, AP Weetman1,3 & A Allahabadia1,3
Background: Community based surveys have revealed that approximately 20% of patients taking thyroxine have low serum TSH concentrations. Likewise, a high proportion of patients (27%) have been found to have high TSH concentrations. Suboptimal thyroxine treatment, in particular overtreatment, is associated with significant potential health risks including atrial fibrillation and osteoporosis. In Sheffield, thyroxine treated patients are routinely enrolled on a computerised thyroid follow-up register, ensuring planned monitoring of thyroid function. Patients are given written notification for TFTs at regular intervals; abnormal TSH values are reviewed by an Endocrine Specialist Registrar, and appropriate thyroxine dose adjustment is advised. Before March 1998, TSH results were communicated to GPs but no specific therapeutic recommendation was made.
Aims: To determine 1. the clinical effectiveness of an actively managed thyroid follow-up register 2. whether specialist endocrine input improves biochemical control of thyroid function.
Methods: We reviewed serum TSH concentrations of all patients on thyroxine treatment over a 6 month period from October 1997 to March 1998, and compared these with data from 2002. TSH concentrations were defined as abnormal if they were outside the reference range.
Results: In 1997-98, 889 patients were tested; TSH was low in 177 (20%) and elevated in 105 (12%).
Of 3514 patients monitored in 2002, low TSH concentrations were found in 440 cases (12.5%) and high TSH concentrations in 334 (9.5%). Between 1997-98 and 2002, the reduction in abnormal TSH concentrations was highly significant (1997-1998 vs 2002, 32% vs 22%, Chisquare = 36.6, p<0.0001).
In conclusion: We found a significant reduction in the number of abnormal TSH values following the implementation of specialist advice on thyroxine dose adjustment. Our data suggest that an actively managed thyroid register can lead to improved biochemical control of hypothyroid patients in the community.