A raised thyroid stimulating hormone result--a 12-month follow-up study in general practice.
BACKGROUND
Subclinical hypothyroidism (SCH) is common in older patients.


OBJECTIVE
To review the management of patients identified with a raised thyroid stimulating hormone (TSH) result in a 12-month period and compare this to current guidelines from the New Zealand Best Practice Advocacy Centre (BPAC).


METHODS
We collected laboratory data on thyroid function tests (TFTs) that were reported between December 2005 and November 2006 from two general practices with an adult population of approximately 21 000. Data were collected on symptoms, investigations, thyroid medication, family history and comorbidities. We used chi-squared tests to compare findings by age, gender and ethnicity.


RESULTS
Older women of European descent were more likely to be to have initial results suggesting SCH. The number of follow-up tests ranged from 0 to 5 tests in a 12-month period. Forty-eight percent of individuals did not have any follow-up investigations. Seventy-three percent of FT4 tests taken are requested concurrently with TSH. Of those who had a repeat TSH test, just over 40% had a result within the reference interval. Twenty-eight percent had two TSH results consistent with SCH. Thirty-five percent of patients with antibody results were positive. The most commonly-recorded symptoms were tiredness and weight gain.


CONCLUSIONS
We found inconsistencies in the management of SCH which were not related to patient characteristics such as age, gender or ethnicity. Further research is needed to determine if SCH is associated with increased morbidity and to provide a clear rationale for management of patients with SCH.
Gibbons
Veronique
V
Department of Primary Care, Waikato Clinical School, University of Auckland, Hamilton, New Zealand. gibbonsv@waikatodhb.govt.nz
Conaglen
John V
JV
Lawrenson
Ross
R
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005194:Family Practice; D005260:Female; D019983:Guideline Adherence; D020249:Hormone Replacement Therapy / Q000706:statistics & numerical data; D006801:Humans; D007037:Hypothyroidism / Q000097:blood* / Q000175:diagnosis* / Q000188:drug therapy; D008297:Male; D008485:Medical Audit; D008875:Middle Aged; D009520:New Zealand; D017410:Practice Guidelines as Topic; D013972:Thyrotropin / Q000097:blood*; D013974:Thyroxine / Q000627:therapeutic use; D055815:Young Adult
D013972:Thyrotropin; D013974:Thyroxine