Study of Optimal Replacement of Thyroxine in the Elderly (SORTED) - results from the feasibility randomised controlled trial.

Vicky Ryan,Lorna Ingoe,Salman Razvi,Scott Wilkes,Simon H. S. Pearce

doi:10.1186/s13044-016-0034-x

Abstract

BackgroundHypothyroidism is a common condition, particularly in the older population. Thyroid hormone requirements change with age and serum TSH levels also alter, especially in older patients. However, in practice laboratory reference ranges for thyroid function are not age-specific and treatment in older patients aims to achieve a similar target thyroid function level as younger age groups.MethodsA dual centre, single blind, randomised controlled trial was conducted to determine the feasibility of a future definitive RCT in hypothyroid individuals aged 80 years or older who were treated with levothyroxine. Potential participants were identified from 17 research-active GP practices (n = 377), by opportunistic invitations (n = 9) or in response to publicity (n = 4). Participants were randomly allocated to either usual (0.4–4.0 mU/L) or a higher (4.1–8.0 mU/L) target serum TSH range. Information on participants’ willingness to enter the trial, acceptability of study design, length of time to complete recruitment and dose titration strategy was collected.ResultsFifteen percent (57/390) of potentially eligible hypothyroid individuals consented to participate in this trial and 48 were randomised to trial medication for 24 weeks, giving a recruitment rate of 12 %. Recruitment averaged 5.5 participants per month over approximately 9 months. Eight participants withdrew (3/24 and 5/24 in the usual and higher TSH arms, respectively) with the commonest reason cited (5 patients) being tiredness. Interestingly, 3/5 participants withdrew from the site that required a visit to a Research Facility whereas only 5/43 participants withdrew from the site that offered home visits. In the higher TSH arm, of those participants who completed the study, approximately half of participants (10/19) reached target TSH.ConclusionsIt is feasible to perform a randomised controlled trial of thyroid hormones in hypothyroid patients aged 80 or older. A definitive trial would require collaboration with a large number of General Practices and the provision of home visits to achieve recruitment to time and target. Power calculations should take into account that approximately 12 % of those approached will be randomised and 1 in 6 participants are likely to withdraw from the study. Finally, several dose adjustments may be required to achieve target serum TSH levels in this age group.Trial registrationISRCTN Number: 16043724 Registered 22 June 2012Clinicaltrial.gov Number: NCT01647750EudraCT Number: 2011-004425-27

Highlights

Hypothyroidism is a common condition, in the older population
Hypothyroidism is more prevalent in women and in older individuals with rates of up to 16 % reported in those aged over 80 years [1, 2]
Hypothyroidism is diagnosed based on results of blood tests with low thyroid hormone levels in the presence of high serum Thyroid Stimulating Hormone (TSH) concentrations

Summary

Introduction

Thyroid hormone requirements change with age and serum TSH levels alter, especially in older patients. Thyroid function changes with age and several reports suggest that the upper limit of the TSH reference range increases with age [6,7,8,9,10]. Evidence obtained from General Practice records suggests LT4 is increasingly being prescribed for older individuals and for minimally raised serum TSH levels [18]. This issue is of increasing importance as the populations in most developed – and many developing – countries are ageing and diagnoses of hypothyroidism are likely to rise.

Methods

Results

Discussion

Conclusion