In my view, this is a deeply questionable paper.
It might be true that the frequency of TFT testing does not conform to their recommended intervals. The question should be "Why?". Not jumping to the conclusion that the lab should take over the responsibility of requesting tests.
There might be any number of reasons for the interval varying, including:
Patient convenience
Patient feeling so bad they request an early test
Patient seeing no benefit in having a test - after all, what would the GP do?, or the patient is feeling fine.
Patient referred to endocrinologist who requests repeat tests
If the GPs are failing to make approrpiate requests, then tell the GPs what they are doing wrong (in your view), and try to understand. Then make suggestions.
Exp Clin Endocrinol Diabetes. 2017 Apr 13. doi: 10.1055/s-0043-103018. [Epub ahead of print]
Monitoring Thyroid Function in Patients on Levothyroxine. Assessment of Conformity to National Guidance and Variability in Practice.
Scargill JJ1, Livingston M2, Holland D3, Duff CJ4, Fryer AA4, Heald AH5.
Author information
1 Department of Clinical Biochemistry, Salford Royal Hospital, Salford, UK.
2 Department of Blood Sciences, Walsall Manor Hospital, Walsall, UK.
3 School of Pharmacy, Keele University Benchmarking Service, Keele University, Staffordshire UK.
4 Department of Clinical Biochemistry, University Hospitals of North Midlands, Stoke-on-Trent, UK.
5 The School of Medicine and Manchester Academic Health Sciences Centre, University of Manchester, Manchester, UK.
Abstract
With demand for endocrine tests steadily increasing year-on-year, we examined thyroid function test (TFT) frequencies in patients on levothyroxine replacement therapy to assess the effect of initial TFT results and request source on TFT re-testing interval. All TFTs performed by the Clinical Biochemistry Departments at the Salford Royal Hospital (2009-2012; 288 263 requests from 139 793 patients) and University Hospital of North Midlands (2011-2014; 579 156 requests from 193 035 patients) were extracted from the laboratory computer systems. Of these, 54 894 tests were on 13 297 patients confirmed to be on levothyroxine therapy in the test cohort (Salford) and 67 298 requests on 11 971 patients in the confirmatory cohort (North Midlands). In the test cohort, median TFT re-testing interval in the total group was 19.1 weeks (IQR 9.1-37.7 weeks), with clearly defined peaks in TFT re-testing evident at 6 and 12 months and a prominent broad peak at 1-3 months. Median re-test interval was much lower than recommended (52 weeks) for those with normal TFTs at 31.3 weeks (30.6 weeks for the confirmatory cohort). Where thyroid-stimulating hormone (TSH) was elevated and free thyroxine (fT4) was below the reference range, re-test interval was much longer than is recommended (8 weeks) at 13.4-17.6 weeks (7.1-23.4 weeks in the confirmatory cohort), as was the interval when TSH was below and fT4 was above the normal range, at 16.7-25.6 weeks (27.5-31.9 weeks in the confirmatory cohort). Our findings show that the majority of TFT requests are requested outside recommended intervals and within-practice variability is high. A new approach to ensuring optimum monitoring frequency is required. Direct requesting from the clinical laboratory may provide one such solution.
© Georg Thieme Verlag KG Stuttgart · New York.
PMID: 28407667
DOI: 10.1055/s-0043-103018
Of course we should be given options of thyroid hormones too. 
