Reducing redundant thyroid stimulating hormone (TSH) testing

Reducing redundant thyroid stimulating hormone (TSH) testing

The Therapeutics Initiative produced individual Portraits on the topic of ordering of thyroid stimulating hormone (TSH) tests for patients aged 18 years and older (2022). The Portraits were released online to clinicians in BC who are registered for the Portrait program. Eligible clinicians (primary care physicians and nurse practitioners) were randomized to have access to the Portrait in two groups, an early group of clinicians were granted online access to the Portrait in March 2024 and a delayed group will be granted access 6 to 9 months later. This Portrait is accompanied by the Therapeutics Letter, “Thyroid testing in primary hypothyroidism” 2024 (March); Limited early release:1-2.

This Portrait is also linked to a UBC Continuing Professional Development (CPD) courseNavigating Thyroid Testing in Primary Hypothyroidism: Practical Approaches for Health Professionals, and a patient handout, Understanding Thyroid Tests: A Patient’s Guide.

To take the course and earn Mainpro+ credits, register through UBC CPD. You will be prompted to login first. If you do not have an account, select “Create new account.” After registering, you will have access to the course.

Abbreviations used for this Portrait

ATC: Anatomical Therapeutic Chemical code assigned to medicine
BCN&M:  British Columbia College of Nurses & Midwives
CPSBC: College of Physicians and Surgeons of British Columbia
FP: Family practitioner
GP: General practice
MSP: Medical Services Plan
NP: Nurse practitioner
PSP: Practice Support Program
RCT: Randomized controlled trials
TSH: Thyroid stimulating hormone

Data definitions

Who received this Portrait?

Clinicians who registered online for a Portrait account and who meet all of the following criteria have access to an individual prescribing Portrait:

  • General practice (GP) physicians or nurse practitioners (NP) registered to practise in British Columbia;
  • Family practitioners (FP) registered by the BC Medical Services Plan and the College of Physicians and Surgeons of BC with an active practice, or physicians registered primarily as GP-emergency medicine and FP-emergency medicine physicians;
  • NPs registered by the BC Medical Services Plan and the BC College of Nurses & Midwives with an active practice;
  • had ≥100 prescriptions of any drug filled at a community pharmacy in 2022 according to PharmaNet data; and
  • have not opted out of the Portrait program.

How were patients assigned to this Portrait?

Patients were included in a prescribing Portrait if they met all of the following criteria:

  • had at least 2 normal TSH tests recorded in the data and ordered by the clinician receiving the Portrait;
  • were aged 18 years or older on the date of the TSH test collection;
  • were BC residents enrolled in the MSP at any time between Jan 1, 2022 and Dec 31, 2022.

Patients were excluded if they:

  • were pregnant or post-partum up to one year before or after the TSH test, determined by a pregnancy-related diagnosis code or fee recorded in the data (up to Dec 31, 2023);
  • had an abnormally low TSH value at any time (hyperthyroidism), defined as a patient with least 1 TSH test with a value below the reference range based on data up to Dec 31, 2022 and regardless of the ordering clinician;
  • were dispensed hydrocortisone (oral) or prednisone (≥10 days’ supply) at any time in 2022; or
  • were dispensed another thyroid preparation other than levothyroxine (ATC H03AA01) at any time in 2022.

Clinicians may have received a Portrait with masked or missing elements (i.e., no bars shown) because they met the above requirements but ordered tests for between 1 and 5 patients for that metric of the Portrait. Portrait’s data access agreement requires the suppression of data elements that contain <6 individuals. To comply with the agreement, the total number of patients may be presented as a range (e.g., 1-5 patients). Clinicians with no orders for TSH tests (“0 tests”) will have this data displayed.

What prescriptions were included in this Portrait?

Levothyroxine (ATC H03AA01) prescriptions were checked in the data to determine inclusion/exclusions as per above. Patients taking hydrocortisone (oral) or prednisone were excluded as well as any dispensed another thyroid preparation (ATC code H03A other than H03AA01) at any time in 2022.

What tests were included in this Portrait?

All thyroid test records (LOINC code 3016-3) that were ordered by the Portrait clinician between Jan 1, 2022 and Dec 31, 2022. The Portrait presents the number of unique patients who had 2 normal TSH tests, 3 normal TSH tests, and 4+ normal TSH tests, as ordered by the clinician.

References and additional information

  1. Province of British Columbia. Thyroid Function Testing in the Diagnosis and Monitoring of Thyroid Function Disorder.
  2. Therapeutics Initiative. Thyroid testing in primary hypothyroidism. Therapeutics Letter. 2024 (March); Limited early release:1-2.

Research component

The research objective is to determine the impact of the Portrait on clinician prescribing or ordering of tests. This impact will be evaluated at an aggregated level over the coming year by comparing pooled data from clinicians in the early group to pooled test-ordering data from clinicians in the delayed group. All data analyzed for this evaluation will not contain names, only encrypted patient and clinician numbers. No clinician or patient will be identified in any reports or publications. Portrait’s data access agreement requires the masking of data elements when <6 individuals (patients or clinicians) are included. For each Portrait, we seek approval from the University of British Columbia Clinical Ethics Review Board. This evaluation is being led by Dr. Anshula Ambasta with Drs Colin Dormuth and Greg Carney, University of British Columbia, Faculty of Medicine, Department of Anesthesiology, Pharmacology, & Therapeutics.

If you have any questions or would like further information, you may contact the Portrait team at (604) 822-4887 or email


Can I request the names of my patients included in this Portrait?

No. Portrait’s data access agreement only permits access to encrypted patient identifiers. There is no way for us to identify individual patients in the data or to provide you with a list.

However, other resources may be available for you. Contact your Practice Support Program (PSP) regional team to discuss how they might help you use your EMR to identify these patients.

I have a unique/specialized practice and do not believe that my data should be compared to GPs. Shouldn’t my comparison cohort be other clinicians with practices similar to mine?

Our ability to accurately include clinicians depends on how each clinician is listed in the BC MSP data. For example, to be included in the program, a clinician must be defined as a Nurse Practitioner or a General Practitioner with a licence status of Private Practice in the MSP data; beyond that, it is difficult to accurately identify any individual’s specific work environment, as many clinicians work in multiple locations. We try to keep Portraits relevant to recipients by having a minimum prescribing/testing criterion for each Portrait topic. Clinicians who did not prescribe the drug or did not order the test typically will not receive a Portrait.

Creating accurate comparison cohorts is difficult for the same reasons. We often include the BC median as a point of interest when it is feasible, but we know that many clinicians have unique or specialized practices and this comparator is not ideal. As we continue to build and refine the Portrait program, we will be able to provide comparisons that are more relevant to a variety of practices.

Portraits are intended to be a tool for you to reflect upon and consider your own prescribing and ordering of tests. Rest assured that we are not directly comparing your prescribing/ordering to any particular cohort. You are the only one who ever sees your own Portrait data, and you can decide for yourself whether you think your prescribing/ordering is in line with the evidence given your unique clinical setting. You will only receive future Portraits for based on minimum inclusion criteria, so you shouldn’t receive anything that is irrelevant to your practice (i.e., for drugs you do not prescribe or tests you do not use).

Why does my Portrait show ranges of patients that I treated (1-20, 20-30, etc.), and not exact numbers?

Portrait’s data access agreement requires the masking of data elements when <6 individuals (patients or clinicians) are included. Therefore, numbers between 1 and 5 patients were masked, and the length of the bar chart was set to 2.5 patients.

I don’t see my question here. Where can I find more information?

Please check out our program FAQ section. We also welcome your feedback. Questions can be directed to our Portrait team by phone (604) 822-4887 or email

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