Monitoring of Hypothyroidism

Hypothyroidism - Rationale for Inclusion of Indicator Set
Hypothyroidism is a common, serious condition with an insidious onset. The mean incidence is 3.5 per 1000 in women, and 0.6 per 1000 in men. The probability of developing hypothyroidism increases with age and reaches 14 per 1000 in women aged between 75 and 80.

There is a clear consensus on how hypothyroidism should be treated.

Monitoring of hypothyroidism is almost entirely undertaken in primary care.

Hypothyroid (Thyroid) Indicator 1
The practice can produce a register of patients with hypothyroidism

Thyroid 1.1 Rationale
A register is a prerequisite for monitoring patients with hypothyroidism. Many patients will have been diagnosed at some time in the past and the details of the diagnostic criteria may not be available. For this reason the patient population should consist of those patients taking thyroxine with a recorded diagnosis of hypothyroidism. The most effective method for identifying the patient population would be a computer search for repeat prescribing of thyroxine with a subsequent check of the records to confirm the clinical diagnosis.

Thyroid 1.2 Preferred Coding
Acquired Hypothyroidism CO4%
Congenital Hypothyroidism CO3%

Thyroid 1.3 Reporting and Verification
The practice reports the number of patients on its hypothyroidism disease register and the number of patients on its hypothyroidism disease register as a proportion of total list size.

Verification - PCOs may compare the expected prevalence with the reported prevalence.

Hypothyroid (THYROID) Indicator 2
The percentage of patients with hypothyroidism with thyroid function tests recorded in the previous 15 months

Thyroid 2.1 Rationale
There is no clear evidence on the appropriate frequency of TSH/T4 measurement. However, the consensus group on thyroid disease recommended an annual check of TSH/T4 levels in all patients treated with thyroxine. In addition they recommend an annual check in patients previously treated with radio-iodine or partial thyroidectomy (Consensus statement for good practice and audit measures in the management of hypothyroidism and hyperthyroidism. BMJ 1996;313:539-544).

Thyroid 2.2 Preferred Coding
Thyroid function tests 442%

Thyroid 2.3 Reporting and Verification
The practice should report the percentage of patients on its hypothyroid register who have had a TSH or T4 undertaken in the last 15 months.

In verifying that this information has been correctly recorded, a number of approaches could be taken by a Primary Care Organisation:

1. Inspection of the output from a computer search that has been used to provide information on this indicator

2. Inspection of a sample of records of patients with hypothyroidism to look at the proportion with recorded TSH/T4

3. Inspection of a sample of records of patients with hypothyroidism for whom a record of TSH/T4 is claimed, to see if there is evidence of this in the medical records.