Exploring reasons for variation in ordering thyroid function tests in primary care: a qualitative study

The ordering of thyroid function tests (TFTs) is increasing but there is not a similar increase in thyroid disorders in the general population, leading some to query whether inappropriate testing is taking place. Inconsistent clinical practice is thought to be a cause of this, but there is little evidence of the views of general practitioners, practice nurses or practice managers on the reasons for variation in the ordering of TFTs.

To find out the reasons for variation in ordering of TFTs from the perspective of primary healthcare professionals Methods: Fifteen semi-structured interviews were carried out with primary healthcare professionals (general practitioners, practice nurses, practice managers) that used one laboratory of a general hospital in South West England for TFTs. Framework Analysis was used to analyse views on test ordering variation at the societal, practice, individual practitioner and patient level.

A number of reasons for variation in ordering across practices were suggested. These related to: primary healthcare professionals awareness of and adherence to national policy changes; practices having different protocols on TFTs ordering; the set-up and use of computer systems in practices; the range of practice healthcare professionals able to order TFTs; greater risk-aversion amongst general practitioners and changes in their training and finally how primary healthcare staff responded to patients who were perceived to seek help more readily than in the past.

The reasons for variation in TFTs ordering are complex and interdependent. Interventions to reduce variation in TFTs ordering need to consider multiple behavioural and contextual factors to be most effective.