Antidiabetic medicines prescribing practices in primary care in Northern England: a mixed-methods study

Antidiabetic medicines are widely used in primary care to prevent, treat and reduce diabetes-related complications. Abundant empirical evidence is available on the management of adults with type 2 diabetes but still much controversy exists about how to prescribe antidiabetic medicines. It is suggested that there are geographical variations in the prescribing of antidiabetic medicines across England, though it is not clear what causes these differences.

The aim of this thesis was to investigate primary care clinicians’ antidiabetic medicines prescribing practices in Northern England. First, a systematic literature review was conducted to understand which antidiabetic medicines were being prescribed, then a second systematic literature review was conducted to understand how much was being spent on these medicines. A qualitative study (n=21) provided information about general practitioners’ experiences with prescribing antidiabetic medicines. This study also explored factors which influences the general practitioners prescribing choices and referral behaviours. A survey (n=125) expanded on the findings from the qualitative study and provided information on general practitioners, nurses and practice pharmacists preferred stepwise approach to prescribing antidiabetic medicines. Then, a case study surveyed the price of two antidiabetic treatments in a cross-national context.

Variation in antidiabetic medicines prescribing was found to be a common and diverse issue in general practice. The choice of antidiabetic medicines was individualised to the patients based on factors such as notions of the severity of the disease as well as patients’ behaviours. The general practitioners described a varying and flexible approach to NICE prescribing guidelines depending on their own ideas and agendas. The interviewees seemed to have varying insight to the clinical practice-evidence gap. The general practitioners’ knowledge about NICE guidelines on type 2 diabetes management (NG28) was indirect as the use was filtered through a number of secondary interpretative channels. The general practitioners described varying antidiabetic prescribing practices. Adequate skills and knowledge about antidiabetic medicines seemed more influential than written sources. The challenges in antidiabetic prescribing were diverse but often characterised to be related to tension between competing factors such as advocating for the best care for the patients or keeping prescribing costs down. A conceptual model was developed which summarises the general practitioners’ beliefs about antidiabetic medicines which influences their prescribing practices on an individual, local and national level.

The importance of antidiabetic prescribing in primary care seems to be well understood by the general practitioners. The general practitioner’s management of adults with type 2 diabetes was in accordance with the NICE guidance. However, the findings suggest that the flexible guidance from NICE has resulted in varying antidiabetic prescribing practices in primary care. There remain areas of uncertainty in antidiabetic prescribing such as in which order to prescribe treatments and how to gain confidence in prescribing the full range of available treatments. Given the complex nature of the challenges in antidiabetic medicines such as suboptimal use of available antidiabetic medicines and varying prescribing guidelines future interventions to optimise prescribing of antidiabetic medicines may need local and national interventions which may require changes in the current prescribing practices in primary care.