Background Research suggests that variation in laboratory requesting patterns may indicate unnecessary test use. Requesting patterns for serum immunoglobulins vary significantly between General Practitioners (GPs). This study aims to explore GP views on testing to identify the determinants of behaviour and recommend feasible intervention strategies for improving immunoglobulin test use in General Practice.

Methods Qualitative semi-structured interviews were conducted with GPs requesting laboratory tests at Cork University Hospital or Kerry General Hospital in the South of Ireland. GPs were identified using a Health Service Executive laboratory list of GPs in the Cork-Kerry region. A random sample (stratified by GP requesting patterns) of GPs was generated from this list. GPs were purposively sampled based on the sampling criteria of: location (urban/rural); length of time qualified; and practice size (single-handed/group). Interviews were carried out between December 2014 and February 2015. Interviews were transcribed verbatim using NVivo 10 software, and analysed iteratively using thematic analysis. Emerging themes were then mapped to the theoretical domains framework (TDF), which identifies 12 domains that can enable or inhibit behaviour change. The behaviour change wheel and behaviour change technique (BCT) taxonomy were then used to recommend potential intervention strategies.

Results Sixteen GPs were interviewed, including ten males and six females. Preliminary analysis, using the TDF and BCT taxonomy, found that serum immunoglobulin test use in General Practice is influenced by many social and contextual factors. The main domains from the TDF which emerged were: ‘knowledge’, ‘environmental context and resources’, ‘social influences’, ‘beliefs about capabilities’, ‘beliefs about consequences’, with the findings identifying a need for ‘shaping knowledge’. In particular, GPs identified education and feedback strategies as feasible interventions to change their behaviour.

Conclusion This study identified GP challenges with serum Immunoglobulin testing, which included difficulty interpreting test results, patient expectations, personal experiences, and the lack of implementation of guidelines and knowledge about when to test for serum immunoglobulins. Study findings and the application of the TDF and BCT taxonomy, will inform the development of a feasible intervention for improving immunoglobulin test use in General Practice.