A qualitative exploration of the motives behind the decision to order a liver function test in primary care

The number of tests ordered in primary care continues to increase influenced by a number of factors not all of which are concerned with diagnosis and management of disease. Liver function tests (LFTs) are a good example of inexpensive tests that are frequently ordered in patients with non-specific symptoms. They remain among the most frequently ordered tests despite their lack of specificity yet the full range of motives behind the decision to order an LFT remains unexplored. To gain an understanding of the family practitioner's (FP) medical and non-medical motives for ordering an LFT and the influence of various social and technical factors on this decision. We interviewed FPs across six practices who were participating in a prospective study of the efficacy of an abnormal LFT to indicate the development of a serious liver disease. Following content analysis of the data from the semi-structured interviews we used the 'attitude-social influence-efficacy' model to categorise the determinants of test ordering behaviour. Factors influencing an FP's decision to order a test were grouped into two broad categories; the first is 'internal' including expectation of efficacy and general attitude towards LFTs. The second group is 'external' and consists of themes of social influence, tests characteristics and defensive medicine. Whilst our sample acknowledged the clinical use of LFTs such as the routine monitoring of medication and liver-specific diagnostic purposes we also found that social and behavioural reasons are strong motivators to order an LFT and may take precedence over clinical factors.