To develop and test a series of vignettes to be used to assess which patient attributes influence the GPs decision to make a diagnosis of asthma.

Project Status

Completed Projects

Chief Investigators

Sarah Dennis, Nicholas Zwar, Guy Marks

Rationale

To develop and test a series of vignettes to be used to assess which patient attributes influence the GPs decision to make a diagnosis of asthma. There is evidence that GPs both under and over diagnose asthma but it is not clear whether there are patient characteristics such as gender, age or smoking status that are more likely to result in the patient being labelled asthmatic. If we can understand how GPs decide which patients to label as asthma or some other condition we will be able to target education or awareness campaigns to improve the diagnosis of asthma.

Aims

The aim of this study is to develop and test a series of vignettes, which will subsequently be used to quantitatively estimate the contribution of various patient attributes to the process of attaching a diagnostic label of asthma in primary care. Using a series of vignettes or case histories has been demonstrated to be a useful method for assessing how GPs make a diagnosis in other chronic conditions. Attempting to identify patients as they are diagnosed with asthma to assess how the diagnosis is made is very difficult and simply asking GPs how they make a diagnosis will only highlight what GPs know they should do rather than what they actually do.

Design and Method

Phase 1: vignette content will be derived from four GP focus groups. Forty GPs from South West Sydney will be invited to take part in one of four focus groups. The GPs will be asked for their opinions on what factors they consider important to enable them to make a diagnosis of asthma and the areas of uncertainty such as the effect of smoking history, sex and age of the patient on the diagnosis of asthma.

Phase 2: The vignettes will be constructed and tested for interpretability and for test-retest repeatability in an independent sample of fifty GPs from South West Sydney. Each GP will be sent a series of short vignettes and will be asked to attach a label of asthma, normality, or an alternative diagnosis. A reply paid envelope will be included for the GPs to return their completed questionnaires. Non-responding GPs will be sent a further questionnaire those who still do not return their questionnaire will be contacted by telephone. Because the series of vignettes may take some time to answer all GPs returning their questionnaire will be sent a voucher to thank them for their time. This testing will also generate estimates of the prevalence of various responses.

Contact

Sarah Dennis Email: s.dennis@unsw.edu.au

Funding

Faculty grant

Project lead centre
GPU
Project stream
Prevention and Management of Long Term Conditions
Project start date
2005
Project end date
2008