RT Journal Article
SR Electronic
T1 Understanding variation for clinical governance: an illustration using the diagnosis and treatment of sore throat.
JF British Journal of General Practice
JO Br J Gen Pract
FD British Journal of General Practice
SP 277
OP 283
VO 52
IS 477
A1 Tom Marshall
A1 Mohammed A Mohammed
A1 Hei Toon Lim
YR 2002
UL http://bjgp.org/content/52/477/277.abstract
AB BACKGROUND: The aim of clinical governance is to improve clinical care. An understanding of the information contained in variation is central to any improvement effort. We must distinguish between variation intrinsic to a process (common cause variation) and variation caused by extrinsic factors (special cause variation). The control chart is a method of distinguishing between these two kinds of variation: it is used in industry to effect improvement and may be useful in primary care. AIM: To illustrate the use of control charts to distinguish between common cause and special cause variation and to guide appropriate action. DESIGN OF STUDY: Analysis of diagnostic and treatment decisions for sore throat. SETTING: Single practice in the West Midlands. METHODS: We identified each general practitioner's (GP's) consultations for sore throat over a two-year period. We grouped these into two diagnostic categories (tonsillitis and non-tonsillar throat infection) and two treatment categories (antibiotics and no antibiotics). These data were illustrated graphically as XY control charts. RESULTS: In this practice, a special cause affects one GP's diagnosis--he is less likely to use the term 'tonsillitis'. A special cause also affects his treatment decisions--he is more likely to prescribe antibiotics. Diagnostic and treatment differences between the remaining GPs are consistent with common cause variation. CONCLUSION: In this practice, action to improve the quality of diagnosis and treatment of sore throat shouldfocus on investigating why one practitioner's diagnosis and treatment differs from that of his colleagues. Control chart analysis is valuable because it enables users to obtain practical guidance for action.