title: Effects of diagnostic uncertainty and misclassification on hospital performance indicators for acute stroke care.
abstract: The Stroke Improvement National Audit Programme (SINAP), now replaced by the Sentinel Stroke National Audit Programme, was established to provide comparative data on hospital performance indicators for stroke, but comparisons are only valid if case ascertainment is complete. In Gateshead we compared initial results from SINAP with those from a pre-existing hospital stroke register, which ran independently for 11 months after SINAP's introduction in 2010, as well as with Hospital Episode Statistics (HES) data. Of 315 confirmed acute stroke cases identified from the three combined data sources, 96 (30%) were omitted from SINAP and 51 (16%) were missed by HES. Of 478 suspected strokes in the combined datasets, 214 were either misclassified by HES or remained with uncertain diagnosis. These patients had much lower mortality and shorter hospital stays than those with confirmed stroke. This diagnostic uncertainty could be an important source of uncontrolled variation in, or even a potential target for manipulation of, hospital performance indicators for stroke.
authors.affiliation: Queen Elizabeth Hospital, Gateshead, UK david.barer@ncl.ac.uk.
authors.forename: David
authors.initials: D
authors.lastname: Barer
authors.affiliation: Queen Elizabeth Hospital, Gateshead, UK.
authors.forename: Tim
authors.initials: T
authors.lastname: Cassidy
mesh_terms: D003951:Diagnostic Errors / Q000706:statistics & numerical data*; D017052:Hospital Mortality; D006757:Hospital Units / Q000592:standards / Q000706:statistics & numerical data; D006801:Humans; D019984:Quality Indicators, Health Care; D020521:Stroke / Q000628:therapy*; D035501:Uncertainty
keywords: Acute stroke; diagnostic uncertainty; hospital episode statistics; hospital mortality rates; hospital performance indicators