Premium
Completeness of case ascertainment in Swedish hospital‐based stroke registers
Author(s) -
Aked Joseph,
Delavaran Hossein,
Norrving Bo,
Lindgren Arne
Publication year - 2020
Publication title -
acta neurologica scandinavica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.967
H-Index - 95
eISSN - 1600-0404
pISSN - 0001-6314
DOI - 10.1111/ane.13187
Subject(s) - medicine , stroke (engine) , epidemiology , case fatality rate , population , cohort , pediatrics , selection bias , emergency medicine , mechanical engineering , environmental health , pathology , engineering
Background There is a worldwide development toward using data from hospital‐based stroke registers to estimate epidemiological trends. However, incomplete case ascertainment may cause selection bias. We examined the completeness of case ascertainment and selection bias in two hospital‐based Swedish stroke registers. Methods First‐ever stroke cases between March 2015 and February 2016 in the catchment area of Skåne University Hospital, Lund, Sweden, were included from multiple overlapping sources: two hospital‐based stroke registers, Riksstroke‐Lund and Lund Stroke Register (LSR); local outpatient and inpatient registers; primary care registers; and autopsy registers. The resulting population‐based cohort was used as reference to assess completeness of case ascertainment and patient characteristics in Riksstroke‐Lund and LSR. Results In total, 400 stroke patients were identified. Riksstroke‐Lund detected 328 (82%) patients, whereas LSR detected 363 (91%). Patients undetected by hospital‐based registers had higher 28‐day case fatality than those detected (44% vs 9%; P = .001). Patients only detected in primary care (n = 11) more often lived in healthcare facilities compared with those detected by hospital‐based registers (57% vs 7%; P = .001). Patients not detected by Riksstroke‐Lund, but detected by population‐based sources, had less severe strokes (median NIHSS 3 vs 5; P = .013). Conclusions Some first‐ever stroke patients, such as those with high early case fatality and those with mild stroke, may go undetected with hospital‐based screening used in clinical stroke registers. This can result in selection bias due to not identifying specific groups of patients including some with high early case fatality and those living in healthcare facilities.