Premium
Potential serious bias in National Clinical Databases with low degree of reported follow‐up
Author(s) -
Bjerre J. J.,
Jensen P. K.,
Sparsø B. H.,
Krogsgaard M. R.
Publication year - 2017
Publication title -
scandinavian journal of medicine and science in sports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.575
H-Index - 115
eISSN - 1600-0838
pISSN - 0905-7188
DOI - 10.1111/sms.12726
Subject(s) - danish , medicine , national database , database , reporting bias , family medicine , medline , demography , computer science , philosophy , linguistics , political science , law , sociology
We identified reasons for the low follow‐up rate in the Danish Knee ligament Reconstruction Register ( DKRR ) and evaluated its influence on the data quality. All 946 primary ACL ‐reconstructed patients in the Capital Region of Denmark during 2012 were identified in the databases of 8 participating hospitals. We studied the patient files and compared them to figures reported to the DKRR . 92.5% of the operated patients was registered in DKRR . The 1‐year follow‐up rate reported to DKRR was 33.4%, and 14.5% filled in patient reported outcomes ( KOOS and Tegner) at 1 year. Only 65% had actually been invited for follow‐up, but among the patients who had been invited 91% were seen. 41% of existing follow‐up data was not reported. Contemporary technology and structured motivation should be introduced to increase validity of data in national clinical databases. Follow‐up >90% in the DKRR is realistic if patents are invited and reported. The unreported data is potentially a serious bias. It is suggested that data from clinics with low follow‐up should not be used in studies involving outcomes based on national databases because of risk of bias.