OBJECTIVES: The usefulness of cases diagnosed in administrative registers for research purposes is dependent on diagnostic validity. This study aimed to investigate the validity and inter-rater reliability of recorded diagnoses of @entity1765 and @entity3119 ( @entity3119 ) in the Swedish National @entity1 Register (NPR). DESIGN: Chart review of randomly selected register cases and controls. METHOD: 100 @entity1765 cases and 100 @entity3119 cases were randomly selected from the NPR based on codes from the @entity66 ( @entity66 ) 8th, 9th and 10th editions, together with 50 @entity302 and 50 @entity308 control cases. The obtained @entity146 records were blindly assessed by 2 senior psychiatrists according to the criteria of the fourth edition of the Diagnostic and Statistical Manual of @entity146 , Fourth Edition, Text Revision (DSM-IV-TR) and @entity66 -10. PRIMARY OUTCOME MEASUREMENT: Positive predictive value ( @entity2286 ; cases diagnosed correctly divided by the sum of true positives and false positives). RESULTS: Between 1969 and 2009, the NPR included 7286 @entity1765 and 24   757 @entity3119 cases. The vast majority (91.3% of tic cases and 80.1% of @entity3119 cases) are coded with the most recent @entity66 version ( @entity66 -10). For @entity1765 , the @entity2286 was high across all @entity66 versions ( @entity2286 =89% in @entity66 -8, 86% in @entity66 -9 and 97% in @entity66 -10). For @entity3119 , only @entity66 -10 codes had high validity ( @entity2286 =91-96%). None of the @entity302 or @entity308 control cases were wrongly diagnosed as having @entity1765 or @entity3119 , respectively. Inter-rater reliability was outstanding for both @entity1765 (k=1) and @entity3119 (k=0.98). CONCLUSIONS: The validity and reliability of @entity66 codes for @entity1765 and @entity3119 in the Swedish NPR is generally high. We propose simple algorithms to further increase the confidence in the validity of these codes for epidemiological research.

Validity and reliability of chronic @entity1765 and XXXX diagnoses in the Swedish National @entity1 Register.

@entity1 :: ('9606', 'Species') :: ['Patient'] @entity308 :: ('MESH:D003866', 'Disease') :: ['depression'] @entity66 :: ('MESH:D004194', 'Disease') :: ['ICD', 'International Classification of Diseases'] @entity146 :: ('MESH:D001523', 'Disease') :: ['psychiatric', 'Mental Disorders'] @entity1765 :: ('MESH:D013981', 'Disease') :: ['tic disorder', 'tic disorders'] @entity2286 :: ('12211', 'Species') :: ['PPV'] @entity302 :: ('MESH:D004827', 'Disease') :: ['epilepsy'] @entity3119 :: ('MESH:D009771', 'Disease') :: ['obsessive-compulsive disorder', 'OCD']
@entity3119 :: (MESH:D009771,Disease) :: ['obsessive-compulsive disorder']
