A review of five cardiology journals found that observer variability of measured variables was infrequently reported.
OBJECTIVE
To investigate the reporting of the analysis of interobserver and intra-observer variability within clinical research studies from five high-impact cardiology journals published in 2005.


METHODS
A cross-sectional study using a combined electronic and manual search identified 180 of 511 eligible articles that reported the assessment of observer variability. Sixty of these were randomly selected for detailed review.


RESULTS
The proportion of the 60 studies reporting interobserver variability, intra-observer variability, or both were 27%, 17%, and 53%, respectively. The reported methodological design of interobserver and intra-observer analyses included a specific protocol in 42% and 33%, identified observers as independent in 31% and 17%, as blinded in 50% and 31%, and identified a prior statistical plan in only 33% and 36%, respectively. Pearson correlation was the most reported measure for continuous variables, and the methods of Bland and Altman were reported in 15% of interobserver and 14% of intra-observer studies, respectively. For categorical variables, a kappa statistic was reported in 82% and 80%, respectively.


CONCLUSIONS
Reliability assessment is hampered by unclear and incomplete reporting of interobserver and intra-observer analysis. For continuous variables, inappropriate methods were most frequently reported as being done.
Gow
Robert M
RM
Children's Hospital of Eastern Ontario Research Institute, 410 Smyth Road, Ottawa, Ontario, Canada K1H 8L1. rgow@cheo.on.ca
Barrowman
Nicholas J
NJ
Lai
Lillian
L
Moher
David
D
D002309:Cardiology / Q000706:statistics & numerical data*; D002986:Clinical Trials as Topic / Q000706:statistics & numerical data; D003430:Cross-Sectional Studies; D006801:Humans; D033181:Information Dissemination / Q000379:methods*; D015588:Observer Variation; D017712:Peer Review, Research; D011643:Publishing; D012107:Research Design