A reliable coding system to define screening prostate-specific antigen tests was developed in a case-control study.
OBJECTIVE
To establish the reliability of a coding system for screening and diagnostic prostate-specific antigen (PSA) testing from patient charts.


METHODS
Two investigators reviewed 448 chart abstractions from a population-based case-control study of PSA screening in the Toronto area. The tests evaluated for reliability were transrectal ultrasound (TRUS), digital rectal examination (DRE), and prostate-specific antigen (PSA).


RESULTS
DRE results were found in 87%, PSA results in 65%, and TRUS results in 12% of the 749 charts. Interobserver agreement was 94% for DRE texture (kappa =.885), 95% for DRE asymmetry (kappa = .868), 85% for DRE physician interpretation (kappa = .698), 97% for final DRE result (kappa = .856), and 87% for TRUS (kappa = .769). Physician interpretation modified the final result in only 6.2% of DREs. Interobserver agreement for PSA coding was 91% (kappa = .787). Of PSA results, pure PSA screening with no symptoms of obstructive urination was found in 19%, symptomatic PSA screening in 46%, and diagnostic PSA testing in 35%.


CONCLUSIONS
We have developed a practical and reliable coding system for TRUS, DRE, and PSA in the context of a case-control study of PSA screening.
Bunting
Peter S
PS
Division of Biochemistry, Department of Pathology and Laboratory Medicine, University of Ottawa, Ontario, Canada. dsailhart@rivnet.net
Neuman
Jan
J
Goel
Vivek
V
Fleshner
Neil
N
Kopec
Jacek
J
Levers
Peter
P
Warde
Padraig
P
D014408:Biomarkers, Tumor / Q000097:blood*; D016022:Case-Control Studies; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods; D008499:Medical Records / Q000592:standards*; D015588:Observer Variation; D010173:Palpation; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging; D012007:Rectum; D014463:Ultrasonography
D014408:Biomarkers, Tumor; D017430:Prostate-Specific Antigen