Danish Prostate Cancer Registry - methodology and early results from a novel national database

Background

Systematized Nomenclature of Medicine (SNOMED) codes are computer-processable medical terms used to describe histopathological evaluations. SNOMED codes are not readily usable for analysis. We invented an algorithm that converts prostate SNOMED codes into an analyzable format. We present the methodology and early results from a new national Danish prostate database containing clinical data from all males who had evaluation of prostate tissue from 1995 to 2011.

Materials and methods

SNOMED codes were retrieved from the Danish Pathology Register. A total of 26,295 combinations of SNOMED codes were identified. A computer algorithm was developed to transcode SNOMED codes into an analyzable format including procedure (eg, biopsy, transurethral resection, etc), diagnosis, and date of diagnosis. For validation, ~55,000 pathological reports were manually reviewed. Prostate-specific antigen, vital status, causes of death, and tumor-node-metastasis classification were integrated from national registries.

Results

Of the 161,525 specimens from 113,801 males identified, 83,379 (51.6%) were sets of prostate biopsies, 56,118 (34.7%) were transurethral/transvesical resections of the prostate (TUR-Ps), and the remaining 22,028 (13.6%) specimens were derived from radical prostatectomies, bladder interventions, etc. A total of 48,078 (42.2%) males had histopathologically verified prostate cancer, and of these, 78.8% and 16.8% were diagnosed on prostate biopsies and TUR-Ps, respectively.

Future perspectives

A validated algorithm was successfully developed to convert complex prostate SNOMED codes into clinical useful data. A unique database, including males with both normal and cancerous histopathological data, was created to form the most comprehensive national prostate database to date. Potentially, our algorithm can be used for conversion of other SNOMED data and is available upon request.

A scheme for the placement of rodenticide baits for rat eradication on confinement livestock farms

We investigated whether the allocation of rodenticide baiting points to specific structural elements would result in complete rat eradication on livestock farms, as opposed to assigning the baiting points only to places where there were obvious signs of rat activity. The goal was to establish an effective rodent-control program that is easy for untrained persons to conduct.Rat-control strategies were examined on 25 farms in Velen (Muensterland), Germany, where an average of 20% of trapped rats were resistant for bromadiolone according to a blood-clotting response (BCR) test. All farms were investigated for signs of rat activity prior to and after the control measure. Differences in the percentage level of farmer compliance in setting up the baiting points as prescribed were analysed for each type of baiting point and in total, and were compared between the group of farms which achieved complete rat eradication and those which did not. Farms achieving complete eradication had an average of 81% compliance with prescribed control plans, whereas a significantly lower compliance level of only 51% was recorded on farms that did not achieve eradication. A >/=75% level of implementation of the control plan always resulted in complete control success. The new method of bait-point allocation was incorporated into a self-explanatory computer program, which was verified to be effective during a rat-control campaign in the restricted area after an outbreak of classical swine fever near Soltau in northern Germany, in July 2001. This program, which is available on the Internet, enables the creation of individualised rat-control plans, including complete documentation of the control measure.