[The National Patient Registry as a tool for continuous production and quality control]

In Denmark, the National Register of Patients has, by law since 1977, received discharge diagnoses, surgical codes, and, in recent years, also codes for specific medical treatments for all hospitalised patients. It is an important source of administrative data and for epidemiological research. This paper summarises the results of an evaluation of the register as a tool for assessing quality in gynaecological departments in Denmark.

We obtained data describing production and quality of abortions, ectopic pregnancies, hysterectomies, endometrial ablations, ovarian cysts, ovarian, cervical, and endometrial cancer, in vitro fertilisation, insemination, and urine incontinence. A search was also made for possible miscodings in order to evaluate the extent of such miscoding and to obtain more valid quality estimates.

The validity and completeness of the diagnosis codes were generally poorer than that of the surgical codes, especially that of the newer medical treatment codes. We found a rather different clinical practice and quality at the 38 gynaecological departments studied. In order to reduce this stochastic noise, we analysed all small departments as a single unit. Generally, the quality was the same in both the larger and the smaller units.

The register seems well suited for routine production and quality control.