The Swedish National Patient Register (NPR) has long been a crucial tool for epidemiological research, providing valuable data for researchers at Karolinska Institutet and beyond. A recent review conducted by researchers at Karolinska Institutet has shed light on the validity of the register, showing that it is good for most diagnoses and very good for surgical procedures.
In the past, a review conducted in 2010 only focused on inpatient care. However, the new review includes specialized outpatient care as well, providing a more comprehensive assessment of the validity of the NPR. Published in the European Journal of Epidemiology, the researchers conducted systematic searches in medical databases and collected reports from members of the Swedish Epidemiological Association to identify all studies validating diagnoses and procedure codes in inpatient care since 2010, as well as studies validating specialized outpatient care. Additionally, results from register validation work carried out by the National Board of Health and Welfare were summarized.
According to Åsa Everhov, Docent at the Department of Medicine Solna and the first author of the article, “Our review shows that the Swedish National Patient Register has good diagnostic accuracy for most diagnoses and very good accuracy for surgical procedures, but with significant variability in PPV and sensitivity depending on diagnosis, coding definitions, reference standards, and data sources.”
Over time, the register has become more complete, with low degrees of underreporting. However, underreporting is slightly higher among private healthcare providers and for specific variables such as drug administration. Ola Olén, the last author of the study and Professor at the Department of Medicine Solna, emphasizes the importance of researchers being aware of these limitations when using the NPR for their studies.
The review highlights the value of the NPR as a valuable resource for epidemiological research in Sweden and internationally. While the register has its limitations, researchers can still benefit from the wealth of data it provides. By understanding these limitations, researchers can continue to utilize the NPR for their studies while taking necessary precautions to ensure the accuracy and validity of their findings.
In conclusion, the Swedish National Patient Register remains a valuable tool for epidemiological research, with good diagnostic accuracy for most diagnoses and very good accuracy for surgical procedures. Researchers can continue to rely on the NPR for their studies, while being mindful of its limitations to ensure the integrity of their research findings.
