Validity of the personality disorder diagnosis in the Swedish National Patient Register

The Swedish National Patient Register (NPR) is an exceptional source of information in clinical epidemiological research. The register is, however, not validated for the diagnosis of personality disorder (PD). We therefore assessed its validity in this patient group, and the group with emotionally unstable PD (EUPD)/borderline personality disorder (BPD).

Records from 100 random adult patients (aged 15-65 years) diagnosed with any PD in the NPR between 1987 and 2015 were analysed using a protocol based on general diagnostic criteria for PD, as well as specific criteria for EUPD/BPD in both ICD and DSM classification systems.

Of the 100 patients, 27 had been given a diagnosis of EUPD, 23 another specific PD and 50 an unspecified PD. Using ICD criteria, 88 of 95 evaluable patients could be confirmed to have a PD, that is an agreement rate of 93%. Using DSM criteria, the agreement was lower (77 patients or 81%). Of 26 evaluable patients with a diagnosis of EUPD/BPD, the diagnosis was confirmed in all cases when using the ICD criteria, but in only 20 when using the DSM criteria.

The NPR is a valid source of data for the diagnosis of PD per se and also of EUPD in women.