Time Trends and Variations in Electroconvulsive Treatment in Denmark 2008 to 2014: A Nationwide Register-Based Study.

OBJECTIVE: The aim of this study was to determine status and variations in the practice of electroconvulsive treatment (ECT) in Denmark in patient characteristics, indications, treatment patterns, and hospital region.

METHOD: All 140,627 ECTs registered in the Danish National Patient Registry between 2008 and 2014 were retrieved together with information on patient characteristics. Annual treated person rates were calculated for sex, age, admission diagnosis, and region.

RESULTS: The overall ECT treatment rate was 36 (95% confidence interval, 34-38) per 100,000 resident population during the study period. The rate was highest in women and increased with age. There were modest, however, stable regional differences in rates (extremal quotient = 1.4). Electroconvulsive treatment was most commonly used in patients with depression with (19.4%) or without (54.9%) psychotic symptoms. The median number of ECTs administered per patient was 10 and highest in patients with schizophrenia, schizoaffective, or bipolar disorders. A total of 51%, 14%, and 33% of ECTs were administered with bilateral, unilateral, and unspecified electrode placement, respectively. There were regional differences in electrode placement specification and use.

CONCLUSIONS: Although some variation was seen across hospital regions and electrode placement, ECT in Denmark was provided with relative stability over time and indications compared with most other countries in Europe and North America.