DEMENTIA AFTER SURGERY IN SWEDEN

Abstract

There is currently a controversy regarding the longterm impact of major surgery on subsequent cognitive performance and risk for dementia. A nested case-control study was performed within the population-based Swedish Twin Registry (STR) based on two samples of individuals: a clinical sample with individuals with a diagnosis of dementia based on clinical assessment within STR studies, and a register sample with dementia diagnosis retrieved from the Swedish National Patient Registry (NPR), Cause of death registry and Prescribed drug registry. All dementia cases were matched with 5 non-demented individuals and combined with information on hospitalizations and surgical procedures recorded in the NPR between 1977-2012. Hospitalizations for surgical or non-surgical conditions are associated with increased risk for dementia, however, hospitalizations for non-surgical reasons or critical illness are associated with a markedly higher risk for dementia than for surgical procedures. The risks of dementia increased with increasing number of non-surgical hospitalizations, and were significant 10 to 20 years past hospitalization. There was no increased risk with surgery after 80 years of age, which may reflect selection bias. Patients and providers should be more concerned about the consequences of repeated hospitalizations or critical illness than about surgery as a major risk factor for dementia.