INTRODUCTION. Most patients admitted to intensive care are discharged to a general ward in the same hospital, but some patients require transfer to another hospital. Indications for interhospital transfers (IHT) include referral for specialist treatment, lack of intensive care beds at the referring ICU and repatriation to ICU in home hospital [1].

OBJECTIVES. To review mortality of ICU-patients undergoing IHT and analyse whether different indications for transfer render different mortalities.

METHODS. Retrospective cohort register study using the Swedish Intensive Care Registry (SIR) during 2016-2018. The SIR collects data from 98.8% of Swedish ICUs including data on discharge from ICUs to other hospitals/ICUs. Transfers were divided into three categories: transfer due to medical reasons, lack of ICU beds or repatriation to ICU in home hospital. We analysed odds ratios (ORs) for dying within 30 days after discharge from ICU using risk adjusted (SAPS3 score) multi-level mixed effect logistic regression with ICUs as random effect.

RESULTS. We identified 12,356 patients who were discharged to another ICU and hospital, i.e. inter-hospital transfers. The unadjusted mortality 30 days after IHT was 17.2 % compared to 12.4 % if discharged to ward in the same hospital. Mortality after IHT varied with the cause of discharge (Figure).Main diagnoses for transfer due to specialist treatment were subarachnoid haemorrhage, head injury and multi-trauma whilst for lack of ICU beds post cardiac arrest, respiratory failure and pneumonia dominated. Risk adjusted analysis showed a significantly increased risk of dying after discharge due to lack of ICU-beds in comparison with other reasons for IHTs

CONCLUSION. The adjusted risk of dying within 30 days after interhospital transfer was greater among critically ill patients when the transfer was due to lack of beds in the referring ICU. The increased mortality lingered for at least 6 months underlining the importance to identify causes and intervene to avoid unnecessary loss of life.