Validation of the German version of the subarachnoid haemorrhage outcome tool (SAHOT)

The subarachnoid haemorrhage (SAH) outcome tool (SAHOT) is the first SAH-specific patient reported outcome measure, and was developed in the UK. We aimed to validate the SAHOT outside the UK, and therefore endeavored to adapt the SAHOT into German and to test its psychometric properties.

We adapted and pilot tested the German version. We applied the SAHOT, Quality of Life after Brain Injury, Hospital Anxiety and Depression Scale, and EuroQol questionnaires in a cohort of 89 patients with spontaneous SAH after discharge. We assessed internal consistency by Cronbach's α, test-retest reliability by intraclass correlation, and validity by Pearson correlations with established measures. Sensitivity to change was evaluated following neurorehabilitation by effect sizes.

The translation of SAHOT resulted in a German version that is semantically and conceptually equivalent to the English version. Internal consistency was good regarding the physical domain (α = 0.83) and excellent for the other domains (α = 0.92-0.93). Test-retest reliability indicated a high level of stability with an intraclass correlation of 0.85 (95% CI: 0.83-0.86). All domains correlated moderately or strongly with established measures (r = 0.41-0.74; p < 0.01). SAHOT total scores showed moderate sensitivity to change (Cohen's d = -0.68), while mRS and GOSE showed no significant sensitivity to change.

The SAHOT can be adapted to other health care systems and societies than the UK. The German version of the SAHOT is a reliable and valid instrument, and can be used in future clinical studies and individual assessment after spontaneous SAH.