Postoperative fatigue; translation and validation of a revised 10-item short form of the Identity-Consequence Fatigue Scale (ICFS)

Postoperative fatigue is a common problem after otherwise uncomplicated surgery. It may defer patients from resuming their daily activities and is often reported to be among their most severe symptoms. There are few validated instruments for assessing postoperative fatigue. Our aim was to translate into Norwegian and explore a Short Form of the Identity-Consequences Fatigue Scale; a fatigue questionnaire specifically developed to assess postoperative fatigue.

The fatigue scale was translated to Norwegian through a forward-backward process, and subsequently validated in a large, mixed surgical population. We performed Principal Component Analyses on the complete 31-item scale and on the 10-item Short Form. The analyses were performed separately on pre- and postoperative data (n=422 and n=315, respectively).

The factor analyses confirmed that the translation was valid and revealed three defined dimensions in the 10-item scale. There was no statistically significant difference between means of reported fatigue when measured with the 31- or 10-item scale. Ninety-eight% of change in fatigue from pre- to postoperative status was retained when using the 10-item scale as compared to the 31-item scale.

The abridged, 10-item Short Form performed equal to the 31-item scale and may replace the complete 31-item ICSF scale in exploring the incidence of pre- and post-operative fatigue.