Toward an understanding of different manifestations of fatigue.

Background: The aim of this study was to determine if patient narratives and interviewer reactions are specific in groups of somatic (SF) and psychogenic fatigue (PF) patients.

Methods: The interview criteria and criteria of the interviewer reaction are tested against group classification. Over a 2-year period, 51 (22 PF and 29 SF) patients fulfilling the inclusion criteria were interviewed by two trained independent interviewers. The tape-recorded interviews were analyzed and blind rated by a set of independent physicians. State and Trait Anxiety Inventories (STAI and TRAI, respectively), Beck Depression Inventory (BDI), and Beck's hopelessness scales were completed by the patients.

Results: SF versus PF patients more often showed a clear versus vague qualitative description (P=.03), clear changes in levels of intensity (P=.03), and clear factors contributing to the increase (P=.02) and decrease (P=.03) of fatigue. In SF, the raters more often felt calm (P=.03), interested (P=.01), and attentive (P=.02). With PF tapes, the raters more often felt impatient (P=.03), surprised (P=.03), and helpless (P=.01). For the TRAI, the mean score of the PF group was significantly higher compared with that of the SF group (P=.004). For all items, Fisher's Exact Test was used.

Conclusions: Our results confirm significant differences in patient narratives and interviewer reactions for the groups examined. The systematic use of interview criteria and analysis of the interviewer reactions may contribute to the better understanding of fatigue.