[Psychometric properties of the Stress Index RadioOncology (SIRO)--a new questionnaire measuring quality of life of cancer patients during radiotherapy].

PURPOSE

In the course of radiotherapy oncological patients often experience considerable psychosocial distress. For its measurement however, no specific questionnaire is available. The Stress Index RadioOncology (SIRO), which is based upon the results of extensive preliminary studies, will be made available as a screening-instrument to facilitate measurement of psychosocial distress of cancer patients, including radiotherapy-induced distress. The aim of this study is, to psychometrically evaluate the preliminary version of the questionnaire, to transfer it to the final version (SIRO) and to gain information about the psychosocial distress of radiooncological patients at the beginning of radiotherapy.

PATIENTS AND METHODS

104 cancer patients (18 to 85 years) with different diagnoses have been included in the study (Table 1). The data have been assessed by means of the preliminary version of the new questionnaire SIRO, the HADS, EORTC QLQ-C30 and LS. With 25 patients semistructured clinical interviews have been conducted.

RESULTS

The requirements for reliability (Table 3) and validity (Table 4) of the SIRO have either been fulfilled or exceeded. The highest distress value has been found in the scale "Psycho-physical Distress", followed by the scale "Partnership Problems", "Radiotherapeutical Distress", and "Information Deficits" (Figure 1). On the item level, the highest distress was experienced due to reduction of efficiency and anxiety (Table 2). With regard to the radiotherapy items, patients were most distressed by fears of possible side effects and by the fact of being irradiated. Patients with palliative treatment option were higher distressed than those with curative treatment (Table 5).

CONCLUSIONS

The preliminary version of the new self-report questionnaire (SIRO) has proven to be valid, reliable and practicable, and can therefore be taken unchanged to measure the psychosocial distress of radiooncological patients.