Development and Initial Validation of the Novel Scale for Assessing Quality of Life of Prostate Cancer Patients Receiving Androgen Deprivation Therapy

Background: There has been no a specific scale to measure quality of life (QOL) for prostate cancer patients receiving androgen deprivation therapy (ADT) to date. This study aimed to develop and initially validate the scale to evaluate QOL for prostate cancer patients receiving ADT.

Methods: The scale was developed following international recommendations. Moreover, the items were all generated through literature review and referenced questionnaires. After being reviewed by expert panelists, the revised scale was formed and then completed by a convenience sample of 200 prostate cancer patients from our hospital. Explore factor analysis (EFA) was applied to test the construct validity, then split-half reliability, Cronbach's alpha, and test-retest reliability were applied to assess the reliability and stability of the scale.

Results: The revised scale contained 22 items and a total of 200 participants had completed the scale. One hundred participants were randomly selected from the total 200 participants to perform EFA with varimax rotation on the revised scale, and "hot flashes" item was deleted for low factor loading. We selected only 3 items from each factor, then, the final scale was formed with 18-items. We selected another 100 participants to perform the EFA again on the final scale. It was demonstrated that the structure with 6 factors explained 72.5% of total variance and factor loading value was above 0.40 in all items of the factors. Moreover, the split-half reliability coefficient, Cronbach's alpha, and test-retest reliability coefficient were calculated to be 0.74, 0.63, and 0.89, respectively, exhibiting good reliability on the whole.

Conclusions: The scale was identified to be a valid and reliable instrument to measure QOL for prostate cancer patients receiving ADT. Moreover, further research is needed to overcome the potential drawbacks.