The Body Image and Relationship Scale: A Swedish translation, cultural adaptation, and reliability and validity testing

Purpose. Testing a newly developed Swedish version of the Body Image and Relationship Scale (BIRS) for test–retest reliability, convergent validity and inter-item analysis in a Swedish context for breast cancer survivors. Methods. A Swedish BIRS version, translation involving the input of experts and breast cancer survivors, with 41 items (BIRS-S) and the Short Form 36 (SF-36) were sent to a sample of 100 breast cancer survivors, mean age 61.7 years, diagnosed with breast cancer 20–42 months prior to the study. Retest was completed within 2–3 weeks. Results. 71 persons completed both dispatches. Reliability using Cronbach's alpha for the BIRS-S total was satisfactory 0.96 (range 0.87–0.93 for the three subscales). Intra-class correlation for the three subscales ranged between 0.88 to 0.93 revealing test–retest to be satisfactory. Convergent validity between the BIRS-S and SF-36 Physical Composite Score was − 0.68 for BIRS-S total. Convergent validity between the BIRS-S and SF-36 Mental Composite Score was − 0.65 for BIRS-S total. Inter-item analysis revealed the correlation between the original BIRS and the BIRS –S to be 0.98 for all three subscales. The new items correlated with the original BIRS ranging from 0.51 to 0.81 and with the BIRS-S ranging between 0.62 and 0.81. Conclusion. The BIRS-S demonstrates satisfactory test–retest reliability and validity according to the primary hypothesis of a moderate correlation to SF-36. It is not a new scale but an adapted version of the original instrument including specific areas of importance for Swedish breast cancer survivors.