1 Rygcenter Syddanmark, Institute of Regional Health Research, Det Sundhedsvidenskabelige Fakultet, SDU2 Center Lillebaelt, Institute of Regional Health Research, Det Sundhedsvidenskabelige Fakultet, SDU3 Clinical Biomechanics, Department of Sports Science and Clinical Biomechanics, Det Sundhedsvidenskabelige Fakultet, SDU4 Department of Sports Science and Clinical Biomechanics, Det Sundhedsvidenskabelige Fakultet, SDU5 unknown6 Department of Sports Science and Clinical Biomechanics, Det Sundhedsvidenskabelige Fakultet, SDU
Background: Low back pain (LBP) is common, and social isolation is both a risk factor for poor recovery and a consequence. However, no studies seem to have validated social isolation measures in LBP populations. Aims: This study assessed the validity of the Friendship Scale (FS), a brief measure of social isolation. Methods: LBP participants were 100 consecutive consenting adult patients attending physiotherapy outpatient clinics, matched (1: 2) by age and gender with a general population sample (GPS; n = 200). FS validation was through factor analysis, internal consistency, sensitivity by known groups, and Rasch analysis. Results: There were significant differences between LPB and GPS on 5 of the 6 FS items. Social isolation on the FS was reported by 26% of the LBP cohort compared with 9% of the GPS. All FS items loaded on the principal component > 0.60, suggesting uni-dimensionality. Internal consistency was alpha = 0.81. The FS was sensitive by pain severity and study cohort. Rasch analysis showed no disordered items, although 2 items were marginally misfitting. Differential item functioning by sex was observed on 1 item; there was no other observed differential item functioning. After removal of the worst fitting item (feeling alone), the remaining items fit the Rasch model. This, however, may have been a function of study samples. Conclusions: Generally, the FS performed well, and its descriptive system contains excess capacity beyond that needed in the study population; that is, those with LBP were not particularly socially isolated, and responses indicating severe social isolation were barely reported by these participants. Overall, the FS appears to be a suitable instrument for assessing social isolation among LBP patients.
Clinical Journal of Pain, 2013, Vol 29, Issue 3, p. 245-252
Friendship Scale low back pain quality of life social isolation validation psychometric RANDOMIZED CONTROLLED-TRIAL PREVALENCE LIFE LONELINESS COMMUNITY POPULATION DISABILITY EDUCATION CARE