The Low Back Activity Confidence Scale (LoBACS): preliminary validity and reliability

Low back pain affects a substantial number of adults each year and is persistent or recurrent for many. Self-efficacy is an important predictor of functional recovery.

The purpose of this investigation was to assess the preliminary reliability and validity of the Low Back Activity Confidence Scale (LoBACS) for individuals with histories of low back pain or lumbar surgery.

Two overlapping samples of patients who had undergone a microdiskectomy participated: a test-retest sample of 21 individuals and a validity sample of 53 individuals.

Low Back Activity Confidence Scale items pertaining to self-efficacy for functional activities (FnSE subscale), self-regulation of back health (Self-RegSE subscale), and regular exercise (ExSE subscale) were generated from existing literature and clinical observations. The test-retest sample completed the LoBACS twice, approximately 10 days apart. The validity sample completed the LoBACS and measures of functional performance, self-reported leisure and occupational physical activity, pain, fear beliefs, disability, and quality of life.

The FnSE, Self-RegSE, and ExSE subscale scores and LoBACS total score had excellent to acceptable test-retest reliability (intraclass correlation coefficients of .924, .634, .710, and .850, respectively) and internal consistency (Cronbach α coefficients of .924, .804, .941, and .911, respectively). The LoBACS subscales were correlated in expected directions with physical performance, physical activity, pain, fear beliefs, disability, and quality of life, providing initial evidence of concurrent validity.

The findings provide preliminary content and concurrent validity and interrater and internal consistency reliability for the LoBACS measure of self-efficacy for individuals with histories of low back pain and lumbar microdiskectomy.