Abstract
BACKGROUND: Frailty and low back pain (LBP) may negatively affect each other in older adults, yet no systematic review has summarized their cross-sectional, temporal, or causal associations. Exploring these associations could provide valuable insights for reducing frailty risk in older adults with LBP. This systematic review aimed to consolidate evidence on the association between frailty and LBP in older adults. METHODS: Four databases (EMBASE, CINHAL, MEDLINE, and SPORTDiscus) were systematically searched from their inception until July 31, 2024. Studies investigating the association between LBP, regardless of chronicity, or LBP-related disability and frailty in older adults were included. LBP was defined as pain occurring between the 12th ribs and inferior gluteal folds. Due to the lack of consensus on the definitions of older adults or frailty, studies were included based on the authors' definitions. Three pairs of independent reviewers screened abstracts and full texts, extracted data, assessed risk of bias, and determined the certainty of evidence. RESULTS: Out of 1,690 articles identified, six cross-sectional studies and one prospective study were included. Low-certainty evidence from four cross-sectional studies suggested that both acute and chronic LBP, with odds ratios from 1.34 to 7.50, separately showed significant correlation with frailty. Pre-frail or frail older adults reported higher chronic LBP intensity, scoring 0.5 to 0.8 points more on the numeric rating scale, and greater LBP-related disability, with scores 1.7 to 7.2 points higher on the Roland Morris Disability Questionnaire, compared to non-frail counterparts. However, there was low-certainty evidence that acute LBP intensity was unrelated to frailty. Very low-certainty evidence from the prospective study indicated that higher acute LBP intensity and disability were associated with transitioning from non-frail to prefrail or frail status. CONCLUSIONS: Our systematic review revealed that older adults with higher LBP intensity or associated disability were more likely to have prefrail or frail status, albeit with low-certainty evidence. However, the findings are limited by the small number of studies, especially prospective research. Future high-quality research should clarify the causation between LBP intensity or disability and frailty in community-dwelling older adults. Research should also explore potential mediators or moderators influencing the LBP-frailty association. These findings could help develop effective prevention and rehabilitation strategies to mitigate the impacts of LBP on frailty, or vice versa.