Bidirectional Longitudinal Association between Back Pain and Loneliness in Later Life: Evidence from English Longitudinal Study of Ageing.

Background: This study examined the bidirectional and temporal-ordinal relationship between loneliness and back pain.

Methods: Data from 7,730 participants in waves 6 (2012-2013), 7 (2014-2015), and 8 (2016-2017) of the national English Longitudinal Study of Ageing were analyzed. Back pain was graded on a scale of 0-10 (0, no discomfort; 10, unbearable pain). Loneliness was measured using the Revised University of California Los Angeles Loneliness Scale. A targeted minimum loss-based estimator was used to examine the bidirectional longitudinal associations between back pain and loneliness.

Results: No loneliness in waves 6 and 7 (relative risk [RR]=0.76; 95% confidence interval [CI], 0.61-0.94), no loneliness in wave 6 but loneliness in wave 7 (RR=0.58; 95% CI, 0.50-0.68), and loneliness in wave 6 but not in wave 7 (RR=0.69; 95% CI, 0.57-0.86) were associated with significant risk reductions of back pain in wave 8 compared with the scenario of loneliness in waves 6 and 7. Mild back pain in wave 6 but moderate back pain (RR=0.55; 95% CI, 0.35-0.86) or severe back pain in wave 7 (RR=0.49; 95% CI, 0.34-0.72) showed a significant risk reduction of loneliness in wave 8 compared with severe back pain in waves 6 and 7.

Conclusion: Loneliness may be a risk factor for back pain, and back pain may be a risk factor for loneliness. The results of this study will inform the development of more effective interventions for loneliness and back pain.