Back pain is a leading cause of disability, and the proportion of adults over age 65 who have back pain is increasing in the United States, particularly among women. Now, research has demonstrated that persistent back pain is also linked with an increased risk of death in older women.
In a prospective cohort study, researchers from the Boston Medical Center sought to examine whether back pain is associated with all-cause and with cause-specific mortality in older women, and whether an association was mediated by disability.
The study’s primary outcome was time to death, assessed using all-cause and cause-specific models. The researchers, led by Eric Roseen, DC, MSc, a research fellow at Boston Medical Center, enrolled 8321 white women with a mean age of 71.5 (standard deviation, 5.1) years, and followed them over a median of 14.1 years.
During the follow-up period, 56% of the patients (n = 4975) died. A higher proportion of women with frequent, persistent back pain died (65.8%) than women who did not experience back pain (53.5%). In an adjusted model, women who had frequent, persistent back pain had higher hazard ratio (HR) for all-cause mortality (HR: 1.24; 95% CI, 1.11-1.39), cardiovascular-related mortality (HR, 1.34; 95% CI, 1.12-1.62), and cancer-related mortality (HR, 1.33; 95% CI, 1.03-1.71).
In a mediation analysis, the researchers found that disability—as measured by limitation s of instrumental activities of daily living, which include slow chair stand time and slow waking speed—explained 47% of the effect of persistent, frequent back pain on all-cause mortality (P <.001).
"To our knowledge, our study is the first to measure disability after measurement of back pain. This allowed for a prospective analysis of back pain that persisted over time and later rates of disability, which may help explain the association between back pain and mortality," Roseen said in a statement. "Our findings raise the question of whether better management of back pain across the lifespan could prevent disability, improve quality of life, and ultimately extend life."
Roseen and his colleagues added that the study’s findings are consistent with prior studies that found that older women who had daily or disabling back pain had an elevated mortality risk, but that the nature of the association remains unclear, and the study was limited by the inclusion of only white woman in the cohort.
According to Roseen, these findings provide a basis for future studies to assess the long-term impact of back pain therapies and self-care strategies for patients who are at risk for earlier death.
Roseen EJ, LaValley MP, Li S, Saper RB, Felson DT, Fredman L. Association of back pain with all-cause and cause-specific mortality among older women: a cohort study. [published online October 22, 2018]. J Gen Intern Med. doi: 10.1007/s11606-018-4680-7.