Abstract
OBJECTIVES: To identify risk factors for back pain leading to restricted activity (restricting back pain) in older persons. DESIGN: Prospective cohort study. SETTING: Greater New Haven, Connecticut. PARTICIPANTS: A total of 731 men and women aged 70 years or older, who were community living and nondisabled in essential activities of daily living at baseline. MEASUREMENTS: Candidate risk factors were ascertained every 18 months for 108 months during comprehensive home-based assessments. Restricting back pain was assessed during monthly telephone interviews for up to 126 months. Incident episodes of (1) short-term (1 episode lasting 1 month) restricting back pain; and (2) persistent (1 episode lasting 2 or more months) or recurrent (2 or more episodes of any duration) restricting back pain were determined during each 18-month interval. The associations between the candidate risk factors and short-term and persistent/recurrent restricting back pain, respectively, were evaluated using a multivariable Cox model. RESULTS: The cumulative incidence was 21.3% (95% confidence interval [CI] 19.6%-23.1%) for short-term restricting back pain and 20.6% (CI 18.6%-22.9%) for persistent/recurrent restricting back pain over a median follow-up of 109 months. In a recurrent event multivariable analysis, female sex (hazard ratio [HR] 1.30; 1.07-1.58), weak grip strength (HR 1.24; 1.01-1.52), and hip weakness (HR 1.19; 1.07-1.32) were independently associated with an increased likelihood of having short-term restricting back pain, whereas female sex (HR 1.48; CI 1.13-1.94), depressive symptoms (HR 1.57; 1.23-2.00), 2 or more chronic conditions (HR 1.38; 1.08-1.77), and arthritis (HR 1.66; 1.31-2.09) were independently associated with persistent/recurrent restricting back pain. CONCLUSION: In this prospective study, several factors were independently associated with restricting back pain, including some that may be modifiable and therefore potential targets for interventions to reduce this common and often recurrent condition in older persons.