Researchers writing in this week’s online issue of Arthritis Care and Research report that moderate to severe chronic pain may influence mortality risk.
Pain that interferes with daily life and was described by patients as “quite a bit” and “extreme” had an increased risk of all-cause mortality, wrote researchers who were led by Diane Smith Ph.D., of Keele University in the United Kingdom. But patients reporting “any pain lasting longer than one day” or having “widespread pain” in the axial skeleton region on the right and left sides of the body and above and below the waist — were not associated with an increased risk of mortality.
Previous studies suggested that mortality risk may be influenced by the severity of pain and its duration. Strong associations have been found between chronic widespread pain and mortality (MRR 2.8; 95%CI 1.3,6.1). Fibromyalgia patients have been reported to have an increased risk of mortality.
This study is based on two population-based studies: the English Longitudinal Study of Ageing (ELSA)) and the North Staffordshire Osteoarthritis Project (NorStOP).
ELSA included 6,324 older adults, 55% female with a median age of 63 years. The length of time in the study for those who died (n=764/12.1%) ranged from zero months to 90 months, with a mean survival of 54.1 months. Within 12 months, 40 deaths (5.2%) occurred. Patients reported being “often troubled” with pain was 35.9% with 6.5% reporting this to be severe pain. At eight years follow-up, those who died were more often older, male, of lower socioeconomic status, often troubled with pain and having a greater severity of pain.
NorStOP included 10,985 patients, 54% female, median age 63 years. The length of time for participants in the study who died (n=1,484/13.5%) ranged from seven days to 3,823 days (mean survival 2,036 days). Within 12 months, 6.5% (n=97) deaths occurred. 71.2% of patients reported “any pain,” 25.% met ACR criteria for widespread pain and 15.7% met Manchester criteria for widespread pain. 18.8% of patients reported pain at 12 anatomical sites or more. 5.5% reported extreme pain. Patients who died were more likely to be older, male, of lower socioeconomic status and more likely to report pain interference.
Why pain may increase the risk of mortality is unclear. It may be due to underlying disease, such as cancer, researchers wrote.
“One of the research implications that follows from our study is the need to identify what it is about ‘interfering’ pain that causes premature mortality. Factors such as comorbid disease, lifestyle behaviors or psychological factors might provide links between pain that specifically disables or interferes with life and premature mortality. For example, pain that impacts on life is linked to a reduction in physical activity which is associated with increasing weight and the onset of health conditions (e.g. cardiovascular disease) that lead to mortality,” researchers wrote.