Pain the main driver of health care use in OA

Pain is the main impetus for seeking medical care among patients with osteoarthritis, with insomnia and depression acting as drivers for increased diversity in the types of health care use, according to recent findings in Arthritis Care & Research.

“Given the complex interactions and mutual exacerbations among pain, insomnia and depression, it is possible that co-occurrence results in cost increases that are greater than simply the sum of the costs of these separate conditions,” Minhui Liu, PhD, RN, of the Johns Hopkins University School of Nursing, and colleagues wrote. “It is important to understand how pain, insomnia and depression independently contribute to [health care use] in older adults with OA and whether there are synergistic effects that jointly drive the increased [health care use].”

To determine the independent and combined effects of pain, insomnia and depression symptoms on health care use among patients aged 60 years and older with OA, the researchers reviewed data from a study of older adults with concurrent OA and insomnia. In that study, which compared the efficacy of three behavioral group interventions to help patients manage their pain and insomnia, 8,057 patients at the Group Health Cooperative in Seattle received surveys regarding their OA pain and sleep problems.

For their own study, Liu and colleagues focused on 2,976 patients who were continuously enrolled in the Group Health Cooperative 1 year prior to survey screening, as well as those receiving primary care services at one of six regional participating clinics and at least one visit recorded in the electronic medical record for OA in the previous 3 years. For these patients, the researchers reviewed survey data related to pain, based on the Graded Chronic Pain Scale; insomnia, based on the Insomnia Severity Index; and depression, using the Patient Health Questionnaire8 for 3 years following the survey. Health care use, including office visits, length of stay, outpatient and inpatient costs, and hip or knee replacement, was also examined.

According to the researchers, approximately 34% of the 2,976 included participants demonstrated at least subclinical insomnia, while 29% presented with at least subclinical depression symptoms, in addition to moderate to severe pain. Among the patients, pain had the largest independent effect on increasing all types of health care use, with depression having moderate effects on increased office visits, length of stay, and outpatient and inpatient costs. Insomnia had mild effects on decreased length of stay. Combined effects of pain with insomnia, and pain with depression were significant for all types of health care use. This effect increased greatly with more severe insomnia and depression symptoms, save for hip or knee replacement.