Pain may be the primary driver for the use of health care services in patients with osteoarthritis (OA), according to a study published in Arthritis Care and Research. Health care service use increases when these patients have comorbid insomnia or depression.
Researchers sought to determine the effects of pain, insomnia, and depression on the use of healthcare services, particularly in older adults with OA. Investigators analyzed data from a National Institutes on Aging-funded clinical trial (Clinicaltrials.gov identifier NCT01142349) in which the efficacy of 3 different behavioral interventions was examined in patients with OA and insomnia. Pain, insomnia, and depression were evaluated with the Graded Chronic Pain Scale, the Insomnia Severity Index, and the Patient Health Questionnaire-8, respectively. Information on health care use was gathered from electronic health records.
Data from 2976 patients (mean age, 72.16±8.81 years) were examined. Patients were primarily white, women, and married (90.86%, 66.23%, and 60.67%, respectively) and were highly educated (57.39% college or higher). All patients experienced mild pain, and approximately 47% of patients reported moderate to severe pain. A total of 55% of participants reported subclinical insomnia, 45% reported subclinical or current depression, 34% reported concurrent moderate to severe pain and subclinical insomnia, and 29% reported concurrent moderate to severe pain and subclinical depression.
Over the course of 4 years, the percentages of patients with no office visits and patients with >24 visits steadily increased. Initially, almost 90% of patients had no hospitalizations, although this percentage decreased over the years.
Among all 3 symptoms, pain had the greatest positive effect on all types of health care use, even after controlling for insomnia and depression. The independent effects of insomnia and depression had an impact on the number of office visits, but not on the length of hospital stay.. The independent effects of insomnia and depression were found to have an impact on outpatient costs (coefficient 1.12; 95% CI, 1.01-1.23 and 1.19; 95% CI, 1.07-1.32, respectively). These effects increased with the severity of insomnia or depression. Inpatient costs were not affected by insomnia or depression, and insomnia or depression did not independently predict the occurrence of hip or knee replacement.
Study limitations include the use of a single health plan, a population of older adults with OA and insomnia only, and the fact that pain, insomnia, and depression were assessed at a single point in time.
“The study underscores the substantial independent impact of pain on use of healthcare services in patients with OA and suggests an absence of synergy among pain, insomnia, and depression,” the researchers concluded. “[T]hese effects increased greatly with increasing severity of insomnia and depression, after controlling for pain. This indicates the important role that concurrent symptomatic conditions may play in increasing the use of healthcare services.”
Liu M, McCurry SM, Belza B, et al. Effects of osteoarthritis pain and concurrent insomnia and depression on health care use in a primary care population of older adults [published online May 10, 2019]. Arthritis Care Res. doi: 10.1002/acr.23695