Examining National Trends in Opioid Use Disorder Hospitalizations in Common Musculoskeletal Diseases

In the last 2 decades, there has been a significant increase in opioid use disorder (OUD)-related hospitalizations in 5 common musculoskeletal diseases, including gout, rheumatoid arthritis (RA), fibromyalgia, osteoarthritis (OA), and low back pain, according study results published in The Journal of Rheumatology.

A recent study conducted in the United States reported a significant increase in chronic opioid use from 2002 to 2015 in patients with RA. On the other hand, another study described no increase in the use of opioids in older Americans with RA, low back pain, or OA. The objective of the current study was to determine the national trends in rates of OUD hospitalizations in 5 common musculoskeletal disorders.

Using data from the US National Inpatient Sample (NIS) between 1998 and 2016, the researchers identified all OUD hospitalizations. They compared the frequency of OUD hospitalizations, time trends, and outcomes from 1998 to 2014 in 5 common musculoskeletal diseases, including gout, RA, fibromyalgia, OA, and low back pain.

The absolute number of OUD hospitalizations was the highest for low back pain between 1998 and 2000 and for OA between 2015 and 2016. The frequency of OUD hospitalizations was low between 1998 and 2000 for all musculoskeletal diseases and increased over the 19-year study period, ranging between a 3.5-fold increase in those with low back pain to a 24-fold increase in patients with gout.

Rates of OUD hospitalizations per 100,000 total NIS claims between 1998 and 2000 and 2015 and 2016 varied across the different musculoskeletal disorders; the rates increased by 5.5-fold (from 1.17 to 7.64) in low back pain, 9.5-fold (from 0.30 to 3.16) in RA, 12-fold (from 0.53 to 6.98) in fibromyalgia, 14-fold (from 0.68 to 10.22) in OA, and 36-fold (from 0.05 to 1.88) in gout.

Mean length of hospital stay was 4.3 days for gout, 3.9 days for RA, 3.7 days for fibromyalgia, 3.9 days for OA, and 3.4 days for low back pain. Median total charges in US dollars were $18,363, $17,398, $15,772, $16,795, and $13,772, respectively.

A total of 104 (1.73%) patients with gout, 171 (1.55%) with RA, 220 (0.85%) with fibromyalgia, 325 (1.04%) with OA, and 314 (0.89%) with OA died during OUD hospitalization.

The inflation-adjusted total hospital charges for OUD hospitalization with vs without rheumatic disease was different: gout, $697 higher; OA, $4759 lower; fibromyalgia, $2082 lower; RA, $1258 lower; and low back pain, $4944 lower.

The study had several limitations, including the use of diagnostic codes for the identification of the study cohort and comorbidities with potential diagnostic misclassification; hospital charges were assessed but since these values may be inflated, they do not reflect the actual cost of hospitalization; and the possibility of residual confounding bias because of the observational study design.

“These findings can better inform patients, providers and policy-makers about the impact of OUD-hospitalizations in those with common [musculoskeletal disorders], and lead to future research of interventions to reduce OUD-hospitalizations in these diseases,” the researchers concluded.

Disclosure: A study author declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.

Reference

Singh JA, Cleveland JD. Time-trends in opioid use disorder hospitalizations in gout, rheumatoid arthritis, fibromyalgia, osteoarthritis, and low back pain. J Rheumatol. Published online October 1, 2020. doi:10.3899/jrheum.191370