BIRMINGHAM, ENGLAND – Almost two-thirds of patients with axial spondyloarthritis (axSpA) have more than one medical condition, and these may cluster together, the results of a single-center, cross-sectional study have shown.
Of 419 patients, 61% had multiple conditions, with a median of at least one other condition in addition to axSpA, but some patients had as many as five. The most common other conditions in patients with axSpA were hypertension (19% of patients), depression (16%), and dyspepsia (11%).
In all, 15 clusters of conditions were found, each dominated by one or two conditions in addition to axSpA. The three largest clusters were hypertension and cardiovascular disease (n = 88), anxiety and depression (n = 50), and dyspepsia (n = 31). In the cohort, 69% of the patients were male; the mean age was 45 years.
“Multimorbidity and comorbidity both essentially mean the same thing but from different perspectives,” Sizheng Steven Zhao, MD, said at the annual conference of the British Society for Rheumatology.
“Many of us will be familiar with comorbidity and this is a concept that has one index disease at the center and we consider all other conditions to be coexisting. This is a model you typically see in hospital settings, so you go to see your rheumatologist for your axSpA and your cardiologist for your cardiovascular disease,” he explained.
“From a patient’s perspective, that’s probably a little less helpful to go from specialist to specialist, each only interested in one condition so, quite rightly, there’s been a push towards providing more holistic care with the patient at the center, and this is really encapsulated by the concept of multimorbidity, which is just defined as the coexistence of any two conditions.” The multimorbidity model is particularly suited to a primary care setting rather than a hospital setting, he added.
“Whatever you want to call it, it’s becoming more of a problem,” Dr. Zhao said. There is increasing multimorbidity as people age, and it’s a common problem in those with rheumatic diseases because of shared risk factors, the consequences of systemic inflammation, and how patients are treated.
Prior studies of multimorbidity in axSpA have either been of individual comorbid diseases or counts. Dr. Zhao, a clinical research fellow at Aintree University Hospital in Liverpool, England, and his associates looked at how coexisting conditions might cluster together to provide insight into how these might be better managed collectively in patients with axSpA.
The investigators used an adapted form of the Radner index for determining multimorbidity in patients consecutively seen at the Aintree University Hospital’s rheumatology clinic between 2010 and 2017. The Radner index was adapted to consider 40 chronic conditions, including fibromyalgia and osteoporosis but excluding rheumatic diseases and their extra-articular manifestations.
Dr. Zhao and his colleagues used regression models adjusted for age, gender, symptom duration, smoking status, body mass index, social deprivation, and NSAID use to see what, if any, effect having one of these clusters of multimorbid conditions might have on quality of life, general health, disease activity, and functional impairment measures. Patients with certain clusters of conditions had worse scores, particularly those with coexisting depression and/or anxiety and those with fibromyalgia, irritable bowel syndrome, or both in addition to axSpA.
“These are important conditions to be aware of in the management of axSpA patients,” Dr. Zhao said.
These data are consistent with what has already been published, with between 50% and 60% of patients having other conditions, particularly depression, said consultant rheumatologist Helena Marzo-Ortega, MD, of Leeds Teaching Hospitals NHS Trust, who chaired the session. “These are really important numbers for us to remember in the clinic,” she said.
None of the investigators reported having relevant disclosures.
SOURCE: Zhao S et al., Rheumatology 2019;58(suppl 3), Abstract 035.