Ankylosing spondylitis diagnosis linked to self-harm attempts

AMSTERDAM – There is an increased relative risk of deliberate self-harm that results in emergency treatment among individuals newly diagnosed with ankylosing spondylitis, according to the results of a large, Canadian population-based study.

A diagnosis of ankylosing spondylitis was associated with a 59% increased risk of deliberate self-harm, compared with no diagnosis (HR = 1.59, 95% CI, 1.16-2.21). While the risk of deliberate self-harm in patients diagnosed with rheumatoid arthritis (RA) was initially elevated, the association was not significant after adjustment for confounding factors (HR = 1.08, 95% CI, 0.87-1.34).

These findings call for heightened awareness among clinicians, study investigator Nigil Haroon, MD, PhD, said in an interview at the European Congress of Rheumatology. “Depression is generally well known to be increased in patients with chronic diseases, especially so with chronic inflammatory rheumatic diseases like ankylosing spondylitis and rheumatoid arthritis,” he said. This may in turn be linked to increased cases of deliberate self-harm, but there have been few studies to determine if this is the case, he said, which may be because it is a relatively rare event in routine clinical practice.

Dr. Haroon, who runs a specialist clinic in ankylosing spondylitis in Toronto, has seen the long-term effects of chronic pain, lack of social support, and inability to sleep on patients’ mood first hand. This is what drove him and other colleagues at the University of Toronto and University Health Network to look at the possibility that this could be linked to an increased risk for depression and perhaps deliberate self-harm among newly diagnosed patients.

To try to estimate the risk, they obtained administrative data on more than 100,000 individuals diagnosed with ankylosing spondylitis or RA in the province of Ontario, Canada, between 2002 and 2014. Excluding those with a history of mental illness or a prior self-harm attempt resulted in the creation of two cohorts of patients – 13,964 with ankylosing spondylitis and 53,240 with RA. Indviduals in these two cohorts were then matched, 4:1, to similar controls in the general population.

The average age of those diagnosed with ankylosing spondylitis was 46 years and of those with RA was 57 years, with more males than females in the ankylosing spondylitis group (57% vs. 43%) and more females than males in the RA group (67% vs. 33%).

The main outcome assessed was the first episode of intentional self-injury or self-poisoning that required emergency treatment that occurred after the diagnosis of ankylosing spondylitis or RA.

Overall, there were 69 deliberate self-harm attempts recorded in the ankylosing spondylitis patient group, compared with 131 attempts in the non-ankylosing spondylitis group. In the RA patient group, there were 129 attempts, and 372 attempts in the non-RA group.

Poisoning was “by far the most common modality” used to intentionally self-harm, used by 67% of patients with ankylosing spondylitis and by 81% of those with RA, Dr. Haroon reported. Contact with a sharp object was the second most common method used to deliberately self-harm by 30% of ankylosing spondylitis patients and 16% of RA patients.

Most (70%) patients were discharged following emergency treatment for a deliberate self-harm attempt, with around 15% of ankylosing spondylitis and 22% of RA patients requiring hospital admission.

“For any chronic disease there is a potential for depression to settle, and we should identify [patients] early, even at the primary care levels itself and try to address it,” Dr. Haroon advised. It’s important to spend time and to develop a good rapport with your patients, he added, which can help them open up and talk about their mood.

The work was funded by the Division of Rheumatology Pfizer Research Chair, University of Toronto. Dr. Haroon reported having no relevant financial disclosures.

SOURCE: Kuriya B et al. Ann Rheum Dis. 2018;77(Suppl 2):195. Abstract OP0296.