Fibromyalgia, a condition that causes persistent widespread pain and fatigue, may be linked to a heightened risk of death as a result of vulnerability to accidents, infections, and especially suicide, suggests a pooled data analysis of the available evidence, published in the open access journal RMD Open.

The findings prompt the researchers to call for regular monitoring of patients' physical and mental health to minimize these risks.

It's not clear what causes fibromyalgia, but its prevalence is increasing, say the researchers. And there's growing recognition that the condition often coexists with other health problems, including rheumatic, gut, neurological, and mental health disorders.

Given the extent of the pain they experience and the likelihood of other painful and debilitating conditions in these patients, it is thought that they are probably at heightened risk of dying before their time.

To strengthen this hypothesis, the researchers reviewed the findings of 8 relevant studies, published between 1999 and 2020, out of an initial haul of 33. They pooled the results from 6 of them, involving a total of 188,751 adults, all of whom had other coexisting conditions.

The analysis showed that fibromyalgia was associated with a 27% heightened risk of death from all causes over time, although this wasn't true for those diagnosed by the 1990 criteria.

But the diagnostic criteria for fibromyalgia have evolved since 1990 in tandem with increasing understanding of the array of clinical symptoms associated with the condition. And they were consequently revised in 2010, 2011, and 2016, point out the researchers.

Specifically, the analysis showed that the risk of death from cancer was 12% lower than it was for the general population of the same age, and only marginally higher (5%) for accidents.

But it was 44% higher for infections, including pneumonia and septicaemia, and more than 3 times as high for suicide.

Whether this heightened risk is due to the fibromyalgia itself or the concomitant conditions isn't clear, note the researchers, as their research wasn't designed to evaluate this. But this is an important issue, they emphasise, which further research needs to address.

And they caution that their findings should be interpreted in the light of differing designs and the small number of participants in the studies included in their analysis.

"Due to significant heterogeneity across the studies, which were also small in number, no clear conclusions can be drawn from the available data," they write. "However, it is possible that for the subgroup of patients diagnosed by the 1990 criteria there is no increased risk for mortality, and for those diagnosed by later versions the risk is increased," they add.

And there are plausible explanations for their findings, they suggest. "The finding of increased mortality associated with accidents can stem from fatigue, unrefreshing sleep, and the concentration difficulties that accompany fibromyalgia, and are a component of its diagnostic criteria since 2010.

"More and more evidence supports immune system involvement and inflammation in fibromyalgia pathophysiology, which can explain the finding of increased mortality from infections. Physical comorbidity may be an additional explanation."

And the reduced risk of a cancer death may be due to these patients' extensive use of health services, they suggest.

The risks identified in their analysis "could represent a serious public health problem, given the high prevalence of the condition," which clinicians don't always take seriously, they note.

"Studies have shown that medical staff are reluctant to accept fibromyalgia as a medical condition, and they face emotional and psychological difficulties interacting with these patients and coping with their disorder," they write.

"Fibromyalgia is often called an 'imaginary condition,' with ongoing debates on the legitimacy and clinical usefulness of this diagnosis. Our review provides further proof that fibromyalgia patients should be taken seriously, with particular focus on screening for suicidal ideation, prevention of accidents, and prevention and treatment of infections," they conclude.