Researchers set out to determine overall morbidity and phenotypic diseasome for migraine by analyzing the EMRs of migraineurs who attended Terveystalo, a private healthcare provider in Finland. The retrospective register study included around 17,600 patients with diagnosed migraine (according to ICD-10 code G43) between January 2012 and December 2017.

Electronic medical record (EMR) data showed migraine is associated with a systematic increase in morbidity across the entire spectrum of the International Classification of Diseases, Tenth Revision ( ICD-10 ), according to a recently published study in The Journal of Headache and Pain.

According to the researchers, this study marked “the first untargeted approach to investigate the whole ICD-10 coded diseaseome and phenotypic disease networks (PDN) in migraine patients” and is “the first study to include a matched cohort population for comparison when constructing PDNs.”

Patients were matched with a 1-to-1, age- and gender-matched control population without migraine. The average age of the migraine cohort was 38.9 years, and females accounted for 78.9% of the group.

In addition to assessing EMRs for the prevalence of ICD-10 codes, “Those with at least two significant phi correlations, and a prevalence >2.5% in migraine patients were included [in] PDNs for further analysis,” the researchers said. “An automatic subnetwork detection algorithm was applied in order to cluster the diagnoses within the PDNs. The diagnosis-wise connectivity based on the PDNs was compared between migraine patients and controls to assess differences in morbidity patterns.”

Overall, results showed the average number of diagnoses per patient increased 1.7-fold in migraineurs compared with control subjects. A total of 1337 unique ICD-10 codes were listed in migraineurs’ EMRs, and a singular diagnosis (without comorbidities) occurred in 1% of the group compared with 13% of controls.

The results further showed the median number of diagnoses among migraineurs was 12 compared with 3 in patients without migraine. The researchers note that because of the large sample size, the differences in prevalence between those with and without migraine are statistically significant (P <.001) for each diagnosis.

“The number of significant phi correlations was 2.3-fold increased, and cluster analysis showed more clusters in those with migraine [versus] controls (9 vs 6). For migraine, the PDN was larger and denser and exhibited one large cluster containing fatigue, respiratory, sympathetic nervous system, gastrointestinal, infection, mental, and mood disorder diagnoses,” the authors said.

Surprisingly, they found diagnostic codes relating to skin, visual, and hearing disorders were listed more frequently in migraineurs’ EMRs compared with those of controls.

The researchers say more studies are warranted to understand the pathophysiological causes and consequences of these results and hope that the study’s findings function as a “benchmark and baseline in understanding migraine morbidity detected as ICD-10 codes in the clinical praxis spectrum.”

Reference

Korolainen MA, Tuominen S, Kurki S, et al. Burden of migraine in Finland: multimorbidity and phenotypic disease networks in occupational healthcare. J Headache Pain. 2020;21(8). doi: 10.1186/s10194-020-1077-x.