Familial Mediterranean Fever in Spain: Time Trend and Spatial Distribution of the Hospitalizations

Abstract

Familial Mediterranean Fever (FMF) is a rare, hereditary, auto-inflammatory disease. The aims of this study were to explore the time trend and geographical distribution of hospitalizations in Spain from 2008 to 2015. We identified hospitalizations of FMF from the Spanish Minimum Basic Data Set at hospital discharge, using ICD-9-CM code 277.31. Age-specific and age-adjusted hospitalization rates were calculated. The time trend and the average percentage change were analyzed using Joinpoint regression. Standardized morbidity ratios were calculated and mapped by province. A total of 960 FMF-related hospitalizations (52% men) were identified across the period 2008-2015, with an increase in hospitalizations of 4.9% per year being detected (p < 0.05). The risk of hospitalization was higher than expected for the national total (SMR > 1) in 13 provinces (5 in the Mediterranean area), and lower (SMR < 1) in 14 provinces (3 in the Mediterranean area). There was an increase in hospitalizations of patients with FMF in Spain throughout the study period, with a risk of hospitalization that was higher, though not exclusively so, in provinces along the Mediterranean coast. These findings contribute to the visibility of FMF and provide useful information for health planning. Further research should take into account new population-based information, in order to continue monitoring this disease.