# Incidence of Pyogenic Arthritis in Aragón, Spain, From 2015 to 2023

## TL;DR

This study analyzed hospitalization trends for pyogenic arthritis in Aragón, Spain, from 2015 to 2023, finding a notable increase in 2022 followed by a decline in 2023.

## Contribution

The study provides a detailed analysis of pyogenic arthritis incidence trends and patient characteristics in a specific region over an eight-year period.

## Key findings

- Pyogenic arthritis incidence increased significantly in 2022 but decreased in 2023.
- Men were more frequently affected than women, with no significant age difference between genders.
- The highest incidence was observed in August and September, and most cases were treated in the public health system.

## Abstract

Aim

The main objective of our study is to analyze the evolution of hospitalizations coded M00.9 (pyogenic arthritis) in Aragón (Spain) since 2015.

Methods

This is an observational, descriptive, and analytical study analyzing cases coded as pyogenic arthritis (M00.9), according to the International Classification of Diseases, version 10 (ICD-10), in both public and private hospitals in the Autonomous Community of Aragón between 2015 and 2023. Primary data were obtained from Aragón’s Health Big Data (BIGAN), linked to the Aragón Health Sciences Institute, and the data were analyzed by us, considering a p-value <0.05 as statistically significant.

Results

A total of 261 patients with pyogenic arthritis were identified. The incidence of pyogenic arthritis showed an increasing trend, with an incidence of 1.76/100,000 inhabitants in 2016 and 1.36/100,000 inhabitants in 2021, which rose to 5.65/100,000 inhabitants in 2022, followed by a decrease in 2023 without reaching the previous levels of 2021. Men accounted for 160 (61.3%) of the 261 patients with pyogenic arthritis, while 101 were women (38.7%). The mean age was 54.96±29.21 years, with no significant age differences between men and women (men 54.8±27.3; women 55.22±32.14). Among zero- to four-year-old children, there were 35 cases (13.41%) (18 boys and 17 girls). There were 119 cases (45.59%) in patients aged >65 years (66 men, 55.46%). In 2016, the incidence was 3.41 cases/100,000 persons aged zero to four years, and 2.87 cases/100,000 persons aged >65 years; in 2022, it was 8.04 cases/100,000 persons aged zero to four years and 12.97 cases/100,000 persons aged >65 years. The monthly distribution did not show significant differences; the highest incidence was recorded in August (28 patients) and September (31 patients). A total of 90.2% of pyogenic arthritis cases were treated in the public health system. The mean length of hospital stay was 13.03±14.53 days. Readmission occurred in 23.37% of patients with pyogenic arthritis. The most frequent comorbidities were: chronic hematologic disease (37.4%), hypertension (35.11%), dyslipidemia (29.01%), rheumatologic disorder (24.05%), mental disorder (20.23%), diabetes (19.85%), and vascular disease (19.47%).

Conclusions

In 2022, there was a significant increase in pyogenic arthritis compared to previous years, with a decrease in 2023 that did not return to the levels prior to 2021. There was a predominance of pyogenic arthritis in men.